Acta Forestalia Fennica vol. 0 | 1993

Male flowering was studied at the canopy level in 10 silver birch (Betula pendula Roth) stands from 8 localities and 14 downy birch (B. pubescens Ehrh.) stands from 10 localities in Finland in 1963–73. Distribution of cumulative pollen catches was compared to the normal Gaussian distribution. The basis for timing of flowering was the 50% point of the anthesis-fitted normal distribution. To eliminate effects of background pollen, only the central, normally distributed part of the cumulative distribution was used. Development was measured and tested in calendar days, in degree days (> 5°C) and in period units. The count of the parameters began in March 19.

Male flowering in silver birch occurred from late April to late June depending on latitude, and flowering in downy birch took place from early May to early July. The heat sums needed for male flowering varied in downy birch stands latitudinally but there was practically no latitudinal variation in silver birch flowering. The amount of male flowering in stands of the both species were found to have a large annual variation but without any clear periodicity.

The between years pollen catch variation in stands of either birch species did not show any significant latitudinal correlation in contrast to Norway spruce stands. The period unit heat sum gave the most accurate forecast of the timing of flowering for 60% of the silver birch stands and for 78.6% of the downy birch stands. Silver birch seems to have a local inclination for a more fixed flowering date compared to downy birch, which could mean a considerable photoperiodic influence on flowering time of silver birch. The species had different geographical correlations.

Frequent hybridization of the birch species occurs more often in Northern Finland than in more southerly latitudes. The different timing in the flowering causes increasing scatter in flowering times in the north, especially in the case of downy birch. Thus, the change of simultaneous flowering of the species increases northwards due to a more variable climate and higher altitudinal variation. Compared with conifers, the reproduction cycles of the two birch species were found to be well protected from damage by frost.

• Luomajoki, E-mail: al@mm.unknown

In this study we analyse how the ion concentrations in forest soil solution are determined by hydrological and biogeochemical processes. A dynamic mode ACIDIC was developed, including processes common to dynamic soil acidification models. The model treats one to eight interacting layers and simulates soil hydrology, transpiration, root water and nutrient uptake, cation exchange, dissolutions and reaction of Al hydroxides in solution, and the formation of carbonic acid and its dissociation products. It includes also a possibility to a simultaneous use of preferential and matrix flow paths, enabling the throughfall water to enter the deeper soil layers in macropores without first reacting with the upper layers. Three different combinations of routing the throughfall water via macro- and micropores through the soil profile is presented. The large vertical gradient in the observed total charge was simulated successfully. According to the simulations, gradient is mostly caused by differences in the intensity of water uptake, sulphate adsorption and organic anion retention at the various depths. The temporal variations in Ca and Mg concentrations were simulated fairly well in all soil layers. For H⁺, Al and K there were much more variation in the observed than in the simulated concentrations. Flow in macropores is a possible explanation for the apparent disequilibrium of the cation exchange for H⁺ ad K, as the solution H⁺ and K concentrations have great vertical gradients in soil. The amount of exchangeable H⁺ increased in O and E horizons and decreased in the Bs1 and Bs2 horizons, the net change in whole soil profile being a decrease. A large part of the decrease of the exchangeable H⁺ in the illuvial B horizon was caused by sulphate adsorption. The model produces soil water amounts and solution ion concentrations which are comparable to the measured values, and it can be used in both hydrological and chemical studies of soils.

• Kareinen, E-mail: tk@mm.unknown
• Nissinen, E-mail: an@mm.unknown
• Ilvesniemi, E-mail: hi@mm.unknown

Two methods of pre-harvest inventory were designed and tested on three cutting sites containing a total of 197,500 m³ of wood. These sites were located on flat-ground boreal forest in north-western Quebec, Canada. Both methods studied involved scaling of trees harvested to clear the road path one year (or more) prior to harvest of adjacent cutblocks.

The first method (ROAD) considers the total road right-of-way volume divided by the total road area cleared. The resulting volume per hectare is then multiplied by the total cut-block area scheduled for harvest during the following year to obtain the total estimated cutting volume. The second method (STRATIFIED) also involves scaling of trees cleared from the road. A volume per hectare is calculated for each stretch of road that crosses a single forest stand. This volume per hectare is then multiplied by the remaining area of the same forest stand scheduled for harvest one year later. The sum of all resulting estimated volumes per stand gives the total estimated cutting-volume for all cut-blocks adjacent to the studied road. A third method (MNR) represent the actual existing technique for estimating cutting volume in the province of Quebec. It involves summing the cut volume for all forest stands. The cut volume is estimated by multiplying the area of each stand by its estimated volume per hectare obtained from standard stock tables.

When the resulting total estimated volume per cut-block for all three methods was compared with the actual measured cut-block volume (MEASURED), the analysis showed that MNR volume estimate was 30% higher than MEASURED. However, no significant difference from MEASURED was observed for volume estimates for ROAD and STRATIFIED methods, which respectively estimated cutting volumes 19% and 5% lower than MEASURED.

• Morasse, E-mail: jm@mm.unknown

Productive coexistence and gain of populations were studied using nine years’ data from field experiments of Taxodium ascendens-intercrop systems in Lixiahe, Jiangsu province, China. A theoretical framework for productive coexistence in agroforestry was developed. Interaction patterns between trees and intercrops were presented within the framework. A model framework was developed to describe the coexistence gain and interaction of populations in T. ascedens-intercrop systems. Facilitation and resource sharing were identified as main contribution to the advantage of species combination in agroforestry. The model of population interaction developed in the present study was accepted for describing the interaction of populations in T. ascendens -intercrop system, because it explained a high proportion of the variance of experimental data and fitted well the observations in most intercropping types. The model provides flexibility for describing different patterns of intra- and inter-specific interactions. Model coefficients were applied to the determination of the ecological compatibility of species.

Managed T. ascendens-intercrop systems were advantageous as compared to a monoculture of trees or arable crops. In T. ascendens stands up to the age of three, arable crops contributed about 50–80% of the total biomass yield of agroforestry. The diameter height growth of T. ascendens was not significantly influenced by intercrops. When the trees were young (during the first three years), T. ascendens did not depress the crop yields, and a land equivalent ratio greater than unity was obtained together with a high yield of both components. The diameter and height of the trees were similar in four spacing configurations with an equal number of trees per hectare up to the age of 8, but wider between-rows open range were beneficial for the intercrops. The relationship between open-ranges and species coexistence was also analysed and the distribution of soil nutrients studied.

• Huang, E-mail: wh@mm.unknown

To enhance the utilization of the wood, the sawmills are forced to place more emphasis on planning to master the whole production chain from the forest to the end product. One significant obstacle to integrating the forest-sawmill-market production chain is the lack of appropriate information about forest stands. Since the wood procurement point of view in forest planning systems has been almost totally disregarded there has been a great need to develop an easy and efficient pre-harvest measurement method, allowing separate measurement of stands prior to harvesting. The main purpose of this study was to develop a measurement method for Scots pine (Pinus sylvestris L.) stands which forest managers could use in describing the properties of the standing trees for sawing production planning.

Study materials were collected from ten Scots pine stands located in North Häme and South Pohjanmaa, in Southern Finland. The data comprise test sawing data on 314 pine stems, diameter at breast height (dbh) and height measures of all trees and measures of the quality parameters of pine sawlog stems in all ten study stands as well as the locations of all trees in six stands. The study was divided into four sub-studies which deal with pine quality prediction, construction of diameter and dead branch height distributions, sampling designs and applying height and crown height models. The final proposal for the pre-harvest measurement method is a synthesis of the individual sub-studies.

Quality analysis resulted in choosing dbh, distance from stump height to the first dead branch, crown height and tree height as the most appropriate quality characteristics of Scots pine. Dbh and dead branch height are measured from each pine sample tree while height and crown height are derived from dbh measures by aid of mixed height and crown height models. Pine and spruce diameter distribution as well as dead branch height distribution are most effectively predicted by the kernel function. Roughly 25 sample trees seem to be appropriate in pure pine stands. In mixed stands the number of sample trees needs to be increased in proportion to the intensity of pines in order to attain the same level of accuracy.

• Uusitalo, E-mail: ju@mm.unknown

A method was developed for relative radiometric calibration of single multitemporal Landsat TM image, several multitemporal images covering each other, and several multitemporal images covering different geographical locations. The radiometrically calibrated different images were used for detecting rapid changes on forest stands. The nonparametric Kernel method was applied for change detection. The accuracy of the change detection was estimated by inspecting the image analysis results in field.

The change classification was applied for controlling the quality of the continuously updated forest stand information. The aim was to ensure that all the manmade changes and any forest damages were correctly updated including the attribute and stand delineation information. The image analysis results were compared with the registered treatments and the stand information base. The stands with discrepancies between these two information sources were recommended to be field inspected.

• Varjo, E-mail: jv@mm.unknown

The methods of secondary wood processing are assumed to evolve over time and to affect the requirements set for the wood material and its suppliers. The study aims at analysing the industrial operating modes applied by joinery and furniture manufacturers as sawn wood users. Industrial operating mode was defined as a pattern of important decisions and actions taken by a company which describes the company’s level of adjustment in the late-industrial transition.

A non-probabilistic sample of 127 companies was interviewed, including companies from Denmark, Germany, the Netherlands, and Finland. Fifty-two of the firms were furniture manufacturers and the other 75 were producing windows and doors. Variables related to business philosophy, production operations, and suppliers’ choice criteria were measured and used as a basis for a customer typology; variables related to wood usage and perceived sawmill performance were measured to be used to profile the customer types.

Factor analysis was used to determine the latent dimensions of industrial operating mode. Canonical correlation analysis was applied in developing the final base for classifying the observations. Non-hierarchical cluster analysis was employed to build a five-group typology of secondary wood processing firms; these ranged from traditional mass producers to late-industrial flexible manufacturers. There was a clear connection between the amounts of late-industrial elements in a company and the share of special and customised sawn wood uses. Those joinery or furniture manufacturers that were late-industrial also were likely to use more component-type wood material and to appreciate customer-oriented sawn wood materials and late-industrial supplier relationships.

• Hartikainen, E-mail: th@mm.unknown

The effective heating values of the above and below ground biomass components of mature Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), downy birch (Betula pubescens Ehrh), silver birch (B. pendula Roth), grey alder (Alnus incana (L.) Moench), black alder (A. glutinosa (L.) Gaertn.) and aspen (Populus tremula L.) were studied. Each sample tree was divided into wood, bark and foliage components. Bomb calorimetry was used to determine the calorimetric heating values.

The species is a significant factor in the heating value of individual tree components. The heating value of the wood proper is highest in conifers. Broadleaved species have a higher heating value of bark than conifers. The species factor diminishes when the weighted heating value of crown, whole stems or stump-root-system are considered. The crown material has a higher heating value per unit weight in comparison with fuelwood from small-sized stems or whole trees. The additional advantages of coniferous crown material are that it is non-industrial biomass resource and is readily available. The variability of both the chemical composition and the heating value is small in any given tree component of any species. However, lignin, carbohydrate and extractive content were found to vary from one part of the tree to another and to correlate with the heating value

• Nurmi, E-mail: jn@mm.unknown

A sensitive framework has been developed for modelling young radiata pine (Pinus radiata D. Don) survival, its growth and size class distribution, from time of planting to age 5 or 6 years. The data and analysis refer to the Central North Island region of New Zealand. The survival function is derived from a Weibull probability density function, to reflect diminishing mortality with the passage of time in young stands. An anamorphic family of trends was used, as very little between-tree competition can be expected in young stands. An exponential height function was found to fit best the lower portion of its sigmoid form. The most appropriate basal area/ha exponential function included an allometric adjustment which resulted in compatible mean height and basal area/ha models. Each of these equations successfully represented the effects of several establishment practices by making coefficients linear functions of site factors, management activities and their interactions. Height and diameter distribution modelling techniques that ensured compatibility with stand values were employed to represent the effects of management practices on crop variation. Model parameters for this research were estimated using data from site preparation experiments in the region and were tested with some independent data sets.

• Mason, E-mail: em@mm.unknown
• Whyte, E-mail: aw@mm.unknown

The accompanying collective research report is the result of the research project in 1986–90 between the Finnish Academy and the former Soviet Academy of Sciences. The project was organized around common field work in Finland and in the former Soviet Union, and theoretical analyses of tree growth determining processes. Based on theoretical analyses, dynamic stand growth models were made and their parameters were determined utilizing the field results.

Annual cycle effects the tree growth. Our theoretical approach was based on adaptation to local climate conditions from Lapland to South Russia. The initiation of growth was described as a simple low and high temperature accumulation driven model. The model was linked with long-term temperature data.

Analysis of field measurements of CO₂ exchange showed that irradiance is the dominating factor causing variation in photosynthetic rate in natural conditions during summer. The penetration of irradiance into Scots pine (Pinus sylvestris L.) canopy is a complicated phenomenon. A moderately simple but balanced forest radiation regime sub-model was constructed.

The common field excursions in different geographical regions resulted in a lot of experimental data of regularities of woody structure. The water transport seems to be a good common factor to analyse these properties of tree structure. The produced theoretical and experimental material was utilized in the development of stand growth model that describes the growth and development of Scots pine stands in Finland and the former Soviet Union. The core of the model is carbon and nutrient balances. This means that carbon obtained in photosynthesis is consumed or growth and maintenance and nutrients are taken according to the metabolic need. Since the fundamental metabolic processes are the same in all locations, the same growth model structure can be applied in the large range of Scots pine. The model enables the analysis of geographical differences in the growth of Scots pine. The present approach enables utilization of structural and functional knowledge gained in places of intensive research, in the analysis of growth and development of any stand.

• Hari, E-mail: ph@mm.unknown
• Ross, E-mail: jr@mm.unknown
• Mecke, E-mail: ph@mm.unknown

Microcatchment water harvesting (MCWH) improved the survival and growth of planted trees on heavy soils in eastern Kenya five to six years after planting. In the best method, the cross-tied furrow microcatchment, the mean annual increment (MAI; based on the average biomass of living trees multiplied by tree density and survival) of the total and usable biomass of Prosopis juliflora (Sw.) DC. were 2,787 and 1,610 kg ha^-1 a^-1 respectively, when the initial tree density was 500 to 1,667 trees per hectare. Based on survival, the indigenous Acacia horrida Span., A. mellifera (Vahl) Benth. and A. zanzibarica (S. Moore) Taub. were the most suitable species for planting using MCWH. When both survival and the yield were considered, a local seed source of P. Juliflora was superior to all other species. The MAI in MCWH was at best distinctly higher than that in the natural vegetation (163–307 and 66–111 kg ha^-1 a^-1 for total and usable biomass respectively); this cannot satisfy the fuelwood demand of concentrated populations, such as towns or irrigation schemes.

The density of seeds of woody species in the topsoil was 40.1 seeds/m² in the Acacia-Commiphora bushland and 12.6 seeds/m² in the zone between the bushland and the Tana riverine forest. Rehabilitation of woody vegetation using the soil seed bank alone proved difficult due to the lack of seeds of desirable species.

The regeneration and dynamics of woody vegetation were also studied both in cleared and undisturbed bushland. A sub-type of Acacia-Commiphora bushland was identified as Acacia reficiens bushland, in which the dominant Commiphora species is C. campestris. Most of the woody species did not have even-aged population but cohort structures that were skewed towards young individuals. The woody vegetation and the status of soil nutrients were estimated to recover in 15–20 years on Vertic Natrargid soils after total removal of above-ground vegetation.

• Kaarakka, E-mail: vk@mm.unknown

Questions of the small size of non-industrial private forest (NIPF) holdings in Finland are considered and factors affecting their partitioning are analysed. This work arises out of Finnish forest policy statements in which the small average size of holdings has been seen to have negative influence on the economics of forestry. A literature survey indicates that the size of holdings is an important factor determining the costs of logging and silvicultural operations, while its influence on the timber supply is slight.

The empirical data are based on a sample of 314 holdings collected by interviewing forest owners in 1980–86. In 1990–91 the same holdings were resurveyed by means of a postal inquiry and partly by interviewing the forest owners. The principal objective was to collect data to assist in quantifying ownership factors that influence partitioning among different kinds of NIPF holdings. Thus, the mechanism of partitioning was described and a maximum likelihood logistic regression model was constructed using seven independent holding and ownership variables.

One out of four holdings had undergone partitioning in conjunction with a change in ownership, one fifth among family owned holdings and nearly a half among jointly owned holdings. The results of the logistic regression model indicate, for instance, that the odds on partitioning is about three times greater for jointly owned holdings than for family owned ones. Also, the probabilities of partitioning were estimated and the impact of independent dichotomous variables on the probability of partitioning ranged between 0.02 and 0.01. The low value of Hosmer-Lemeshow test statistics indicates a good fit of the model, and the rate of correct classification was estimated to be 88% with a cut-off point of 0.5.

The average size of holdings undergoing ownership changes decreased from 29.9 ha to 28.7 ha over the approximate interval 1983–90. In addition, the transition probability matrix showed that the trends towards smaller size categories mostly concerned the small size categories. The results can be used in considering the effects of the small size holdings for forestry and if the purpose is to influence partitioning through forest or rural policy.

• Ripatti, E-mail: pr@mm.unknown

The paper examines the needs, premises and criteria for effective public participation in tactical forest planning. A method for participatory forest planning utilizing the techniques of preference analysis, professional expertise and heuristic optimization is introduced. The techniques do not cover the whole process of participatory planning, but are applied as a tool constituting the numerical core for decision support. The complexity of multi-resource management is addressed by hierarchical decision analysis which assesses the public values, preferences and decision criteria toward the planning situation. An optimal management plan is sought using heuristic optimization. The plan can further be improved through mutual negotiations, if necessary. The use of the approach is demonstrated with an illustrative example. Its merits and challenges for participatory forest planning and decision making are discussed and a model for applying it in general forest planning context is depicted. By using the approach, valuable information can be obtained about public preferences and the effects of taking them into consideration on the choice of the combination of standwise treatment proposals for a forest area. Participatory forest planning calculations, carried out by the approach presented in the paper, can be utilized in conflict management and in developing compromises between competing interests.

• Kangas, E-mail: jk@mm.unknown
• Loikkanen, E-mail: tl@mm.unknown
• Pukkala, E-mail: tp@mm.unknown
• Pykäläinen, E-mail: jp@mm.unknown

The factors affecting the non-industrial, private forest owners’ (NIPF) strategic decisions in management planning are studied. A genetic algorithm is used to induce a set of rules predicting potential cut of the forest owners’ choices of preferred timber management strategies. The rules are based on variables describing the characteristics of the landowners and their forest holdings. The predictive ability of a genetic algorithm is compared to linear regression analysis using identical data sets. The data are cross-validated seven times applying both genetic algorithm and regression analyses in order to examine the data-sensitivity and robustness of the generated models.

The optimal rule set derived from genetic algorithm analyses included the following variables: mean initial volume, forest owner’s positive price expectations for the next eight years, forest owner being classified as farmer, and preference for the recreational use of forest property. When tested with previously unseen test data, the optimal rule set resulted in a relative root mean square error of 0.40.

In the regression analyses, the optimal regression equation consisted of the following variables: mean initial volume, proportion of forestry income, intention to cut extensively in future, and positive price expectations for the next two years. The R² of the optimal regression equation was 0.3 and the relative root mean square error from the test data 0.38.

In both models, mean initial volume and positive stumpage price expectations were entered as significant predictors of potential cut of preferred timber management strategy. When tested with complete data set of 201 observations, both the optimal rule set and the optimal regression model achieved the same level of accuracy.

• Pesonen, E-mail: mp@mm.unknown
• Kettunen, E-mail: ak@mm.unknown
• Räsänen, E-mail: pr@mm.unknown

In the first part of the study, the selected wood and fiber properties were investigated in terms of their occurrence and variation in wood, as well as their relevance for thermomechanical pulping process and related end-products. It was concluded that the most important factors were the fiber dimensions, juvenile wood content, and in some cases, the content of heartwood being associated with extremely dry wood with low permeability in spruce. The following pulpwood assortments of which pulping potential was assumed to vary were formed: wood from regeneration cuttings, first-thinnings wood, and sawmill chips.

In the experimental part of the study, the average wood and fibre characteristics and their variation were determined for the raw material groups. Subsequently, each assortment – equalling about 1,500 m³ roundwood – was pulped separately for 24 h period. The properties of obtained newsgrade thermomechanical pulps were then determined.

Thermomechanical pulping (TMP) from sawmill chips had the highest proportion of long fibres, smallest proportion of fines, and had generally the coarsest and longest fibers. TMP from first-thinned wood was the opposite, whereas that from regeneration cuttings fell in between these two. High proportion of dry heartwood in wood originating from regeneration cuttings produced a slightly elevated shives content. However, no differences were found in pulp specific energy consumption. The obtained pulp tear index was clearly the best in TMP made from sawmill chips and poorest in pulp from first-thinned wood, which had generally inferior strength properties. No big differences in any of the strength properties were found between pulp from sawmill residual wood and regeneration cuttings. Pulp optical properties were superior in TMP from first-thinnings. No noticeable differences were found in sheet density, bulk, air permeance or roughness between the three pulps.

The most important wood quality factors were the fibre length, fibre cross-sectional dimensions and percentage juvenile wood. Differences found in the quality of TMP assortments suggest that they could be segregated and pulped separately to obtain specific product characteristics and to minimize unnecessary variation in the raw material and pulp quality.

• Tyrväinen, E-mail: jt@mm.unknown

Linear optimization model was used to calculate seven wood procurement scenarios for years 1990, 2000 and 2010. Productivity and cost functions for seven cutting, five terrain transport, three long distance transport and various work supervision and scaling methods were calculated from available work study reports. All methods are based on Nordic cut to length conditions. Finland was divided in three parts for description on harvesting conditions. Twenty imaginary wood processing points and their wood procurement areas were created for these areas. The procurement systems, which consists of the harvesting conditions and work productivity function, were described as a simulation model. In the LP-model the wood procurement system has to fulfil the volume and wood assortment requirements of processing points by minimizing the procurement cost. The model consists of 862 variables and 560 restrictions.

Results show that it is economical to increase the mechanical work in harvesting. Cost increment alternatives effect only little on profitability of manual work. The areas of later thinnings and seed tree- and shelterwood cuttings increase on cost of first thinnings. In mechanized work one method, 10-tonne one grip harvester and forwarder, is gaining advantage among other methods. Working hours of forwarder are decreasing opposite to the harverster. There is only little need to increase the number of harvesters and trucks or their drivers from today’s level. Quite large fluctuations in level of procurement and cost can be handled by constant number of machines, by alternating the number of season workers and by driving machines in two shifts. It is possible, if some environmental problems of large-scale summer time harvesting can be solved.

• Rummukainen, E-mail: ar@mm.unknown
• Alanne, E-mail: ha@mm.unknown
• Mikkonen, E-mail: em@mm.unknown

In the study, the potential allowable cut in the district of North-Savo, Eastern Finland was clarified  based on the non-industrial private forest landowners’ (NIPF) choices of timber management strategies. Alternative timber management strategies were generated, and the choices and factors affecting the choices of timber management strategies by NIPF landowners were studied. The choices of timber management strategies were solved by maximizing the utility functions of the NIPF landowners. The parameters of the utility functions were estimated using the Analytic Hierarchy Process (AHP).

The level of the potential allowable cut was compared to the cutting budgets based on the 7th and 8th National Forest Inventories (NFI7, NFI8) in Finland, to the combining of private forestry plans, and to the realized drain from non-industrial private forests. The potential allowable cut was calculated using the MELA system that has been used in calculating the national cutting budget.

The data consisted of the NIPF holdings that had been inventoried compartmentwise and had forestry plans made in 1984–92. The NIPF landowners’ choices of timber management strategies were clarified by a mail inquiry.

The most preferred strategy obtained was ”sustainability” (chosen by 62% of landowners). The second was ”finance” (17%) and the third ”savings” (11%). ”No cuttings”, and ”maximum cuttings” were the least preferred (9% and 1%, resp.). The factors promoting the choices of strategies with intensive cuttings were: a) ”farmer as forest owner” and ”owing fields”, b) ”increase in the size of the forest holding”, c) agriculture and forestry orientation in production, d) ”decreasing short-term stumpage earnings expectations”, e) ”increasing intensity of future cuttings”, and f) ”choice of forest taxation system based on site productivity”.

The potential allowable cut defined in the study was 20% higher than the average of the realized drain in 1988–93, which was at the same level as the cutting budget based on the combining of forestry plans in Eastern Finland. The potential allowable cut defined in the study was 12% lower than the NFI8-based greatest sustained allowable cut for the 1990. Using the method, timber management strategies can be clarified for private forest owners.

• Pesonen, E-mail: mp@mm.unknown

The relationship between site characteristics and understorey vegetation composition was analysed with quantitative methods, especially from the viewpoint of site quality estimation. Theoretical models were applied to an empirical data set collected from the upland forests of Southern Finland comprising 104 sites dominated by Scots pine (Pinus sylvestris. L.) and 165 sites dominated by Norway spruce (Picea abies (L.) H. Karst.). Site index H₁₀₀ was used as an independent measure of site quality.

A new model for the estimation of site quality at sites with a known understorey vegetation composition was introduced. It is based on the application of Bayes’ theorem to the density function of site quality within the study area combined with the species-specific presence-absence response curves. The resulting probability density function may be used for calculating an estimate for the site variable

Using this method, a jackknife estimate of site index H₁₀₀ was calculated separately for pine- and spruce-dominated sites. The results indicated that the cross-validation root mean squared error (RMSE_cv) of the estimates improved from 2.98 m down to 2.34 m relative to the ”null” model (standard deviation of the sample distribution) in pine-dominated forests. In spruce-dominated forests RMSE_cv decreased from 3.94 m down to 3.19 m.

In order to assess these results, four other estimation methods based on understorey vegetation composition were applied to the same data set. The results showed that none of the methods was clearly superior to the others. In pine-dominated forests RMSE_cv varied between 2.34 and 2.47 m, and the corresponding range for spruce-dominated forest was from 3.13 to 3.57 m.

• Lahti, E-mail: tl@mm.unknown

The study presents a theory of utility models based on aspiration levels, as well as the application of this theory to the planning of timber flow economics. The first part of the study comprises a derivation of the utility-theoretic basis for the application of aspiration levels. Two basic models are dealt with; the additive and the multiplicative. Applied here solely for partial utility functions, aspiration and reservation levels are interpreted as defining piecewisely linear functions. The standpoint of the choices of the decision-makers is emphasized by the use of indifference curves. The second part of the study introduces a model for the management of timber flows. The model is based on the assumption that the decision-maker is willing to specify a shape of income flow which is different from that of the capital-theoretic optimum. The utility model comprises four aspiration-based compound utility functions.

The theory and the flow model are tested numerically by computations covering three forest holdings. The results show that the additive model is sensitive even to slight changes in relative importance and aspiration levels. This applies particularly to nearly linear production possibility boundaries of monetary variables. The multiplicative model, on the other hand, is stable because it generates strictly convex indifference curves. Due to a higher marginal rate of substitution, the multiplicative model implies a stronger dependence on forest management than the additive function. For income trajectory optimization, a method utilizing an income trajectory index is more efficient than one based on the use of aspiration levels per management period. Smooth trajectories can be attained by squaring the deviation of the feasible trajectories from the desired one.

• Mykkänen, E-mail: rm@mm.unknown

The effect of scarification, ploughing and cross-directional ploughing on temperature conditions in the soil and adjacent air layer have been studied during 11 growth periods by using an unprepared clear-cut area as a control site. The development of seedling stand was followed to determine its shading effect on the soil surface.

Soil preparation decreased the daily temperature amplitude of the air at the height of 10 cm. The maximum temperatures on sunny days were lower in the tilts of the ploughed and in the humps of the cross-directional ploughed sites compared with the unprepared area. Correspondingly, the night temperatures were higher and so the soil preparation reduced the risk of night frost. In the soil at the depth of 5 cm, soil preparation increased daytime temperatures and reduced night temperatures compared with unprepared area. The maximum increase in monthly mean temperatures was almost 5°C, and the daily variation in the surface parts of the tilts and humps increased so that excessively high temperatures for the optimal growth of the root systems were measured from time to time. The temperature also rose at the depths of 50 and 100 cm.

Soil preparation also increased the cumulative temperature sum. The highest sums accumulated during the summer months were recorded at the depth of 5 cm in the humps of cross-directional ploughed area (1,127 dd.) and in the tilts of the ploughed area (1,106 dd.), while the corresponding figure in the unprepared soil was 718 dd. At the height of 10 cm the highest temperature sum was 1,020 dd. in the hump, and 925 dd. in the unprepared area.

The incidence of high temperature amplitudes and frequency of high temperatures at the depth of 5 cm decreased most rapidly in the humps of cross-sectional ploughed area and the ploughing tilts towards the end of the study period. The decrease was attributed principally to the compressing of tilts, the ground vegetation succession and the growth of seedlings. The difference between the prepared and unprepared area did not diminish. The increase in temperature due to soil preparation, thus, lasted at least over 10 years.

• Kubin, E-mail: ek@mm.unknown
• Kemppainen, E-mail: lk@mm.unknown

The presence/absence data of 27 forest insect taxa (Retinia resinella, Formica spp., Pissodes spp., several scolytids) and recorded environmental variation were used to investigate the applicability of modelling insect occurrence based on satellite imagery. The sampling was based on 1,800 sample plots (25 m by 25 m) placed along the sides of 30 equilateral triangles (side 1 km) in a fragmented forest area (approximately 100 km²) in Evo, Southern Finland. The triangles were overlaid on land use maps interpreted from satellite images (Landsat TM 30 m multispectral scanner imagery 1991) and digitized geological maps. Insect occurrence was explained using either environmental variables measured in the field or those interpreted from the land use and geological maps. The fit of logistic regression models carried between species, possibly because some species may be associated with characteristics of single trees while other species with stand characteristics. The occurrence of certain insect species at least, especially those associated with Scots pine, could be relatively accurately assessed indirectly on the basis of satellite imagery and geological maps. Models based on both remotely sensed and geological data better predicted the distribution of forest insects except in the case of Xylechinus pilosus, Dryocetes sp. and Trypodendron lineatum, where the differences were relatively small in favour of the models based on field measurements. The number of species was related to habitat compartment size and distance from the habitat edge calculated from the land use maps, but logistic regressions suggested that other environmental variables in general masked the effect of these variables in species occurrence at the present scale.

• Väisänen, E-mail: rv@mm.unknown
• Heliövaara, E-mail: kh@mm.unknown

Anthesis was studied at the canopy level in 10 Norway spruce (Picea abies (L.) H. Karst.) stands from 9 localities in Finland was studied in 1963-74. Distribution of pollen catches were compared with the normal Gaussian distribution. The basis for the timing studies was the 50% point of the anthesis-fitted normal distribution. Development was characterized in calendar days, in degree days (>5°C) and in period units. The count of each unit began on March 19 (included). Male flowering in Norway spruce stands was found to have more annual variation in quantity than in Scots pine (Pinus sylvestris L.) stands studied earlier.

Anthesis in spruce in Northern Finland occurred at a later date than in the south. The heat sums needed for anthesis varied latitudinally less in spruce than in pine. The variation of pollen catches in spruce increased towards north-west as in the case of Scots pine. In the unprocessed data, calendar days were found to be the most accurate forecast of anthesis in Norway spruce. Locally, the period unit could be a more accurate parameter for the stand average. However, on a calendar day basis, when annual deviations between expected and measured heat sums were converted to days, period units were narrowly superior to days.

The geographical correlations respected to timing of flowering, calculated against distances measured along simulated post-glacial micgation routes, were stronger than purely latitudinal correlations. Effects of the reinvasion of Norway spruce into Finland are thus still visible in spruce populations just as they were in Scots pine populations.

The proportion of the average annual heat sum needed for spruce anthesis grew rapidly north of a latitude of ca. 63° and the heat sum needed for anthesis decreased only slightly towards the timberline. In light of flowering phenology, it seems probable that north-western third of Finnish Norway spruce populations are incompletely adapted to the prevailing cold climate. A moderate warming of the climate would therefore be beneficial for Norway spruce. This accords roughly with the adaptive situation in Scots pine

The PDF includes a summary in Finnish.

• Luomajoki, E-mail: al@mm.unknown

The profitability of fast-growing trees (Eucalyptus camaldulensis Dehnh., Acacia mangium Willd. and Melia azedarach L.) was investigated in the north-eastern and eastern provinces of Thailand. The financial, economic, and tentative environmental-economic profitability was determined separately for three fast-growing plantation tree species and for three categories of plantation managers: the private industry, the state (the Royal Forest Department) and the farmers. Fast-growing tree crops were also compared with teak (Tectona grandis L. f.), a traditional medium or long rotation species, and Para rubber (Hevea brasiliensis (Willd. ex A. Juss.) Müll. Arg.) which presently is the most common cultivated tree in Thailand.

The optimal rotation for Eucalyptus camaldulensis pulpwood production was eight years. This was the most profitable species in pulpwood production. In sawlog production Acacia mangium and Melia azedarach showed a better financial profitability. Para rubber was more profitable and teak less profitable than the three fast-growing species. The economic profitability was higher than the financial one, and the tentative environmental-economic profitability was slightly higher than the economic profitability.

The profitability of tree growing is sensitive to plantation yields and labour cost changes and especially to wood prices. Management options which aim at pulpwood production are more sensitive to input or output changes than those options which include sawlog production. There is an urgent need to improve the growth and yield data and to study the environmental impacts of tree plantations for all species and plantation types.

The PDF includes a summary in Finnish.

• Niskanen, E-mail: an@mm.unknown
• Luukkanen, E-mail: ol@mm.unknown
• Saastamoinen, E-mail: os@mm.unknown
• Bhumibhamon, E-mail: sb@mm.unknown

The objective of this study is both theoretical and empirical. On the theoretical level strategy concept, its operationalization and measurement are analysed and clarified. On the empirical level marketing strategies and competitive strategies are described by country. The study also identifies the strategic marketing decisions characterizing different countries or competitive strategies. Furthermore, the relationships between strategies and marketing structures and functions are analysed. The connections between marketing strategy and competitive strategy are analysed on both the theoretical and empirical level. The data of the study consists of personal interviews of 102 large sawmills. The data was collected from Finland, Western USA and British Columbia, Canada.

On the theoretical level, the strategy concept is analysed by classifying the concepts used in strategy research into five different types. The data of the study makes it possible to empirically compare two different strategy concepts and three countries. Marketing strategy is analysed in terms of decisions concerning products, customers, market areas and marketing competence. The Finnish sawmills differ from the Western North American sawmills with a more advanced marketing strategy emphasizing specialty- and custom-made products and few customers and market areas. The Finnish sawmills are also applying more advance competitive strategies. Hypotheses concerning the relationships between marketing strategy and competitive strategy gain support from the empirical findings. Connections between marketing strategy and marketing structures and functions were found to exist, which provides validation for the used operationalization of the marketing strategy concept.

The PDF includes a summary in Finnish.

• Niemelä, E-mail: jn@mm.unknown

Diameter and volume increment as well as change in stem form of Scots pine (Pinus sylvestris L.) were analysed to predict tree increment variables. A stem curve set model is presented, based on prediction of the diameters at fixed angles in a polar coordinate system. This model consists of three elementary stem curves: 1) with bark, 2) without bark, and 3) without bark five years earlier. The differences between the elementary stem curves are the bark curve and the increment curve. The error variances at fixed angles and covariances between the fixed angles are divided into between-stand and within-stand components. Using principal components, the between-stand and within-stand covariance matrices are condensed separately for stem curve with bark, bark curve and increment curve. The two first principal components of the bark curve describe the vertical change in Scots pine bark type and the first principal component of the increment curve describes the increment rate. The elementary stem curves, bark curve and increment curve as well as corresponding stem volumes, bark volume and volume increment can be predicted for all trees in the stand with free choice of sample tree measurements. When only a few sample trees are measured, the stem curve set model gives significantly more accurate predictions of bark volume and volume increment for tally trees than does the volume method, which is based on the differences between two independent predictions of volume. The volume increment of tally trees can be predicted as reliably with as without measurement of sample tree height increment.

The PDF includes a summary in English.

• Ojansuu, E-mail: ro@mm.unknown

The aim of the study was to determine how timber truck transport business succeeds in the competition within its sector, and the effect it has on profitability structure of the sector. Furthermore, strategic groups were looked at in depth, as well as the competitive strategies of the most successful companies and groups of companies. The theoretical competitive strategy was operationalized.

A total of 53 timber truck transport entrepreneurs were interviewed. The average age of the entrepreneurs was 51 years. Of the businesses, 35% were partnership companies, 6% open companies, and 59% self-employed. The business owned an average 1.5 trucks, and at the time of interviewing their average age was four years. Nearly nine out of ten entrepreneurs had no schooling for the line of business, and four out of five had no short-term training. The attitude of the timber truckers toward their activities was more like that of self-employed persons than that of entrepreneurs. A total of 61.5% of them reporter that they carried on entrepreneurship simply to assure themselves a job.

The operational profitability of the sector has been good in the years 1984 to 1990, and the business profitability fairly good. The median equity ratio in the sector has remained at about 20% and the ratio of debts to turnover about 40%. The sector has been more profitable than forest machine contracting primarily due to the barriers to entry into the sector.

Cluster analysis, using Ward’s method, was used for seeking out strategic groups. The lengths of the customer relationships proved a significant barrier to mobility. The most successful business used the competitive strategy of cost weighted focussing. This was done through optimization of the capacity utilization rate and through choice of correct customers. The strategic position for successful business was judged to be good in the future. Success in the future will require above all activeness and innovation ability.

The PDF includes a summary in English.

• Mäkinen, E-mail: pm@mm.unknown

Timing of anthesis in 21 Scots pine (Pinus sylvestris L.) stands from 14 localities in Finland was studied at the canopy level in 1963-74. Distribution of pollen catches were compared with the normal Gaussian distribution. The basis for the timing studies was the 50 per cent point of the anthesis-fitted normal distribution. Development was characterized in calendar days, in degree days (>5°C) and in period units. The count of each unit began on March 19 (included).

Period unit was found to be the most accurate delineation of development. Locally, calendar days were sometimes a more accurate parameter. Anthesis in Northern Finland occurred at a later date than in the south as was expected, but at lower heat sum. The variation in the timing of anthesis and the variation of pollen catches increased northwards. The geographical correlations calculated against distances measured along simulated post-glacial migration routes were stronger than purely latitudinal correlations. Effects of the reinvasion of Scots pine into Finland are thus still visible in pine populations.

The proportion of the average annual heat sum needed for anthesis grew rapidly above a latitude of 63° even though the heat sum needed for anthesis decreased towards the timberline. In light of flowering phenology, it seemed probable that the northern populations in Scots pine in Finland have still not completely adapted to the prevailing cold climate at these latitudes. A moderate warming of the climate would therefore be beneficial for Scots pine.

The PDF includes a summary in Finnish.

• Luomajoki, E-mail: al@mm.unknown

The heating values of wood, inner and outer bark, and foliage components of seven small-size tree species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula pubescens Erhr., B. pendula Roth, Alnus incana (L.) Moench, A. glutinosa (L.) Gaertn., Populus tremula L.) were studied. Significant differences were found between species within each component. However, the differences between species for weighted stem, crown and whole-tree biomass are very small. The weighted heating value of the crown mass is slightly higher than that of the stem in all species. The heating value of stem, crown and whole-tree material was found to increase with increasing latitude.

The effective heating value of wood correlated best with the lignin content, inner bark with carbohydrate, and outer bark with carbohydrates and the extractives soluble in alkalic solvents. It is suggested that the determination of the heating value might be used as an indicator of the cellulose content of coniferous wood.

The PDF includes a summary in Finnish.

• Nurmi, E-mail: jn@mm.unknown

A theoretical framework to analyse the growth of Scots pine (Pinus sylvestris L.) is presented. Material exchange processes and internal processes that transport, transform and consume materials are identified as the components of growth. Hierarchical system is lined out. Momentary uptake of material at a single exchange site depends on the environmental condition next to the exchange site, the internal state of the biochemical system of the plant and the structure of the plant. The internal state depends on the exchange flows over period of time and the structural growth depends on the internal state. The response of these processes to the fluxes is controlled by the genetic composition of the plant.

The theoretical framework is formulated into a mathematical model. A concept of balanced internal state was applied to describe the poorly known internal processes. Internal substrate concentrations were assumed to remain constant but tissue-specific. A linear relationship between the quantity of foliage and wood cross-sectional area was assumed to describe balanced formation of structure. The exchange processes were thus described as a function of external conditions. The stand level interactions were derived from shading and effects of root density on nutrient uptake.

The approach was tested at different levels of hierarchy. Field measurements indicated that the hypothesis of the linear relationship described well the regularities between foliage and sapwood of a tree within a stand when measured at functionally corresponding height. There was considerable variation in the observed regularities in the range of geographic occurrence of Scots pine. Model simulations gave a realistic description of stand development in Southern Finland. The same model was also able to describe growth differences in Lapland after considering the effect of growing season length in the parameter values. Simulations to South Russia indicate stronger deviation from the observed patterns.

The simulations suggest interesting features of stand development. They indicate strong variability in the distribution of carbohydrates between tree parts during stand development. Internal circulation of nutrients and the reuse of the same transport structure by various needle generations had a strong influence on the simulation results.

The PDF includes a summary in Finnish.

• Nikinmaa, E-mail: en@mm.unknown

The study deals with medium-term economic planning for a multi-branched farm enterprise on which agriculture and forestry plus associated livelihoods are practiced. A personal enterprise consisting of the earning economy sphere of an individual person or family is found to provide a suitable point of departure and framework for farm enterprise planning. In this case, the consumer economy cash withdrawals of the entrepreneur and members of his family are linked to the planning model. In a combined planning model of this type serving the management of the agricultural entrepreneur’s entire economy, the problems of both the real process (chiefly pertaining to agriculture and forestry) and the financial process are solved simultaneously and optimally with regard to the goal function, taking into consideration the model’s production factor, financing, taxation and other such constraints. The model also takes into account the possibility of investing money in financial targets (e.g. governments bonds and stocks).

The study consists of constructing a multi-periodic, combined planning model in the form required by linear optimization. The model is applied to the economic planning of a farm and its adjoining woodlot located in south-western Finland. In order to simplify the presentation of the matter, the case calculation is made to apply to a planning period only two years; the time span in the formulae used in the model is actually ten years. For the same reason, the number of treatment alternatives for the stands in the woodlot may appear to be unrealistically small.

Within the planning period the model does not require the use of the calculation rate of interest typical of partial models; instead, it itself provides the solution to where to invest and what the financing costs will be. An essential feature of the model is that the plan for the entire farm is not compiled by adapting to one another the plans made separately for farming, forestry etc., and financing; instead, the entire real process and financial process plan are obtained as the solution for the model.

The PDF includes a summary in Finnish.

• Hämäläinen, E-mail: jh@mm.unknown
• Kuula, E-mail: mk@mm.unknown

The effects and relative efficiency of alternative forest taxes are analysed theoretically. The Fisherian two-period model of consumption, savings and timber harvesting is extended by incorporating the management intensity decision and deriving the concept of long-run timber supply. The effects of lump-sum (site productivity), realized income (yield) and ad valorem property taxes on short-run timber supply, management intensity, and long-run timber supply are established. As the core of the study, the alternative taxes are compared in order to determine the appropriate forest tax regime in terms of production efficiency. The efficiency criterion generally requires that the excess burden of taxation at any given tax revenue should be kept to a minimum. The study distinguishes between an initially undistorted economy and an economy with pre-existing distortions due to capital income taxation (interest charge deductions). When the effects on forest management decisions of forest and capital income taxes are considered as a whole, a neutral forest taxation is no longer efficient. The non-timber benefits of a forest are incorporated to examine the robustness of the tax results with respect to the objective function. Finally, forest tax issues specific to Finland are considered, and administrational and equity aspects are discussed.

The PDF includes a summary in Finnish.

• Ovaskainen, E-mail: vo@mm.unknown

A nonlinear programming algorithm was combined with two individual-tree growth simulators consisting of distance-independent diameter and height growth models and mortality models. Management questions that can be addressed by the optimization model include the timing, intensity and type of thinning, rotation age, and initial density. The results were calculated for Norway spruce (Picea abies (L.) H. Karst.) stands on Oxalis-Myrtillus site in Southern Finland, where the stand density after clearing of a seedling stand is about 2,000 trees/ha.

The optimum thinning programs were characterized by late first thinnings (at dominant height of 15–17 m) and relatively high growing stock levels. It was optimal to thin from above, unless mean annual increment was maximized instead of an economic objective. In most cases, the optimum number of thinnings was two or three. Compared to a no-thinning alternative, thinnings increased revenues by 15 –45% depending on the objective of stand management. Optimum rotation was strongly dependent on the interest rate.

Hooke and Jeeves’ direct search method was used for determining optimum solutions. The performance of the optimization algorithm was examined in terms of the number of functional evaluations and the equivalence of the objective function values of repeated optimizations.

The PDF includes a summary in Finnish.

• Valsta, E-mail: lv@mm.unknown

The study was carried out at Padasjoki, Southern Finland, where moose (Alces alces L.) density on the winter range had been over 1.5 individuals/km². Moose browsing intensity, expressed in terms of number of twigs eaten and biomass used, increased with stand density (biomass). Total biomass consumption (dry weight) per sample plot and per sapling. The number of bites increased, but the percentage biomass removed did not differ when stand density increased. A relatively large bite size was observed on the plots of low stand density. The quantity of food, which on average was of relatively low quality, was obviously important due to the benefit gained through reducing the search time.

The nutritive value of the browse, expressed in terms of chemical compounds indicating low food digestibility, was lower in the dense than in the sparse Scots pine stand. However, the amount of crude protein and arginine were relatively high in the dense stand. We concluded that shading affected the nutritional status of saplings on high density plots.

Although the biomass removed by moose per sapling was high for low density plots, the remaining biomass was larger than that on the high-density plots owing to the relatively large twig biomass of saplings. The number of saplings per hectare without main stem breakage increased significantly as stand density increased.

The PDF includes a summary in Finnish.

• Heikkilä, E-mail: rh@mm.unknown
• Mikkonen, E-mail: tm@mm.unknown

The study presents a growth and yield prediction model for a Pinus kesiya (Royle ex Gordon) stand by diameter classes. The material consists of temporary sample plots taken from a plantation inventory, of permanent sample plots established in commercial compartments and of an espacement trial. The mean basal area of the stand, variance and skewness of the diameter distribution are predicted. From these variables the parameters of the Weibull function are derived. Site class is assumed to be known or is calculated from measured information. Mortality is also predicted by estimating the number and mean size of dead trees. Thinnings are defined by the number of trees removed and by their relative size. If measured tree level data at the initial situation is available it can be utilized in the predictions, however, simulations can also be performed with stand level information. The minimum information needed for the prediction is planting density, site class as well as the times and removals of thinnings.

The calculations show that by decreasing the planting density of P. Kesiya from the present 1,330 stems/ha or by conducting early precommercial thinning both the relative and absolute amount of large sawlogs in the total production increase. An increase in the present planting density only slightly increases total yield. It is obvious that the presently recommended rotation of 25 years is too short for producing large sawlogs, especially on poor sites. This rotation period is suitable for small sawlog production while for pulpwood regimes shorter rotation periods can be used. If thinnings are done before the maximum current annual growth is reached stands will react well, but later on the ability to respond to thinnings decreases rapidly. Thinnings from below accelerates the production of large sawlogs more than thinning from above or systematic thinning. If all sawlog sizes are considered no great differences between thinning type exist. The study recommends different thinning regimes according to site class. Separate programs are recommended for the production of sawlogs and pulpwood.

The used thinning reaction model needs refinement and further studies with annual measured thinning trial material.

The PDF includes a summary in Finnish.

• Saramäki, E-mail: js@mm.unknown

Two operative forest site class estimation methods utilizing satellite images have been developed for forest income taxation purposes. For this, two pixelwise classification methods and two post-processing methods for estimating forest site fertility are compared using different input data. The pixelwise methods are discriminant analysis, based on generalized squared distances, and logistic regression analysis. The results of pixelwise classifications are improved either with mode filtering within forest stands or assuming a Markov random field type dependence between pixels. The stand delineation is obtained by using ordinary segmentation techniques. Optionally, known stand boundaries given by the interpreter can be applied. The spectral values of images are corrected using a digital elevation model of the terrain. Some textural features are preliminary tested in classification. All methods are justified by using independent test data.

A test of the practical methods was carried out and a cost-benefit analysis computed. The estimated cost saving in site quality classification varies from 14% to 35% depending on the distribution of the site classes of the area. This means a saving of about 2.0–4.5 million FMK per year in site fertility classification for income taxation purposes. The cost savings would rise even to 60% if that version of the method were chosen where field checking is totally omitted. The classification accuracy at the forest holding level would still be similar to that of traditional method.

The PDF includes a summary in Finnish.

• Tomppo, E-mail: et@mm.unknown

The investigation examines the development potential of small sawmills in rural Finland. Development is defined with qualitative bias, given small sawmills’ limited possibilities for large-scale investments. Potential is defined in terms of the behavioural limitations to development. The investigation assumes that small sawmill entrepreneurial behaviour is essentially satisficing, and that the concept of bounded rationality is applicable. The empirical material concerns a random sample of 399 sawmills from all regions in Finland collected in connection with the 1990 small sawmill inventory.

Three sets of enterprise/entrepreneurial attributes are constructed using principal component analyses: i) entrepreneurial skills & organization, ii) small sawmill outlets, and iii) information attributes. Development potential is measured by employing discriminant analyses to test these attributes against four a priori sawmill classifications: i) sawmill production structure, ii) entrepreneurial development intentions, ii) sawmill operating environments, and iv) sawmilling as a livelihood. Each of these analyses contributes to an understanding of the entrepreneur-enterprise dialectic.

Based on the use of Pred’s behavioural matrix, small sawmill entrepreneurs’ quantity & quality of information and their ability to use information are examined with respect to sawmill typologies. In this way, the entrepreneur-enterprise dialectic is given a third dimension, that of the entrepreneurs’ partial space. The analysis is therefore able to examine development potential from the standpoint of an entrepreneur-enterprise-environment (partial space) trialectic.

The PDF includes a summary in Finnish.

• Selby, E-mail: js@mm.unknown
• Petäjistö, E-mail: lp@mm.unknown

The basic objective in planning a forest road network is to minimize the total cost of terrain transportation, road transportation, road construction and maintenance by controlling the road location, road network density and road quality, besides environmental and ecological considerations. Studies on the optimization of forest road network have encountered difficulties in taking into account the spatial diversity of forest terrain and stands. The spatial data handling-network routing system developed in this study proves to be useful in assisting forest managers to carry out the planning of forest road networks by covering the spatial and economic analysis.

The PDF includes a summary in Finnish.

• Tan, E-mail: jt@mm.unknown

The influence of log properties (diameter, length, taper, volume, density and quality), sawing pattern, yield, sawing efficacy, stoppages, consumption of electric power and thereby on the financial result of sawing was examined. In addition, the significance of various revenues and costs were studied from the point of view of the financial result of sawing. The revenues from sawing are composed of revenues obtained from sawn goods, chips, sawdust and bark. The costs in sawing are made of raw material, capital, labour, energy and other costs. The results were calculated per diameter class and applying the basic principle of targeting all returns and costs on the different diameter classes.

The results are based on test sawings of a total of 1,606 Scots pine logs representing eight diameter classes,  using conventional frame saw sawing patterns. In addition, a sawing simulator was used. Log top diameter had a significant influence on the financial result obtained when calculations were made per log volume. The financial result obtained for the biggest diameter class exceeded that of the smallest diameter class by FIM 99.1/m³. Sawing revenues accounted for FIM 66.0/m³ and sawing costs for FIM 33.1/m³ of this difference. In addition to being influenced by the top diameter, the yield and sawing efficacy were observed to have a clear influence on the financial result. The influence of stoppages was smaller.

The only means of gaining significant improvement in the annual result obtained from sawing were improvements in the revenues from sawn goods or reductions in the cost of raw material. Increase of the minimum diameter led to a significant improvement in the annual result obtainable from sawing only if the production time remained unchanged; i.e., when correspondingly more logs from the other diameter classes were sawn. If the production time was reduced by an amount corresponding to the increase in minimum diameter, then the annual result fell dramatically except in the case of minimum diameter.

The PDF includes a summary in English.

• Hakala, E-mail: hh@mm.unknown

The present paper deals with the effects of clearcutting on soil and air temperature and the development of temperature conditions during the 12 growing seasons following clearcutting of a Norway spruce (Picea abies (L.) H. Karst.) stand on a Vaccinium-Myrtillus forest type in Kainuu, northeast Finland. The uncut control site had a growing stock of 140 m³/ha. The temperature measurements were carried out by means of thermographs, Grant measuring devices and minimum and maximum glass thermometers.

Clearcutting had no significant influence on temperatures measures at 2 m above the ground in a meteorological screen and no changes occurred in them during the period studied, while on the ground level and in the adjacent layer of air the daily maxima increased and the daily minima decreased as compared with uncut forest. The greatest difference was over 10°C between the maximum temperatures at 10 cm and almost 8°C between the minimum temperatures. Night frosts were considerably more common at 10 cm above the ground in the clearcut area than in uncut forests.

Temperature differences were smaller in the soil than close to ground level. Day temperatures were 2–3°C higher in the clearcut area than in uncut forests, and differences between night temperatures at this depth were even smaller. Correspondingly, temperatures were 3–5°C higher at depths of 50 cm and 100 cm in the clearcut area during the whole measuring period. The differences between the temperatures in the clearcut area and uncut forests did not diminish to any significant extent during the 12 years despite the stocking of the former area with seedlings.

The PDF includes a summary in Finnish.

• Kubin, E-mail: ek@mm.unknown
• Kemppainen, E-mail: lk@mm.unknown

The utilization of available food resources by the moose (Alces alces L.) was studied in a Scots pine (Pinus sylvestris L.) plantation containing an admixture of deciduous species. Rowan (Sorbus aucuparia L.) and aspen (Populus tremula L.) were highly utilized compared to pine and both silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.). However, they were not capable of withstanding continuous browsing by moose owing to their diminished biomass. In total, the browsing intensity (number of browsed twigs/tree) on pine and birch was about double of that on rowan and aspen.

The number of browsed twigs per tree increased as the amount of available main branches increased. The number of bites per available branch, as well as the maximum diameter of the bites, decreased as the density of the plantation increased. Silver birch was more used by moose than pubescent birch as well as planted silver birch compared with naturally regenerated trees.

Main stem breakage was especially common in winter 1988, the average height of the pine and birch trees being over two meters. The tops of broken stems were commonly utilized as food. The increase in moose density and the relatively deep snow cover evidently promoted the incidence of serious damage. The number of undamaged trees/ha was greater in dense than in sparse parts of the stand.

The PDF includes a summary in Finnish.

• Heikkilä, E-mail: rh@mm.unknown

The first three-year effects of PK(MgB) and NPK(MgB) fertilization on the dry mass accumulation and nutrient cycling were studied in a Scots pine (Pinus sylvestris L.) stand growing on a drained low-shrub pine bog in Eastern Finland. The total dry mass of the tree stand before fertilization was 78 tn/ha, of which the above-ground compartments accounted for 69%. The annual above-ground dry mass production was 6.3 tn/ha, 51% of it accumulating in the tree stand.

The study period was too short for detecting any fertilization response in the stems. The total dry mass accumulation was not affected, because the increase in foliar and cone dry masses after both fertilization treatments, and that of the living branches after NPK fertilization, were compensated by the decrease in the dry mass of dead branches.

The nutrients studied accounted for 392 kg/ha (0.49%) of the total dry mass of the tree stand before fertilization. The amounts were as follows; N 173 kg/ha (44%), Ca 90 kg (23%), K 58 kg/ha (15%). The rest (18%) consisted of P, Mg, S and micronutrients combined. The unfertilized trees took up the following amounts of nutrients of the soil: N 15.6, Ca 12.8, K 4.1, P 1.3, MG 1.7, and S and Mn 1.5 kg/ha. The uptake of Fe and Zn was 510 and 130 g/ha and that of B and Cu less than 100 g/ha. More than 50% of the nutrient uptake, except for that of K and Fe, was released in litterfall. The results indicated very efficient cycling of K, Mn and B between the soil and trees.

The fertilized stands accumulated more N, P, K and B than the unfertilized ones during the tree-year study period. The increased accumulation corresponded to 35% (52 kg/ha) of the N applied on the NPK fertilized plots, 10% of the P, 25% of the K and 10% of the B on the PK and NPK fertilized plots. The increased amount of B released in litterfall after fertilization was equivalent to 4% of the applied B. Fertilization inhibited the uptake of Mn and Ca.

The PDF includes a summary in Finnish.

• Finér, E-mail: lf@mm.unknown

Spectral characteristics of rapid changes in forest and the spectral separability of change categories were studied through the analysis of satellite scanner images. A computational model of the spectral reflectance of a Scots pine (Pinus sylvestris L.) stand as a function of time was constructed and compared with empirical data. The study area, centred at 61°51’ N, 24°22’ E, was located in boreal forest in Southern Finland. Ground truth data consisted of forest stands and sample plots. Spectral data comprised multitemporal Landsat Thematic Mapper and Spot images as well as spectroradiometer measurements. The separability of the changes was tested with statistical tests and classifications. The separability varied according to the change category. A scheme for fully automated change monitoring system was presented.

The PDF includes a summary in Finnish.

• Häme, E-mail: th@mm.unknown

Willow (Salix sp.) species and clones have been selected in Finland, originally for basket willow husbandry, since 1910's. Screening for biomass willows started in 1973 by the Foundation for Forest Tree Breeding. Biomass willow research for energy started in 1978. The objective of the study was, based on theoretical background, on historical record of Finnish willow research between 1910–80 and on analysis of the Finnish biomass willow research of the 1980s, a further selection of exotic and indigenous willows for energy and chemicals.

Swedish selection of 63 exotics, mainly of Salix viminalis L. and S. burjatica Nazarov, was screened in Kompparnäs willow research site in the southern coast of Finland in 1983–89. S. viminalis showed both high yield potential and good crop certainty. The yield variation in S. burjatica were big due to rust (Melampsora sp.) infection followed by lowered winter hardiness. Three recommendable S. viminalis clones for Southern Finland were found.

Finnish indigenous species were screened based on collection (375 clones) in 1974–74 of the Foundation for Forest Tree Breeding, and the Finnish 4H-organization (566 clones) in 1978–79 in test sites in Suomusjärvi, Nurmijärvi, Kannus and Haapavesi. Salix myrsinifolia Salisb. was most productive of the indigenous willows. Five recommendable clones were selected. The second most productive indigenous was S. phylicifolia, with three recommendable clones. Based on willow hybridization studies in the Finnish Forest Research Institute, a considerable additional selection effect, boosted by heterosis, was found from the progenies. Further intraspecific crossings of geographically distant clones of S. myrsinifolia are recommended.

Based on the results, S. viminalis is recommended for practical biomass forestry application in the southernmost agroclimatic zone of Finland. S. myrsinifolia is recommended for further research and development in the other zones.

The PDF includes a summary in Finnish.

• Pohjonen, E-mail: vp@mm.unknown

The field of work of the 7th National Forest Inventory was carried out during 1977–84. This report consists of the analysis of the forest resources, long-term development of forests and the results by ownership categories in Finland.

The area of forestry land, 26.4 million ha, has decreased slightly because of the increase of build-up areas and communication routes. Forest land, which is suitable to growing wood profitably, amounted 20.1 million ha. It has increased, although not as fast as earlier, due to drainage and fertilization of scrub and waste land swamps and the afforestation of agricultural land.

The growing stock volume was 1,660 million m³ and the estimated gross annual increment 68.4 million m³. A large quantity of young, rapidly growing stands, and fellings markedly below the increment, are the principal factors increasing the growing stock. The volume of Scots pine (Pinus sylvestris L.) has increased most but the greatest proportional increase has been in the volume of broadleaved trees.

The silvicultural quality of stands has improved and the increase in saw log tree volume has resulted in an increase in the total growing stock volume. The proportional volume of saw logs, however, has decreased. Both aging mature stands and postponed thinnings increase the risk of losses due to mortality and decay. Too dense stands retard the diameter growth of trees. The proportion of unsuccessful artificial regeneration has increased.

The area of private forests has slightly decreased, while companies and collective bodies have increased their ownership. Non-farmer private ownership already accounts for one half of the area of private forests. The silvicultural quality of company forests is best and the increase of the growing stock and its increment is proportionally greatest in these forests.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown
• Salminen, E-mail: ss@mm.unknown

Biogeographical patterns of the Scolytidae in Fennoscandia and Denmark, based on species incidence data from the approximately 70 km x 70 km quadrats (n = 221) used by Lekander et al. (1977), were classified to environmental variables using multivariate methods (two-way indicator species analysis, detrended correspondence analysis, canonical correspondence analysis).

The distributional patterns of scolytid species composition showed similar features to earlier presented zonations based on vegetation composition. One major difference, however, was that the region was more clearly divided in an east-west direction. Temperature variables associated with the location of the quadrat had the highest canonical coefficient values on the first axis of the CCA. Although these variables were the most important determinants of the biogeographical variation in the beetle species assemblages, annual precipitation and the distribution of Picea abies also improved the fit of the species data.

Samples with the most deviant rarity and typicality indices for the scolytid species assempblages in each quadrat were concentrated in several southern Scandinavian quadrats, in some quadrats in northern Sweden, and especially on the Swedish islands (Öland, Gotland, Gotska Sandön) in the Baltic Sea. The use of rarity indices which do not take the number of species per quadrat, also resulted high values for areas near Stockholm and Helsinki with well-known faunas. Methodological tests in which the real changes in the distribution of Ips acuminatus and I. amitinus were used as indicators showed that the currently available multivariate methods are sensitive to small faunal shifts even, and thus permit analysis of the fauna in relation to environmental changes. However, this requires more detailed monitoring of the species’ distributions over longer time spans.

Distribution of seven species (Scolytus intricatus, S. laevis, Hylurgops glabratus, Crypturgus cinereus, Pityogenes salasi, Ips typographus, and Cyleborus dispar) were predicted by logistic regression models using climatic variables. In spite of the deficiencies in the data and the environmental variables selected, the models were relatively good for several but not for all species. The potential effects of climate change on bark beetles are discussed.

The PDF includes a summary in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Väisänen, E-mail: rv@mm.unknown
• Immonen, E-mail: ai@mm.unknown

The aim of this study was to explain both theoretically and empirically the formation of the unit price of a woodlot in the early 1980’s in Finland. The structure of the market in which woodlot transactions take place is described by analysing the volume of markets, the heterogeneity of the woodlots, institutional regulation of woodlot ownership and information concerning the market. The decision-making processes of both woodlot seller and buyer are examined using a theoretical model. Using a woodlot transaction sample for 1983 and 1984 woodlot unit price is explained empirically.

The PDF includes a summary in Finnish.

• Vehkamäki, E-mail: sv@mm.unknown

Factors determining newsprint consumption in Finland in 1960–1986 were analysed. An econometric recursive multi-equation model describing the structure of the newspaper industry was formulated and estimated to obtain information on direct factors influencing newsprint demand. Short-term and long-term demand elasticities for newspapers and newspaper advertising were estimated.

The results indicate that the main factors affecting newsprint consumption are total circulation of newspapers, volume of newspaper advertising and the change in newsprint substance weight. Total newspaper circulation was found to depend on the rate of household formation and real household income changes. Demand for newspapers was shown to be price-inelastic. Structural analysis indicates that income elasticity of newspaper demand has increased slightly over time.

The volume of newspaper advertising was shown to affect newsprint consumption via the effects on pagination. Newspaper and television advertising were found to be independent of each other. The impact of the reduction in the basis weight was found to be substantial. The estimation of long-term elasticities of demand for newspapers and newspaper advertising using dynamic models revealed that demand rigidities exist.

The case study of Finland proposes three reasons why newsprint demand has not shown clear signs of reaching a saturation level. First, although population growth has stagnated in major consuming countries, the number of households has been increasing continuously. Second, income elasticity of newspaper demand does not show a declining trend. Third, the main driving force behind the buoyant demand is the resurgence of demand for newspaper as an advertising medium. In forecasting newsprint consumption, in addition to projections of economic growth, attention must be paid to the rate of household formation, the development of the advertising sector, the factors affecting competition between alternative media and the resulting media-mix in advertising, and changes in the substantial weight.

The PDF includes a summary in Finnish

• Katila, E-mail: mk@mm.unknown
• Riihinen, E-mail: pr@mm.unknown

Mineral soil sites where Scots pine (Pinus sylvestris L.) were suffering from Gremmeniella abietina die-back (Lagerb.) M. Morelet. were characterized and classified in Central Finland. The tree stand, ground vegetation, soil type and site topography were described in 163 sample plots in 16 stands. The sites were classified according to system developed by Cajander and numerically using TWINSPAN analysis based on the ground vegetation. The site topography of severely damaged stands was checked from colour infrared aerial photographs. The disease was most severe in depressions and frost pockets. Apart from topography no significant correlations were found between disease severity and site factors. No typical vegetational pattern of forest type of the severely affected stands could be detected. Most of the stands were growing on medium-coarse, unfertile soil with a rather thick humus layer.

The PDF includes a summary in Finnish.

• Sairanen, E-mail: as@mm.unknown

The Scots pine (Pinus sylvestris L.) pruning experiments were established in different geographical regions of Finland. The pines were pruned in 16 different times during the year. Half of the trees were inoculated with conidia of Phacidium coniferarum (Hahn). Annual cankers were produced in the inoculated trees pruned during October–December. The safe pruning season ended in autumn when the five-day mean temperature decreased below +7°C. The unsafe pruning season terminated when the temperature remained permanently over 0°C. Dry-pruned branches were infected only if the phloem had been wounded. The mycelia of the fungus were pathogenic in the phloem in the inoculations made from October to March. The fungus occurred commonly in slash and in pines wounded during the autumn. The fungus has a one-year life cycle.

The PDF includes a summary in Finnish.

• Uotila, E-mail: au@mm.unknown

The aim of this study was to investigate the ecophysiological and morphological characteristics of two salt-tolerant tree species, Eucalyptus camaldulensis Dehn. and Combretum quadrangulare Kurz. A greenhouse experiment with different levels of NaCl salinity (0, 0.5, 1.0, 1.5, and 2.0%) was set up and the results were compared with those of a field study on non-saline and saline soils. The determination of optimum gas exchange and the development and evaluation of photosynthetic models with and without water deficit were also included in this study.

Morphological characteristics under saline conditions showed that shoot height and diameter growth, shoot internode length, root length/biomass, leaf width and length, leaf area, number and biomass, and shoot/root and leaf/root ratios decreased with salinity, while leaf thickness increased with salinity. More growth was allocated to the roots than to the leaf canopy. Ecophysiological studies in laboratory showed that photosynthesis, stomatal conductance and water potential decreased with salinity, while the CO₂ compensation point increased with salinity. Transpiration, dark respiration and photorespiration increased at low salinity but decreased at high salinity levels. In the field study, however, there were no significant differences in stomatal conductance and opening between saline and non-saline soils. Model predictions supported the results of the field measurements. Adaptation to salinity was reflected in an acclimatization of tree structure in the field study. There were both functioning and structural changes of seedlings in the greenhouse experiment

In terms of ecophysiological and morphological characteristics, E. Camaldulensis showed better salt tolerance than C. Quadragulare both in the greenhouse experiment and field study

The PDF includes a summary in Finnish.

• Luangjame, E-mail: jl@mm.unknown

The premises of several models obtained from literature on bud dormancy release in trees from cool and temperate regions differs from each other with respect to responses to air temperature during the rest period of the buds. The predicted timing of bud burst in natural conditions varied among the models, as did the prediction of the models for the outcome of a chilling experiment.

Experimental results with two-year old seedlings of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) did not agree with any of the models. The experimental results also deviated from abundand earlier findings, which also disagreed with any of the models. This finding suggests that Finnish provenances of Scots pine and Norway spruce differ from more southern provenances with respect to temperature regulation of bud dormancy release.

A synthesis model for the effects of air temperature on bud dormancy release in trees was developed on the basis of the previous models and the experimental results of both the present and previous studies. The synthesis model contains part of the original models as special cases. The parameters of the synthesis model represent several aspects of the bud dormancy release of trees that should be addressed separately with each species and provenance in experimental studies. Further aspects of dormancy release were discussed, in order to facilitate further development of the models.

The PDF includes a summary in Finnish.

• Hänninen, E-mail: hh@mm.unknown

The establishment of moose (Alces alces L.) winter feeding sites, their utilization and their effect on damage to young Scots pine (Pinus sylvestris L.) plantations was studied in Ruokolahti-Imatra area in Eastern Finland in 1987–89. During the period, the density in the area was about 3–5 moose/ 1,000 ha.

Six feeding sites were established by fertilization, offering mineral lics and the tops of aspen and Scot pine and by salting the tops of pine. The moose preferred the feeding site to control areas during both summer and winter. In winter browsing was very heavy, especially in those areas located in or close to traditional wintering areas. In winter no moose were seen in the summer habitats.

The extent of, and fluctuations in moose damage were studied in 47 Scots pine plantations in the immediate surroundings of the feeding sites (29 plantations), control areas (18 plantations) and also 68 randomly selected pine plantations. Before the experiment began in 1987 four plantations had been seriously damaged. During the study period only one plantation was seriously damaged. However, it could not be conclusively proved that damage to the pine plantations had been reduced as a result of the feeding sites. The results of the study can be put into practice elsewhere to create better living conditions for moose in their winter habitats. However, the food offered at the feeding site should be in the right proportion to the number of animals wintering in the area, so that the risk of damage to nearby plantations would be kept as small as possible.

The PDF includes a summary in Finnish.

• Lääperi, E-mail: al@mm.unknown

The study examines the factor demands of the Finnish pulp and paper industry. In the theoretical part of the study, factor demand equations are derived using neoclassical production theory. In the empirical part, econometric factor demand model is estimated using annual time-series data for the period 1960–86. The relationship of factor demands and their prices are examined in terms of own price, cross price and substitution elasticities.

It is assumed that the ”representative firm” in the pulp and paper industry is minimizing its costs of production at a given output level. In addition, a number of other assumptions are made which enable the production technology to be represented by a cost function, in which the inputs are capital, labour, energy and raw materials. From the cost function, the factor demand equations, i.e., the cost share equations are derived by applying Shephard’s lemma. The equations are transformed to estimable form using translog approximation for the underlying factor share functions.

The study differs from the previous factor demand studies by applying the error correction model based on the Granger Representation Theorem and the results of the cointegration literature to model the dynamics of the factor demand. This approach provides a statistically consistent method for estimating the long-run static factor demand equations and the corresponding short-run equations. In general, the econometrics of integrated processes (e.g. stationarity and cointegration tests) applied in the present study have not been applied before in factor demand systems models.

The empirical results of the study indicate that the error correction approach can be applied to estimations of the factor demands for the pulp and paper industry. In both industry sectors, the adjustment to short run disequlibrium (price shocks) appears to be fairly rapid. The most significant results of the calculated elasticities are that the factor demands of pulp and paper industries clearly react to changes in factor prices and that there are significant substitution possibilities between the different inputs. The absolute values of the elasticities are, on average, somewhat larger than have been obtained in previous studies.

The PDF includes a summary in Finnish.

• Hetemäki, E-mail: lh@mm.unknown

Resistance to browsing by mammals differs among birch species, and among origins and families of European white birch (Betula pendula Roth). The variation in resistance is large even among individual seedlings of the same family.

On the surface of the bark of European white birch seedlings there are resin droplets, and the number of droplets is strongly and positively correlated with resistance to browsing by hares. The resistance of European white birch apparently is not expensive metabolically because the rapid growth rate of seedlings was positively correlated with hare resistance, and no correlation was found between seedling size and vole resistance. In cafeteria experiments voles and hares were very discriminating in their feeding on birch seedlings. In field experiments, however, environmental heterogeneity partly masked differences in vole resistance among birch families. Fertilization of seedlings seems not to have a clear effect on resistance to hares. On the other hand, there were indications that greenhouse temperature had an effect on resistance to voles. Practical forestry applications of differences in resistance, e.g. use of species hybrids and clonal forestry, are discussed. The prospects for resistance breeding are good.

The PDF includes a summary in Finnish.

• Rousi, E-mail: mr@mm.unknown

The aim of the present study was to evaluate and develop the use of natural regeneration of Norway spruce (Picea abies (L.) H. Karst.) in private forestry. The study was carried out using a line-plot survey with permanent circular sample plots. In total 40 regeneration sites were measured. The study includes results from three successive inventories: prior to the shelterwood cutting, in the summer after the cutting, and one year after the cutting. Regression and logistic regression analyses were used to construct models describing the effect of various factors on the restocking of the stands.

The standing volume prior to the shelterwood cutting was on average 236 m³/ha (ranging from 80 to 428 m³/ha) and after the cutting 120 m³/ha (39–220 m³/ha). The average number of stems per hectare decreased from 435 to 186. Prior to the shelterwood cutting 22% of the stands were satisfactorily restocked. After the cutting and one year later these percentages were 6 and 29%, respectively. Prior to the shelterwood cutting the number of acceptable seedlings was 1,440/ha, in the summer and year later 1,308/ha and 1,546/ha, respectively. Prior to the shelterwood cutting the characteristics of the mother stands did not correlate well with the number of seedlings. The change in the number of seedlings during the initial stage of shelterwood method depended on height of the seedling stand, amount of logging waste and number of germlings prior to the cutting. The risk to fail in regeneration was highest in the poorly restocked, sparse shelterwood stands, where a fast expansion of grass vegetation took place.

The PDF includes a summary in English.

• Leinonen, E-mail: kl@mm.unknown
• Leikola, E-mail: ml@mm.unknown
• Peltonen, E-mail: ap@mm.unknown
• Räsä­nen, E-mail: pr@mm.unknown

At the beginning of the investigation period the total biomass of the Scots pine (Pinus sylvestris L.) stands on the ordinary sedge pine mire was 48 t/ha. The biomass of the mixed stands of Scots pine and birch (Betula pubescens Erhr.) on the herbrich sedge pine mire was 91 t/ha, out of which 60% was from pine. The biomass of the Norway spruce (Picea abies (L.) H. Karst.) on the Vaccinium-Myrtillus spruce mire was 148 t/ha. The average annual net increment of the stand biomass was 5.8 t/ha in the unfertilized pine stand and 6.7 t/ha in the NPK and micronutrient fertilized one during the six-year investigation period. The corresponding figures in the mixed stand were 7.2 t/ha and 7.6 t/ha. The net increment of the biomass in the unfertilized spruce stand was 6.9 t/ha and in the fertilized 8.4 t/ha. A considerable proportion of the net increment was lost to the ground as litter in all stands.

The nitrogen, phosphorus, potassium, magnesium, iron, manganese, zinc, copper and boron cycles were investigated. The annual nitrogen uptake from the soil was 26–42 kg/ha, that of phosphorus 2.5–3.4 kg/ha, potassium 4.5–12 kg/ha, calcium 12–29 kg/ha, magnesium 2–4 kg/ha, iron 1.4–6.6 kg/ha, manganese less than 2 kg/ha and the other nutrients only some grams. Only part of the fertilized nutrients was fixed in the stand.

The PDF includes a summary in Finnish.

• Finér, E-mail: lf@mm.unknown

Due to the high level of salaries and cost of social security, strict ergonomic standards, specific logging conditions, predominance of private ownership, and strong influence of environmental and conservation aspects, the Nordic countries have been forced to develop completely new logging technology to meet their own specific requirements. Demanding domestic markets have created a strong base for the production and export of forest machines. In the 1980’s Finland has become the leading manufacturer of logging machinery in Europe.

The Finnish logging technology rests typically on the log-length method and the use of load-carrying forwarders. This constrains the export of logging machinery in many countries, but as increasing emphasis is placed on thinnings, improved timber recovery, productivity, ergonomics, and protection of environment, increasing interest is shown in this technology.

The paper presents a synthesis of logging in Finland. The technical logging conditions, development of mechanization, present technology, productivity of work, and forest machine industry are explained and reviewed from the view point of a foreign reader.

The PDF includes a summary in Finnish.

• Hakkila, E-mail: ph@mm.unknown

Genetic variation in the physiological characteristics and biomass accumulation of Acacia mangium Willd. was studied in both field and laboratory conditions. Variation in the growth characteristics, foliar nutrient concentration, phyllode anatomy and stomatal frequency was analysed in 16 different origins under field conditions in Central Thailand. Family variation and heritability of growth and flowering frequency were calculated using 20 open-pollinated families at the age of 28 months. The effect of environmental factors on diameter growth in different provenances is also discussed.

Under laboratory conditions, such physiological characteristics as transpiration rate, leaf conductance and leaf water potential were measured at varying soil moisture conditions. The responses of photosynthesis, photorespiration and dark respiration as well as the CO₂ compensation point to temperature and irradiance were also investigated. All physiological characteristics indicated differences among provenances. An attempt was made to relate the results obtained in the laboratory to the growth performance in the field. Recommendations on provenance selection for the planting of A. mangium in Thailand are also given.

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• Atipanumpai, E-mail: la@mm.unknown

The investigation concerns the nature of the dialectic relationships between small-scale entrepreneurs in peripheral areas and their business environments.

The investigation is weighted towards a theoretical and philosophical examination of the ways in which the behaviours of real-world entrepreneurs relate to their business environments. The theoretical framework first examines the assumption of intended or bounded rationality, which recognizes that human beings are in possession of imperfect information and imperfect ability, so that their perceived world is only an approximation of the real world. Following this, an epistemology is sought which enables the individual entrepreneur to be considered as the creator of his own world, and to compare this private world to the shared context of a wider set of spatial and social relations. Such an epistemology is found in existential phenomenology, which is subjected to a critical review.

As an empirical case study, the investigation examines the small sawmill entrepreneurs of North Karelia, Finland. The empirical investigation examines the aspects of the small-scale entrepreneurs’ business attitudes, perceived business environments, and their ability to use business-related information. The existential man-environment dialectic is revealed by relating these attributes to the entrepreneurs’ social setting and the level of entrepreneurship as revealed by the sawmill typology.

The PDF includes a summary in Finnish.

• Selby, E-mail: js@mm.unknown

The process of capital accumulation in timber production has been examined in this study. A detailed explanation of new investment in forest industry in terms of productive capacity as the determinant of national forest policy target growing stock and silviculture is presented. The basis of the explanation of forest industry productive capacity was a linear vertically integrated input-output production model. The model was used to derive a macroeconomic equilibrium condition specifying forest sector aggregate demand as an integral part of the national economy. Timber production has been constructed as a state variable system and the Maximum Principle used to derive silvicultural investment criterion. The derivation of the investment criterion was formulated as a dynamic problem in a labour surplus economy with linkage between savings and choice of silvicultural technology defined via income distribution between wages and profit. Maximization of aggregate consumption was specified as the goal of timber production.

By assuming a state of sub-optimal savings rate, it is shown that the real cost of labour is not zero in a labour surplus economy. Because unemployment labour is not a free commodity, it is concluded that capital-intensive silvicultural technology represents an optimal means of maximizing aggregate consumption in labour surplus economy, contrary to the recommendation of social marginal productivity theory.

The PDF includes a summary in Finnish.

• Omwami, E-mail: ro@mm.unknown

A monotony preserving taper curve can be constructed by using a quadratic spline. An algorithm is presented which is suitable for this purpose. It is used to the construction of a taper curve when several measured diameters of a tree are available. These taper curves are formed for different sets of measurements and their properties are evaluated. It appears that the monotony preserving quadratic spline can give a better taper curve than the usual cubic spline.

The PDF includes a summary in Finnish.

• Lahtinen, E-mail: al@mm.unknown

The dependence of the rates of photosynthesis and transpiration are studied on the environmental factors and on the control of the plant metabolism with Scots pine (Pinus sylvestris L.) in the natural environment. The importance of the different environmental factors to the photosynthetic production are evaluated. In modelling the dependence of the rates of photosynthesis and transpiration on the environmental factors and on the control processes, a dynamic system analysis approach is applied. Irradiance, temperature and water are explored during the annual cycle. Field measurements of the CO₂ exchange and environmental factors over three years are used in the analysis of the rate of the photosynthesis. The effect of different environmental factors on photosynthetic production is evaluated by model estimations using weather data in a 20-year period.

The PDF includes a summary in Finnish.

• Korpilahti, E-mail: ek@mm.unknown

Germination tests in varying photoperiod- and temperature-regimes showed that for early autumn collections, germination of Scots pine (Pinus sylvestris L.) seeds is delayed, especially at low incubation temperature (+10°C) and in darkness. The presence of light during germination (8- or 24-hour photoperiod) or high incubation temperature (+20°C) enhanced germination. As autumn proceeded, a greater proportion of seed were able of germinate in darkness and also in low temperature regime. This result was consistent in both populations studied – in seeds from natural stand (Hyytiälä, Southern Finland) and in seeds from the Hyytiälä clone archive trees, growing in the same site.

An attempt was made to relate the development of germinability during autumn to previously accumulated chilling unit (optimum temperature +3.5°C) sum. Germination percent variation in subsequent cone-collection could not, however, be explained with accumulated chilling.

The PDF includes a summary in Finnish.

• Nygren, E-mail: mn@mm.unknown

The study concerns with the methodology and efficiency of integrating multitemporal satellite image data with permanent sample plots in a continuous forest inventory and compartment wise estimation. The generalized least squares estimation for the population, and the unsupervised stratification for compartments, are the main estimation methods employed. The experimental material is composed of real and simulated multitemporal images (Landsat TM) and field data. Precision analyses for the estimation and comparisons for a number of estimation and updating methods, as well as statistical options are given.

The PDF includes a summary in Finnish.

• Peng, E-mail: sp@mm.unknown

The study analyses Finnish academic dissertations in forestry sciences on the basis of number published and yearly trends, length, topic, sources of funding and guidance, and the doctoral candidates’ background and career development before and after disputation.

From 1912–1984, 131 dissertations in forest sciences were published. The majority of them were written in Finnish. The length averaged 151 pages. In general, the more rapidly the dissertation was prepared, the better grade it received.

The majority of doctors in forest sciences come from well-to-do families, in cities located in Southern Finland. They constitute 2–6% of the total number of graduating foresters. At the time of disputation their average age has been 36 years. Doctors have used job changes to improve their position in the hierarchy of their employing institutions.

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• Leikola, E-mail: ml@mm.unknown

Multivariate methods are used to classify pine mires on the basis of edaphic properties into fertility groups in order to estimate the effect of fertilization in relation to site fertility. The data is based on two field inventories of NPK fertilization experiment in which 2,624 sample trees on 164 sample plots from 19 experimental fields were measured on Scots pine (Pinus sylvestris L.) dominated stands. The edaphic properties (total contents of nutrients and related properties) are based on 1,350 volumetric sub-samples of fertilized and non-fertilized control plots.

In a DECORANA ordination, based on standardised volumetric soil variables N-P and acid-base gradients jointly describing trophic status were distinguished. Mainly on the basis of these two gradients a TWINSPAN analysis divided the material into five edaphic groups. To independently allocate sample plots into fertility groups, discriminating multiple regressions were formed using the TS edaphic groups as class variable.

The effect of N, P, K, NP, NK, PK, and NPK treatments on tree growth was estimated on the basis of change in relative basal area increment during two growth periods. During five-year period immediately after fertilization N and P treatments evoked the strongest increase in growth. On the nutrient poor sites, the effect was almost double that on the fertile sites. The effect of N was short lasting while the P treatment still affected growth after 5–11 years. Although K treatment had little influence on tree growth needle samples collected 11 years after fertilization indicated increased K uptake on fertilized plots.

Generally, the effect of fertilization on absolute stand volume growth was small. During the 11-year study period the total increase in growth gained with NPK was some 3–4 m³/ha. Despite strong relative response of individual sample trees, due to low stand volume fertilization (and drainage) had practically no effect on volume growth on the sites of lowest fertility.

The PDF includes a summary in Finnish.

• Westman, E-mail: cw@mm.unknown

The relationship between canopy structure and photosynthetic radiation regime are studied in a theoretical basis. In modelling the canopy structure, a statistical approach is applied and the radiation field inside a stand is described in terms of random variables and their distribution. A comparison is made between horizontally homogenous stands and grouped forest stands in order to assess the influence of grouping of foliage on the irradiance distribution in a forest stand. Results show that grouping considerably reduces the interception of radiation and causes a large spatial variation. In coniferous stands the grouping of needles into shoots and the effect of penumbra are shown to have an important influence on the distribution of radiation on the needle area.

The PDF includes a summary in Finnish.

• Oker-Blom, E-mail: po@mm.unknown

The timing of the tetrad phase of microsporogenesis in sixteen tree species, belonging to the genera of Abies, Larix, Picea, Pinus, Alnus, Betula, Corylus and Populus, was studied. The tetrad phase of microsporogenesis in conifers and in Populus tremula L. was reached from late March to early June including the yearly and latitudinal variation. The tetrad phase in Betulaceae was reached in late July to mid-August. The microsporogenesis in Betulaceae species differed in ecophysiological terms from the other species studied in that the timing in Betulaceae was rather day-length dependent than heat sum-correlated. In conifers and in Populus the timing of tetrad phase correlated with heat sums accumulated and did not correlate with day length or any kind of thermal threshold. This difference was, however, judged to be associated to seasonal adaptive strategies rather than taxonomic relationships.

The PDF includes a summary in Finnish.

• Luomajoki, E-mail: al@mm.unknown

The effect of different fertilizer treatments on the invertebrate fauna on coniferous forest soil were investigated during the years 1979-83 both in field and in laboratory experiments. Fertilizers tested were urea (both alone and with P and K), ammonium nitrate and ashes. Ash-treatment was also controlled by raising the pH at the same level with Ca(OH)₂.

Both ashes and urea resulted in considerable changes in the soil fauna. Nematodes, especially bacterial feeders, increased temporarily. Some families of Coleoptera invaded the urea-treated plots. Enchytraceid worms and several microarthropod species decreased, as well as the total animal biomass. Ash-treatment influenced more slowly than did urea-fertilizing, but it caused more permanent changes. Ammonium nitrate with lime had little influence in the field. All fertilizers affected more strongly when mixed with soil in laboratory. pH alone proved to explain most of the changes observed, but nitrogen as a nutrient also plays role independently of acidity.

The PDF includes a summary in Finnish.

• Huhta, E-mail: vh@mm.unknown
• Hyvönen, E-mail: rh@mm.unknown
• Koskenniemi, E-mail: ak@mm.unknown
• Vilkamaa, E-mail: pv@mm.unknown
• Kaasalainen, E-mail: pk@mm.unknown
• Sulander, E-mail: ms@mm.unknown

The goal-setting in forest policy and the means available for achieving the desired goal of forest policy are examined in this study. Examination of the goal is done using a macromodel of a closed economy. In the model GNP is assumed to be linearly dependent on the supply of raw wood. The model is used to derive the marginal conditions of the optimum equilibrium forestry with respect to the growing stock and the silviculture. The effect on the forest owners’ behaviour of the following means are examined: the taxation of ”pure income” from forestry, the taxation of income from selling raw wood, unit sales taxation and ad valorem sales taxation of forestry and corresponding sales subsidies, the support of silvicultural investments and the channelling of income from wood sales into silvicultural investments. The marginal conditions have been defined according to the maximum principle. An empirical study concerning the raw wood market in the case of softwood logs, and silvicultural investments in the case of young stand tending, has been carried out on the basis of the theoretical examination.

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• Vehkamäki, E-mail: sv@mm.unknown

An extensive field-based survey was conducted to establish the distribution of site types on drained peatlands, the condition of the drainage networks, the post-drainage development of the tree stands, their structure and silvicultural condition and the corresponding requirements for operational measures. The data is based on sampling of the forest drainage undertaking during 1930–78 and consists of 1,312 km inventory transect, 6,030 relascope sample plots and 21,700 studied ditches.

Of the studied peatlands more than 60% were Scots pine (Pinus sylvestris L.) mires, slightly under 20% Norway spruce (Picea abies) mires, and under 10% each treeless mires and paludified upland forest sites. The remaining peatland area that is to be considered suitable for forest drainage according to criteria used by Heikurainen (1960) now consists mainly of spruce mires and paludified upland forest types; about 1 million ha both groups still remain undrained.

The proportion of ditches in need of ditch cleaning was estimated to be under 10% in the youngest drained areas and under 30% in the oldest. The mean tree stand volumes of the drained peatlands of different site types show the same dependence on the trophic level as in earlier studies but the volumes seem to be some 5–10% lower. These results compare favourably with those of the 7th national forest inventory.

Trends in the post-drainage development of tree stand volumes and increment are also, generally, in accordance with earlier findings but have somewhat lower values. The development of the nutrient-poor site type stands, especially in Northern Finland, seems to be significantly poorer than was earlier assumed.

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• Keltikangas, E-mail: mk@mm.unknown
• Laine, E-mail: jl@mm.unknown
• Puttonen, E-mail: pp@mm.unknown
• Seppälä, E-mail: ks@mm.unknown

The vegetation and number of physical and chemical soil properties were studied on a random sample of closed upland forest stands in Southern Finland. The material consists of a total of 410 sample plots. Two-way indicator species analysis (TWINSPAN) was carried out in order to produce a hierarchical clustering of samples on the basis of the vegetation data. Discriminant analysis and analysis of variance were applied in order to find environmental correlations of the vegetation clustering.

The vegetation was found to indicate the nutrient regime of the humus layer well, but to a less extent the properties of the sub-soil. The understorey vegetation was found to be jointly dependent on the site fertility and on the properties of the tree stand, especially on the tree species composition. Although the forest vegetation appears to be distributed rather continuously along an axis of increasing site fertility, relatively unambiguous classification can be based on the appearance of indicator species and species groups.

The results of the study were interpreted as indication that operational site classification done using the vegetation is rather good method for classification in closed forest stands. Different methods produce relatively consistent, natural and ecologically interpretable classifications. The results also imply that the vegetation cover and the humus layer develop concurrently during the development of the ecosystem, but the differentiation of the site type is regulated simultaneously by a number of interacting factors ranging from mineralogical properties of the parent material to the topographical exposition of the site. As the plant cover depicts all these primary factors simultaneously, only a relatively rough ecological site classification can be based on the vegetation.

The PDF includes a summary in Finnish.

• Kuusipalo, E-mail: jk@mm.unknown

Soil respiration readings are reported for three ameliorated peatland sites of different types, covering a period of four years, during which the sites were drained and treated with various fertilizers. Respiration is shown to increase exponentially with temperature, varying mostly in the range 100–500 mg CO² m^-2 h^-1. The changes in soil respiration followed those in surface temperature with a time-lag of approximately 3–3.5 hours. At one site, where the groundwater table dropped by about 0.5 m after ditching, soil respiration increased 2.5-fold within a few weeks, whereas at the other two sites both the fall in the groundwater table and the resultant changes in soil respiration were small.

The fertilizers tested were slow-dissolving PK, fast-dissolving PK, wood ash, slow-dissolving PK + urea, slow-dissolving PK + Nitroform (urea formaldehyde) and slow-dissolving PK + urea + a micro-element mixture. Application of fast-dissolving PK + urea led to a rapid increase in soil respiration at the site poorest in nutrients, and slow-dissolving PK to a slow increase in respiration. The greatest, steady increase of all was achieved by treatment with ash. At the sites with a higher natural nutrient content the application of fertilizers usually led to a decline in soil respiration lasting 1–2 years, after which the initial level was normally regained. Treatment with micro-elements caused an initial fall in soil respiration values in all three biotopes, followed by a pronounced increase.

The PDF includes a summary in Finnish.

• Silvola, E-mail: js@mm.unknown
• Välijoki, E-mail: jv@mm.unknown
• Aaltonen, E-mail: ha@mm.unknown

The 75th Anniversary volume of the Society of Forestry in Finland (now the Finnish Society of Forest Science) consists of three invited papers.

Professor Viljo Holopainen contributed the article ”The Society of Forestry in Finland during the period of active science and forest policy”. The article gives an account of the founding of the Society and its early activities, and views the main trends in the development of forest science in Finland. The emphasis is on a review of the science policy practiced in Finland during the past few decades, the changes that have taken place in forestry and forest policy and the challenges facing forest research in the changed circumstances. The development in the organization and material resources of forest research is examined in relation to the general trends in science policy. The author also gives an extensive account of the Society’s activities.

Professor Aarne Nyyssönen’s article ”International connections of Finnish forestry research” is an account of the international connections that forestry research in Finland has had in recent years. The author begins with international cooperation in university level education, especially in research training. He then proceeds to examine the international organizations in the field of forestry research, their tasks, activities and the role of Finnish researchers in them. A special form of cooperation, based on bilateral agreements between Finland and other countries is brought up. The greatest importance is attached to Nordic cooperation.

Professor N.A. Osara studies the comprehensive question ”World forestry: some trends and prospects”. The article begins with a review of forest resources, which points out several alarming problems in the tropical and subtropical zones as well as in industrialized countries. Prospects for expansion in the consumption of wood and wood-based products, industry and trade are studied in relation to wood availability and renewable forest resources. The author concludes that forestry can contribute to the improvement of rural conditions all over the world. He also stresses the importance of forest management not only for wood production but also for soil and water management.

The PDF includes a summary in English.

• Holopainen, E-mail: vh@mm.unknown
• Nyyssönen, E-mail: an@mm.unknown
• Osara, E-mail: no@mm.unknown
• Hämäläinen, E-mail: jh@mm.unknown
• Donner, E-mail: kd@mm.unknown

The effects of modern forestry on northwest European forest invertebrates are summarized and analysed mainly on the basis of published literature. The direct influence of different practices including clear-cutting, thinning, burning-over, ploughing, changes in tree species composition of stands, fertilization, insecticides, pheromones and biological control are discussed from a forest zoological point of view. Also, the indirect effects of general changes in boreal forest dynamics, loss of primeval forests, cessation of natural fires and the dominance of young stands are described. The direct effects of different silvicultural practices on the species composition and diversity of forest invertebrates are usually considered to be striking but transient. However, when large areas are treated, the species associated with primeval forests, especially with the wood composition system in them, as well as the species associated with fires, seem to have drastically declined. In northwest Europe, efficient forestry has not caused such serious pest problems as is known from tropical countries or North America.

The PDF includes a summary in Finnish.

• Heliövaara, E-mail: kh@mm.unknown
• Väisänen, E-mail: rv@mm.unknown

The applicability of operations research, database management systems and geographic information systems for decision-making in long-distance transport of wood in the Saimaa area in Central Finland were reviewed. Due to the complexity of the transport problem a geographic information system is the most applicable. However, investment in such a system for only long-distance transport decision-making is unjustified. A spatial database – heuristic programming system was developed. It was applied to studying the competitiveness and search for possible areas for rationalization of water transport in particular and long-distance transport in general. The system proved to be a useful aid in long-distance transport research. Also, with the increased use of computers for planning at the field level, a system similar to that described could be a powerful managerial aid.

The PDF includes a summary in Finnish.

• Pulkki, E-mail: rp@mm.unknown

The problems caused by the temporal and spatial microvariation in irradiance during field measurements of photosynthesis are studied. It is concluded on the basis of variation analyses based on irradiance data measured in a Scots pine (Pinus sylvestris L.) stand that the microvariation should be measured by integrating it over the measurement time and space.

However, the curvlinearity of the light response of photosynthesis results in biased estimates when linear integration (mean irradiance) is used. The significance of the bias is examined using a simulation technique on irradiance material. Whether the actual integral of photosynthesis can be approximated with mathematical method is next studied. The method gave satisfactory results only for a low curvature response, but the latter method was applicable also to the high curvature response. However, both methods presuppose that the mean and variance are known. Measurement of the variance is based on integration of the second power.

A new method, where the nonlinearity problem is avoided, is presented to measure fluctuation of the irradiance. The method enables the shoot geometry to be taken into account and it is also applicable to transpiration studies.

The PDF includes a summary in Finnish.

• Smolander, E-mail: hs@mm.unknown

The paper concerns relationship between climatic factors and annual ring indices mainly in Southern Finland. The studied index series were from papers of different authors and from different localities. The monthly mean temperatures and precipitation sums were derived from the measurements of meteorological stations. Effective temperature sums for different periods of the year were calculated from the monthly mean temperatures.

The autocorrelation functions were estimated for each index series. The autocorrelations at lag I were significant except for one series. Altogether the differences in the structures of the index series were noticeable, especially between the Scots pine (Pinus sylvestris L.) index series. The influence of climatic factors on the annual ring index variation was studied using cross correlation analysis, simple distributed lag models and transfer function-noise models.

The decisive factor for the annual ring index variation of Norway spruce (Picea abies (L.) H. Karst.) appears to be the effective temperature sum of the growing season. Warm periods during latter parts of previous summer had a negative effect on indices. For the variation of the Scots pine indices the most important climatic factors were the effective temperature sum of the latter part of the growing season and, especially on the arid sites, the precipitation sum during May-July.

The PDF includes a summary in Finnish.

• Henttonen, E-mail: hh@mm.unknown

This paper is the final report of a study on the damage of tree transplants induced before the trees are planted in the field. The injury development is viewed as a transient rather than a ”step-like” process. The main objective of the study is to develop concepts and methods for recognizing and analysing the dynamic aspects of that process. The report consists of three parts: i) characterization of the environments to which the plants are exposed, ii) theoretical part of model development, and iii) experiments with bare-rooted Scots pine (Pinus sylvestris L.) transplants in which the model was applied.

The results of the first part indicate fast temporal variation of the environmental stress factors, and a slow response of the plant in terms of visible injury symptoms. A model is developed in the second part of the paper for analysing the relationship between the fast stress variables and the slow injury variables. The model is employed in the third part of the study for developing experiments in which the transplants were subjected to different stress conditions. The conclusions emphasize the hazardous role of root desiccation. Similar injury development was observed over a range of different planting sites. Controlling high temperatures during the transportation and storage of the plants was introduced as an indirect method for avoiding the risk of root desiccation.

The PDF includes a summary in Finnish.

• Kauppi, E-mail: pk@mm.unknown

The aims of the present study were to determine physical and physio-chemical properties of some Finnish forest tree nursery soils, and to examine relationships between these properties and the amount of organic matter in the soil.

The following soil tillage layer properties of 33 fields belonging to 8 forest tree nurseries were determined: soil particle size distribution, organic matter content, bulk density and density of solids, total pore space, soil water volume at potentials pF 2.0 and 4.2, available water content and air space at potential pF 2.0, active acidity, electrical conductivity index and cation exchange capacities at pH 4.5 and 8.0. The soil texture class of the tillage layer parent material was sand, only in a few cases did higher percentage of silt and clay indicate a morainic nature of parent material. The amount of organic material in the soils varied within wide limits, reflecting differences in amelioration policy between the single nurseries.

Relationships between the physical properties of the soil parent material and those related to fertility were in most cases strongly influenced by the amount of soil organic matter. Soil density values decreased as the organic matter content increased from 2 to 25%, giving rise to the increase in the total pore space. However, the amount of water held at potential pF 2.0 and the available water content did not increase with increasing organic matter content. This was due to the absence of the particle fraction in the sand. Nursery soil amelioration, involving in most cases a mixture of Sphagnum peat with sand, thus gives rise to an increase in the content of drainable water.

Cation exchange capacities were positively correlated with the organic matter content. However, the absolute number of exchange sites expressed as equivalents in the tillage layer did not increase in accordance with the increase in organic matter content due to the influence of the organic matter content upon the ratio of solids in the voids.

The PDF includes a summary in English.

• Westman, E-mail: cw@mm.unknown

The applicability of five mathematical programming methods, namely standard linear programming, parametric programming, goal programming, mixed integer programming and integer programming is discussed as a planning tool for the choice of wood procurement method.

Theoretically, the goal programming approach seems to be the best routine for mathematical handling of problems related to wood procurement. The parametric approach must include enough large post-optimality analysis routine. If the effect of the variables expressed with different measures is to be studied, interpretation of the economic information given by the approach becomes a problem. The other drawback is that the approach does not allow determination of the hierarchy of the goals objectively as they depend on the subjective preferences of the decision maker.

From the practical point of view, standard linear programming is the best method if the objective function can be formulated in economic terms, for instance. If there are several goals to be attained or satisfied the best method is goal programming.

According to the sub-studies, every method under consideration can be used as a solution routine for the minimization of wood procurement costs. In cost minimization the best methods are goal programming and standard linear programming. The best method for harvesting system evaluation purposes is parametric because it allows varied cost calculations within a certain cost range. The best method for harvesting equipment investment planning is mixed integer programming with binary decision variables.

The more complicated and restricted the problem environment is, the better the mathematical programming approach will be, also in harvesting related problems.

The PDF includes a summary in English.

• Mikkonen, E-mail: em@mm.unknown

Analysis of sample tree data showed that the major part of the residual variation of the stem volume estimates occurs within the forest stands. The division of the residual variation into the variation within and between populations is the basis for the mean-square error formulae of the volume estimators. Efficiency of different sample tree measurement combinations has been studied by comparing the errors of the volume estimates to the sampling costs. The measurement of the upper diameter (d6) is of less value than is generally suggested.

The PDF includes a summary in Finnish.

• Kilkki, E-mail: pk@mm.unknown

An attempt was made in the study to determine the annual periods available for foliage spraying when cleaning Scots pine (Pinus sylvestris L.) dominated seedling stands. The study was made in nine experimental fields which were established in different parts of Finland. The spraying was applied throughout the growing season by DM, MCPA and Roundup. The results were inventoried one year after the treatments.

The results showed that there were big differences both in the destruction of hardwood sprouts and in the survival of pine seedlings due to the time period of the spraying. Threshold points were observed in the range of effect of DM and MCPA. By means of these it is possible to time the spraying treatments in such a way that there remains only slight damage to pine, but hardwood sprouts are destroyed totally. The results varied with Roundup so much, among other things due to rain, that such threshold points could not be determined. This preparation both had a milder effect on the hardwood seedlings and caused slighter damage to pine than the other preparations.

In Sodankylä in Northern Finland, the pines attained a good resistance to arboricides when the efficient temperature sum of the growing season was 550, but in Punkaharju in Central Finland only when it was 850. The seed provenance of the seedlings had an effect on the resistance. The threshold temperature sums of resistance in pine were on the average 70–74% from the long-term average number of degree days at the origin of the seed. The effect on the hardwood trees grew weaker as the long-term average was filled. Resistance of pine followed with a specific lag the lignification of the shoot and the ceasing of the growth of the needles.

The PDF includes a summary in English.

• Pohtila, E-mail: ep@mm.unknown
• Pohjola, E-mail: tp@mm.unknown

Improvement of Finnish forest industries’ competitiveness in the world markets through productivity increase as branch and plant level requires the search for appropriate comprehensive productivity indicators and the analysis of factors underlying productivity variations. These were the main objectives of the study. The data was based on the information on individual plants in 1974, obtained from the files of Industrial Statistics in the Central Statistical Office in Finland.

The study uses neoclassical average production functions as the starting point and the theory is expanded to cover factors underlying productivity variation when measured with regard to labour, capital, material input, and total factor input. For the measurement of the latter an index formula is suggested which would not necessarily incorporate neoclassical assumptions as they cannot be assumed valid in the Finnish forest industries. The estimation results of average production functions suggest increasing rate of returns in sawmilling but in pulp and paper production evidence remains inconclusive. The elasticity of substitution is unlikely to be constant and the non-homotheticity assumption cannot be rejected.

The productivity variation is, in general, best explained by a relatively simple model with capital-labour ratio, plant size and output quality as explanatory factors. Further trials with input quality, input price ratio, process characteristics, and the rate of capacity utilization improved the models only marginally in most cases, which may have been partly due to the failure to measure the variables successfully.

The cross-section results are compared with those of an earlier time-series study. The estimation results of average production functions yield somewhat different information in the long and short run. Both cross-section and time-series productivity models illustrate the importance of output level in total productivity.

The PDF includes a summary in Finnish.

• Simula, E-mail: ms@mm.unknown

The paper is the final report of a study on the estimation of value increment and inherent variables of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) stands. The main aim was to obtain improved criteria for decision-making concerning the priority of stands for regeneration.

The construction of various estimation models and their reliability are discussed in detail. The study, together with some previous papers, has resulted in a system which on the basis of a number of easily assessed stand variables gives for the stands concerned the volume of stems, percentages of timber assortments, stumpage value, volume increment and value increment.

The following examples are given with regard to the practical application of the results, in addition to the determination of the relative maturity of stands: 1) The study of various trends in stand development; the comparison between the volume and value variables. 2) The estimation of timber assortments needed for a cutting budget, trees marked for felling etc. 3) The calculation of the value of forests.

The PDF includes a summary in English.

• Nyyssönen, E-mail: an@mm.unknown
• Ojansuu, E-mail: ro@mm.unknown

The aim of the present work was to clarify the structure of selected natural Pinus kesiya Royale ex Gord. And P. merkusii Jungh. et de Vriese stands, with particular attention on the amount and quality of naturally-occurring seedlings and young trees. Furthermore, basic information required in the management of pine stands in watershed areas of northern Thailand was obtained.

Large number of pine seedlings were found in P. kesiyana stands only. Two of the examined four localities where this species occurred also included various intermediary height classes under the mature trees. In dense stands the number of seedlings was generally smaller as compared with lower seed tree densities. Neither one of the two localities where P. Merkusii was investigated indicated sufficient natural regeneration. Young pines (over 5 m height) seemed to survive the frequent ground fires quite well, whereas younger seedlings were destroyed and the ground layer vigour was lowered in these cases.

In situ sowing experiments at the beginning of the dry season indicated a faster development and better survival of emerging P. Kesiya seedlings as compared to P. Merkusii. Soil preparation and exposure to sun decreased the survival of seedlings in both species. Utilization of natural regeneration and direct sowing of pines as a silvicultural method as well as the general significance of the two pine species in the succession of plant communities under the influence of forest fires is also discussed.

The PDF includes a summary in Finnish.

• Turakka, E-mail: at@mm.unknown
• Luukkanen, E-mail: ol@mm.unknown
• Bhumibhamon, E-mail: sb@mm.unknown

The report concludes a series of studies on the early development of young Scots pine (Pinus sylvestris L.) stands. The basis assumption made in the study series was that the within-stand light regime is the main driving force for total tree growth and its allocation of photosynthates for crown, stem and root growth. An individual tree growing in a stand under a varying light regime which is controlled by the stand structure, is the basic unit used in the study. The photosynthesis of an individual tree is determined by the light regime. The stand is formed from individual trees.

The model is applied in simulation of the growth and development of tree stands. Several computer runs representing various densities, height distributions and tree species mixtures were carried out. Potential application areas, properties of the model and future needs of investigations are discussed.

The PDF includes a summary in English.

• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown
• Mäkelä, E-mail: am@mm.unknown
• Ilonen, E-mail: pi@mm.unknown
• Kanninen, E-mail: mk@mm.unknown
• Korpilahti, E-mail: ek@mm.unknown
• Nygren, E-mail: mn@mm.unknown

The possibilities of using microwave techniques in detecting the trafficability of peatlands is discussed. Three microwave methods were tested. 1) A FM-CW radar using 1.0–1.8 GHz frequency was used to measure the frost thickness of peat layer. It was possible to follow the variations in snow and frost layer thickness. Total reflected power might indicate the wetness class of the peatland, which is also a trafficability factor. 2) A short-pulse radar with 100 MHz frequency was tested in summer condition. Good profiling of peat layers was obtained, giving basic information for trafficability analysis. 3) A mapping of brightness of temperature of peatlands in summer conditions using a 790 MHz radiometer. The measured brightness temperature was correlated with vegetation cover, thus giving some information of trafficability.

The PDF includes a summary in English.

• Saarilahti, E-mail: ms@mm.unknown

This study examines the extent, structure and development of the publishing activity of Finnish forest sciences between 1909–1978. The subject comprises the four main forestry series; Acta Forestalia Fennica, Silva Fennica, Communicationes Forestales Fenniae and Folia Forestalia. Collectively, 532 authors produced 1,715 publications containing 90,134 pages.
The total number of pages of forest science publications doubled every 25 years. Only a small number of short research reports (few pages) and long monographs (over 200 pages) were published. The median age class of the authors was 36–40 years. The so called Lotka’s law, which describes the productivity of the researchers, proved to be valid in forest sciences. According to this law, among other things, one tenth of the researchers produced approximately half of all publications. Despite changes, the structure of the publisher community remained roughly constant. Every year approximately 30% of the author community was composed of new members, whilst 19–26% of authors stopped publishing.

• Leikola, E-mail: ml@mm.unknown

Taper curve models based on simultaneous equations were derived. The data consisted of 492 Scots pines (Pinus sylvestris L.) from Southern Finland. Two systems of simultaneous equations were constructed, one without the crown ratio and the other with the crown ratio as an exogenous variable. The endogenous variables consisted of 24 relative-height diameters and the height of the tree. The parameters of the model were derived by the ordinary least squares method.

In most applications, the height of the tree was exogenised. The logarithmically linear relationships between the relative-height diameters were utilized in the solution algorithm. The algorithm included both standard matrix operations and an iterative part in which the taper curve was fitted to any measured diameters by the natural cubic spline interpolation formula.

The models were applied to the derivation of taper curves, stem volumes, timber assortment percentages, and stem values. An experiment was also made to derive diameter and height increments from the taper curve model.

The reliability of the models was tested on the original data.

The PDF includes a summary in Finnish.

• Kilkki, E-mail: pk@mm.unknown
• Varmola, E-mail: mv@mm.unknown

Studies on Finnish Scots pine (Pinus sylvestris L.) plus tree clones by monoterpene and isozyme analyses was undertaken to further investigate mating system, population structure and pollination. Six allozyme systems (3 GOT, 1 GDH and 2 LAP) were properly analysed on the basis of segregation. Monoterpenes were analysed from needle material and segregation in high and low 3-carene content was found to depend on two alleles C and c. Thus, six allozyme systems and one monoterpene system were used as markers in this study.

It was shown that the northern clonal group maintains a much genetic variation as the central or southern clonal groups. The conditional probability of self-fertilization in about 20-year old clones estimated by the multilocus model was 14.1%, of which 8% originate from mating between trees that carry the same alleles to one of the maternal parent at some loci and 6% through self-fertilization.

There was no prominent difference in allele frequency of male gametes that pollinated the very early or very late flowering clones. The northern clonal group has higher a lower frequency of alleles GOT B2 and B3 respectively than of the southern clonal groups. The artificial plus tree selection, particularly in northern Finland, appears to favour heterozygous genotypes for the alleles that control 3-carene content n Scots pine.

The PDF includes a summary in Finnish.

• Chung, E-mail: mc@mm.unknown

Fertility of surface peat from sedge pine mires was studied by measuring several edaphic growth factors: bulk density, volume weight of organic matter, ash content, acidity, electric conductivity, effective cation exchange capacity, degree of base saturation, and total contents of N, P, K, Ca and Mg. The 168 temporal sample plots were situated on virgin sedge mires in different parts of Finland, and the 30 permanent sample plots on two uniform sedge mires.

The results showed that peat bulk density and volume weight of organic matter tend to increase with increasing site quality. Ash content increased gradually in the site series from small sedge mire to the herb-rich sedge mire. The relationship between the total content of macronutrients in peat and the site quality is clear. The importance of bulk density in evaluating the site quality is further emphasized when taking into account its significant correlation to contents of N and P. The soil variables follow the accepted quality gradient of the site series. Consequently, the plant sociologically based site classification seems to reflect satisfactorily the average soil properties. However, the within site variation was significant.

• Westman, E-mail: cw@mm.unknown

Variation in the radial growth of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) was studied in 10 localities in Southern Finland. The aim of the study was to utilize the information on variation in the growth indices for growth estimation, and to evaluate the relative accuracy of growth estimation based on the data from increment boring, in comparison to other methods.

The climatic variation in periodic growth (5-year-period) in Southern Finland is about 11% of the normal level. The results suggest that the data from 10 localities can be used in the computation of the index series for Southern Finland and that the data from 10 relascope plots are required in the study of the climatic variation in tree growth in a given locality. The standard error of the estimate in actual growth estimation for past and future periods by the stand function method is about 23%, the errors of the method involving increment boring being 6% and 16% respectively in past and future growth estimation. The respective methods yield about 20% and 13% error in average growth estimation. With aid of the average growth indices for Southern Finland in local growth estimation the accuracy is distinctly improved, the error being equal to 12% only, while the accuracy in other cases is slightly improved.

The PDF includes a summary in Finnish.

• Thammincha, E-mail: st@mm.unknown

Two approaches were applied in measuring the scenic value of forest landscapes. In the field, the scenic value of forest lands representing clear cut areas, as well as young closed stands and mature stands with varying tree species composition, were assessed. In the laboratory, the scenic value of the same stands was measured with the help of photographs of the same stand. The same persons representing forest students (36 persons) and city dwellers (25 persons) made the evaluation.

Stands of moderate density containing individual tall trees and a coniferous undergrowth had the greatest scenic value, independently of the tree species composition. However, birch was preferred to Scots pine and Norway spruce. Measurements made in the field by means of interviews, and in the laboratory based on photographs, gave very similar results. Photographs seem to represent a reliable tool for estimating the scenic value of forest landscapes.

The PDF includes a summary in English.

• Savolainen, E-mail: rs@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

Flowering time and characteristics of cones and seed development of Scots pine (Pinus sylvestris L.) plus tree clones originating from various parts of Finland and planted (grafts) in Southern Finland (61° 48’ N, 29° 19’ E) were studied during 1976-1978.

The flowering time (in terms of period unit (p.u.) sums for flowering) of the Scots pine plus tree clones showed characteristics specific to each population and the characteristics appear mainly adapted to the local temperature factor within Finland. Generally, the development of floral organs, cones and seed in the spring and summer seasons also showed a temperature dependence in that the reproductive organs are developed rapidly and/or favourably under higher temperature conditions within its optimum range.

In this respect, establishment of northern Scots pine seed orchards in Central or Southern Finland or an optimum flowering, and a favourable seed development with an optimum physiological reproductive isolation from surrounding Scots pine populations can be justified. Problem arising from the north-south transfer of seed orchards and the significance of trees’ growth rhythm are discussed in connection with tree improvement.

The PDF includes a summary in Finnish.

• Chung, E-mail: mc@mm.unknown

The aim of the study was to search for differences in ergonomic effects between lateral 1, 2, 3 and 4 Hz whole-body vibrations of the forest tractor driver. Healthy male volunteers, both professional drivers and students, were exposed to 692 different vibrations in four different experiments, total number of subjects being 34.

Increase of vibration displacement affected clearly the subjects’ manipulating ability. The subjective magnitude rating of vibration correlated with energy content of vibration, but no correlation was found between subjective rating and heart rate, blood pressure or urinary catecholamine excretion, although the last variables mentioned indicate the energy consumption of the body. The professional drivers rated the vibration with smaller ratings than amateur drivers.

Frequency alteration of tractor vibration can be a possibility for reduction of vibrational effects as a tool for industrial hygiene.

The PDF includes a summary in Finnish.

• Wuolijoki, E-mail: ew@mm.unknown

The aim of this investigation was to examine the dependence of stand volume and increment on different growth factors on drained peatlands drained 20 years ago. Measurements were made in 1977-79 on 35 sample plots in Central Finland on relatively poor pine bogs with a thick peat layer.

It became evident that the stand volume, increment and radial growth and growth development are primarily functions of groundwater depth. Groundwater depth is dependent, in the first place, on ditch depth and ditch condition. With regard to the variation in ditch spacing (ca. 35-70 m) under examination, the effect of ditch spacing on the stand was insignificant. As a practical recommendation it was concluded that ditches should be kept deep enough (> 70 cm) in order to maintain undisturbed stand development.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

An attempt was made in this study to determine which nutrients and in what amounts should be used in the fertilization of Scots pine (Pinus sylvestris L.) seedling stands on nutrient-poor open bogs in order to obtain optimum seedling growth and to minimize the risk of elk damage.

The most important nutrient to improve seedling growth in the experiments was phosphorus. Already rather small amounts produced a significant effect although the effect of higher dosages seemed to be longer lasting. After fertilization also nitrogen gave significant increase in growth. The number of seedlings damaged by elk increased the most on N-fertilized plots. Also, phosphorus increased the occurrence of elk damage, but effect seemed to be related to the better growth and more suitable size of P-fertilized seedlings. The effect of potassium on seedling growth and on occurrence of elk damage was negligible.

The PDF includes a summary in English.

• Laine, E-mail: jl@mm.unknown
• Mannerkoski, E-mail: hm@mm.unknown

The Forest Financing Committee played an important role in Finnish Forestry in the 1960's. This voluntary working group prepared three plans for financing basic forest improvement work from 1965 to 1975.

The report describes the origin of the MERA I (1965–70) and the volunteer work of the Forestry Financing (MERA) Committee in preparing the second and third programmes (1966–75). It deals the initiative of the Committee aiming to finance forest improvement works also from international sources, resulted later on to the Forest Improvement Project (1973–76). Its costs were covered for 16% by the International Bank for Reconstruction and Development in form of a State Loan. The report includes comments about the forest policy in Finland during the 60s and 70s as well as the results of the programmes.

The PDF includes a summary in Finnish and Swedish.

• Palosuo, E-mail: vp@mm.unknown

The paper is the final report of the Inter-Nordic Terrain-machine Project (1972–1975). It deals with the requirements for a terrain classification for forestry, its factors and classes, and presents a terrain classification.

The mechanization of hauling, which took place in the field of forestry in the 1950's, added to the need for a terrain classification. Different terrain classifications based on different terrain factors have been developed in many countries. In the meeting of IUFRO Section 32 held in Montreal in 1964, it was found that a general system was needed for measuring and describing those terrain conditions having a significant influence on forest operations. The requirements for such a classification system are given in the paper. Because some of the requirements are contradictory, the classification must be a compromise. The most important factors from the forestry point of view are presented in the article.

The terrain classification presented in this report consists of two stages. The first stage is a primary terrain classification, in which terrain factors are measured or described objectively. The second is a secondary descriptive classification. Only factors essential to the activity in question are taken into account. After this, in a secondary functional stage, the requirements of the employer of the system, e.g., working method, machines etc., are also taken into account.

The PDF includes a summary in Finnish.

• Eriksson, E-mail: te@mm.unknown
• Nilsson, E-mail: gn@mm.unknown
• Skråmo, E-mail: gs@mm.unknown

The paper concerns the estimation of the increment of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) stands in the southern half of Finland. For the methods based on stand tables, tree functions forecasting the annual increment of diameter and height during the next 5-year period are presented. The main results of the study, however, are the functions for the volume increment percentage of pine and spruce stands. The independent variables are: forest site type, tree species, stand age and volume, and mean diameter. The standard error of estimate is about 17% in the best functions. Calculations were made also with regard to the application of the results in growth estimation of large forest areas.

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• Nyyssönen, E-mail: an@mm.unknown
• Mielikäinen, E-mail: km@mm.unknown

The net photosynthetic rate per unit of foliage was studied in two-year old cuttings of Norway spruce (Picea abies (L.) H. Karst.), representing four clones, at varying temperature and soil moisture. The CO₂ compensation point (Γ), photorespiration, dark respiration, and water balance were also investigated. All these characteristics indicated differences among the clones. A correlation between CO₂ exchange and transpiration suggested that stomatal control determined at least a part of this variation during a favourable water balance. An inverse relationship existed between Γ and net photosynthetic rate, and the same curvilinear model explained this variation in unstressed as well as stressed plants at a given temperature. An increase in Γ seems to be a normal result of water stress, particularly at high temperature, indicating an increase in mesophyll resistance to CO₂ diffusion. This result was in agreement with calculated values of mesophyll resistance. It also supported our earlier conclusions about the significance of mesophyll resistance during water stress.

• Luukkanen, E-mail: ol@mm.unknown

In the experiment Scots pine (Pinus sylvestris L.) seedlings were transplanted out in the field. The effect of the treatments on gas metabolism and daily height increment were examined. The seedlings were 5-year old Scots pine plants growing in clay pots, covered with plastic bags. Transpiration and photosynthetic rates were monitored with open IRGA measuring system for a few days before being subjected to the treatments and for one month after. In addition, the daily amounts of transpired water and daily height increments were measured. A model for the potential rate of each metabolic process was constructed.

Planting and additional exposure had a strong and rather permanent effect on the self-regulation of the processes. This effect is very similar to that caused by water deficit. Exposure makes the disturbance more pronounced. Transpiration of the transplanted seedlings decreased in a few days after planting to less than half of the potential value and that of the exposed ones decreased to a quarter of the potential value. The daily amounts of photosynthesis decreased to half of the potential value. There was no recovery in photosynthesis during the whole monitoring period of four weeks. There was a slight recovery in transpiration about five weeks after transplanting.

Thus, the treatment probably generated stress conditions throughout the whole growing period, which is characterized by strong self-regulation of photosynthesis and transpiration, thus causing an essential decrease in the total amount of CO₂ fixed. The photosynthesis was depressed especially at elevated temperatures after planting, as during water deficit. Planting and additional exposure did not produce any detectable changes in the dependence of the growth rate on temperature or in the effect of self-regulation on height growth. On the other hand, the level of growth was decreased as a result of planting out.

The PDF includes a summary in Finnish.

• Hallman, E-mail: eh@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Räsänen, E-mail: pr@mm.unknown
• Smolander, E-mail: hs@mm.unknown

The data used to control the developed methods are presented in chapter two. The third chapter presents the statistical analysis conducted. The factor analysis shows that tree stand characteristics must be divided into three factors to able the information needed for site indexing to distinguish different site classes. The phases of model development are presented and the results of calculations with control data are shown.   

The results indicate that for calculations of nature-normal forests the suitable amount of tree stand characters for creating the site indexing function, is three.  These are: number of trees (N), basal area of the stand (G) and mean height (H).

The PDF contains a summary in Finnish. 

• Kangas, E-mail: yk@mm.unknown

The aim of the study was to search for measurement methods of muscle fatigue in forest work. Lactic acid concentration of capillary blood was measured from test persons after submaximal and maximal strain tests in laboratory and during forest work. At rest the lactic acid content was affected mainly by the body dimensions and blood pressure. In a maximal strain test it was affected mainly by the age. In submaximal forest work lactic acid content concentrated below the attitude factor indicating working pace and below the body dimensions so that bigger persons had a higher lactic acid concentration than smaller persons.

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• Wuolijoki, E-mail: ew@mm.unknown

The aim of the study was to identify the microbes which reach the cut surface of Norway spruce (Picea abies (L.) Karst.) stumps during the first year after felling by means of air born spores, determine their occurrence frequency and the combinations in which they occur, investigate the colour changes in the wood caused by microbes and identify the microbial species isolated from the sap- and heart-wood.

The material consisted of 360 spruce stumps. 300 of the stumps were innoculated with five different fungi (Phlebia gigantea, Botrytis cinerea, Gliocladium deliquescens, Trichoderma viride, Verticicladiella procera) in order to inhibit air-born attack by Heterobasidion annosum. 60 stumps were left untreated as controls.

The cultural characteristics of the following fungi isolated from the stumps have been described e.g.: Ceraceomerulius serpens, Chondrostereum purpureum, Cylindrobasidium evolvens, Peniophora pithya, Phlebia gigantea (Phlebiopsis gigantea) , P. subserialis, Sistotrema brinhmannii, Bjerkandera adusta, Coriolellus serialis, Trametes zonata, Armillariella mellea, Panellus mitis, Nectria fucheliana (microconidial-stage), Ascocoryne cylichnium (conidial-stage), Leptographium lundbergii, Acremonium butyri, Gliocladium deliquescens, Verticicladiella procera.

The proportion of Basidiomycotina fungi out of the whole material was 53 %, Ascomycotina and Deuteromycotina fungi 37,6 % and bacteria 7,3 %.

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• Hallaksela, E-mail: ah@mm.unknown

The purpose of the study was to produce information which is needed when planning the influencing the timber sales propensity of private forest owners. The study deals with the relations between communication behaviour and cutting behaviour as well as the attitudes and norms connected with them. On the basis of the results of this study, the choice of psychodynamic model can be recommended as a main strategy of influencing the timber sales propensity of forest owners. The paper gives the information basis for the choice of channels and messages of influencing.

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• Juslin, E-mail: hj@mm.unknown

In this paper a precise definition is given of the term physiological clock and the role of this clock in biological developmental and growth processes is mathematically studied. The heat sum method employed in the study of the annual cycle of development of forest trees has been used as the starting point. The mathematical principles of this method are analysed and it is shown that, on the same principles, a fairly general physiological clock can be constructed. Also, two growth models are presented in which this generalized physiological clock proves to play an important role.

The PDF includes a summary in Finnish.

• Sarvas, E-mail: js@mm.unknown

The purpose of this paper was to determine the proportions of nutrients remaining in the forest and removed from the forest as a result of cutting. The Norway spruce (Picea abies (L.) H. Karst.) phytomass remaining after clear cutting was studied in the categories of tree-top waste, branches, twigs, needles and cones. The bole wood, measured in solid cubic metres, was converted to kilogrammes on the basis of relative density determinations, and the amount of stump and root material estimated from the known amount of bole wood and comparable data presented in the literature. The nutrients studied were N (Kjeldahl), P (colour reaction), K, Ca, Mg, Fe and Mn (atomic absorption spectrophotometer). The wood and bark were studied separately. Details of the mineral composition of the bedrock are also presented.  

The harvested timber was found to account for 46 % of the total phytomass, or 58 % of the aerial phytomass, while the stump and root material represented one fifth of the total phytomass. The needles and bark contained the highest proportions of nutrients, especially in the case of nitrogen and phosphorus, the needles containing 32 % of total nitrogen and 26 % of total phosphorus. The surface waste wood contained on average more than double the amount of nutrients compared with the harvested bole wood, including more than six times the amount of phosphorus. Approximately one fifth of the nutrient contained in the total phytomass was removed on cutting. The high proportion of basic rocks in the area is suggested as an explanation of the nutrient status at the site, which is in many ways better than that described in the results of other investigations.  

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• Kubin, E-mail: ek@mm.unknown

The Oulanka National Park is situated in the district of Kuusamo on the eastern border of Finland, close to the Arctic Circle and within the coniferous forest zone. It covers a surface area of 107 km², and is known for the richness of its vegetation and flora, a product of a varied bedrock pattern including occurrences of dolomite. A description is given of the vegetation of the 9 forest and 47 peatland types distinguishable in the area by means of tables based on quadrat surveys. The distribution of each forest and peatland type is described in a vegetation map. The vegetation types are discussed in terms of the structure of their soil and the ecological and floristic features of their plant cover.

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• Söyrinki, E-mail: ns@mm.unknown
• Salmela, E-mail: rs@mm.unknown
• Suvanto, E-mail: js@mm.unknown

The transport unit in roundwood towing on Lake Iso-Saimaa in Central Finland comprises a tug and a raft of bundled wood with a towline between them. There are several factors influencing the economic size of the transport unit in roundwood towing. These are changing with the enterprises and along with general developments. In this paper these factors or factor groups are seen from the point of view of the enterprise. The main question is to determine the most economic combination of tug and raft size.

From the point of view of the towing enterprises the unit costs of transport are the most decisive factor. Both the size of the raft as well as the power of the tug influence strongly the unit costs. As a long-term goal a raft of about 35,000 m³ and a tug of 550 kW or more is considered to be advisable. The width of channels and sounds then allow a free passage for rafts being 36–40 m wide.

The PDF includes a summary in Finnish and in French.

• Roitto, E-mail: yr@mm.unknown

The article is the first part of a wider project aiming to study the measurement practices of stand’s height-over-age based classifications and to develop new methods for actually measuring the side index.  

The first part of the article presents the concepts of site indexing and discusses it with a mathematical model. The second part of the article examines the structure of site indexing system regarding the reliability of the method. Third part presents the factors affecting the method development and the fourth part discusses the possible site index classes and their characteristics.   

The PDF contains a summary in Finnish. 

• Kangas, E-mail: yk@mm.unknown

The aim of the present study was to explain how the Finnish paper industry increased its production and its exports, broadened its markets and managed to show a profit in its activities during the period between the two world wars, despite the restrictive international commercial policies then prevailing, and despite the economic depression of the thirties. Newsprint has been treated as a subject for detailed examination.

The study is based on a comparative investigation of the price received by the paper mills for their paper and the costs of production. Since the market price of paper fell during the twenty years in question, one must examine how the mills responded to the reduction in selling price. Technically the study ranges from the valuation of the standing timber to the handing over of the finished product to the buyer. Between 1929 and 1933 the cost of producing newsprint fell by 387 marks per ton.

The most significant factor in maintaining competitive power was the technical development and increased output brought about in the mills. That alone accounted for half the savings achieved. The reduction in the buying price of wood and in delivery costs accounted for about a third of the difference in production costs, and other factors for the remaining fifth. In addition, the devaluation of the Finnish mark was crucial. Measures taken to reduce costs were effective in so far as the paper mills, with only one or two exceptions, maintained their competitiveness in international markets and managed not only to retain but also to extend their markets.

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• Ahvenainen, E-mail: ja@mm.unknown

The paper presents some preliminary results of a 10-year-old study the purpose of which is to determine the effect of simultaneous variations in the intensity of drainage and fertilization on the development of planted and natural seedlings on peatlands under various climatic conditions. The development of the Scots pine (Pinus sylvestris L.) seedlings appeared to be better the more intensive the degree of drainage and fertilization used. The increase in the temperature sum had a positive effect on the development of pine seedlings and decreased the mortality rate.

The best growth result was obtained with a 10 m ditch spacing and strong fertilization. As it is difficult to decrease the 10 m ditch spacing for cost reasons, it can be concluded that on such oligotrophic peatlands as were used in this experiment, only an average growth level in the seedling stands can be reached even with the most efficient forest improvement measures. Broadcast fertilization used in the experiment, at least in large doses, increases seedling mortality, as well as the coverage of the ground vegetation, particularly that of cottongrass and fireweed, and also the shrub height, thus increasing competition. It cannot be recommended for afforestation, and today spot fertilization is used. According to this experiment natural seedlings seem once they have recovered after the first years, to grow better than the planted seedlings. This was true especially in the north and in areas, where drainage was not efficient. The height and height growth of the seedlings were to a large extent dependent on the temperature sum.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown
• Laine, E-mail: jl@mm.unknown

The paper is a continuation of an earlier report by the author on the same subject (Acta Forestalia Fennica 133, 1973). Norway spruce (Picea abies (L.) H. Karst.) wounds were inoculated with Peniophora gigantea (Phlebiopsis gigantea) and the discolorations starting from the wounds were investigated three years after the wounding. Fomes annosus (Heterobasidion annosum) had infected 17 % of the total number of wounded trees. If no microbes were growing at the furthest point of the discoloration that had started from the wound, the discoloration advanced upward from wounds made at breast height at a rate of 61 cm/year in the dominant and 36 cm/year in the suppressed trees. In the dominant trees, a year after the wound was inflicted the discoloration had advanced at a rate of 50 cm/year and after three years the rate was 61 cm/year. This difference is not significant. Where microbes were present at the furthest point of discoloration, the discoloration had advanced 27 cm/year in one year and 42 cm/year in three years. Also, this difference is not significant.

A microbe was isolated from the furthest point of discoloration in only 13 out of 42 possible cases. The most common microbe was Stereum sanguinolentum. Bacteria showed the fastest rate of advance.

The PDF includes a summary in Finnish.

• Kallio, E-mail: tk@mm.unknown