Articles containing the keyword 'PAR'

This study examined the relationships between forest management planning units and patches formed by forest habitat components. The test area used was a part of Koli National Park in North Karelia, eastern Finland. Forest management planning units (i.e. forest compartments) were defined by using a traditional method of Finnish forestry which applies aerial photographs and compartment-wise field inventory. Patches of forest habitat components were divided according to subjective rules by using a chosen set of variables depicting the edaphic features and vegetation of a forest habitat. The spatial distribution of the habitat components was estimated with the kriging-interpolation based on systematically located sample plots. The comparisons of the two patch mosaics were made by using the standard tools of GIS. The results of the study show that forest compartment division does not correlate very strongly with the forest habitat pattern. On average, the mean patch size of the forest habitat components is greater and the number of these patches lower compared to forest compartment division. However, if the forest habitat component distribution had been considered, the number of the forest compartments would have at least doubled after intersection.

• Uuttera, E-mail: ju@mm.unknown
• Hyppänen, E-mail: hh@mm.unknown

A shoot-root carbon:nitrogen allocation model, based on the two processes of transport and chemical conversion, is described and explored. The view is proposed that all allocation models, whether built for the purposes of theoretical investigation or practical application, should start with this irreducible framework. In the present implementation, the processes operate according to: for substrate sources, dependence on shoot and root sizes, with possible product inhibition; for transport, movement down a substrate concentration gradient; for substrate sinks or utilization, linear bisubstrate kinetics. The dynamic and equilibrium properties of the model are explored. Failure of this approach to allocation will indicate to the modeller that additional mechanisms to control the processes are needed, and the mode of failure will indicate the type of mechanisms required. Additional mechanisms are discussed which may involve hormones or teleonomic (goal-seeking) controls, and may be added to the irreducible framework. However, these additions should not replace the irreducible framework of transport and chemical conversion, because they do not in reality. Modifications to the basic model to reflect some possibilities such as ontogenesis with the transition from exponential growth towards a steady state or with the scaling of within-plant transport resistances, the influence of hormones, and active transport, are described.

• Thornley, E-mail: jt@mm.unknown

Process-based tree growth models are recognized to be flexible tools which are valuable for investigating tree growth in relation to changing environment or silvicultural treatments. In the context of forestry, we address two key modelling problems: allocation of growth which determines total wood production, and distribution of wood along the stem which determines stem form and wood quality. Growth allocation and distribution are the outcome of carbon translocation, which may be described by the Munch theory. We propose a simpler gradient process to describe the carbon distribution in the phloem of conifers. This model is a reformulation of a carbon diffusion-like process proposed by Thornley in 1972. By taking into account the continuity of the cambium along the stem, we obtain a one-dimensional reaction-diffusion model which describes both growth allocation between foliage, stem and roots, and growth distribution along the stem. Distribution of wood along the stem is then regarded as an allocation process at a smaller scale. A preliminary sensitivity analysis is presented. The model predicts a strong relationship between morphology and foliage-root allocation. It also suggests how empirical data, such as stem analysis, could be used to calibrate and validate allocation rules in process-based growth models.

• Deleuze, E-mail: cd@mm.unknown
• Houllier, E-mail: fh@mm.unknown

Linear programming (LP) is an important method for allocation of wood inventory stock. It is, for instance, used alone in tactical planning systems, which currently are in wide use at the higher hierarchical level in the functionally decentralized planning of the Finnish forest industry. Unfortunately, LP as a solution method has not been capable of handling spatial data that seem to characterize planning systems in geographical decentralization. In the present study, GIS was used to assimilate data from different wood procurement functions, to calculate transportation distances and cost figures, and to write the data in ASCII files, which were then used as input for the LP model. Using the experiments and methods of GIS on a planning system developed according to participatory planning, the results of this study suggest that the participatory method was faster than the conventional LP method, when solved using actual data. The participatory method was also capable of providing the same global optimum for a wood allocation problem. The implications of these results for improving operational and tactical planning of wood procurement in Finland are discussed.

• Palander, E-mail: tp@mm.unknown

The purpose of this study was to compare the Weibull distributions estimated for the entire growing stock of a stand and separately for Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) H. Karst.) in describing the basal area diameter distributions in mixed stands. The material for this study was obtained by measuring 553 stands located in eastern Finland. The parameters of the Weibull distribution were estimated using the method of maximum likelihood. The models for these parameters were derived using regression analysis. Also, some parameter models from previous studies were compared with the measured distribution. The obtained distributions were compared using the diameter sums of the entire growing stock, diameter sums by tree species and of the sawtimber part of the growing stock. The results showed that far more accurate results were obtained when the distributions were formed using parameter models separately for the different tree species than when using parameter models for the entire growing stock. This was already true when considering the entire growing stock of the stand and especially when the results were examined by tree species. When the models for the entire growing stock were applied by tree species in relation to basal areas, the results obtained were overestimates for Norway spruce and underestimates for Scots pine. The models from earlier studies, where parameter models were estimated separately for tree species from the National Forest Inventory data, showed good fits also in regard to the data of this study.

• Maltamo, E-mail: mm@mm.unknown

In a silviculture experiment in east-central Maine, USA, natural regeneration was sampled to measure the effects of: (1) a range of partial harvest intensities, and (2) repeated partial harvest at one intensity. Under the first objective, five treatments were compared with residual basal areas ranging from 15 to 24 m² ha^-1 for trees ≥1.3 cm diameter at breast height. For the second objective, regeneration was evaluated after four harvests at 5-year intervals. Prior to harvests, the overstory of all the treated stands was dominated by Tsuga canadensis (L.) Carr., Picea spp. A Dietr., and Abies balsamea (L.) Mill. Eleven species or species groups were identified among the regeneration: A. balsamea, T. canadensis, Picea spp., Thuja occidentalis L., Pinus spp. L., Betula papyrifera Marsh., Acer rubrum L., Betula populifolia Marsh., Populus spp. L., Fagus grandifolia Ehrh. and Prunus serotina Ehrh. Regeneration abundance was measured as counts of seedlings or sprouts taller than 15 cm but with diameters less than 1.3 cm at breast height (1.37 m). Regardless of harvest treatment, total regeneration was profuse, ranging from over 25,000 to nearly 80,000 trees ha^-1. Regeneration was dominated by conifers with a total angiosperm component of 10 to 52 percent approximately 5 years after harvest and 11 to 33 percent after 10 years. Consequently, in forests of similar species composition, tree regeneration following partial harvests should be sufficiently abundant with an array of species to meet a variety of future management objectives.

• Brissette, E-mail: jb@mm.unknown

The prescribed burning of a 7.3 ha clear-cut and a 1.7 ha partially cut forest (volume 150 m³/ha) was carried out in Evo (61 °12'N, 25°07'E) on 1 June 1992. The forest was a mesic Myrtillus site type forest dominated by Norway spruce (Picea abies (L.) H. Karst.). Practically all the trees and the above-ground parts of the understorey vegetation died in the fire, while the mor layer was thinned by an average of 1.5 cm.

A study was made on the change of germinated seedling population in time and their dependence on environmental factors. Seedlings of Norway spruce, Scots pine (Pinus sylvestris L.), silver birch (Betula pendula Roth), pubescent birch (B. pubescens Ehrh.) and rowan (Sorbus aucuparia L.) were inventoried in 1993 and in 1994 on permanent plots, four times per growing season. Autoregression models were used to compare regeneration of tree species in the burned forest with regeneration in the burnt clear-cut area, and to study the effect of distance from nearest seed source to regeneration.

The average number of seedlings germinating in 1993 was higher than in 1994, probably because of differences between these consecutive years in regard to the amount of seed rain and weather conditions. The number of Norway spruce and rowan seedling was higher inside the forest area than in the clear-cut area. The distance to the bordering forest and to the closest seed tree did not explain the result. It is suggested that the more stable microclimatic conditions under the shade of dead tree promote germination and seedling establishment in the forest area. As rowan is a bird-dispersed species, it is likely that dead trees help the dispersal of rowan seed by providing birds place to sit and defecate. The shade provided by dead trees may influence the further succession of the tree stand and vegetation composition and diversity.

• Vanha-Majamaa, E-mail: iv@mm.unknown
• Suominen, E-mail: rs@mm.unknown
• Tonteri, E-mail: tt@mm.unknown
• Tuittila, E-mail: et@mm.unknown

The use of random parameter models in forestry has been proposed as one method of incorporating different levels of information into prediction equations. By explicitly considering the variance-covariance structure of observations and considering some model parameters as random rather than fixed, one can incorporate more complex error structures in analysing data.

Competition indices and variance component techniques were applied to 92 Scots pine (Pinus sylvestris L.) -dominated permanent sample plots on drained peatlands in Northern Finland. By quantifying stand, plot, and tree level variation, it was possible to identify the level (stand, plot or tree) at which the explanatory variables contributed to the model. The replication of plots within stands revealed little variation among plots within a single stand but significant variation occurred at stand and tree levels. Positive and negative effects of inter-tree competition are identified by examining simple correlation statistics and the random parameter model.

• Penner, E-mail: mp@mm.unknown
• Hökkä, E-mail: hh@mm.unknown
• Penttilä, E-mail: tp@mm.unknown

The effects of wood ash and PK fertilization on natural regeneration and sowing of Scots pine (Pinus sylvestris L.) were studied in field experiments on nitrogen-poor (N_tot 0.87–1.26%) peat substrates. The study material was derived from three drained, nutrient-poor pine mires (64°52’ N, 25°08’ E) at Muhos, near Oulu, Finland. The experimental fields were laid out in 1985 as a split-split-plot design including the following treatments; mounding, natural regeneration and sowing and fertilization; PK (400 kg ha^-1) and wood ash (5,000 kg ha^-1). The seedlings were inventoried in circles in July–August 1991.

Changes in the vegetation were small and there were no statistical differences due to the fertilization treatments in the ground vegetation. PK or ash fertilization did not cause vegetation changes harmful to Scots pine regeneration on nitrogen-poor peatlands. Both sowing and fertilization significantly increased the number of pine seedlings, but not their height. Wood ash increased seedling number more than PK fertilizer. The number of seedlings varied from 7,963 (control) to 42,781 ha^-1 (mounding + sowing + ash). The seedling number was adequate for successful regeneration even on non-mounded, non-fertilized naturally regenerated plots.

The number of birch seedlings varied more than that of pine (370–25,927 ha-¹). Mounding especially increased the number of birches. The difference between PK fertiliser and ash was less pronounced than that for pine. In addition, to the field studies the effects of ash and PK fertilizer on the germination of Scots pine seeds was studied in a greenhouse experiment. Soaking in ash solutions strongly reduced seed germination, while the PK solution was less harmful.

• Silfverberg, E-mail: ks@mm.unknown

Semiparametric models, ordinary regression models and mixed models were compared for modelling stem volume in National Forest Inventory data. MSE was lowest for the mixed model. Examination of spatial distribution of residuals showed that spatial correlation of residuals is lower for semiparametric and mixed models than for parametric models with fixed regressors. Mixed models and semiparametric models can both be used for describing the effect of geographic location on stem form.

• Kangas, E-mail: ak@mm.unknown
• Korhonen, E-mail: kk@mm.unknown

Change in dry matter partitioning, ¹⁴C-incorporation, and sink ¹⁴C-activity of 1.5-year-old Scots pine (Pinus sylvestris L.) seedlings grown in growth chamber conditions were studied during a 91-day experiment. On five sampling dates, seedlings were labelled with ¹⁴CO₂ and whole-plant allocation patterns were determined. Intensively growing shoots modified the dry matter partitioning: during shoot growth the proportion of roots decreased but after that it increased. Based on their large proportion of dry matter, the needles (excluding current needles) were the strongest sink of carbon containing 40% of the incorporated ¹⁴C. Despite their small initial sink size, the elongating shoots (current main shoot + current branch) and their needles were the second strongest sink (30–40% of the total ¹⁴C) which reflects their high physiological activity. The proportion of ¹⁴C in the current year’s main shoot increased during shoot growth but decreased as the growth began to decline after 70 days. 10–20% of the total assimilated ¹⁴C was translocated to the roots. Laterals above 2nd order were the strongest sink in the root system, containing twice as much ¹⁴C as the other roots together. Alternation between shoot and root growth can be seen clearly: carbon allocation to roots was relatively high before and after the period of intensive shoot growth. Changes in root sink strength resulted primarily from changes in root sink activity rather than sink size.

• Lippu, E-mail: jl@mm.unknown

Five ploughed research areas from Finnish Norther Karelia were selected for comparison studies of plough ridges and untouched soil. Measurements were made at a depth of 10 cm in sample plots on both mineral and paludified mineral soil and peatland parts of these areas. In summer 1987 daily soil water matric potential was measured using tensiometers, and volumetric soil moisture content and density were determined from soil samples at two dates during the summer. Water characteristics of the core samples were also determined. On paludified mineral and peat soils the water table depth from the soil surface was measured.

The results indicated that in plough ridges matric potential was lowest. Plough ridges were also seen to dry and wet faster and to a greater degree than untouched soils. In untouched soils, soil water relations and aeration were not affected by the distance to the furrow. The effect of the plough ridge was smallest on peatland, where there was a good capillary connection from plough ridge to the ground water, if the ditches were not very effective. The soil in the ridges did not dry too much to restrict seedling growth. The untouched surface soil in poorly drained peat and paludified minear soil was, at least in a rainy growing season, often and also for long times so wet that 10% minimum air space required for good seedling root growth was not available.

The PDF includes an abstract in English.

• Mannerkoski, E-mail: hm@mm.unknown
• Möttönen, E-mail: vm@mm.unknown

The winter 1986–87 was unusually cold; the snow cover remained thin and consequently the soil froze to a considerable depth. In spite of the severe frost, the lowest temperatures measured at the ground surface was -10.3°C and in the soil at the depth of 10 cm -5.8°C. The temperature sum of the following summer was unusually small and the soil frost melted more slowly than usual. The winter frosts did not have a decisive influence on the survival of planted seedlings.

The PDF includes an abstract in English.

• Kubin, E-mail: ek@mm.unknown

The element content (Ca, Mg, K, Na, Fe, Mn, Zn, Cu, Pb, S) of Scots pine (Pinus sylvestris L.) bark and Bryoria lichens, as well as the occurrence and coverage of epiphytic lichens and the length of Bryoria species, were studied in the vicinity of Kolari cement works, NW Finland. Fruticose Bryoria species had the highest coverage on pine trunks at a distance of 2 km or more from the cement works. At a distance of 1 km the foliose – or even crustose – Parmeliopsis species were most abundant, while nearer to the works lichens were almost completely absent. The length of Bryoria was reduced at distances of less than 2 km from the cement works. The calcium content in Bryoria species increased very steeply close to the works; by a factor of 60 at a distance of 1 km compared to 16 km. No corresponding increase in other elements was observed near the cement works. All the elements studied in pine bark showed a significant negative correlation with distance, and a significant positive correlation with the calculated dust deposition levels. There were only minor differences between the north and south of the pine trunks, or the side facing or away from the works. Pine bark analysis is recommended for element accumulation studies.

The PDF includes an abstract in English.

• Kortesharju, E-mail: mk@mm.unknown
• Kortesharju, E-mail: jk@mm.unknown

The results of an intercalibration of sulphur analysis by 24 laboratories are evaluated. The analysis was made by one or more of six methods. The following three methods were found to be satisfactory as regards relative speed and reliability: Leco S analysis, X-ray fluorescence, and vacuum ICO emission spectroscopy.

The PDF includes an abstract in English.

• Jarva, E-mail: mj@mm.unknown
• Tervahauta, E-mail: at@mm.unknown

The earliest manor parks, which are a special form of cultivated forests, were created at the end of the 18th century. The surrounding of the main buildings was divided into two parts, an aesthetic park and yard serving household and economic purposes. Early in the 19th century, large parks were created which represented dominant aesthetic ideals but, on the other hand, formed a ”wild” counterpart to the structured inner world of the main building. A good example is Ratula Manor and its park, which represent the diversity of the cultivated forest of the 19th century manors.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in English.

• Lönnqvist, E-mail: bl@mm.unknown

The paper describes some examples from Paris and Helsinki areas, where trees are essential landscape elements. It is typical in France to plant trees around town squares, market places and along streets and roads. In Finland trees are almost always kept close to the house, together with other vegetation protecting the entrance and windows. These traditional uses of trees should be studied to serve landscape management.

The paper is based on a lecture given in the seminar ‘The forest as a Finnish cultural entity’, held in Helsinki in 1986. The PDF includes a summary in Finnish.

• Guignard, E-mail: mg@mm.unknown

The effect of the size of seed crop, dispersal of seeds and the early development of seedlings on the density and spatial distribution of young Scots pine (Pinus sylvestris L.) stands are evaluated on the basis of theoretical models. The models include (i) number and spatial distribution of parent trees on the regeneration area, (ii) size of annual seed crop, (iii) seed dispersal from a particular parent tree, (iv) germination of the seeds (germination percentage), (v) death of ageing seedlings after the establishment process, and (vi) height growth of the seedlings.

As expected, stand density and spatial distribution varied within a large range in relation to the density of the parent trees and the distance from them. The simulations also showed that natural seedling stands can be expected to be heterogenous due to the geometry of seed dispersal, emphasizing the frequency of young and small trees. The properties of the seedling stands were, however, greatly dependent on the density of the parent trees and the length of the regeneration period.

The PDF includes an abstract in Finnish.

• Kellomäki, E-mail: sk@mm.unknown
• Hänninen, E-mail: hh@mm.unknown
• Kolström, E-mail: tk@mm.unknown
• Kotisaari, E-mail: ak@mm.unknown
• Pukkala, E-mail: tp@mm.unknown

Comparative analysis could offer a number of advantages in the science of forest policy. Comparisons make use of the compiled material from different countries, point to new origins and solutions of issues of forestry and allow to question the common presuppositions in the national forest policy in a critical way.

The basic requirement of fruitful comparative research is a common scientific framework. In the light of empirical-analytical theory it is more promising to compare only one factor across regions than the whole system. The forest administration could be such a suitable object of comparison in particular because it is to be found all over the world, and it has a formal and partly public organization with a number of similarities. The product of forest administration is policy. The significance of the bureaucratic behaviour in agenda setting, policy formulation, legitimating, and implementation with regard to an issue of forest policy is to be analysed.

The two significant fields of analysis, namely forest administrations and the issues of forest policy characterize the strategies of research. By making use of a collection of papers dealing with forest bureaucracy we can select countries for comparison according to the following criteria: socioeconomic context, space and time. The next step is to analyse comparatively the behaviour of the forest bureaucracy in treating a special forest issue. The explanations can be tested empirically in different countries. Perhaps the dying of the forest could be a suitable issue as an object of comparative analysis which again could enlarge our knowledge about the forest administration as a political factor.

• Krott, E-mail: mk@mm.unknown

The basic density of the wood of the rowan tree (Sorbus aucuparia L.) is almost the same along the stem but that of the bark is increasing along the stem. The moisture content of the wood and of the bark is increasing along the stem. Its strength in the bending and in the compression is high. The volume shrinkage is high.

The PDF includes an abstract in Finnish

• Maasalo, E-mail: km@mm.unknown

Paratization of Petrova resinella L. in the gall stage was studied in the surrounding of Harjavalta, south-western Finland, in relation to industrial air pollution. Of the studied 283 galls, 28% produced a moth, 52% of the larvae/pupae were paratisized, and 20% were empty or contained a dead larva. The proportion of paratisized galls did not depend on the distance from emission sources of industrial air pollutants.

The PDF includes an abstract in Finnish.

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

The paper demonstrates the possibility of using data from small relascope sample plots in the derivation of the regression models which predict the Weibull function parameters for the dbh-distribution. The Weibull parameters describing the basal area dbh-distribution were estimated for relascope sample plots from the Finnish National Forest Inventory. In the first stage of the estimation nonlinear regression analysis was employed to derive initial parameter estimates for the second stage, in which the maximum likelihood method was used. The parameter estimates were employed as dependent variables for the derivation of the regression models; the independent variables comprised of the compartment-wise stand variables generally estimated in ocular inventories.

The PDF includes an abstract in Finnish.

• Kilkki, E-mail: pk@mm.unknown
• Päivinen, E-mail: rp@mm.unknown

The study deals with the interaction of various soil preparation and reforestation methods. The most favourable time of the year for broadcast sowing and the effect of stabilization after soil preparation on restocking were studied as special problems.

Prescribed burning, scalping and disc ploughing made a better combination with sowing than planting, and ploughing better combination with planting than sowing. The longer the period was between sowing and germination the fewer seedlings emerged. The best stocking was clearly resulted with sowing in June. Stabilization of soil after preparation had a negative effect on reforestation results.

The PDF includes a summary in English.

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

Berry yield of rowan tree (Sorbus aucuparia L.) was studied by picking and weighing the berries in a tree, counting the number of clusters by the eye, estimating the number of clusters by samples of 0.5 m², and by counting the dropped berries. In the last tree methods average weight of berries in a cluster was assessed by weighing a sample of clusters. The size of the tree and the abundance of the berries influenced the choice of method. The first two methods suited for small trees, the third for a tall tree with berries in abundance, and the fourth for those cases where birds had eaten a large portion of the berries.

The berry yields of 88 rowan trees were studied in Central Finland in 1983, a year of exceptionally high berry yield. The yield of berries averaged 23 kg per tree, the number of clusters 1,249 per tree and the number of berries 42,500 per tree.

The PDF includes a summary in English.

• Raatikainen, E-mail: mr@mm.unknown
• Rossi, E-mail: er@mm.unknown
• Vänninen, E-mail: iv@mm.unknown

The paper presents a method based on two phase sampling and applicable to forest inventories. The first phase estimates are obtained from satellite imagery and, if required, from extra material such as maps. Second phase estimates are measured in the field. The method is flexible and also applicable to compartmentwise forest inventories. The experiments were based on six study areas with 439 relascope plots. The correlation coefficients between first and second stage estimates varied largely according to the study area.

The PDF includes a summary in Finnish.

• Poso, E-mail: sp@mm.unknown
• Häme, E-mail: th@mm.unknown
• Paananen, E-mail: rp@mm.unknown

The yield of Gyromitra esculenta (Pers.) Fr. was surveyed during 1973–82 in a Norway spruce (Picea abies (L.) H. Karst.) dominated stand in Central Finland. The soil surface was treated with different light methods, mainly removing the vegetation and humus layer.

It was shown that is possible to improve the natural yield of G. esculenta by breaking the soil surface. In the 286 m² of treated the yield could be improved over 50 fold compared to the control area. In the untreated control area, the yield per hectare was 0.98 kg/yr. In treated plots the yield was 52.4 kg/yr (in the best year 191 kg/ha/yr). Fruit bodies of G. esculenta were found in treated plots every year after the soil treatment. The yield was at its best in the two first years declining later to the level of 10–20% of the first year’s yield.

The best natural yield was reached in the last year. The previous year’s precipitation was an important factor influencing the yield of the mushroom.

The PDF includes a summary in English.

• Jalkanen, E-mail: rj@mm.unknown
• Jalkanen, E-mail: ej@mm.unknown
• Jalkanen, E-mail: jj@mm.unknown
• Jalkanen, E-mail: mj@mm.unknown

The concepts of the terms compartment and compartment-wise forest inventory have been studied empirically by repeated delineation and intensive systematic plot samples. The material consisted of 16 study areas of some 8–90 hectares in size in Southern Finland and of more than 1,000 relascope plots. Stands and compartments were found to be rather heterogenous. Alternative photographs, working techniques and test persons were studied. An endeavour for better accuracy in compartment inventories is recommended.

The PDF includes a summary in English.

• Poso, E-mail: sp@mm.unknown

The objective of the study was to compare different reforestation methods on ploughed areas in Finnish Lapland. Four species were compared: Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies (L.) H. Karst.), silver birch (Betula pendula Roth) and Siberian larch (Larix sibirica Ledeb.). The experiments were established in different parts of Lapland on different types of sites in 1970–72.

In Scots pine there was a difference of 15 percentage points in survival of seedlings between the best and worst methods of regeneration. Containerized seedlings and paper pot seedlings had the best survival rates. In Norway spruce the respective difference between sowing and planting was about 20 percentage points. In favour of planting. The survival rate can be increased by about 20 percentage points by selecting the right tree species. The average height varied from 25 cm (the sowed Norway spruce) to 179 cm (the planted silver birch) after 10 growing seasons. The birch was planted at the most fertile sites only. The longer time passed from the afforestation the clearer was the effect of the local growing conditions on the development of the seedlings. The elevation of the site was one factor seemed to influence the success of the seedlings.

The PDF includes a summary in English.

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

The role played by the medium and fine silt and clay contents in determining the quartiles and the degree of stratification from a cumulative particle-size curve was studied in order to determine what time savings could be made in the sedimentation phase of soil mechanical analysis. The clay content of the samples was, in general, found to be so small that it did not affect the parameters studied. In contrast to this, the medium and fine silt content affected the lower quartile of the distribution for many soils classified as finer than medium sand. Consequently, only the omission of the determination of the clay fraction can be recommended as a time-saving measure in mechanical analysis.

The PDF includes a summary in Finnish.

• Lipas, E-mail: el@mm.unknown

The publication comprises proceedings of a conference held in Helsinki in 1981. Forest tree populations are investigated for population genetic structure, mating systems, mechanisms of genetic adaptation and ecological adaptation. Methods and techniques used in population genetic research of forest trees are presented. Much concern is given to applications by means of forest tree breeding, particularly the seed orchard breeding technique. Generally, the application of population genetics in cultivated forests is discussed.

The PDF includes a preface and the presentations of the conference (25 short papers) in English, and a comprehensive summary of the themes of the conference in Finnish.

• Tigerstedt, E-mail: –

The areas of soil cultivation in regeneration sites using different methods in 1976–1979 and the cultivation units in use in Finland in 1979 were studied by means of a questionnaire. Application of soil cultivation methods appears to have become strongly polarized: in Southern Finland disc plowing with wheel tractors are used, whilst in Northern Finland wing plowing with crawler tractors is the most popular method, each being practically the only alternative in the respective area.

The PDF includes a summary in English.

• Kaila, E-mail: sk@mm.unknown
• Päivänen, E-mail: jp@mm.unknown

The particle size distribution affects several properties of the soil, thus, the ability to define the texture type of the soil as accurately as possible in field conditions is essential. The soil particle size classification devised by Atterberg (1912) is used in Finnish forestry. The study is based on a small laboratory material. The correlation between some characteristics of the soil particle size distribution, field capacity and cation exchange capacity were determined.

The particle size characteristics such as the relative proportion of different particle sizes, average particle size (Md) and parameters depicting the degree of sorting were determined. The relative proportion of soil particles below 0.06 mm correlated best with both field capacity and cation exchange capacity. Similarly, the average particle size and the degree of sorting correlated well with the field capacity and the cation exchange capacity.

The use of sorting characteristics is not well-suited to the type of soil sample material containing a high proportion of particles of varying size as was used in this material. Such characteristics are probably more easily applicable to the fine sand and sand sediments which are predominant in Finnish forest soils. The most useful particle size distribution characteristics in soils having a great variation in particle sizes were the average particle size and the relative proportion of silt and clay. Thus, the nutrient and water status of the soil can be predicted to some extent by examining the percentage of silt and clay, average particle size and the degree of sorting.

The PDF includes a summary in English.

• Sepponen, E-mail: ps@mm.unknown

Variation of cellular proportion within the same growth rings counted from the pith of the stems and branches in four trees of Betula pendula Roth was studied. The fibre percentage decreased from breast height to the crown and then increased in the branches. The reverse trend was found in the percentage of vessels and parenchyma, although the latter varied relatively little. No statistically significant differences were found in the percentages of fibres, vessels and rays within the same growth rings counted from the pith between the stems and branches. In both the stem and the branches, the proportion of fibres increased and that of vessels and rays decreased from the pith to the surface. Even crown formed wood differed from that of stem formed. 

The PDF includes a summary in Finnish. 

• Bhat, E-mail: kb@mm.unknown
• Kärkkäinen, E-mail: mk@mm.unknown

The article describes the results of the studies made in 24 Finnish housing areas. They show that the building density is not as important as the way of building and the site planning, in the view of preserving natural vegetation in the site. Building on slopes was difficult with modern building techniques because of the extensive earthwork required. 

This paper was presented in the ‘Man and the Biosphere’ programme Project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki. 

The PDF includes a summary in English. 

• Rosengren, E-mail: cr@mm.unknown

The potentials of forests in abatement of urban noise and air impurities are discussed based on literature and calculations. Excess attenuation of 6–7 dB seems to be possible in noise abatement applying Norway spruce (Picea abies (L.) H. Karst.) plantations. The potential in dust sedimentation is of 10,000–20,000 kg/ha/year and absorbtion to 7 kg/ha/yr. Forests seem also have considerable potential for control of climatic conditions in urban areas. Management of forests in urban environment is discussed. 

This paper was presented in the ‘Man and the Biosphere’ programme Project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki. 

The PDF includes a summary in English. 

• Kellomäki, E-mail: sk@mm.unknown

Pyynikki is a unique natural park in the centre of the city of Tampere in Southern Finland. Currently, the forest of Pyynikki is losing its vigour because of aging and environmental factors. In 1977 a policy was designed for the regrowth of Scots pine (Pinus sylvestris L.) forest and improvement of the condition of the trees to avoid the situation that the whole pine forest (34 ha) would be regrown at one time. The period of regrowth of pine forest is 60 years. It is accomplished by cutting small openings, on which 4-year old potted pine saplings are planted. Birch will be planted only on two spots. The aim is that the forest scenery will be maintained as undamaged as possible. The condition of the growing forest will be improved by fertilization and thinning.

This paper was presented in the ‘Man and the Biosphere’ programme project 2 seminar held on August 24–25 1978 in Hyytiälä research station of University of Helsinki.

The PDF includes a summary in English.

• Enivaara, E-mail: ae@mm.unknown

The study is the first report of a larger project concerning fire ecology in the Finnish boreal forests. Modern forestry has never been practiced in the Ulvinsalo strict nature reserve (2,500 ha) in Northern Finland in the county of Kuhmo. Forest fires have been uncommon because of mosaic of mineral and peat soils. The forests are mostly Norway spruce (Picea abies (L.) H. Karst.) dominated with Scots pine (Pinus sylvestris L.) often as the oldest trees of a stand. Forest fires were dated by counting annual rings from cambium to the fire scar in pines. 73 stands covering 1,207 ha were surveyed, over 80% of which was on mineral soil.

50% of the area had burned at least once during the life time of the present pine trees. 48 different forest fires were found, the first being from the year 1712 and the latest from 1969. The average time elapsed between the fires was about 82±43 years, and range 18–219 years. It was assumed that the stands where no fire scars were found, had, however, regenerated after fires but no fires have occurred since after that. In latter part of the 19th century 21 forest fires were dated, in the other half centuries only 4–9. This may have been caused by the increased human activity in the late 1800’s. The fire rotation of the area is 280 years, and spruce is almost the only tree species, which can regenerate in the present situation.

The PDF includes a summary in English.

• Haapanen, E-mail: ah@mm.unknown
• Siitonen, E-mail: ps@mm.unknown

In the densely populated Central Europe, forestry has always had different functions than in Scandinavia or Canada. Today the increasing pressures on the environment and more numerous demands of the people have put emphasis on environmental management and the demands of recreation in forest management practiced in the area. This paper outlines the trends in the utilization of forests in Central Europe, and especially in the Federal Republic of Germany, due to these changing targets. The regulations concerning forestry in Baden-Würtenber, and the forest plan of the Bavarian state forests are used as an example to clarify the principals of forest management and planning.

• Schmidt-Vogt, E-mail: hs@mm.unknown

Needle fascicles of Scots pine (Pinus sylvestris L.) were rooted in a standard Jacobsen’s germination apparatus. The apparatus was found to be suitable for rooting at least on laboratory scale. The best rooting substrate was living Sphangnum, which remained sufficiently moist in the germination containers throughout the experiments. In a comparison of various growth substrate treatments, the best result was obtained with a combination of IAA (100 mg/l) and thiamine (5 mg/l). The rooting percentage using these growth substances with Sphagnum as the rooting medium was in the first experiment 30 and in the second 48.

The PDF includes a summary in Finnish.

• Yli-Vakkuri, E-mail: py@mm.unknown
• Pelkonen, E-mail: pp@mm.unknown

In the article some aspects concerning the measurement of environmental factors are discussed. Special attention is given to the following questions: The correct way of determining the active surface in a forest ecosystem, the time factor in measurement processes, and the mutual correlative relationships between the environmental factors. Analysis of the data is also taken into consideration.

The PDF includes a summary in English.

• Leikola, E-mail: ml@mm.unknown

The paper deals with the establishment and present situation of the national parks in USA. The aim of the establishment of national parks was, on the one hand, to preserve part of the natural environment, and on the other hand, to reserve areas suitable for recreation. In addition to the national parks, or rather within them, so-called wilderness areas have been established since 1964. In these areas even such measures as fire and insect control are avoided to the greatest extent possible. The use of the wilderness areas for recreation is restricted to foot and horse trails as well as watercourses, all motorized transportation being prohibited. Campgrounds are provided with only the most primitive comforts. So far only a few wilderness areas have been established in the national parks, but there are tens of suitable areas that have been reserved for this purpose.

The PDF includes a summary in English.

• Salo, E-mail: ls@mm.unknown

The article is a report of a study tour of five Finnish foresters in Germany on September 27 – October 2. 1971. As in most industrial countries, the recreation use of forests is rapidly expanding and, therefore, its needs are considered in the management of forests. Two examples of intensively used recreation forests are described, Schönbuch near Stuttgart and the Bavarian Forest National Park at the Czechoslovakian border. These forests are effectively used for both timber production and recreation at the same time. Some other effects of urbanization on forests also are discussed in the article.

The PDF includes a summary in English.

• Mikola, E-mail: pm@mm.unknown

The Sinivuori Nature Park, located in the northeast part of the county of Häme in Southern Finland represents the rare fertile forest lands in the country, and belong partly to the so-called centre of herb‐rich forests of Häme. Sinivuori is one of the smallest nature reserves in Finland (64 ha). The detailed vegetation analysis was performed in 1969, supplemented by earlier and later observations. The area was divided into 69 one-hectare squares for the study of the flora and vegetation.

The most common rock in the park is mica schist. The pH of the soil is relatively high, in average 6.6. Thermal-time sum is 1,100–1,200. The vegetation differs to a large extent from the surrounding areas. 169 vascular plants were found in the area, some of which very rare in the area. The paper lists the plants and their abundance in the area, and the vegetation is described by the forest types. Distribution maps are presented for the species.

The PDF includes a summary in German.

• Rutanen, E-mail: kr@mm.unknown

The study attempts to establish to what extent the present regional allocation of the forest improvement subsidies equalize the profitability of forest drainage in Finland. The benefit/cost ratio has been used to describe the regional variation of the profitability

The study revealed that the forest improvement subsidies granted in 1968, even the highest possible subsidies, did not equalize the profitability of forest drainage. According to the results, the northern regions are at a disadvantage compared to the southern parts of the country. To fully equalize the profitability of forest drainage the average subsidies granted in 1968 should have been raised in the second financing zone from 22 to 32%, in the third zone from 32 to 60%, and in the fourth, northernmost zone from 43 to 86%. The study also suggests that the boundary lines of the financing zones should run, at least in Central and Northern Finland, from southeast to northwest instead from east to west, as it is now.

The PDF includes a summary in English.

• Numminen, E-mail: jn@mm.unknown

The purpose of forestry has hitherto been seen mainly as economic conservation, i.e. the use and management of timber resources on a sustainable yield basis. Along with the rising standard of living, however, amenity values of the environment will become more appreciated, which means that forestry and forest industries will be concerned with conservation of immaterial resources of nature as well. Since inland lakes cover some 10% of the surface area of Finland, and forests occupy more than 70% of the land area, forests and lakes are essential constituents of the Finnish environment during both work and leisure.

The main task of the pulp and paper industry in conservation is the control of water pollution. Today some 10% of Finnish lakes are polluted. Pulp and paper industries contribute 75% of the total waste water load of the Finnish lakes. Increasing water pollution can be prevented by improved processing technology, waste water treatment, and economic use of industrial wastes. Thus, the waste water load of the lakes has not increased in the last 10 years, despite doubling of pulp and paper production. According to the prognoses, by the year 2000 the waste water load from pulp and paper industries will be reduced to one half or one fourth of the present level although the capacity will still be increasing.

In forest management more emphasis should be paid on the aesthetic and recreational values of forests. Along with increasing leisure the need for recreational areas is growing. Scenic and recreational aspects must be considered in the management of industrial forests, too. With wise management, high timber yield is compatible with the maintenance of an enjoyable environment. Good silviculture takes account of timber production, wildlife management and landscape architecture simultaneously. National forestry development programs must be based on the principle of the multiple use of forests.

The PDF includes a summary in English.

• Mikola, E-mail: pm@mm.unknown

The aim of the study was to find out more about pine weevil (Hylobious abietis L.) injuries in Scots pine (Pinus sylvestris L.) seedling stands and their control by means of DDT. For this purpose, inventories were made of seedling stands established earlier. Control experiments were made on burnt areas by planting seedlings dipped in a DDT emulsion.

The results of the inventories show that injuries caused by pine weevils can, in certain circumstances, especially in seedling stands established by planting, cause the complete failure in artificial regeneration. The extent and quality of the injuries vary greatly according to planting method, treatment of the cutting area, age of the seedling stand, environmental factors, and weather conditions. The most extensive injuries occur in regeneration areas of old Norway spruce stands burnt after clear cutting and planted with Scots pine seedlings. Injuries are greater in seedling stands established by planting, especially after broadcast burning, than in seedling stands originating either from artificial or natural seeding. The quality of the patch for sowing or planting has a considerable effect on the quantity and character of the injuries: in a patch from which organic matter has been removed, injuries do not appear or they are slighter. Seedlings can be protected effectively and economically by dipping their tops up to the root collar, in a DDT emulsion before planting.

The PDF includes a summary in English.

• Nenonen, E-mail: mn@mm.unknown
• Jukola, E-mail: jj@mm.unknown

The purpose of the study was to find out the most economical fuel for central heating boilers in different parts of Finland. The most common central heating fuels and boilers used in Finland were compared in the study.

The present consumption of different fuels and the regional distribution of the boilers of a few main types was investigated. The costs were calculated according to the costs level of February 1957. To be able to compare the costs, both variable costs and fixed costs were calculated. The heat output produced annually in the different boilers was studied to divide the fixed costs into costs per heat unit.

Comparison of the total costs per heat unit showed that cost of wood or imported fuels (oil, coke, coal etc.) was about on the same level in the coastal areas close to import harbours, but wood was the cheapest fuel for central heating in inland.

The article includes an abstract in English.

• Leskinen, E-mail: ol@mm.unknown
• Vuorelainen, E-mail: ov@mm.unknown

The 4.4 km² sized area of Rokua is a sandy ridge situated in the transitional zone between Central and Northern Finland. It has been suggested to become a new national park due to its, in the area unique landscape and geological characteristics.

The vegetation of the area has been little studied. A vegetation analysis was performed in 1945, 1947 and 1949. Due to low nutrients in the sandy soil, the number of species is relatively low, including 236 vascular plants. The climate is continental. Lichen covering of soil in the Scots pine (Pinus sylvestris L.) dominated forests is mostly intact compared to the more northern areas, because grazing of reindeer has been little. Fellings have increased in the surrounding areas of the planned national park. The article includes a detailed description of vegetation and flora in the area.

The article includes a summary in German.

• Jalas, E-mail: jj@mm.unknown

Silva Fennica Issue 80 includes presentations held in 1952 in the 7th professional development courses, arranged for foresters working in the Forest Service. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

Soil preparation improves formation of seedlings in natural regeneration sites. This presentation describes mechanization of the work using four different machines. According to the study, the effectiveness and quality of the work has improved compared to the earlier machines, and the method is becoming a competitive alternative to slash burning.

• Hautamäki, E-mail: th@mm.unknown

The article is report of the Nature Park and National Park Committee appointed by the Government of Finland in 1950. It contains a proposal for establishment of new nature parks and natural parks on state-owned lands in Finland. The article also includes a draft of act and decree for establishment of the new nature parks and national parks.

In order to replace the nature reserves lost through the 1944 Armistice with new areas and to create a comprehensive network of nature and national parks, including Southern Finland, the committee proposes new protected areas. The proposal includes the following nature parks: Jussaari, Vaskijärvi, Vesijako, Sinivuori, Häädetkeidas, Salamajärvi, Ulvinsalo, Paljakka, Runkaus, Maltio, Sompio, and Kevo. National parks include Liesjärvi, Linnansaari, Petkeljärvi, Pyhähäkki, Rokua, Oulanka-Juuma, and Lemmenjoki. The total area of the suggested new 23 nature reserves is 1,425 km². The committee suggets that the administration of the new nature parks and national parks should remain in the responsibility of Forest Service and Forest Research Institute.

The article contains a summary in English

• Luonnon- ja kansallispuistokomitea, E-mail: –

A vegetation survey was conducted in the Pisavaara national park in Northern Finland in 1946 and 1947. The national park (49,9 km2) includes southern half of the Pisavaara hills. The rock is quartzite. The most common vegetation type is dry upland forest type, but also fresh mineral soil sites are typical for the area.

The most common forest type, Empetrum-Myrtillus type coveres almost as much of the area as all the other forest types combined. The article describes in detail the vegetation of all forest types and gives a complete list of all plant species found in the survey. Total of 291 vascular plants was found, 242 of which were native to the area. In addition, 49 anthropochores had spread to the area when the forest ranger’s cottage was built. Number of species growing in the northern edge of their natural range is. Southern species can be found in the southern slopes of the hill.

The article includes an abstract in German.

• Teivainen, E-mail: lt@mm.unknown

Silva Fennica Issue 64 includes presentations held in 1947 in the third professional development courses, arranged for foresters working in the public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. Two of the presentations were published in other publications than Silva Fennica.

This presentation describes execution of land acquisition act that came into effect in 1945. The act gave principles of transfer of state forest land for settlement.

• Kallio, E-mail: kk@mm.unknown

The article is based on the writer’s visits in the area in 1933 and 1939. Pyhätunturi national park was established in 1938. The fell of Pyhätunturi rises up to 540 meters above the sea level, and 357 meters above the surrounding area. The soil is predominantly stony, and the rock is quartzite. The climate is continental with low rainfall. This results in a barren area, where array of plant species is limited with the exception of few gorges with fertile river valleys. The forests have remained mostly in natural state.

Vegetation is arranged in three zones: forested area, subalpine fell birch area and alpine bare top of the fell. Scots pine (Pinus sylvestris L.) forms timberline more often than Norway spruce (Picea abies (L.) H. Karst.). Coniferous forests rise up to 365 meters on the northern slopes and up to about 385 on the southern slopes of the fell. It is followed by fell birch zone (Betula tortuosa, now Betula pubescens subsp. Czerepanovii) up to about 450-475 meters on the eastern and northern slopes, and 475-490 meters on the western slopes. The most common forest site type is Empetrum-Myrtillus site type. Herb-rich spruce swamps along the rivers have highest diversity of species. The article describes the plant species found in forests, peatlands, fell birch zone and top of the fell in detail. In all 162 different vascular plant species and 16 non-indigenous species were found in the area.

The article includes an abstract in German.

• Kalliola, E-mail: rk@mm.unknown

An act passed by the government of Finland in 1922 prescribed that state-owned forest lands will be parcelled out to landless population. A survey was made in 1934-1935 by Forest Service (Metsähallitus) to investigate the success of the establishment of settlements, and which disadvantages it may have had in forestry in the state forests. In the survey 1,194 farms were inspected.

According to the directives of settlement, the farms should be able support a family of four adults. The area of arable land was in average 5-15 hectares. In addition, the farm should have pasture and forest enough to supply it most of the household timber. According to the study, the regulations had been applied variably. Usually the farms had been given more land than was required. It was estimated that farms had been given 110,000 hectares more forest land for gathering household timber than required in the act. Many farms had sold timber, in some cases to that extent it endangered supply of household timber.

Parcelling out land had affected the management of state forests. If a region had surrendered large forest areas for settlement, it could not follow its cutting plan. Also, there was relatively little state-owned forests in southern Finland, and the effects of parcelling out land were stronger. The report concludes that in general it was not appropriate to parcel out forest land. The execution of settlement should have beeb given to Forest Service.

The article includes a German summary.

• Jokinen, E-mail: pj@mm.unknown

Silva Fennica issue 46 includes presentations held in professional development courses, arranged for foresters working in public administration in 1937. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service. 

This presentation describes the effect of properties of soil on forest regeneration. 

• Aaltonen, E-mail: va@mm.unknown

Silva Fennica issue 42 includes presentations held in professional development courses, arranged for foresters working in public administration in 1936. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service

This presentation describes the implementation of the Land Settlement Act on parcelling out land in the state-owned lands in Finland.

• Jokinen, E-mail: pj@mm.unknown

Silva Fennica Issue 39 includes presentations held in professional development courses in 1935 that were arranged for foresters working in public administration. The presentations focus on practical issues in forest management and administration, especially in regional level. The education was arranged by Forest Service.

This presentation describes parcelling out of land for new farms in state forests.

• Jokinen, E-mail: pj@mm.unknown

A review on the availability of forest work in the private forests in Finland was compiled on the request of the Unemployment Council. Private forests, and forests of municipalities and parishes covered 52.7% of the forest lands in Finland, according to the forest inventory made in 1922-1924. The proportion of private lands were estimated to increase in the future when state lands were parceled out to private land owners. Shifting cultivation, forest fires and selective fellings have influenced condition of the private forests. The interest to improve productivity of the forests has, however increased in 1920s and 1930s, which increases work opportunities.

The work opportunities in private forests is estimated to be 27.6 million man-days and 5.4 million horse-days annually.  Wood harvesting and hauling are the main source of employment with 20.3 million man-days. The workforce is estimated to be 75,920 men and 16,200 horses, but more intensive forest management could increase the numbers to 91,900 and 18,100, respectively. To improve the condition of private forests, it should be obligatory to mark the trees for cutting before the fellings. One means to improve forest management would be cooperation between the forest owners.

The PDF includes a summary in German.

• Pelttari, E-mail: pp@mm.unknown

Metsähallitus (Forest Service) decided to protect two areas around Hiisijärvi lake in Eastern Finland already in 1916. Later, a natural park was suggested to be established in the area. A survey of the vegetation in the area was composed in 1931-1932. The total land area of the protected area was 3.5 km³. A vegetation map was drawn based on a nature inventory. A detailed description of the forest site types, peatland types, aquatic flora and the vegetation of the area are included in the article. The calcareous soil promotes rich vegetation. Typical for the area are also rich fens. The area can be divided to a eutrophic and a oligotrophic part.

The PDF includes a summary in German.

• Brandt, E-mail: ab@mm.unknown

The article is a review on early forest regeneration and management in Finland. Beginning of the 1900s marks change in attitudes and resources for forest management. The state increased the funding of forest regeneration and improvement in the state forests in 1928. State funding is directed also to forest improvement in the private forests, and organizations established to promote forest management in the private forests are reorganized. For instance, District Forestry Boards were appointed the forest improvement work in private lands, in addition to promotion of private forestry. Sowing increased in the state forests from 772 ha to 1,566 ha, in forests of the forest companies from 3,006 ha to 4,954, and in private forests from 1,417 ha to 1,566 ha in 1923-1926. The figures of private forests are, however, incomplete. The most usual methods are patch sowing and broadcast sowing on snow. Seeds used in sowing increased from 3,357 kg to 14,387 kg, and planting from 413 ha to 1,020 ha in 1923-1930. Almost half of the sown areas were in the state forests, and most of the planted area in the forests of the companies. Scots pine (Pinus sylvestris L.) was the main tree species in artificial regeneration, and Norway spruce (Picea abies (L.) H. Karst.) was more popular in planting.

The PDF includes a summary in German.

• Cajander, E-mail: ec@mm.unknown

Systematic draining of peatlands begun in the state forests of Finland in 1908. It was considered necessary, because 41.4% of the state forests, 5.6 million hectares, consist of peatlands. Of the peatlands, 1.9 million hectares was estimated to be suitable for draining. Furthermore, paludification still continues in the forest lands. By the year 1926, a total of 52,275 hectares of peatland had been drained in the state lands.

Certain factors decide whether the peatland is suitable for draining: the growth increment capacity after draining, technical difficulties in draining, and difficulties in regeneration. Peatland type indicates the growth capacity of the drained peatland. The peatland should turn at least to Vaccinum forest site type or better type to be worth of draining. If the peat layer is thin, the quality of peat is an important deciding factor. The peatland may also be too expensive to drain due to, for instance, long ditches, main ditches difficult to dig, small inclination, uneven surface, and deep cavities at the bottom. The younger the trees of the stand, the faster the growth of the stand revives. The peatlands usually regenerate naturally provided there is sufficient seed trees, and there is seldom need for artificial regeneration.

The PDF includes a summary in English.

• Lukkala, E-mail: ol@mm.unknown

The article describes the geography and vegetation of Pummanginniemi area in Petsamo (now a Russian municipality of Pechenga; in 1926 the area was part of Finland in north-east Lapland), which has been suggested to become a natural park. Geologically it represented the only paleozoic area in Finland, constituting of layered rocks, mostly of slates and sandstones. The cape Pummanginniemi is situated on the cost of the Arctic Ocean, and it is known for its rich birdlife. Towards the inland, there is a plateau the vegetation of which is alpine. The area is situated above the mountain birch zone.

• Häyrén, E-mail: eh@mm.unknown

Farm forestry in northern Ostrobothnia has met different kinds of obstacles that decrease its profitability, some national, some local. One of the later is partitioning of land. The purpose of this investigation was to survey the division of farm land in the coastal municipalities of northern Ostrobothnia in Finland, where the conditions are among the most unfavourable in the country in this respect. The material used in the investigation was collected in a previous study about the structure of the farms in the area. First part of the paper summarises the history of partitioning of land in Finland.

The results show that division of the woodlots of a farm are in the coastal municipalities of northern Ostrobothnia very disadvantageous for forestry. The average distance of a woodlot to the farmhouse is 8.3 km, but there is a great variation between the municipalities, and the distance varies from 30 to 1.9 km. The form of the lots, as the long ribbon-like woodlots in the municipality of Liminka, complicates often practical forestry. In addition, the number of separate woodlots is high, in average 9.2 per farm.

The great distance of the woodlots from the main farms hinders the use of forests and diminishes the financial result of forestry. Unfavourable form of the woodlots posts similar hindrances to harvesting of timber and forest management as the long distances and high number of separate plots. The problem is heightened by the abundance of peatlands in relation to productive forest lands in the area.

The PDF includes a summary in German.

• Alho, E-mail: pa@mm.unknown

Work studies conducted in Finland and Sweden on forest work have shown that the performance of different workers or even of a same worker vary greatly, although external conditions such as the size and other properties of the trees, weather etc. are similar. It has been decided in the Northern Countries that as it is impossible to assess the working speed of a man, it is not possible to find out the average work performances, not even from long term time studies. The only way is to collect performance statistics.

Metsäteho (Forest Work Studies Section of the Central Association of Finnish Woodworking Industries) has collected since 1946 statistics on the working sites of forest industry companies in different parts of Finland on the preparation on timber. To make it comparable the material has been converted to uniform values by using the ratios given by the work time studies of various forest jobs conducted by Metsäteho. The ratios are necessary in trying to determine average performances by statistical means. The actual length of time each man is at work on different days and the actual number of days is needed, because in Finland the workers can themselves decide fairly freely the length of a working day. In forest work, wages are paid for the quantity prepared, not for time. The statistics collected by Metsäteho include information on the length of the working days, and conditions in each forest, such as the size of the trees, form of stem, branchiness, bark thickness, terrain, density of the forest, weather conditions etc.

The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

The PDF includes a summary in English.

• Vöry, E-mail: jv@mm.unknown

Finland was the first country, in connection with World War II, from which reparations were demanded. In September 1944 Soviet Union demanded indemnifications of 300 million dollars, payable in commodities (timber products, paper, wood pulp, sea-going and river craft, sundry machinery). Later similar obligations of deliveries in kind were applied to Rumania, Bulgaria, Hungary and Italy. Germany were to pay in kind for the losses caused by her to the Allied nations in the course of the war.

The article discusses the principle of war indemnities to be paid exclusively in kind, which was a new one, and compares it to the situation after World War I. One reason for the principle was a negative lesson drawn from the experiences after the previous war. A reparation system of payment in kind is the most suitable system for a country like the Soviet-Union, as it requires, at least some degree of economic planning by a centralized system.
The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.

• Suviranta, E-mail: bs@mm.unknown

The article presents the development of the saw-alike tools from the Stone Age to Iron Age and to modern times. The most common forms of saws are described and the history of studies on the theme as well.

Repairing of a saw after work is described in detail. The seven phases of the work are: fastening and tightening the saw to the frame, evening the row of the saw tooth, determining the depth of the gullet area, sharpening the teeth, setting of the saw, and check-up of the repair.  

The PDF contains a summary in Finnish. 

• Aro, E-mail: pa@mm.unknown

Residences of priests in Evangelical Lutheran parishes in Finland, and the forest holdings belonging to them, have been received in different ways. Some have been donated to the church, some belonged originally to the state, and some have been parceled out from the lands of local farmers. The forests holdings were, therefore, not considered to be property of the church. The use of the forests was limited, and they were managed by a forest management plan under supervision of Metsähallitus (Forest Service). The aim of the study was to survey the extent of forests properties of the parishes, how they have been managed, and their incomes to the parishes in 1933-1938.

The 784 residences had 217,600 hectares of forests. The forest holdings of the residences were larger than private forests in general. Also the forest resources, as well as the stocks of standing timber were larger than in private forests. The growing stock has grown further, because increment has exceeded the fellings. The fellings and income of the forestry had been increasing. At the same time, the costs of forestry were increasing. The forest holdings were divided unevenly between the parishes. About 15% of the parishes had no forest income, while the annual income of 10% of them was over 100,000 Finnish marks. In average, the forest income coverd 21.8% of all income of the parishes. Thus, the amount of forest income influenced the height of the church taxes.

The PDF includes a summary in German.

• Lappi-Seppälä, E-mail: ml@mm.unknown

The length of drivable water courses in Finland was about 43,800 km in 1936, while the length of the water courses used by the floating associations was 12,467 km. The aim of the survey was to study the volume of timber in private (or separate) floating and co-operative floating operated by the floating associations in Lake Saimaa water system, and how floating was administrated in the area.

According to the study, the floating channels of the area are in good condition. Floating of timber in rafts is common in Lake Saimaa water system. The proportion of co-operative floating is smaller than in the other major water systems in Finland, and the administration of floating is, therefore, unusual. The reason for this is the nature of the water system, the wood procurement policy of the industry, the disinterest of the private forest owners towards organized floating, and the way the authorities apply the Water Rights Act. The present system is beneficial to the forest companies that float big quantities of timber, but increase of co-operative floating would avail the small and medium industry and floaters, wood selling forest owners and the workforce.

The PDF includes a summary in German.

• Seppänen, E-mail: os@mm.unknown

The article is a report of the exotic tree and shrub species found in major parks and gardens in the city of Tampere, in Southern Finland, and the surrounding areas, including fruit trees and berry bushes. The survey of species was conducted in 1934-1935. There was a total of 221 tree and shrub species in the 245 parks and gardens of the city. Exotic species was found 193, of which 37 was introduced only recently. The frequency of 199 species in Tampere area and the condition of each species is listed. Most common are the native species of the genus Picea, Pinus, Betula, Acer, Prunus and Sorbus. Of the exotic species only Malus pumila (Mill.) is commonly cultivated. Relatively common are Ulmus montana (With.), Tilia cordata (Mill.) and Fraxinus excelsior (L.).

The PDF includes a summary in German.

• Saarnijoki, E-mail: ss@mm.unknown

The data has been collected from an old natural meadow in Sortavala, Karelia (on that time it was part of Finland). The vegetation on that meadow was very homogenous. All plants of the selected species (Trollius europaeus; Ranunculus auricomus; R. acer; Potentilla erecta; Alchemilla vulgaris; Geum rivale; Prunella vulgaris; Chrysanthemum leucanthemum; Polygonum viviparum) were collected from the sample plots with their roots. The seedlings were then ordered into age classes, and the shortest possible time before inflorescence was determined. To find out the germination time sowing trials were conducted.

The seedlings are very abundant in the youngest age classes and then the amount of plant individuals sinks quickly. The reasons for dying are e.g. insufficient amount of nutrients available and the lack of winter hardiness.   

The PDF contains a summary in Finnish.  

• Linkola, E-mail: kl@mm.unknown

The state of Finland controls the private forestry by legislation and by promoting forest management. The initial reason for regulating the private forestry in the 1600s was to prevent forest devastation and the decrease of the forest resources in the country. The Private Forest Act came into effect in 1929. It required that regeneration of the forest is cared for after fellings and that an announcement is given of planned fellings. There are several organizations to promote private forestry and advice the private forest owners, for instance, District Forest Boards, Central Forestry Association Tapio and the Forest Management Associations. It is concluded that the Private Forest Act and the organizations have fulfilled their objectives.

• Toijala, E-mail: vt@mm.unknown

The export of roundwood from Finland was studied based on the official statistics of foreign trade. The volumes were converted to solid volumes under bark. Roundwood (logs and masts) or raw timber trade consisted mainly of saw logs. The main tree species was Scots pine (Pinus sylvestrs L.) and Norway spruce (Picea abies (L.) H. Karst.). The annual volumes varied from 29,200 m³ in the war year 1918 to 657,200 m³ in 1924. Before the World War I the roundwood was exported mainly to Sweden and Russia, after the war the trade to Russia ceased. Also split spillet was a significant export item before the war. The export peaked in 1916 to 3 million m³, but decreased after the war to 30,000‒40,000 m³. The most important export item in the group of hewn timber has been Egyptian rafters, with annual export of 15,000‒284,600 m³ with the exception of the time of war. The export of spars exported to other countries than Egypt was highest before the war with 125,000 m³. The export of sleepers varied strongly, peaking in 1922. The total export of roundwood varied from 131,000 m³ in 1918 to 4.3 million m³ in 1927. Roundwood has mainly been exported to the European countries. Before the war, the main trading partners were United Kingdom and Russia. After the war the share of United Kingdom was nearly half of the volume, and Russia was replaced with Sweden.

The PDF includes a summary in German.

• Pöntynen, E-mail: vp@mm.unknown

The article is a review on the history of forestry in Pekkala estate, a private woodland estate in Ruovesi in Southern Finland. The estate had 7,300 hectares of land in 1929, of which 500 hectares were agricultural lands. It was owned by the Aminoff family since 1822.

The household wood harvesting of the tenants was considered a problem until the farms of the tenants (crofters) became independent in 1921, when the farms of the tenants were parceled out from the main estate. The shifting cultivation of tenants was banned already in 1824. Demand of wood was low until 1870s. in 1865 the freeing of regulation of sawmills increased the demand of wood in Finland, and gave start to significant timber sales in Pekkala estate. The first forest officers were hired in the estate at the time. The first guidelines of forest management for the estate were compiled in 1912, and the first survey of the forests was made in 1916, and repeated in 1922 and 1926. The fellings were planned in consideration of the growth of the forests.

The volume 34 of Acta Forestalia Fennica is a jubileum publication of professor Aimo Kaarlo Cajander. The PDF includes a summary in German.

• Helander, E-mail: ah@mm.unknown

The mean has a great importance in statistics in general and also in forest statistical calculations. The meaning of the average tree and its characteristics is important also for the practical forest mensuration work. However, the question is how are the statistical numbers of a mean tree related to the statistical numbers of the stand.   

Study is based on the strip-wise survey of forests in southern Finland. From that information the 30 sample plots were chosen, 10 of each of most typical forest site types, MT, VT and CT. The stands are of different ages and development classes, varying from 14 to 159 years.

For the determination of the average tree are the statistical numbers of five characteristics needed: volume, basal area, diameter, height and form factor. The stereometric mean tree of the stand can be calculated with only one statistical method and that solution is absolute.

Theoretically and statistically absolute solution for the problem is the continuous solution by the mean that is weighted with the number of stems. This solution however is not very useful in practical sense.

A simple, practical and adequately exact solution for determining the average tree by approximation procedure of a certain arithmetic mean. 

• Lönnroth, E-mail: el@mm.unknown

The article is a detailed review on the problems in the general parceling out of land (isojako) in Kuusamo, Kemijärvi and Kuolanjärvi counties from the context of forest policy. The disputes about division of the land originate from military tenure contracts (knihtikohtrahti) made with the local tenants in 1700s. Later some counties got alleviations in the contracts concerning taxation and partition of land. These alleviations delayed the parceling out of land in the area. According to the article, from the forest policy point of view, the inhabitants in Kuusamo, Kemijärvi and Kuolanjärvi were conveyed disproportionately large forest properties from the state due to the military tenure contracts. This gave them undue benefits from the state compared to the neighbouring counties.

The PDF includes a summary in German.

• Pekkala, E-mail: mp@mm.unknown

This study was conducted for the request of state forest committee. The aim was to study the economic situation of tenants of state lands in Kuru, Parkano and Ikaalinen, situated in Central Finland. The chosen 30 farms were located in relatively remote parts of the state forests in the area. Half of the farms were established already in 1800-1860 for shifting cultivation or fishing, and the land was not always suited for farming. The state forests were in general on the poorest lands of the areas. They were relatively small; third of them had less than 2 hectares of agricultural land. Household timber harvesting required a permission from a local forest officer of Metsähallitus (Forest Service). The legal rights of the tenants were fairly secured, but many wished to get right to purchase the farm land. Due to the poor lands and insufficient fertilizing, the crops were lower than in small farms in average. The forests around the farms were mixed forests of poor quality, due to the wood utilization of the tenants.

The PDF includes a summary in German.

• Pekkala, E-mail: mp@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

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 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

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 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

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 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 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

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 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.

The PDF includes a summary in English.

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

Residue of the wood is good raw material for pulp and board industries, but the question of the use of barking waste still remains to a great extent unsolved. This research deals with the possibilities to utilize the barking waste of sawmill industry in general and, in particular, its use as a soil improver and substrate for plants. It also explains the industrial manufacturing method of composted bark, bark humus, developed by the author as well as the properties of bark humus and the economy of bark humus and the economy of manufacturing.

The PDF includes a summary in Finnish.

• Isomäki, E-mail: oi@mm.unknown

• Kemppainen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland; Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0009-0000-6184-8812 E-mail: kalle.kemppainen@uef.fi
• Kärhä, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland E-mail: kalle.karha@uef.fi
• Laitila, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-4431-3319 E-mail: juha.laitila@luke.fi
• Sairanen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0009-0008-8632-3797 E-mail: anttsair@student.uef.fi
• Kankaanhuhta, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-5785-5972 E-mail: ville.kankaanhuhta@luke.fi
• Viiri, UPM-Kymmene Plc, UPM Forest, Peltokatu 26 C 4, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com
• Peltola, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0003-1384-9153 E-mail: heli.peltola@uef.fi

The poor cost-effectiveness of mechanized planting (MECP) is the main reason for the low mechanization rate of planting. In this study, we investigated the productivity of the mechanized excavator-based planting of Norway spruce (Picea abies [L.] H. Karst.) seedlings based on data collected by the Risutec Asta documentation system. We also compared the costs of a MECP chain with two different manual planting (MAP) chains, where mounding was carried out by a crawler excavator (EXC) or a continuously advancing mounder (CONT). The MECP of seedlings was carried out using an EXC equipped with a Risutec PM-160 planting device. Generally, the nine study sites in western Finland contained few surface obstacles (e.g., the logging residues had mainly been harvested), which made the conditions very suitable for MECP. The average production time taken by the MECP was 9 h ha^-1. The operating hour (G₁₅-h) productivity averaged 215 seedlings G₁₅-h^-1 , with the mean planting time being 13.8 s seedling^-1. Loading 160 seedlings into the seedling cassette took approximately 10 min (3.8 s seedling^-1). Overall, the cost of the MECP was about 5% lower than for the EXC + MAP. However, when productivity was set at <200 seedlings G₁₅-h^-1 , the cost of the MECP was higher than that of the EXC + MAP. Based on our findings, the most cost-efficient planting chain was CONT + MAP. However, based on our results, the required level of productivity can be achieved if the sites are suitable for MECP and the machine operators are skilled.

• Kemppainen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland; Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0009-0000-6184-8812 E-mail: kalle.kemppainen@uef.fi
• Kärhä, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0002-8455-2974 E-mail: kalle.karha@uef.fi
• Laitila, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0003-4431-3319 E-mail: juha.laitila@luke.fi
• Sairanen, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0009-0008-8632-3797 E-mail: anttsair@student.uef.fi
• Kankaanhuhta, Natural Resources Institute Finland (Luke), Yliopistokatu 6, FI-80100 Joensuu, Finland https://orcid.org/0000-0001-5785-5972 E-mail: ville.kankaanhuhta@luke.fi
• Viiri, UPM-Kymmene Plc, UPM Forest, Peltokatu 26 C 4, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com
• Peltola, School of Forest Sciences, University of Eastern Finland (UEF), P.O. Box 111, FI-80101 Joensuu, Finland https://orcid.org/0000-0003-1384-9153 E-mail: heli.peltola@uef.fi

• Jåstad, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-1089-0284 E-mail: eirik.jastad@nmbu.no
• Nagel, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0002-3171-0262 E-mail: niels.oliver.nagel@nmbu.no
• Hu, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway https://orcid.org/0000-0003-0001-5993 E-mail: junhui.hu@nmbu.no
• Rørstad, Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway E-mail: per.kristian.rorstad@nmbu.no

Mechanical site preparation (MSP) is a common practice that precedes the planting of Norway spruce (Picea abies (L.) H. Karst.) in Nordic forests. Mounding has become the most used method in spruce planting in recent years. This study examined the effects of different mounding treatments (spot and ditch mounding, inversion, unprepared control with or without herbicide application) and a mechanical vegetation control (MVC) treatment done 3–4 years after planting on the post-planting growth of spruce container seedlings and their development to saplings during the first 11–13 years on two forest till soils in central Finland, one on flat terrain and other on a southwest slope. On these fine-textured soils the spot and ditch mounding methods favoured spruce saplings development. Inversion and unprepared plots showed weakest growth. On the site with flat terrain, 11 years post planting, spruce saplings were 78–144 cm (38–80%) taller and their breast height diameters were 11–13 mm (60–74%) thicker for ditch or spot mounding than for inversion or herbicide treatment. On the site with sloped terrain the differences were minor between the MSP treatments. MVC improved spruce height growth on sites which did not have intensive MSP, especially on control saplings planted on unprepared soil in herbicide and inversion treatments. On the flat terrain, MVC reduced the density of resprouts to be removed later in pre-commercial thinning. As a conclusion, spot or ditch mounding favoured the growth of spruce over inversion especially on flat terrain with fine-textured soil.

• Uotila, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: karri.uotila@luke.fi
• Luoranen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-1776-2357 E-mail: timo.saksa@luke.fi
• Laine, Metsä Forest, Revontulenpuisto 2, FI-02100 Espoo, Finland https://orcid.org/0000-0002-6448-8274 E-mail: tiina.laine@metsagroup.com
• Heiskanen, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-0549-835X E-mail: juha.heiskanen@luke.fi

Tree carbon (C) and nitrogen (N) concentrations and C:N ratio are critical for understanding the elemental compositions of forests, N use efficiency, productivity and the biogeochemical cycles. We evaluate differences in C and N allocation among biomass compartments of three N‑fixing tree species of Espinal Argentine eco-region; the scaling relationship between C and N and the C:N ratio variation among compartments and tree size. Neltuma affinis (Spreng.) C.E. Hughes & G.P. Lewis, Neltuma nigra (Griseb.) C.E. Hughes & G.P. Lewis and Vachellia caven (Molina) Seigler & Ebinger plants (n = 30 for each species) were felled, grouped by stem basal diameter-based size classes and partitioned into 3 biomass compartments: stem (st), large branches (lb) and small branches + leaves, flowers and fruits (sbl). C and N concentrations were markedly influenced by species and biomass compartments. In general, sbl compartment presented more N than the st and lb, while C concentrations in Neltuma stems were the highest. Overall, no isometric C–N scaling relationships were found in different compartments. C:N variations in compartments were positively correlated with N concentrations but did not exhibit any significant association with C concentrations. C:N ratios differed significantly among species and biomass compartments. The C:N ratio for compartments ranked in an order of st > lb > sbl. C:N ratio variability in sbl was the least. Only in N. affinis and V. caven stems C:N relationship differed among tree size. Our results provide evidence of the importance of using in situ C and N concentration per main tree species and biomass compartments, to more accurate estimates of C and N stocks.

• Sione, National University of Entre Ríos, Faculty of Agricultural Sciences, Ruta 11 Km 10,5 (3101) Oro Verde, Entre Ríos, Argentina; CICyTTP-CONICET (National Research and Technological Investigation Council), Materi y España (3105) Diamante, Entre Ríos, Argentina https://orcid.org/0000-0002-2119-0363 E-mail: silvana.sione@fca.uner.edu.ar
• Ledesma, National University of Entre Ríos, Faculty of Agricultural Sciences, Ruta 11 Km 10,5 (3101) Oro Verde, Entre Ríos, Argentina https://orcid.org/0000-0002-9264-1766 E-mail: silvia.ledesma@fca.uner.edu.ar
• Aceñolaza, National University of Entre Ríos, Faculty of Agricultural Sciences, Ruta 11 Km 10,5 (3101) Oro Verde, Entre Ríos, Argentina; CICyTTP-CONICET (National Research and Technological Investigation Council), Materi y España (3105) Diamante, Entre Ríos, Argentina https://orcid.org/0000-0002-5033-3466 E-mail: pablo.acenolaza@fca.uner.edu.ar
• Wilson, National University of Entre Ríos, Faculty of Agricultural Sciences, Ruta 11 Km 10,5 (3101) Oro Verde, Entre Ríos, Argentina https://orcid.org/0000-0002-1214-1041 E-mail: wilson.marcelo@inta.gob.ar

Forest buffers beside surface water can mitigate negative effects of logging. To gain more information on buffer implementation in operational forestry, forest buffers were inventoried during 2018 on 174 harvested and site-prepared compartments traversed by or bordering streams, ditches and lakes in three regions across Sweden 2–4 years after clearcutting. Most of the inventoried stream and ditch reaches were ≤5 m wide. The water reaches were categorized as lakes (n = 16), natural streams (n = 50), modified streams (n = 21) or ditches (n = 87). Forest buffers with 100% shoreline coverage were present along all lake reaches and 55% and 10% of the natural or modified stream and ditch reaches, respectively. Buffers were absent beside 14% of the natural or modified stream reaches and 61% of the ditch reaches. Lake reaches had significantly wider buffers on average than ditch reaches and natural or modified stream reaches. The mean (SE) buffer widths beside lakes, natural or modified stream reaches and ditch reaches across all three regions and shoreline coverage classes were 12 (1.1), 6.6 (0.6) and 1.5 (0.5) m, respectively. The character of the local stream networks (natural or modified streams or ditches) containing each inventoried reach, were assessed using map information and the reaches´ field classifications. This illustrated the difficulty of judging a streams´ character based solely on field inspections of individual reaches on forest land where historic drainage activities have been performed. We recommend that also upstream and downstream conditions should be considered when planning environmental measures to protect surface water bodies.

• Ring, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden https://orcid.org/0000-0002-8962-9811 E-mail: eva.ring@skogforsk.se
• Johansson, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83 Uppsala, Sweden E-mail: fredrik.johansson@skogforsk.se
• von Brömssen, Department of energy and technology, Division of applied statistics and mathematics, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden https://orcid.org/0000-0002-1452-8696 E-mail: Claudia.von.Bromssen@slu.se
• Bergkvist, Mellanskog, Uppsala Science Park, Box 127, 751 04 Uppsala, Sweden E-mail: isabelle.bergkvist@mellanskog.se

Hybrid aspen (Populus tremula L. × P. tremuloides Michx.) is known with outstanding growth rate and some favourable wood characteristics, but models for stand management have not yet been prepared in northern Europe. This study introduces methods and models to predict tree dimensions, diameter at breast height (dbh) and tree height for a hybrid aspen plantation using data from repeatedly measured permanent sample plots established in clonal plantations in southern Finland. Dbh distributions using parameter recovery method for the Weibull function was used with Näslund’s height curve to model tree heights. According to the goodness-of-fit statistics of Kolmogorov-Smirnov and the Error Index, the arithmetic mean diameter (D) and basal area-weighted mean diameter (DG) provided more stable parameter recovery for the Weibull distribution than the median diameter (DM) and basal area-weighted median diameter (DGM), while DG showed the best overall fit. Thus, Näslund’s height curve was modelled using DG with Lorey’s height (HG), age, basal area (BA), and tree dbh (Model 1). Also, Model 2 was tested using all predictors of Model 1 with the number of trees per ha (TPH). All predictors were shown to be significant in both Models, showing slightly different behaviour. Model 1 was sensitive to the mean characteristics, DG and HG, while Model 2 was sensitive to stand density, including both BA and TPH as predictors. Model 1 was considered more reasonable to apply based on our results. Consequently, the parameter recovery method using DG and Näslund’s models were applicable for predicting tree diameter and height.

• Lee, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland https://orcid.org/0000-0003-1586-9385 E-mail: daesung.lee@luke.fi
• Siipilehto, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, FI-00790 Helsinki, Finland E-mail: jouni.siipilehto@luke.fi
• Hynynen, Natural Resources Institute Finland (Luke), Natural resources, Vipusenkuja 5, FI-57200 Savonlinna, Finland https://orcid.org/0000-0002-9132-8612 E-mail: jari.hynynen@luke.fi

Over 20% of regeneration operations will be on drained peatland in the next decade in Finland. There are only a few studies comparing the planting success and the risk of pine weevil (Hylobius abetis (L.) feeding damage on mineral soil and drained peatland. Thirty sites planted with Norway spruce (Picea abies (L.) H. Karst.) container seedlings in 2009 in Southern and Central Finland were inventoried three growing seasons after planting. Prediction models for the probability of survival, pine weevil damage and the presence of ground vegetation cover were done separately for peatland and mineral soil sites. The planting success was 17% lower on peatland sites (1379 surviving seedlings ha^–1) than on mineral soil (1654 seedlings ha^–1). The factors explaining the survival were the ground vegetation cover and type of the planting spot on the peatland, and the ground vegetation cover on mineral soil. On mineral soil, 76% of the planting spots were on cultivated mineral soil while on peatland only 28% of the seedlings were planted on similar spots. There were also fewer seedlings that were surrounded by dense ground vegetation on mineral soil (4%) than on peatland (14%). Pine weevil feeding damage did not differ significantly on peatland (23%) or mineral soil (18%). The more time there was from clear-cutting, the more the probability of pine weevil feeding damage was reduced on both soil classes. Additionally, cover vegetation in the vicinity of the seedlings increased on mineral soil. Cultivated planting spots, especially those covered by mineral soil, prevented pine weevil feeding and reduced the harmful effects of vegetation on the seedlings both on mineral soil and peatland.

• Luoranen, Natural Recourses Institute Finland (Luke), Production systems, Juntintie 154, FI-77600 Suonenjoki, Finland https://orcid.org/0000-0002-6970-2030 E-mail: jaana.luoranen@luke.fi
• Viiri, UPM Forest, Peltokatu 26 C, P.O. Box 85, FI-33100 Tampere, Finland https://orcid.org/0000-0003-3952-9481 E-mail: heli.viiri@upm.com

Ageing and competition reduce trees’ ability to capture resources, which predisposes them to death. In this study, the effect of senescence on the survival probability of Norway spruce (Picea abies (L.) Karst.) was analysed by fitting alternative survival probability models. Different model formulations were compared in the dataset, which comprised managed and unmanaged plots in long-term forest experiments in Finland and Norway, as well as old-growth stands in Finland. Stand total age ranged from 19 to 290 years. Two models were formulated without an age variable, such that the negative coefficient for the squared stem diameter described a decreasing survival probability for the largest trees. One of the models included stand age as a separate independent variable, and three models included an interaction term between stem diameter and stand age. According to the model including stand age and its interaction with stem diameter, the survival probability curves could intersect each other in stands with a similar structure but a different mean age. Models that did not include stand age underestimated the survival rate of the largest trees in the managed stands and overestimated their survival rate in the old-growth stands. Models that included stand age produced more plausible predictions, especially for the largest trees. The results supported the hypothesis that the stand age and senescence of trees decreases the survival probability of trees, and that the ageing effect improves survival probability models for Norway spruce.

• Siipilehto, Natural Resources Institute Finland (Luke), Natural resources, Latokartanonkaari 9, P.O. Box 2, FI-00790 Helsinki, Finland E-mail: jouni.siipilehto@luke.fi
• Mäkinen, Natural Resources Institute Finland (Luke), Production systems, Latokartanonkaari 9, P.O. Box 2, FI-00790 Helsinki, Finland https://orcid.org/0000-0002-1820-6264 E-mail: harri.makinen@luke.fi
• Andreassen, Norwegian Institute of Bioeconomy Research (NIBIO), NO-1431 Ås, Norway E-mail: kjellandreassen@gmail.com
• Peltoniemi, Natural Resources Institute Finland (Luke), Bioeconomy and environment, Latokartanonkaari 9, P.O. Box 2, FI-00790 Helsinki, Finland https://orcid.org/0000-0003-2028-6969 E-mail: mikko.peltoniemi@luke.fi

In Nordic forests, consistent evidence about better seedling survival rate and increased growth due to site preparation have been obtained in numerous studies. Proper site preparation method can reduce costs of the whole regeneration chain through its effects on survival of planted seedlings, abundance of natural regeneration and competition in early stand development. This study compared the natural regeneration of birches (silver birch (Betula pendula Roth) and downy birch (B. pubescens Ehrh.)), amount of exposed mineral soil, and growth of planted seedlings between spot mounding and inverting site preparation methods. Present study was conducted in eight forest stands established in 2012 or 2015. Even though difference was not statistically significant, inverting exposed less mineral soil than spot mounding and thus reduced the natural regeneration of birch seedlings by 6135 seedlings ha^–1 compared to spot mounding. However, the variation between regeneration areas was remarkable. There was no difference in seedling mortality or growth between the site preparation methods. In order to achieve high growth of conifers, moderate amount of exposed mineral soil and thus less naturally regenerated birch, inverting should be favored over spot mounding.

• Laine, Metsä Group, P.O. Box 208, FI-70101 Kuopio, Finland E-mail: tiina.laine@metsagroup.com
• Kankaanhuhta, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: ville.kankaanhuhta@luke.fi
• Rantala, Metsä Group, P.O. Box 10, FI-02020 METSÄ, Finland E-mail: juho.rantala@metsagroup.com
• Saksa, Natural Resources Institute Finland (Luke), Natural resources, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: timo.saksa@luke.fi

Genetic parameters of growth and stem quality traits were estimated for open-pollinated silver birch Betula pendula Roth progenies in Latvia at the age of 10 and 14 years. Tree height and stem volume were found to be under strong genetic control at both inventories (narrow-sense heritabilities varied from 0.41 to 0.66). Mainly low heritabilities were found for stem defects, yet genetic control of branch diameter, stem straightness and overall stem quality varied from low to high depending on study site. High additive genetic coefficient of variation was found for stem volume (25.3–32.5%). Genetic correlations among growth traits were strong and positive (0.90–0.99). Mainly weak genetic correlations between growth and quality traits implied simultaneous improvement. Still, strong negative correlations between branch angle and stem straightness might result in enlarged knot size for straighter logs. The genetic age-age correlations were strong. Weak genotype by environment interaction and stability of best genotypes over different sites was indicated by strong genetic correlations between trials. Each growth or quality trait alone showed substantial improvement in terms of estimated genetic gain (up to 62% over trial mean for stem volume). Therefore, selection index combining both growth and stem quality may be developed.

• Gailis, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: arnis.gailis@silava.lv
• Zeltiņš, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia https://orcid.org/0000-0002-6286-5814 E-mail: pauls.zeltins@silava.lv
• Purviņš, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: andis.purvins@silava.lv
• Augustovs, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: juris.augustovs@silava.lv
• Vīndedzis, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: valts.vindedzis@silava.lv
• Zariņa, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: inga.zarina@silava.lv
• Jansons, Latvian State Forest Research Institute Silava, 111 Rigas street, Salaspils LV-2169, Latvia E-mail: aris.jansons@silava.lv

Hybrid aspen (Populus tremula L. × P. tremuloides Michx.) is a deciduous tree species suitable for producing large amounts of renewable biomass during short rotations. Its potential under North European conditions could be largely extended if not only agricultural land but also forest land was used for cultivation. Unfortunately, the knowledge of appropriate forest site conditions and effects of site preparation methods on hybrid aspen establishment is limited. In this paper, two studies that explore these questions are presented. In the first study, the sensitivity to acid soils was tested under greenhouse conditions in two type of soils: a) peat soil limed to certain pH levels (3.4–5.7) and b) collected forest soils where pH varied from 3.9 to 5.3. The lowest pH level resulted in reduced growth, elsewhere no significant differences were found. The second study was applied in the field and investigated the effect of four site preparation methods on survival and growth. The methods were: 1) control with no site preparation, 2) patch scarification, 3) mounding and 4) soil inversion. While no differences were found for survival, mounding was generally the method with the highest growth and patch scarification was least successful. The result was probably an effect of good soil aeration and less competition from vegetation after mounding. The field study also revealed clonal differences in growth performance, which stresses the importance of clone selection prior to planting. The results of these studies indicate that hybrid aspen is less sensitive to variation in pH and site preparation methods compared with other poplar species, as have been found in similar studies.

• Hjelm, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden E-mail: karin.hjelm@skogforsk.se
• Rytter, Skogforsk, Ekebo 2250, SE-268 90 Svalöv, Sweden http://orcid.org/0000-0001-6183-4832 E-mail: lars.rytter@skogforsk.se

Riparian trees, especially relict trees, are attractive and important for research to understand both past and recent biogeographical and evolutionary processes. Our work is the first study to elucidate the genetic diversity and spatial genetic structure of the canopy-dominating riparian Pterocarya fraxinifolia (Juglandaceae) along two altitudinal gradients in different river systems of the Hyrcanian forest, which is one of the most important refugium of relict trees in Western Eurasia. Altitudinal gradients were chosen along two river systems at 100, 400 and 900 m a.s.l. Leaf samples were collected from 116 trees, and the genetic diversity was evaluated with eight SSR markers. Overall, 39 alleles were identified for all of the populations studied. The observed heterozygosity (Ho) varied from 0.79 to 0.87 (with a mean of 0.83). The results of the AMOVA analysis indicated that the variation within populations was 88%, whereas the variation among populations was 12% for all of the gradients. A structure analysis indicated that 93% of the trees were grouped in the same gradient. The genetic distance based on Fst confirmed the structure result and indicated a high rate of gene flow among the investigated populations. Based on high gene flow (low differentiation of the population along the same river) and the clearly distinct genetic structure of the investigated gradients, it can be concluded that rivers are the main seed dispersal vector among P. fraxinifolia populations. The genetic diversity of P. fraxinifolia did not show any trend from upstream to downstream. The high level of gene flow and uniform genetic diversity along each river suggest the “classical” metapopulation structure of the species.

• Yousefzadeh, Department of Environmental Science, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran E-mail: h.yousefzadeh@modares.ac.ir
• Rajaei, Department of Forestry, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, Noor, Mazandaran, Iran E-mail: r.rajaei@modares.ac.ir
• Jasińska, Laboratory of Systematics and Geography, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, PL-62-035 Kornik, Poland E-mail: jasiak9@wp.pl
• Walas, Laboratory of Systematics and Geography, Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, PL-62-035 Kornik, Poland E-mail: lukaswalas@wp.pl
• Fragnière, Department of Biology and Botanic Garden, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland E-mail: yann.fragniere@unifr.ch
• Kozlowski, Department of Biology and Botanic Garden, University of Fribourg, Chemin du Musée 10, CH-1700 Fribourg, Switzerland; Natural History Museum Fribourg, Chemin du Musée 6, CH-1700 Fribourg, Switzerland E-mail: gregor.kozlowski@unifr.ch

Detailed pre-harvest information about the volumes and properties of growing stocks is needed for increased precision in wood procurement planning for just-in-time wood deliveries by cut-to-length (CTL) harvesters. In the study, the non-parametric Most Similar Neighbour (MSN) methodology was evaluated for predicting external quality of Scots pine and Norway spruce, expressed as stem sections fulfilling the saw log dimension and quality requirements of Finnish forest industry, as they affect the recovery of timber assortments and the value of a pre-harvest stand. Effects of external tree quality were evaluated using saw log recovery and saw log reduction caused by stem defects, as well as total timber value (€) and average unit value (€ m^–3) in a stand. Root mean square error (RMSE) of saw log recovery and reduction were 9.12 percentile points (pp) for Scots pine and 6.38 pp for Norway spruce stands. In the unit value considerations, the predictions compared with measurements resulted in the RMSE of 3.50 € m^–3 and the bias of 0.58 € m^–3 in Scots pine stands and 2.60 € m^–3, and 0.35 € m^–3 in Norway spruce stands, respectively. The presented MSN based approach together with the utilization of the external stem quality database included in the ARVO software could provide dimension and external quality predictions usable for pre-harvest assessment of timber stock at a stand level. This prediction methodology is usable especially in analyses where timber assortment recoveries, values and unit prices are compared when different bucking objectives are used.

• Malinen, University of Eastern Finland, School of Forest Sciences, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: jukka.malinen@uef.fi
• Kilpeläinen, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: harri.kilpelainen@luke.fi
• Verkasalo, Natural Resources Institute Finland (Luke), Production systems, Yliopistokatu 6, FI-80100 Joensuu, Finland E-mail: erkki.verkasalo@luke.fi

Physical soil properties have a marked influence on the quality of forest sites and on the preconditions for forest growth and management. In this study, water retention characteristics (WRC) and related physical soil properties in addition to vegetation coverage and tree stand data were studied at upland forest sites in Finland. Fixed and mixed models between soil and site characteristics were formed to estimate physical and hydrologic soil characteristics and the site quality with indirect co-varying variables. In the present data, the site quality index (H100) shows a high coefficient of determination in respect to the temperature sum. It is also related to soil fine fraction content, topsoil pH and water retention at field capacity. The thickness of the humus layer is predictable from the pH and cover of xeric and mesic plant species. The soil fine fraction content (clay + silt) is closely related to water retention at field capacity, the soil layer and site type, and without WRC to the temperature sum and site index and type, as well as the slope angle. The soil bulk density is related to organic matter, depth (layer) or alternatively to organic matter, slope and field estimated textural class (fine, medium, coarse). Water retention characteristics were found to be best determinable by the fine fraction content, depth and bulk density. Water content and air-filled porosity at field capacity are closely related to the fine fraction. This study provides novel models for further investigations that aim at improved prediction models for forest growth, hydrology and trafficability.

• Heiskanen, Natural Resources Institute Finland (Luke), Soil ecosystems, Neulaniementie 5, FI-70100 Kuopio, Finland E-mail: juha.heiskanen@luke.fi
• Hallikainen, Natural Resources Institute Finland (Luke), Applied statistical methods, Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: ville.hallikainen@luke.fi
• Uusitalo, Natural Resources Institute Finland (Luke), Forest technology and logistics, Korkeakoulunkatu 7, FI-33720 Tampere, Finland E-mail: jori.uusitalo@luke.fi
• Ilvesniemi, Natural Resources Institute Finland (Luke), Biorefinery and bioproducts, Tietotie 2, FI-02150 Espoo, Finland E-mail: hannu.ilvesniemi@luke.fi