Articles containing the keyword 'cutting'

A gap-model was used with forest inventory data in taking ground-true site, soil and tree characteristics into account in predicting the effects of climate change on forests. A total of 910 permanent sample plots established in the course of national forest inventory (NFI) in Finland and located on mineral soil sites in southern Finland were selected as the input data. The climatological input used in the simulations consisted of interpolated means of and deviations from long-term local temperature and precipitation records. The policy-oriented climate scenarios of SILMU (Finnish Research Programme on Climate Change) were used to describe the climate change. The temperature changes in the climate scenarios were increases of ca. +1.1 °C (low), +4.4 °C (medium) and +6.6 °C (high) compared to the current climate in 110 years. The simulation period was 110 years covering the time years 1990–2100.

Southern Finland, divided into fifteen forestry board districts, was used as the study region. Regional development of stand volume, cutting yield, and total wood production of forests under different climate scenarios were examined. The annual average growth in simulations under current climate was close to that observed in NFL Forests benefited from a modest temperature increase (Scenario 2), but under Scenario 1 the growing stock remained at a lower level than under the current climate in all parts of the study region. In wood production and cutting yield there were regional differences. In the southern part of the study regional wood production under Scenario 1 was ca. 10% lower than under the current climate, but in the eastern and western parts wood production was 5–15% higher under Scenario 1 than under the current climate. The relative values of total wood production and cutting yield indicated that the response of forests to climate change varied by geographical location and the magnitude of climate change. This may be a consequence of not just varying climatic (e.g. temperature and precipitation) and site conditions, but of varying responses by different kind of forests (e.g. forests differing in tree species composition and age).

• Talkkari, E-mail: at@mm.unknown

The results of regenerating 54 and 36–38-year old strip cuttings were surveyed in the Kivalo Research Forest (N 66°20’, E 26°40’). 15 measurement plots were placed on each strip. The most common forest type was Hylocomnium-Myrtillus type. Regeneration of the strips proved to be slow. Most of the spruces growing on the strips probably originated from the time before the cutting. The average number of stems was 1,155 per ha, of which one third consisted of broadleaved trees. The average volume increment of stem wood after cutting had been about 1 m³/ha/yr, but it was increasing at the time of the inventory. Both the reforestation of the strips and the development of the emergent stands were dependent on elevation and site fertility. Site fertility was indicated by the abundance of Vaccinium myrtillus.

The PDF includes an abstract in English.

• Pohtila, E-mail: ep@mm.unknown

Four teams of two workers were time-studied in clearcutting of a cypress plantation and three teams in sulky skidding. The heart rate was recorded every 30 s. The average heartrate in timber cutting was 117.5 ± 13.4 P/min, and it was mainly dependent on worker’s working capacity. Average work load index was 41 ± 3% when working at 97% performance. The production rate was then 2.5 m³/h (crew). In sulky skidding the heart rate was lower, 106 ± 1.1 P/min, as well as the work load (WLI 30 ± 1%) and performance rating (87%). The low production rate (1.1 m³/h) (crew)) over 45 m distance is mainly due to under-dimensioned load size. The energy expenditure in timber cutting was 21.4 kJ/min and in sulky skidding 16.3 kJ/min. Daily energy expenditure was 15.0 MJ/d, and most of the timber cutters belonged to the class ”exceptionally active”.

The PDF includes an abstract in Finnish.

• Saarilahti, E-mail: ms@mm.unknown
• Bakena, E-mail: eb@mm.unknown
• Mboya, E-mail: gm@mm.unknown
• Minja, E-mail: tm@mm.unknown
• Ngerageze, E-mail: tn@mm.unknown
• Ntahompagaze, E-mail: jn@mm.unknown

An empirical analysis of the Finnish non-industrial private forest owners indicates that forestry extension has an effect on the supply of timber and the use of cutting potentials. This effect appears to be indirect rather than direct. The use of extension services is likely to increase the frequency of timber sales, which in turn, increases the use of the allowable cut via increased volume of actual cuttings. Forestry extension can also be considered as an intermediate variable through which certain background conditions and owner characteristics affect the use of cutting potential.

• Järveläinen, E-mail: vj@mm.unknown

The Forest 2000 Programme is a long-term programme for forestry and the forest industries in Finland. It attempts to obtain a better integration of timber production and other forms of forest use. The total annual cut is to be increased by 15 million m³ by the year 2010. This is almost one third greater than the level during the first few years of the 1980’s. In order to achieve the cutting targets, the cut area will have to be increased by almost one third by the turn of the century. The area of thinnings will experience the greatest increase. Considerable changes are proposed in silvicultural and basic improvement work. According to the programme, the growth of the raw-material base and the consumption of the wood-based products will permit an annual increase of about 3% in the production of the forest industries as a whole until the end of the century. This would be the same as the target growth rate of the GNP.

The PDF includes an abstract in Finnish.

• The Forest 2000 Programme sub-commitee, E-mail: –

Different sampling methods (the percentage cover scale, the graphical method, two-point quadrat methods, the five-, nine- and twelve-class cover scales, and the biomass harvesting) were used in estimating abundance of ground vegetation in clear-cut areas and on an abandoned field in Southern and Central Finland. The results are examined with the help of DCA ordinations. In addition, the species numbers and diversity indices obtained by different sampling methods are compared.

There were no large differences in DCA configurations between the sampling methods. According to all the sampling methods, a complex soil fertility-moisture gradient (a forest site type) was interpreted as the main ordination gradient in the vegetation data for clear-cut areas. However, different sampling methods did not give similar estimates of species numbers and diversity indices.

The PDF includes a summary in Finnish.

• Jukola-Sulonen, E-mail: ej@mm.unknown
• Salemaa, E-mail: ms@mm.unknown

Ascocalyx abietina (now Gremmeniella abietina Lagerb.) infects Scots pine (Pinus sylvestris L.) by means of ascospores or conidia. Ascospores are dispersed by the wind, while the conidia are splash dispersed. The infection rate is positively correlated with the number of inocula. The aim of this study was to determine the extent to which G. abietina spreads to the trees surrounding the diseased trees and to find the correct time to perform sanitation cutting.

The results were obtained from Ascocalyx-inventory carried out in a Scots pine progeny test at Loppi, Southern Finland. Three Siberian provenances were totally destroyed, while the Finnish progenies remained relatively healthy. The two rows adjacent to the destroyed plots were inventoried separately.

There were 29.7% more diseased or dead trees in the two adjacent rows than in the rest of the same plots. The difference was statistically significant. The trees had probably been infected by conidia, because the effect of the destroyed plot only extended to the adjacent two rows. Furthermore, pycnidia had mainly developed on the dead shoots.

On the basis of the life cycle of the fungus and the results, the correct time to carry out sanitation cutting is the first winter after the disease symptoms have appeared. If it is done later, the disease could be spread and bark beetles (Tomicus spp.) could propagate in dying trees. Susceptible provenances may spread the disease to surrounding resistant trees owing to the increasing number of spores.

The PDF includes a summary in English.

• Uotila, E-mail: au@mm.unknown

This article reviews experiments and practical experience of forest management by the selection system in Finland. In an experiment of 25-year duration the annual growth of uneven-aged Norway spruce (Picea abies (L.) H. Karst.) stands was only about 50% of the average annual yield of even-aged stands in normal rotation on the same site.

In Finland the selection system is applicable under exceptional conditions only, viz. In intensively managed park stands and, on the other hand, on very marginal sites, e.g. on peat bogs and mountains near the tree-line. Even normal silviculture, however, may include cuttings which somewhat resemble selection system, e.g. removal of standards or restoration of mismanaged forests.

The PDF includes a summary in English.

• Mikola, E-mail: pm@mm.unknown

Length of the regeneration period is a criterion commonly used for comparing different reforestation methods. The time factor should be evaluated using a realistic system for long-term planning. In this paper the preliminary evaluation is made by simplified calculations based on the development series. The slow regeneration method is assumed to be otherwise equal to the rapid one but it has a 5- or 10-years delay at the beginning, and the rotation is thus the final cutting age plus 5- or 10-years delay. Cost of the time delay is taken to be the difference in reforestation costs that makes the rapid and the slow methods equivalent. Calculations are made using zero costs for the slow method; but if the cost of the slow method increases, the critical cost difference decreases very slowly. The final cutting age and the regeneration method must be decided simultaneously. Therefore, the cost of the time delay is presented as a function of final cutting age. By maximizing the average annual revenue, rotation can be even increased if more rapid but more expensive regeneration method is used.

The PDF includes a summary in English.

• Lappi, E-mail: jl@mm.unknown

Cutting propagation of forest trees has recently been done in Finland mainly by the Foundation for Forest Tree Breeding. The aim has been to develop methods which could be used in forest nurseries for large scale production of rooted cuttings. Methods are being developed for tree species which seem to offer possibilities for economically profitable vegetative propagation. The most important tree species has been Norway spruce (Picea abies (L.) RH. Karst.), and also larches (Larix sp.), lodgepole pine (Pinus contorta), birches (Betula sp.), alders (Alnus sp.) and hybrid aspen (Populus tremula x P. tremuloides) are propagated. The sensitive rooting phase takes place in plastic greenhouses which have ventilation on the roof top, mist irrigation equipment and separate heating systems for the air and the ground. Methods used for cutting propagation of Norway spruce, lodgepole pine, larch species and broadleaved trees are described.

The PDF includes a summary in Finnish

• Niiranen, E-mail: jn@mm.unknown

The aim of the study was to compare the newly introduced brush cutter to ordinary hand tools in clearing of cutting areas and thinning young birch (Betula sp.) and Scots pine (Pinus Sylvestris L.) stands. Working with a prototype of the brush cutter, Brushmaster, reduced the total working time by 15-20% compared to bush knife and axe, in spite of the cutter’s weight. At rainy weather the advantage of Brushmaster dissapeared because of clogging of the cutter’s air filter. The prototype proved to be more effective when clearing a cutting area, and hand tools seemed to be faster if damage to the remaining trees have to be avoided.

In addition, eight either lighter or more effective motor saws or brush cutters were compared mutually, and the effect of motor effect, weight, handiness, arrangement of suspenders and handles is discussed. With these improved types of the cutter it was possible to shorten the total working time in thinning of stands (mostly clearing of young stands) to 30-40% of the total working time compared to hand tools. The most modern saws appeared to be best adapted in clearing cutting areas.

The article includes an abstract in English.

• Sirén, E-mail: gs@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 clearing of felling areas. 

• Tertti, E-mail: mt@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 forest management planning in the state forests.

• Lakari, E-mail: ol@mm.unknown

Metsähallitus (Forest Service) commissioned a study about condition of forests on the coast of Gulf of Finland in the Karelian Isthmus. The study was made because of a growing concern on overcutting of the private forests in the area. Dominant tree species in the area is Scots pine (Pinus sylvestris L.). In fresh mineral soil sites Norway spruce (Picea abies (L.) H. Karst.) grows in mixed forest with pine or as pure stands. The forests are in average 50 to 70 years old. Younger or older stands are less frequent.

At the beginning of 18^th century the local peasants sold plots for Russians, and a villa area was created along the coast. When Finland became independent, many of the properties changed owners. Timber harvesting of the forests increased and many small sawmills increased the demand of wood. Because of the cuttings, productivity of the forests decreases and danger for wind damage in the forests increases.

The author suggests that legislation created to prevent deforestation as well as counselling should be applied to improve forest management. In addition, a protective area should be formed in the Karelian Isthmus where forest preserving directives should be followed.

A summary in German is included in the PDF.

• Ilvessalo, E-mail: li@mm.unknown

The present investigation revealed that the influence of a forest cover on the water economy of the soil is very great in Finland. Cutting of the forest gave cause to a rise of the ground water table, which, when clear-cutting is in question, reached a magnitude of 20–40 cm. The water supplies of the soil increased 40–60 mm. In the winter, too, the ground water remaind at a lower level in the forest than in opening, however, the difference is rather small. Thinnings had same kind of effect as clear-cuttings, but the influence of even heavy thinnings was still relatively small.

The water supplies of the soil after felling decreased mainly due to the decrease in the interception in the canopy. When the water table is at the same level in the forest and in opening, evapotranspiration might be greater in the forest than in openings. However, when the water level is during the growing season considerably lower in the forest than in an opening, the evapotranspiration is strongly decreased in the forest, which means that more water is evaporated and transpirated from the opening than from the forest. Because the water table is at a higher level in the opening than in the forest, runoff from clear-cut areas has exceeded that from the forest. This means that the influence of felling on the water economy of the soil is actually even greater than indicated in this work.

The results mean that the influence of the forest cover makes up that of drainage. This affects the need for maintenance of ditches. On the other hand, the final cutting will rise the ground water strongly.

The PDF includes a summary in English.

• Heikurainen, E-mail: lh@mm.unknown

The forest management practices in Finland are closely related to the industrial history in the country. The selection cutting method used previously has now been gradually disappearing, and differences in the quality of forest management can still be observed between different owner groups. The national forest inventories indicate that farm woodlots show the poorest silvicultural state among the ownership categories. This study analyses social and economic causes responsible for variation in the silvicultural state of farm woodlots managed jointly with a cultivated land holding. The study is based on the data of third national forest inventory in Finland, and a factor analysis was calculated using the data.

Although the model developed explains more than a half of the total variance of the level of silviculture, only less than third of this is clearly explained by economic and social factors. The remaining two thirds are explained by the ’nature factor’, which includes both economic and site factors. This affects the effect of different kinds of forest policy measures. Of the variables in the model, the strongest influence in the level of silviculture have income, size of woodlot, size of land area under cultivation and distribution of forest types. The differences in the level of silviculture between different woodlots and different districts, may be explained by the theory of cumulative process. Regional differences in economic phenomena cannot be explained without taking into consideration the social value hierarchy in each region, which determines the range of variation of economic variables.

The PDF includes a summary in English.

• Riihinen, E-mail: pr@mm.unknown

Because the ‘rental cut method’ is rather arduous and based partly on subjective analysis, new forms for a cutting budget has been developed. One of them is a method called stock development forecast, and another method will be described in this paper. The main characteristics of the present growing stock affecting the allowable cut are the forest area, site quality, forest composition by age and development classes, volume, and increment.

In the method described in this paper an analysis of the desirable stock is necessary. The allowable cut is a function of the current and desirable stock and the increment during the budget period. The budget is based on information about the forest area, site quality, growing stock and its structure, collected from an inventory. The desirable stock is described in the same sub-groups as is the current stock. An increment forecast is prepared by compound and an interest formulae and increment percentages are presented as a function of the stock age. The allowable cut shows the average amount of the cut during the management plan period.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown
• Nyyssönen, E-mail: an@mm.unknown

Two lines can be defined in the management planning for the State Forests of Finland: 1) general planning for regions and inspectional sub-regions based on forest inventory, and 2) management plans for individual districts based on the revision of each district after 10–15 years. Long-term planning is has recently been alleviated by several new methods, such as stock-development forecast and yield tables.

A stock-development forecast and cutting budget were prepared separately for each State Forest region. The present growing stock was based on the data collected in the inventory in 1951–1955. Desirable stock for each region was calculated. The methods to calculate total cut during near future, allowable cut, allowable cut by timber products, the long-term development of the allowable cut, and conditions for realizing the allowable cut are presented in the paper.

The development of the growing stock towards a desirable condition requires also realization of a silvicultural program. Because the Finnish forest industry is expanding vigorously, the amount of the allowable cut on a sustained basis must be estimated carefully. Otherwise the demand for wood may exceed the supply. Though there are many sources of error in preparing a long-term cutting budget, it was considered necessary for State Forestry. An approximate estimate of the largest cut on a sustained basis and a program of silvicultural measures necessary to increase the yield gradually has been worked out.

The PDF includes a summary in English.

• Linnamies, E-mail: ol@mm.unknown

An estimate of value of a forest holding is needed, for instance, when the holding is sold. There is, however, no standard method for forest valuation. This paper describes a method based on yield in terms of value that is estimated on the basis of cutting budget. The first, mensurational part of the investigation concentrates on calculation of cutting budget that can be used in forest valuation. Second part studies how chronological order of fellings changes allowable cut in forests that differ by age-class distribution and other structural properties. Structure and variation in the structure of silviculturally different forests are determined for the forests that form the data for the investigation.

According to the study, even if the forests studied in the investigation included forests which structure differed in their age-class distribution from normal forests, they could be managed in a such way that in 5-6 decades the age-class distribution resemble that of a normal forest, and have growing stock that correspond the stock of forests in Southern Finland, about 80-110 m3/ha. Based on this, the cutting budgets of the later decades of the first rotation can be assumed to be nearly even. The original age-class distribution of the forest affects, however, allowable cut of the forests during the first decade. The revenues of the first decade have small impact on the value, the later decades strong. Consequently, development of the most valuable part of the allowable cut, timber trees, has big impact on the value. The results show that in young forests the planned cut including the proportion of timber trees increases, in middle-aged forest it is relatively even, and in old forest declining. The results indicate the order of magnitude the planned cut can be in near future in diferent kinds of forests, and when different felling regimes are used to reach different goals.

The PDF includes a summary in German.

• Kallio, E-mail: kk@mm.unknown

The purpose of this study was to clarify increment forecast methods in connection with the cutting budget. The emphasis is laid on the Finnish increment per cent methods. A tentative attempt is made to carry out a passage calculation. Increment forecasts are accomplished for diameter class distribution of a 60 years old Scots pine (Pinus sylvestris L.) stand. The increment data for the growing stock are taken from the domestic increment calculating tables.

When comparing the results of the two methods, the increment values are expressed in rabatt per cent in which the forecasted annual increment is in proportion to the initial value of the growing stock. It will be emphasized that the weak point in the domestic budgets is in the relation between the increment of the developable stock and the increment of the exploitable stock. Almost all the Finnish increment data are from the developable trees and the estimates of the increment of the exploitable trees have not been on sufficient facts.

The PDF includes a summary in English.

• Kuusela, E-mail: kk@mm.unknown

Pine swamps are easily regenerated by natural regeneration of Scots pine (Pinus sylvestris L.). Usually seeding felling is used, but also strip system or clear cutting and regeneration along stand edge has been suggested. This article discusses the regeneration by clear cutting and sparing the existing undergrowth. The article focuses on pine swamps to be drained and the ones in natural state.

Pine swamps in natural state usually have plenty of trees of smaller diameter classes, that can be trusted to form the future tree generation after the felling. This shortens the rotation by 20-30 years. The undergrowth has been shown to recover quickly. The method suits for regeneration of drained peatlands but could fit also for regeneration of pine swamps in natural state.

The seedlings in the pine swamps are mainly 1-5 years old, and the stock is changing. It seems that larger trees produce a wider selection of age groups, but the seedlings survive longer under smaller mother trees. Part of the younger generations of seedlings seem to be destroyed when the peatland is drained. Further studies are needed to investigate how the draining and felling are to be performed to spare the young seedlings.

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

The PDF includes a summary in German.

• Heikurainen, E-mail: lh@mm.unknown

The archives of the advisory organizations for private forest owners in Finland, Regional Forestry Boards and Forest Management Associations, include statistics of fellings in private forests. This investigation assesses felling areas and proportion of different kinds of fellings in 1945-1952 based on the statistics. The statistics does not include fellings where the trees have been marked by a forest owner.

The total area marked annually for cutting was in average 498,300 ha. As there is 1,24 million ha of private forests in Finland, the marking gives opportunity to improve the silvicultural state of private forest relatively quickly. The share of regeneration fellings has increased after the Second World War in many parts of the country. The result indicates that the annual cuttings in private forests have corresponded the amount of fellings that has been estimated necessary according to the National Forest Inventory. There are, however, big differences between different parts of the country.

The PDF includes a summary in German.

• Yli-Vakkuri, E-mail: py@mm.unknown

Permanent sample plots are considered to be the most reliable basis for investigations into structure and development of stands. Such sample plots, established since 1924 in Finland, have been used to study thinnings of varying intensity. These studies are yet too short to give comprehensive conclusions. It is also possible to base the studies on sample plots measured in managed forests and gain in this way information suitable for practical purposes. In this investigation development of stands treated by two different methods, repeated thinnings and repeated selection cutting were studied in pure, even-aged Scots pine (Pinus sylvestris L.) stands in Southern Finland, on three forest types.

The results show that volume increment level of naturally normal stands seem to have been reached easily by stands treated with repeated thinnings. With advancing age, the growing stock of thinned stands fall short from the natural stands. As thinnings have removed primarily the poorest trees, the increment is distributed over trees of a larger size more in thinned than in naturally normal stands.

When intensive cuttings have resulted in a relatively small growing stock, the decrease in volume increment leads to considerable decrease in volume. The size of the tree has no essential effect – within certain limits - on the volume increment of the stand, if the volume removed is similar. However, every intermediate thinning removing largest-sized trees may result in the prolonged rotation. Since the volume increment of an older stand is much smaller than earlier, intermediate thinnings removing largest-sized trees should be avoided if the aim is the greatest volume yield. The growing stock of middle-aged or older stands untreated or treated with slight cuttings only can as a rule be considerably reduced without volume increment declining.

The PDF includes a summary in English.

• Nyyssönen, E-mail: an@mm.unknown

The aim of the study was to develop a method for calculating a cutting budget that is adapted to the present forest management practices. The cutting budget determines the volume of annual cuttings for a forest holding in a certain period of time. Effect of fellings on the cutting budget depends on the cutting methods used. The study aimed at proving that growth of the forest can be estimated based on growing stock and structure of the forests for a certain time period. Accordingly, adequate drain can be defined in advance. The cutting budget is based on age-class distribution of the forest holding, which is most applicable for even-aged forestry. Calculation is based on area of the forest land and estimated volume of the growing stock. Also, the quality of the forest soil can be taken into account when age-class distribution is used. A suitable period for estimating a cutting budget is suggested to be 20 years, which is divided in two 10-year periods. The cutting budget it is included in a forestry plan. An example of a cutting plan based on the method is presented.

The PDF includes a summary in German.

• Lihtonen, E-mail: vl@mm.unknown

Effectiveness of 18 different saw blades of wooden bow saw from four producers (Oy Suomen Sandvik Sahat, Epilä Oy, Ab Orsa Sågbladsfabrik Oy, Kone ja Terä Oy) was tested in 1937. The experiments were divided into test series according to type of maintenance of the blade and tree species (Scots pine, Norway spruce and birch) to be sawn. Each saw blade was sharpened into four different sharpening angles (54°, 60°, 64°, 70°). Four blades had markedly longer sawing times compared to the others. These blades had a special serration. In addition, two blades with sparse serration had slightly poorer results than the blades in general. When the tree species were compared, birch (Betula sp.) was slowest to saw followed by Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.).

The PDF includes a summary in German.

• Aro, E-mail: pa@mm.unknown

A time study was conducted in saw log harvesting site in state forests of Evo in Southern Finland in 1934. Felling was performed in teams of two loggers. Two teams were observed. The work was divided into several stages of work: felling, branching, cross-cutting, barking and making of top log. On the site grew Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.).

The daily working hours not including breaks was in average 5 hours and 33 minutes. The most time-consuming stage of the work was barking of the stem (55% of working time for Scots pine and 47% for Norway spruce), followed by felling (22.5% for pine and 19.4% for spruce), branching (11.7% and 21.6%) and cross-cutting (11.3% and 11.8%). Temperature affects barking strongly. Scots pine is slower to bark than Norway spruce. Similarly, butt and middle logs are slower to bark than top logs. It took in average 79.02 min to process one solid m³ of timber with bark and 91.45 min without bark.

The PDF includes a summary in German.

• Seppänen, E-mail: vs@mm.unknown

Annual variations in wood utilization makes it complicated to estimate the balance between wood utilization and wood production of forests. According to the article, the balance is unsustainable especially in the private forests in the southern part of Finland. The annual wood utilization of the country was 37.3 million m³ in 1913, and the annual wood production 35.2 million m³, according to a report of a committee that was appointed to find methods to prevent overcutting. The committee suggested legislation to forbid forest devastation. Also the growth of the forests could be increased, if the forests are well managed, the article argues. To prove this, the potential wood production capacity is estimated for the municipalities of Viipuri, Mikkeli and Kuopio, and compared to the present wood production and wood utilization of the area.

The PDF includes a German summary.

• Ilvessalo, E-mail: yi@mm.unknown

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

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

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

The PDF includes a summary in Finnish.

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

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

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

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

The PDF includes a summary in English.

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

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

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

The PDF includes a summary in Finnish. 

• Kubin, E-mail: ek@mm.unknown

The aim of the study was to discover a model by which the determination of the discount value of a woodlot can be simplified so as to make it possible to avoid both the computation of a cutting budget and the customary discount procedure itself. The regression analysis of the cutting budget data that indicates the discounted amount of the fellings to be expected and the assortment composition can be discovered rather accurately as a function of the measured stand characteristics only.

The PDF includes a summary in German.

• Ahonen, E-mail: la@mm.unknown

This study is concerned with silvicultural selection from above. The material consists of 18 Scots pine (Pinus sylvestris L.) sample plots in the southern half of Finland in experimental forests. The method is motivated by the great difference between the stumpage prices of saw timber and pulpwood. The method suggested includes the removal of individuals belonging to the predominating canopy, to achieve high levels of income from the stand at an early stage. The method is applied at when the growing stock is attaining saw-timber size. Before that the stand is treated with thinnings from below. It is supposed that the volume of growing stock is maintained at a level as high as that in below-thinned stands, and that rotation is of normal length.

On the average, the increment in basal area, as well as volume increment, is greater in stands selectively cut from above than in those treated with low thinnings of the same degree. Initially, selection from above seems to exert a negative effect upon the development of dominant height; later, the dominant height reassumes the same rate of increment as in the below-thinned stands. Selection from above also means an increase in saw-timber production, although it involves a reduction in the mean size of saw timber. The investigation includes growth and yield tables for pine stands treated with silvicultural selection from above.

The results of the investigation prove that silvicultural selection from above is at least as profitable as low thinning. This provides freedom for stand treatment, and contributes to the application of a method most suitable for the owner in each individual case. It is further stressed that the maintenance of a high wood capital in the stand is far more important than the method of thinning applied.

The PDF includes a summary in English.

• Vuokila, E-mail: yv@mm.unknown

The aim of this study was to assess the effect of cutting of different intensities on the hydrology of drained peatland. The study concerned with measuring changes in the ground water level, throughfall, and snow cover, and specially runoff. This study focused on the phenomena that occur during the growing season. Seven sample plots were measured in an area in Central Finland which had been drained about 50 years earlier and had Scots pine (Pinus sylvestris L.) stand of uniform age.

To survey the hydrological effects of cuttings, 20%, 40% and 60% of the stand volume was removed in thinnings. In addition, one sample plot was clear-cut. During the first two years after cutting the interception diminished, and throughfall increased by 7% for the 20% thinning, by 8% for the 40% thinning and by 12% for the 60% thinning. Clear cutting increased the throughfall by 29%. The thinnings increased the depth of the snow cover the more the heavier the thinning.

Even the lightest thinning raised the ground water table, but the difference between 20% and 40% thinning was not marked. Cuttings increased runoff the greater the heavier the cutting. The hydrological changes of fellings were detrimental for the site. However, there was a marked change only between the 40% and 60% thinnings. Fertilization had a favourable effect on the hydrology of the peatland by increasing the depth of ground water table, and decreasing the throughfall.

The PDF includes a summary in Finnish.

• Heikurainen, E-mail: lh@mm.unknown

The purpose of this study was determining the optimum cutting program for forest stands by the application of dynamic programming. Calculations have been made for even-aged Scots pine (Pinus sylvestris L.) stands in Southern Finland, aged 50-100 years. Three logging cost levels, thinning from below and from above, and rates of interest of 1, 2, 3, 4, and 5% was applied. Both optimum routes and the economic results of different cutting programs was analysed.

According to the results, the higher the rate of interest is, the lower the density remains, and shorter the rotation is. The starting level of the growing stock may influence the treatment of the stand for tens of years. If logging costs change, so that harvesting small wood becomes relatively more expensive in the future, the density of growing stock will increase. However, heavy thinnings today are recommendable, to avoid expensive thinnings in the future.

The density of the growing stock should be higher if thinning from above is applied, instead of thinning from below. The growth of the stands thinned from below needs to be greater than the growth of stands thinned from above, to justify thinnings from below. Too high density often results in larger losses than do too low a density or the wrong rotation. Thinnings seem to be profitable even at much higher logging costs than those of today. The maturity of the stand is determined both by the age and the density of the growing stock. The stand may be mature because of great age, high density combined with a relatively high age, or because the growing stock is too low in density.

The PDF includes a summary in Finnish.

• Kilkki, E-mail: pk@mm.unknown
• Väisänen, E-mail: uv@mm.unknown

The aim of this study was to develop cutting budget methods for a forest undertaking. Cutting budget provides information on the future income from the forest undertaking, and on the development of the forest.

Two cutting budget models have been developed, by the application of simulation and linear programming. Both of the models are deterministic in nature, i.e. there is only one possible outcome once the stated input information has been given. To make the models simpler, it has been assumed that thinning and clear cutting with reforestation are the only activities that can occur in the forest. The models are directly applicable only to forests consisting of even-aged Scots pine stands at three different forest types. However, they can easily be extended to cover forests comprising several tree species and more sites.

In the light of this study, simulation seems today to be more appropriate than linear programming in the preparation of cutting budgets. However, the increasing capacity of computers may even in the near future make linear programming quite competitive, especially as if it is borne in mind that the theoretical basis of linear programming is much firmer than that of simulation. The most advisable cutting budget method might consist of a combination of simulation and linear programming. Simulation could be employed to find a rough cutting schedule, and linear programming to test and improve the solution.

The PDF includes a summary in Finnish.

• Kilkki, E-mail: pk@mm.unknown

The purpose of the present investigation was to study the extent of human interference with the forests of different epochs in the district of north Ostrobothnia in Northern Finland, and its effect on the condition of the forests.

The study revealed that the quantities of wood removed were not most detrimental to the condition of the forest; the regionally irregular loggings and the logging methods employed were the most harmful. The old forms of wood utilization, tar industry, shipbuilding, sawmill industry and timber exports, were characterized by timber selection. Public opinion considered it the only recognized cutting method long after the conditions had changed and silvicultural methods should have been used.

The spread and abandonment of selection cuttings are illustrated in the results of first National Forest Surveys in Finland. According to the first survey (1921–1924), nearly half of the loggings in the province of Oulu were based on selection, which spoiled and devastated 41% of the forests. In the 1930s one-fifth of the North Ostrobothnian forests were weakened by selection cuttings, in 1960s the figure was 6%. The article also summarises the extent of tar and pitch production, sawmill industry, shipbuilding and household wood consumption of wood in the area.

The PDF includes a summary in English

• Alho, E-mail: pa@mm.unknown

Modern forestry, which mainly consists of clear-cutting, is one of the most important factors influencing today’s boreal forests. In Sweden, the breaking point for modern forestry is generally considered to be around 1950. Recently, our common knowledge of the implementation of clear-cutting in Sweden has increased, and new research indicates that clear-cutting systems were already applied before the 1950s. In this case study, we used aerial photographs from the 1940s to analyze the extent of contemporaneous clear-cuts and even-aged young forests in an area in northern Sweden. Our results show that almost 40% of the study area had already been clear-cut by the end of the 1940s, but also that clear-cutting had been applied to 10% of the forest land in the early 1900s. This implies that the historical development of forestry in northern Sweden is more complex than previously thought, and that certain proportions of the forest land were already second-generation forests in the 1950s. Our results have implications for the use of concepts such as “continuity forest”, suggesting that this concept should employ a time frame of at least 100 years.

• Lundmark, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden https://orcid.org/0000-0001-8402-7152 E-mail: hanna.lundmark@slu.se
• Östlund, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden https://orcid.org/0000-0002-7902-3672 E-mail: lars.ostlund@slu.se
• Josefsson, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden https://orcid.org/0000-0002-8734-5778 E-mail: torbjorn.josefsson@slu.se

Downy birch (Betula pubescens Ehrh.) stands on drained peatlands are often considered useless because they typically do not yield good-quality sawn timber. However, covering an area of ca. 0.5 million hectares and with total yields of up to 250 m³ ha^–1, downy birch stands on peatlands in Finland have a potential for pulpwood and/or energy wood production. We examined the financial performance of alternative management regimes (with or without thinnings, different thinning intensities, several rotation lengths) combined with alternative harvesting methods (pulpwood, energy wood, or integrated, energy wood being delimbed stems or whole trees). We used data from 19 experimental stands, monitored for 20–30 years. For harvesting removals we considered both actual thinning removals and final-cutting removals with alternative timings that were based on the monitoring data. We assessed the profitability as a combination of the net present value of the birch generation and the bare land value of future generations of Norway spruce (Picea abies (L.) Karst.). The most profitable management was growing without thinnings until whole-tree final cutting at the stand age of 40–45 years with an advanced multi-tree harvesting method. In contrast, the standard method in whole-tree final cutting resulted in the lowest profitability, and an integrated method with the energy wood as delimbed stems was the best of the standard methods. Thinnings were unprofitable especially when aiming to produce energy wood, whereas aiming for pulpwood, light precommercial thinning was competitive. Commercial thinning at the traditional “pulpwood stage” had little effect on profitability. The best stand age for final cutting was 40–65 years – earlier for very dense stands and whole-tree energy wood harvesting with advanced method, later for precommercially thinned stands and pulpwood harvesting.

• Niemistö, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Kampusranta 9 C, 60320 Seinäjoki, Finland E-mail: pentti.niemisto@luke.fi
• Kojola, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: soili.kojola@luke.fi
• Ahtikoski, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Paavo Havaksentie 3, 90014 University of Oulu, Finland E-mail: anssi.ahtikoski@luke.fi
• Laiho, Natural Resources Institute Finland (Luke), Management and Production of Renewable Resources, Latokartanonkaari 9, 00790 Helsinki, Finland E-mail: raija.laiho@luke.fi

• Ring, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: eva.ring@skogforsk.se
• Högbom, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: lars.hogbom@skogforsk.se
• Nohrstedt, Swedish University of Agricultural Sciences, Department of Soil and Environment, P.O. Box 7014, SE-750 07 Uppsala, Sweden E-mail: hans-orjan.nohrstedt@slu.se
• Jacobson, Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: staffan.jacobson@skogforsk.se

• Sullivan, Department of Forest and Conservation Sciences, Faculty of Forestry, University of BC, 2424 Main Mall, Vancouver, BC, Canada V6T 1Z4 E-mail: tom.sullivan@ubc.ca
• Sullivan, Applied Mammal Research Institute, 11010 Mitchell Avenue, Summerland, BC, Canada V0H 1Z8 E-mail: dru.sullivan@appliedmammal.com

• Légaré, Université Laval, Faculté de foresterie, de géographie et de géomatique, Pavillon Abitibi-Price, Québec, Canada E-mail: jpl@nn.ca
• Hébert, Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec (Québec), G1V 4C7, Canada E-mail: christian.hebert@rncan.gc.ca
• Ruel, Université Laval, Faculté de foresterie, de géographie et de géomatique, Pavillon Abitibi-Price, Québec, Canada E-mail: jcr@nn.ca

• Lafleur, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada E-mail: benoit.lafleur@uqat.ca
• Fenton, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada E-mail: njf@nn.ca
• Paré, Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, QC G1V 4C7, Canada E-mail: dp@nn.ca
• Simard, Département de Géographie, Université Laval, Pavillon Abitibi-Price, 2405 rue de la Terrasse, Québec, QC G1V 0A6, Canada E-mail: ms@nn.ca
• Bergeron, NSERC-UQAT-UQAM Industrial Chair in Sustainable Forest Management, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada E-mail: yb@nn.ca

• Ky-Dembele, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden (catherine.dembele@slu.se) E-mail: kydembele@hotmail.com
• Bayala, World Agroforestry Centre, West Africa and Centre Regional Office, Sahel Node, BP E5118 Bamako, Mali E-mail: jb@nn.ml
• Savadogo, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden E-mail: ps@nn.bf
• Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden E-mail: mt@nn.se
• Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden E-mail: pco@nn.se
• Boussim, Université de Ouagadougou, Unité de Formation et Recherche en Sciences de la Vie et de la Terre, 03 BP 7021, Ouagadougou 03, Burkina Faso E-mail: ijb@nn.bf

• Nurminen, Metsätoimisto Tuomo Nurminen, Joensuuntie 5 B 8, FI-41800 Korpilahti, Finland E-mail: tn@nn.fi
• Korpunen, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: hk@nn.fi
• Uusitalo, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: ju@nn.fi

• Granhus, Norwegian University of Life Sciences, Dept. of Ecology and Natural Resource Management (INA), P.O.Box 5003, NO-1432 Ås, Norway E-mail: aksel.granhus@umb.no
• Fjeld, Swedish University of Agricultural Sciences, Dept. of Forest Resource Management, SE-901 83 Umeå, Sweden E-mail: df@nn.se

• Nurminen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: tuomo.nurminen@joensuu.fi
• Korpunen, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: hk@nn.fi
• Uusitalo, Finnish Forest Research Institute, Parkano Research Unit, Kaironiementie 54, FI-39700 Parkano, Finland E-mail: ju@nn.fi

• Luoranen, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: jaana.luoranen@metla.fi
• Lappi, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: lj@nn.fi
• Zhang, College of Horticulture, Agricultural University of Hebei, Baoding, Hebei, China E-mail: gz@nn.cn
• Smolander, Finnish Forest Research Institute, Suonenjoki Research Unit, Juntintie 154, FI-77600 Suonenjoki, Finland E-mail: hs@nn.fi

• Kojola, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: soili.kojola@metla.fi
• Penttilä, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: tp@nn.fi
• Laiho, University of Helsinki, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: rl@nn.fi

• Øyen, Norwegian Forest Research Institute-Bergen, Fanaflaten 4, N-5244 Fana, Bergen, Norway E-mail: bernt-havard.oyen@skogforsk.no
• Nilsen, Norwegian Forest Research Institute-Bergen, Fanaflaten 4, N-5244 Fana, Bergen, Norway E-mail: pn@nn.no

• Nieuwenhuis, University College Dublin, Dept. of Forestry, Belfield, Dublin 4, Ireland E-mail: maarten.nieuwenhuis@ucd.ie

• Lundqvist, Deparment of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden E-mail: lars.lundqvist@slu.se
• Spreer, Sveaskog Förvaltnings AB, Ljusdal, Sweden E-mail: susanne.spreer@sveaskog.se
• Karlsson, Field Research Unit, Swedish University of Agricultural Sciences, Siljansfors, Sweden E-mail: christer.karlsson@slu.se

• Modig, Statens fastighetsverk, Jokkmokk, Sweden E-mail: em@nn.se
• Magnusson, Skogsstyrelsen, Bräcke, Sweden E-mail: bm@nn.se
• Valinger, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden E-mail: ev@nn.se
• Cedergren, Mariehamn, Åland E-mail: jc@nn.se
• Lundqvist, Deparment of Forest Ecology and Management, SLU, SE-901 83 Umeå, Sweden E-mail: lars.lundqvist@slu.se

• Koivula, Department of Ecology and Systematics, Division of Population Biology, P.O. Box 65, FIN-00014 University of Helsinki, Finland E-mail: matti.koivula@helsinki.fi
• Niemelä, Department of Ecology and Systematics, Division of Population Biology, P.O. Box 65, FIN-00014 University of Helsinki, Finland E-mail: jn@nn.fi