Current issue: 56(1)
Under compilation: 56(2)
We describe the methodology applied in the 12th national forest inventory of Finland (NFI12) and describe the state of Finland’s forests as well as the development of some key parameters since 1920s. According to the NFI12, the area of forestry land (consisting of productive and poorly productive forest, unproductive land, and other forestry land) is 26.2 M ha. The area of forestry land has decreased from 1920s to 1960s due to expansion of agriculture and built-up land. 20% of the forestry land is not available for wood supply and 13% is only partly available for wood supply. The area of peatlands is 8.8 M ha, which is one third of the forestry land. 53% of the current area of peatlands is drained. The volume of growing stock, 2500 M m3, is 1.7 times the volume estimated in NFI1 in the 1920s for the current territory of Finland. The estimated annual volume increment is 107.8 M m3. The increment estimate has doubled since the estimate of NFI2 implemented in late 1930s. The annual mortality is estimated to 7 M m3, which is 0.5 M m3 more than according to the previous inventory. Serious or complete damage was observed on 2% of the productive forest available for wood supply. The amount of dead wood is on average 5.8 m3 ha–1 in productive forests. Since the NFI9 (1996–2003) the amount of dead wood has increased in South Finland and decreased in North Finland both in protected forests and forests available for wood supply (FAWS). The area of natural or almost natural forests on productive forest is 380 000 ha, out of this, 42 000 ha are in FAWS and 340 000 ha in protected forests.
In remote sensing-based forest inventories 3D point cloud data, such as acquired from airborne laser scanning, are well suited for estimating the volume of growing stock and stand height, but tree species recognition often requires additional optical imagery. A combination of 3D data and optical imagery can be acquired based on aerial imaging only, by using stereo photogrammetric 3D canopy modeling. The use of aerial imagery is well suited for large-area forest inventories, due to low costs, good area coverage and temporally rapid cycle of data acquisition. Stereo-photogrammetric canopy modeling can also be applied to previously acquired imagery, such as for aerial ortho-mosaic production, assuming that the imagery has sufficient stereo overlap. In this study we compared two stereo-photogrammetric canopy models combined with contemporary satellite imagery in forest inventory. One canopy model was based on standard archived imagery acquired primarily for ortho-mosaic production, and another was based on aerial imagery whose acquisition parameters were better oriented for stereo-photogrammetric canopy modeling, including higher imaging resolution and greater stereo-coverage. Aerial and satellite data were tested in the estimation of growing stock volume, volumes of main tree species, basal area and diameter and height. Despite the better quality of the latter canopy model, the difference of the accuracy of the forest estimates based on the two different data sets was relatively small for most variables (differences in RMSEs were 0–20%, depending on variable). However, the estimates based on stereo-photogrammetrically oriented aerial data retained better the original variation of the forest variables present in the study area.
Simulation and modeling have become more common in forest biomass studies. Dynamic simulation has been used to study the supply chain of forest biomass with numerous different models. A robust predictive multi-year model requires biomass availability data, where annual variation is included spatially and temporally. This can be done by using data from enterprises, but in some cases relevant data is not accessible. Another option is to use forest inventory data to estimate biomass availability, but this data must be processed in the correct form to be utilized in the model. This study developed a method for preparing forest inventory data for a multi-year simulation supply model using the theoretical availability of feedstock. Methods for estimating quality changes during roadside storage are also presented, including a possible parameter estimation to decrease the amount of data needed. The methods were tested case by case using the inventory database “Biomass Atlas” and weather data from a weather station in Mikkeli, Finland. The data processing method for biomass allocation produced a reasonable quantity of stands and feedstock, having a realistic annual supply with variation for the demand point. The results of the study indicate that it is possible to estimate moisture content changes using weather data. The estimations decreased the accuracy of the model and, therefore, estimations should be kept minimal. The presented data preparation method can generate a supply of forest biomass for the simulation model, but the validity of the data must be ensured for correct model behavior.
The distances between the lines in the line survey in the first two National Inventories of Finland were too long to supply data for every State Forest district. Consequently, the Third National Forest Inventory offered an opportunity to supplement the inventory for State Forests in 1954 and 1955, and to gather data on forest resources of the State Fforests. On the basis of the results, a management plan for the State Forests was drafted. The first part of the paper describes the inventory procedure and results of the inventory, the second deduces future cuttings and a forest management programme.
In 1955 the total land area of the State Forests was 9.49 million ha. Drained peatlands cover 126,000 ha, drainable peatlands 798,000 ha and undrainable peatlands 2,621,000 ha. The average volume of growing stock in all State Forests was 55.2 m3/ha, including productive and unproductive forest land. The average increment in all State Forests was 1,39 m3/ha on productive land and in all lands in average 1,14 m3/ha.
Cutting budgets for the progressive yield were prepared by checking the silvicultural cut and estimating the allowable cut. They were made by age classes, developmental stages and for each region. The stock development was forecasted for a period of 40 years. In average the allowable cut was larger during the first decade than during the second. Allowable cut was estimated by the tree species and by timber assortments. The management plan included future forest management work, such as intermediate fellings, regeneration fellings, site preparation, artificial regenereation, tending of seedling stands, and draining of peatland.
The PDF includes a summary in English.
An investigation was carried out in the area of Beas River in India in the conifer forests of the region to study the possible supply of raw material for forest industries. The investigation based on an agreement between the Government of Finland and the Government of India about techcnical assistance to India.
The results of the survey suggest that though the Himalayan conifer forests are scattered and they lie on high altitude and in difficult terrain, their potential value is very important to the Indian national economy. Their extraction is feasible in much larger scale than now. The present yield coming to the markets is 30-10%, or even less, of the obtainable yield under intensive management and integrated utilization of wood. The obtainable yield could support comparatively large saw milling as well as pulp and paper industries.
The problems in developing the Himalayan conifer forestry cover the field of forest management, silviculture, re-forestation, logging, relations between forestry and the local population, forest administration, sales policy and industrial planning. Estimating the actual possibilities requires reliable resource inventories. Cultivation of trees for primitive sleeper production should be abandoned, management systems modified in accordance with the principle of progressive yield. The future management should be based on the exploitation of the existing over-mature stock and on the growth of the new stands.
The PDF includes a summary in Finnish.
The first estimates on the forest resources of Finland were presented in the middle of the 1900th century. The first line survey was conducted in 1912 in Central Finland. In 1921-1923 a survey of the forests of the whole country was commenced. The method consisted in measurement of sample plots in conjunction with ocular estimation of all the stands within the range of the lines. The methods were further developed in the second National Forest Survey in 1936-1938, which payed special attention to the silvicultural condition of the forests, and the growth in the light of climatic variation. When 3.3 million ha of forests were ceded to the Soviet Union in the peace treaty of 1944, the results of the survey had to be recalculated. The next survey was conducted 1951-1953. In this survey, the recovery of stands on drained peatlands was studied. The results of the inventories show that forest resources of Finland had icreased since the 1936-1938 survey.
The first investigation of wood utilization in Finland was carried out in 1927, after the first National Forest Survey had provided information on the forest resources, and knowledge of the other side of the forest balance was desired. The most difficult part was to determine the domestic wood consumption of the rural population. This was accomplished by studying 1,337 sample farms. The second investigation was commenced in 1938, and third in 1954.
These two investigations have made it possible to determine the annual removal and annual growth, and by comparing these results, growth balance. A forest balance is an essential condition for judicious forestry.
The Acta Forestalia Fennica issue 61 was published in honour of professor Eino Saari’s 60th birthday.
This investigation concerns the felling volumes in Finland in 1935-1945 as regards future fellings. The statistics are divided in two time periods: 1935-1939, when there was an upward trend in the trade cycle, and 1940-1945, when the trade was disturbed by the Second World War. Fellings of household timber and for sales are presented separately.
Removal was annually in average 38.1 million cubic meters (cbm) without bark in 1935-1939, and 29.8 million cbm in 1940-1945. According to the statistics, felling volumes decreased by about one quarter after the period of 1935-1945. Reduction was largest in private and company forests, but smaller in the state forests. The increment balance for the 1935-1945 shows an excess of growth that gives an accumulated yield of 24.4 million cbm.
In private forests the cut is about half as large as the growth of the standing stock due to the poor silvicultural condition of the forests. Private forests account for about ¾ of the total forest area in Finland. In the state lands the cut is 130% of the growth. The report introduces also rental cut, a method developed by the writer, which defines the volume to be cut aiming at the same time to optimise the future increase of the yield. The principle is to preserve the young and vigorous stands, while cutting stands that have low growth.
According to the statistics, the felling volume of private forests has followed the variations in demand. It seems likely that in the coming years the fellings will not be kept within the limits calculated by the rental cut. Consequently, the reserve formed during the war will be utilized. To meet the demand of wood, forest management must be improved and preference should be given to regeneration fellings. Improving transportation systems, such as roads, would give access to forest resources that are now difficult to harvest.
The PDF includes a summary in English.
According to the 1st national forest inventory of Finland, municipalities owned 178,000 hectares of forests in 1922, about 0.7% of the total forest area of the country. Only 60,000 hectares of these belonged to urban municipalities. The amount had increased to 73,000 hectares by 1938. Although the area was small, forests were important for municipal economy. The aim of this study was to investigate the state and forest management practices of forests in urban municipalities. The data was collected mainly by interviewing the authorities of the municipalities in 1936-1938.
Forests covered 50-80% of the area of the urban municipalities, the total area varying from 111 hectares to 7,791 hectares. Only four municipalities owned more than 5,000 hectares of forests. Annual profit of forestry in all urban municipalities totalled about 4.6 million Finnish marks in 1931-1935. Quality of productive forest lands was relatively good, but the volume and growth of the forests rather low. The silvicultural state of the forests could be improved. The article points out that this requires continuous planning. The basis of this is forest management plan, which has been demanded of municipal forests since 1893. However, some of the urban municipalities still lacked a forest management plan, or it was not fully used in forest management.
The PDF includes a summary in German.
The article is a review on the forest resources, forestry and forest policy in the United States based on the publication A National Plan for American Forestry, published in 1933. The earlier estimates of forest resources of America have been proved to be exaggerated. The annual drain had been estimated to be twice the annual growth of the forests. The author disagrees with the estimates, and argues that the growth, if calculated with the American method, do not give right figures of the sustainable fellings.
The situation is better than estimated. The national plan of forestry suggests that the public ownership of the forests should be increased to 60% from the present 20%. In addition, there are plans to introduce public control of private forests in the American forestry so that fellings do not risk the sustained yield of the forests. Rapid depletion of the saw timber resources in the North-Eastern and Lake States, and the high lumber prices lead to the assumption that the timber resources of the United States are in decline. The following decrease in lumber consumption lead to surplus of sawmill capacity, and to increasing competition in the sector.
The PDF includes a summary in English.
A presentation based on the historical development of Russia is given in the form of an overview of the development of Russian forest resources, of the wood, non-wood, and biological aspects of the forest ecosystem. The list of non-wood forest resources includes resin, saps, oils, berries, wild nuts, mushrooms, hay harvesting, game animals, etc. The dynamics of the system are presented in the light of the data of the Forest State Account (FSA) of Russia for the period 1956–1993. The most significant changes in the dynamics of Russia's forest resources are related to concentrated, large-scale wood harvesting operations. The dynamics of non-wood resources follow the process of the economic recession in all parts of the forest sector of Russia, the said recession having begun in the mid-1980s. The forests of Russia are considered to be of immense social and cultural value and a globally significant factor contributing to the sustainable development of forest resources.
Model-based information systems have proved valuable planning tools for analysing the production possibilities of forests as well as for understanding forest resources dynamics, stand management practices and forest economics. Computerized forest models implemented in the users’ information systems facilitate the transfer and application of research results in practical forestry.
Conclusions and visions concerning modelling are drawn from experiences in developing the MELA system and its application in solving timber production problems on both the national and forest holding level in Finland. The precondition for predicting forest resource dynamics and for planning the utilization of forests is to accept conditions, uncertainties and a restricted period of time.
The interactive process of forest resource, growth and drain monitoring, and forest management planning supported by forest research and modelling, are the means to enable an operational information base for a dynamic regulation and adaptation strategy for forest resource management under changing conditions and uncertainty.
The PDF includes an abstract in Finnish.
Europe’s forest area has increased 5 million ha since the late 1960s. The growing stock has increased 43% and the net annual increment 55% in exploitable forests since 1950. A part of the reported increase is caused by sampling inventories, which have been made in greater part of the countries. Sampling inventories have corrected earlier underestimates of the growing stock and the increment.
The difference between the annual net increment and fellings has increased since 1950. The net increment, 584 million m3, exceeded fellings, 408 million m3, by 176 million m3, in exploitable forests in 1990. If fellings could be increased to equal the increment, Europe would be an exporter of forest products.
A greater increase in the density, in the age and in the mean volume of forests per hectare threaten the biological stability of the growing stock. Degrading of the stock, increasing natural losses and deteriorating environmental qualities of forests can only be prevented by increased fellings and by forest regeneration.
The PDF includes an abstract in Finnish.
The article is a presentation given by the author on occasion of visit from Austrian timber industry and foresters (August 17th 1923), and again for the German visitors (August 20th 1923) in Punkaharju, Finland. The speech gives an overview of Finland’s forest resources region by region starting from far north. Also the most important uses and changes of forest as well as forest industry locations are mentioned.
In this paper, the author explains the characteristics of the Japanese forestry planning system and points out some of the problems found therein from the viewpoint of the management of privately-owned forests relating to the economic background and governmental policy.
The forestry planning system is a centralizes type of planning, the planning begins at the top and flows downward and outward the periphery. In order to make this planning system an effective instrument, the district forestry planning founded under the system must approach the problem of how to combine the resources of the forest with the district’s inhabitants and the forest owners; and further, the extent of the effective union of the district and the local timber manufacturing must be examined.
Comprehensive state laws regulating the practice of forest management on private lands are in effect in seven of the United States. Established to protect a wide range of non-timber forest resources and to ensure reforestation after harvest, these laws may impose significant administrative costs on states and significant compliance costs on landowners and timber operators. Total state administration costs for 1984 are estimated at $10.1 and total private sector compliance costs are estimated at $120.5 million, for a total regulation cost of $130.6 million.
The resource protection effectiveness of state forest practice regulation is difficult to quantify. However, agreement is strong that regulation has led to significant improvements in forest resource conditions and has helped to increase reforestation.
A nation that wishes to enhance its social and economic well-being through more intensive utilization of its forest resources must develop a rather comprehensive policy statement to ensure that the expanded exploitation does not lead to the destruction of these resources. The policy must specify the goals to be achieved, provide general direction on how these goals can be achieved, and develop a system of checks-and-balances to ensure achievement of the long-term objectives. The policy must consider resource protection, the economic needs at the various levels of government, the social impacts of utilization on ways of life in all areas of the nation, and the infrastructure needed in the short and long terms.
Use of tropical forest resources is analysed as part of the world forest resources and global development of forest industry. Finland’s role in the international division of labour of forest industry is investigated. Factors of competitiveness are analysed in order to differentiate specific adjustment constraints in Finland due to competition from developing countries.
It is concluded that in the long run there are two major factors which are restricting the growth of Finnish forest industry. First, tightened resources constraints, and second, competitive shifts in external markets due to new sources of production. Finland has already reached its wood-producing limits of sustained yield. Technological advances in the use of short-fibre raw materials for pulp and paper making, as well as in making programmes for establishing fast-growing plantations, have facilitated the utilization of tropical forest areas. In the short term, however, the competitive threat from LDC wood-processing industry is primarily directed to home markets rather than to exports.
The PDF includes an abstract in Finnish.
The area of world forests is gradually declining because of various human activities, such as shifting cultivation, uncontrolled logging and industrial pollution. Continuation of the trends would have detrimental ecological, economic and social effects on global scale. The diversity of the problem is wide. The situation in the tropical developing countries differs from that in the industrialized world. With the present rates of population growth and unchanged forest policies, the fuelwood shortage in developing countries is rapidly aggravating. The need for more agricultural land tends to prejudice conscious efforts to increase wood production.
The industrialized countries are experiencing problems in introducing forest policy means to maintain sufficient timber supply. Rapidly increasing pollution problem cause a serious hazard to the existence of the whole forest ecosystem. Forestry has primarily been a national issue of relatively low priority in political decision-making, which has resulted in insufficient action to remedy the situation at national and international level.
The renewability of forest resources represents a strategic asset, the importance of which is bound to increase in the long-run potential for badly needed economic and social change in the world’s poor rural areas will be lost.
The PDF includes a summary in Finnish.
About 60%, 20.5 million hectares, of Finland is covered by forests. Of this area 10.5 million hectares are peatlands. The forests are divided in fertile forest land (17 million hectares), forest land of low productivity (3.5 million hectares) and nonproductive lands (about 10 million hectares). Scots pine (Pinus sylvestris L.) is the dominant species in 60%, Norway spruce (Picea abies (L.) H. Karst.) in 23%, and Betula sp. 17% of the forests. The younger age classes are poorly represented, but despite the abundance of older age classes, the growing stock and productivity of the forests are not very high. The reason is low density of the forests, unfavorable tree species composition and the condition of the forests. Timber is used as household timber in towns and in rural areas (16.5 million m3), in traffic (1.3 million m3), fuelwood in industry (3 million m3), raw material in wood industry (9.1 million m3) and export (4 million m3). State owns 36.9% of forest lands, companies and associations 8.1% and other private forest owners 53.5%. The article describes the administration of state and private forests, and forest education in Finland. There was about 600 sawmills, 25 mechanical pulpwood mills, 24 pulp mills and 31 paper mills in the country in 1920.
About 60%, 20.5 million hectares, of Finland is covered by forests. Of this area 10.5 million hectares are peatlands. The forests are divided in fertile forest land (17 million hectares), forest land of low productivity (3.5 million hectares) and nonproductive lands (about 10 million hectares). Scots pine (Pinus sylvestris L.) is the dominant species in 60%, Norway spruce (Picea abies (L.) H. Karst.) in 23%, and Betulasp. 17% of the forests. The younger age classes are poorly represented, but despite the abundance of older age classes, the growing stock and productivity of the forests are not very high. The reason is low density of the forests, unfavorable tree species composition and the condition of the forests. Timber is used as household timber in towns and in rural areas (16.5 million m3), in traffic (1.3 million m3), fuelwood in industry (3 million m3), raw material in wood industry (9.1 million m3) and export (4 million m3). State owns 36.9% of forest lands, companies and associations 8.1% and other private forest owners 53.5%. The article describes the administration of state and private forests, and forest education in Finland. There was about 600 sawmills, 25 mechanical pulpwood mills, 24 pulp mills and 31 paper mills in the country in 1920.
A strip survey was made to define the forest and peatland site class distribution and the condition of the forests in Savo and Karelia in central and eastern parts of Finland. According to the survey, 24% of the forested lands are peatlands. Fresh mineral soil sites (26%) were the most common mineral soil site type. Intermediately dry forest soil sites covered 22% of the area, forest sites with grass-herb vegetation 12,79%, rich grass-herb forest soil sites 3,16% and dry forest soil sites 9,59% of the forested area. The most common tree species were Scots pine (Pinus sylvestris L.), 39%, Betula sp., 26%, Norway spruce (Picea abies (L.) H. Karst.), 18%, and grey alder (Alnus incana (L.) Moench), 10% of the forest land. The article includes a review about the wood harvesting in the forests, and their present silvicultural state. According to the study, about 30% of the forested lands (not including peatlands) were unproductive; mostly mixed alder and birch stands of poor quality or open lands.
The PDF includes a summary in German.
The field of work of the 7th National Forest Inventory was carried out during 1977–84. This report consists of the analysis of the forest resources, long-term development of forests and the results by ownership categories in Finland.
The area of forestry land, 26.4 million ha, has decreased slightly because of the increase of build-up areas and communication routes. Forest land, which is suitable to growing wood profitably, amounted 20.1 million ha. It has increased, although not as fast as earlier, due to drainage and fertilization of scrub and waste land swamps and the afforestation of agricultural land.
The growing stock volume was 1,660 million m3 and the estimated gross annual increment 68.4 million m3. A large quantity of young, rapidly growing stands, and fellings markedly below the increment, are the principal factors increasing the growing stock. The volume of Scots pine (Pinus sylvestris L.) has increased most but the greatest proportional increase has been in the volume of broadleaved trees.
The silvicultural quality of stands has improved and the increase in saw log tree volume has resulted in an increase in the total growing stock volume. The proportional volume of saw logs, however, has decreased. Both aging mature stands and postponed thinnings increase the risk of losses due to mortality and decay. Too dense stands retard the diameter growth of trees. The proportion of unsuccessful artificial regeneration has increased.
The area of private forests has slightly decreased, while companies and collective bodies have increased their ownership. Non-farmer private ownership already accounts for one half of the area of private forests. The silvicultural quality of company forests is best and the increase of the growing stock and its increment is proportionally greatest in these forests.
The PDF includes a summary in English.
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
In the 1930s studies showed that state of the standing crop and forests of small private forest holdings in Finland was weak. In 1960s it was regarded necessary to study the possible change in the silvicultural state of these forests. Therefore, sample stands of the small holdings surveyed in 1930 by Osara were surveyed anew in the areas of Karelia and Savo, and in Central Finland in 1963–1964. A line plot survey was combined with ocular estimation as in 1930, but in 1963–1964 the lines and sample plots were placed denser than in 1930 to reach similar number of sample plots.
In 1930 the state of the forests of the small holdings was in average very weak, but according to Osara, the age classes younger than 50 years had similar stand volume than in the all the forests of the southern half of the country. The results of this survey show that the volume, structure, growth and development class structure of the forests in average have improved since 1930. In many respects the forests have reached the average state of forests in the southern half of Finland. The most serious problem is the large proportion of broadleaved trees. Thus, the silvicultural state of the forests should be further improved.
The PDF includes a summary in German.
The Economic Council asked Heikinheimo, Holopainen and Kuusela to prepare a report on the development of Finland’s forest resources up to the beginning of the next century. The expansion of forest industry beyond the level foreseen in earlier forecasts, the large-scale removal and neglect of the basic improvements required have weakened the condition of the wood production to such an extent that extensive measures are needed to ensure the continuity of the supply of wood. The results of the calculations are formed in three separately analysed alternatives.
Alternative I: Realisation of the Teho programme and the removal corresponding to it. The development of the growing stock according to the programme would only permit a cut amounting to an annual drain of ca. 51 million m3 up to the year 2000. After that it would be possible gradually to increase the removal. This drain would not itself to utilise fully the already existing production capacity of the industry.
Alternative II: Consequences of the predicted removal if the Teho programme is realised as such. The wood utilization forecast based on the premises given to the team show that the annual drain will grow in 1964–1975 from 52 to 58 million m3, and thereafter by 0.5% annually. This would lead to over-cutting, and exhaust the present growing stock by the turn of the century. If annual total drain of ca. 58 million m3 would after 1975 be sufficient, exhaustion of the growing stock would be postponed for 4–5 years.
Alternative III. Teho programme expanded in conformity with the removal forecast. A new programme is proposed, which includes, among others, large scale fertilization of fully grown firm forest land at about the rate of 100,000 ha/year, intensified artificial regeneration, assurance of the supply of planting stock and seed, increase of forest drainage from the present 155,000 to 250,000 ha/year by 1970, site preparation of the cutting areas for artificial regeneration, increase of tending or seeding stands to 300,000 ha/year, replacement of fuelwood by other fuels, increase of wood import and new forest roads.
Line plot survey has proven the best method to assess forest resources in the Northern countries on a country level; it is cost effective and gives reliable results. The accuracy of the survey depends on, however, how close the lines are set. To get homogenous statistics of an entire country, the survey should not span over too long a period. Thus, the distance between the lines should be chosen wide enough to give accurate results quickly for the whole country, while accepting slightly less exact results for its smaller districts.
If line survey is performed on large areas, it is not possible to count and measure trees, measure the tree growth. etc. along the whole length of the line because of its costs. Therefore, more precise measurements are limited to sample plots, which are spaced evenly along the lines. Between the sample plots, the volume and growth of each stand touching the line are estimated visually. These visual estimates have often systematic faultiness, which can be eliminated with correlation calculations. Visual observations gather information, for instance, about land owner, soil type, land-use class, forest site type, tree species and age class of the stand, density, wood volume ja annual growth per hectare, and the current silvicultural state of the stand. With help of this kind of information it is possible to get sufficient statistics about the forest resources of a country.
A summary in Finnish is included in the PDF.