Analysis of experimental thinning management options in the Taiga Model Forest area

Transcription

1 Metsätieteellinen tiedekunta Faculty of Forestry Analysis of experimental thinning management options in the Taiga Model Forest area Vadim Goltsev 2005 Final Thesis of MSc in European Forestry Joensuu

2 2 Acknowledgements I am extremely grateful to my supervisors Prof. Paavo Pelkonen and Prof. Taneli Kolström for their scientific support, valuable advices and for their patience during the study. Implementation of this study was possible thanks to the great opportunity that was given to me by the University of Joensuu, the Master of European Forestry program and by the Finnish Forest Research Institute. I thank Prof. Timo.Karjalainen, of the Finnish Forest Research Institute for his comprehensive support of this study. It has been a great pleasure and a priceless experience to work in the research team of the Finnish Forest Research Institute. I wish to thank my third supervisor researcher Timo Leinonen, of the Finnish Forest Research Institute, who collaborated with me through all the scientific hardship and provided me with invaluable assistance and support. I would also like to thank Dr. Kari T. Korhonen, the Finnish Forest Research Institute, for his help in calculations of timber volume. I thank researcher Yuri Gerasimov of the Finnish Forest Research Institute for his advises. Special thank to Mr. David Gritten and Mr. Blas Mola, for their friendly support through all my studies, to all my friends and colleagues This study has been financially supported by the project Intensification of forest management and improvement of wood harvesting in Northwest Russia (project ) as a part of the Academy of Finland research programme Russia in Flux.

3 3 1. INTRODUCTION The Taiga Model Forest project Intermediate felling The Russian instructions of intermediate felling Allotment of forests for intermediate felling Organization of cutting area Selection of trees for intermediate felling Technology Terms of performance the intermediate felling Control of effectiveness and quality of the intermediate felling Current situation with intermediate felling in Russian Federation The Finnish instructions on intermediate felling General regulations Terms and kinds of cutting The Swedish instructions on intermediate felling Aim of the study MATERIALS AND METHODS Location of the experimental territory Inventory of the model forest Processing of the inventory data The inventory results The experimental method Scheme of an experimental plot Structure of the experiment Problems Implementation of the thinning Distinctions between the Swedish and Finnish thinning Quality of the performed intermediate felling.. 28

4 Productivity of the intermediate felling Calculation of stock of timber on the sample areas of the Taiga Model Forest Ground vegetation of the model forest Characteristics of performed thinning and results of inventory of ground vegetation cover on experimental plots 50/1 and 50/ RESULTS Comparison of the Russian, Finnish and Swedish systems of intermediate felling Qualitative evaluation of performed thinning Comparison of prime cost of cuttings in the Russian Federation and Finland Analyses of timber assortment structure of timber removal Influence of the thinning on ground vegetation Comparison of the results with the other study of changes of ground vegetation Influence of forest management on number of species Influence of forest management on coverage of plant species Volume of timber on the experimental areas DISCUSSION AND CONCLUSIONS 58 Appendix.. 61 Appendix 1. Description of the sub-projects of the Taiga Model Forest project. 61 Appendix 2. Principles and criteria of the Forest Stewardship Council, which are related to timber harvesting.. 62 Appendix 3. Sub-project Economic sustainability and appropriate technology REFERENCES. 65

5 5 1. INTRODUCTION The Taiga Model Forest project The Ministry of Agriculture and Forestry in Finland, Enso Ltd. (now StoraEnso Ltd.) and United Nations Environmental Program established the Taiga Model Forest project in the beginning of 1997 (Kolström and Leinonen 2000). The State Forest Committee of the Republic of Karelia supported the Russian dimensions of the project. The project was a part of the Finnish-Russian Development Program on Sustainable Forest Management and Conservation of Biological Diversity in Northwest Russia. The University of Joensuu, Forest and Environmental Group ltd., the State University of Petrozavodsk and the Research Institute of the Republic of Karelia oversaw the practical implementation of the project. Russian Karelia was chosen as the site for implementation of the project (Fig 1). Taiga Model Forest area Fig. 1. Location of the Taiga Model Forest (Leinonen et al 2000)

6 6 In this region of Russia, forest environment, forestry and forest industries have the most important meaning for ecological, economical and social conditions. Therefore it is particularly significant to develop sustainable forestry to provide a high level of multifunctional utilization of forest resources of the region and at the same time to improve social and ecological functions of the forests. The Taiga Model Forest project was planned as an instrument of multilateral study of relations between forestry, economics and society in the Republic of Karelia and to promote the most modern forestry technologies. The main aim of the project was to study economic, ecological and social effects of forestry on a local level in the Matrosy forest area to meet the requirements of sustainable forestry. The project was divided into the following subtasks: to study economical sustainability of forestry and to develop forest management and harvesting methods for the local area; to study social sustainability of forestry and the interaction between local people and forestry and to organize multiple use of the local area; to study ecological sustainability of forestry and to analyse biodiversity of the model area and its neighbouring areas; to develop an efficient information system for the project as a part of the strengthening of institution involved with the project and improvement of forest education The forest area of 2465 ha was leased around Matrosy village close to Petrozavodsk for the establishment of the model forest. To solve the problems, the project was divided into six sub-projects in compliance with the above tasks, (for description of the sub-projects see the appendix 1). During the project great attention was paid to intermediate felling as an instrument of sustainable forest management Intermediate felling Intermediate felling is widely spread and plays an important role in forestry of many countries. In 2003 in Finland intermediate felling accounts for 67% of total area of cuttings (Finnish Statistical Yearbook of Forestry 2004). Such widespread thinning would be impossible without scientific basis of their application and detailed

7 7 investigations of all aspects of the intermediate felling. In Fenno-Scandinavia and in Russia, great attention is also spared to the studying of different questions of development and application of intermediate felling. Saramäki, et al (1997) reported that there are 534 different research papers related to thinning, published in the Fenno- Scandinavia and Russia. The most studied aspects of intermediate felling are economical and technical questions, influence of thinning on forests and wood quality, causes and peculiarities of damage to the remaining trees after implementation of intermediate felling. A significant amount of research activity in the field of intermediate felling brings positive results. In Sweden, for example, during eight years ( ), the degree of mechanisation of thinning increased from 10% to more than 60% and at the same time the average frequency of damages to the remaining trees during processor thinning decreased from 14% to 7.5% (Fröding 1992). In Fenno-Scandinavia, the wide application of thinning to satisfy the needs of the forestry industry is justified, because regular thinning allows the avoidance of natural mortality of stands; furthermore early revenues and faster growth of diameter are obtained (Mielikäinen 1991). Some researchers present the following data: the selective thinning from below increased average volume by 10 30%, mean diameter by 5 14% and height 2 7% (Isomäki and Väisänen 1980). Moreover, thinning has influence on mechanical characteristics of timber, for instance, such as wood density. Moskaleva and Porotov (1982) investigated density of wood in 33 years pine stands where thinning was performed 18 years ago. In general the wood density increased by 7% compared with the density before thinning. The changing of a forest s characteristics by thinning is possible because of influence of thinning on the forest ecosystem as a whole. One of the principal parts of a forest ecosystem is the forest microclimate and it changes very often as a result of thinning. Decreasing of density of the forest canopy after thinning causes increasing of the sun s radiation under forest canopy, as a result, temperature of air and soil rises (Nefedova et al 1993). At the same time intermediate felling can cause some negative changes in forest ecosystems from a forestry point of view. Regular thinning increases the washing of nutritious elements from the humus layer of forest soil downwards away from active roots (Melnitskaya et al 1989), but the main negative factor of thinning is damages

8 8 caused to the remaining trees. Frödig (1992), showed that for different methods of thinning the average damage frequency is 5.3%. Damages reduce the quality of remaining wood and moreover, a large quantity of damaged trees can result in the rapid expansion of some dangerous fungus species, for example, root rot fungus, such as Fomitopsis annosa (Swedjemark and Stenlid 1993). The above described aspects of intermediate felling have been studied for a long period. However, in view of the fast development of international cooperation in the field of forestry, new research adds to the mentioned above aspects. Some countries, such as Finland and Sweden, are exporters of the newest forestry technologies, but for the efficient application of the exported technologies, a lot of problems have to be solved. These problems related to distinctions in the productivity of labour, in approaches to forest management, in forestry standards and legislation of different countries. To find a solution of some modern problems of forestry the Taiga Model Forest Project was established in North-west Russia The Russian instructions of intermediate felling Intermediate felling in Russia is regulated by special instructions, which are provided by the Ministry of Natural Resources of the Russian Federation. Each region of Russia has its own rules regarding intermediate felling. The rules are based on instructions and standards, which are common for the whole of Russia. In accordance with the instructions, the intermediate felling is one of the main management tools applied to form forests for economical, ecological, social and protective purposes (Nastavleniya po rybkam ykhoda 1995). The correct application of the intermediate felling allows the improvement of tree species structure and the wood quality of the forest, increasing stability of the forest ecosystem, to maintain and to strengthen the ecological functions of the forest, to increase the volume of forest usage and to accelerate the reception of valuable timber. Depending on the age of forest, the Russian system of intermediate felling is divided into three types of cutting: Young stand tending (until the age of 20 years). Tending is especially important, because it puts a basis of the future forest. According to current forest condition cutting

9 9 is implemented to remove trees of non-essential species, to decrease forest density and to arrange the allocation of trees on the forest area. Thinning of middle-age stands (from the age of 20 till 50 years). The cuttings are carried out at the time of intensive formation of the forest structure and therefore it has a significant role. In the Republic of Karelia, the instructions of intermediate felling is pointed to increasing of wind resistance of stands (it is especially important for spruce forests), selection of perspective trees and creation of the best conditions for growing of those trees as the main task for this cutting. The right selection of perspective trees allows get high-quality forest in the future and increases effectiveness of an accretion cutting, as in this case, consequent selective cutting can give relatively large-scale timber. During implementation of the intermediate felling useless, damaged by insects and diseases, low-quality trees have to be removed. In coniferous mixed forests with a significant part of deciduous the cutting is carried out more intensively at the expense of deciduous species. Thinning of maturing stands (older than 50 years). The main task of this cutting is the creation of the best possible conditions for growing valuable tree species to obtain prescribed forestry aims in the future. In mixed forests in case of competent performance of the intermediate felling is possible get a profit due to cutting of timber of the best deciduous trees. The Russian system of intermediate felling has two kinds of cutting, which are used sometimes as separate operations - sanitary felling is directed to control the sanitary conditions of forests, and pruning operations. Implementation of the sanitary felling is needed to improve sanitary state of forests by removal of trees damaged by insects or diseased and dead trees. The cuttings are divided into two types selective and sanitary clear cuttings. The aim of the pruning operations is to get a high-quality saw wood in the future Allotment of forests for intermediate felling A state forestry body (leshoz) designates implementation of intermediate felling after inventory of the forest area. The possibility to prescribe thinning, if basal area per hectare or number of stems has exceeded the values are shown in the table 1.

10 Table 1. The values of basal area, m 2 and number of stems, 1000 per ha Quality of Age locality* Pinus silvestris II -/ / / / / /0.7 III -/ / / / / /0.9 IV -/ / / / / /1.1 Picea abies II -/ / / / / /0.8 III -/ / / / / /0.9 IV -/ / / / / /1.0 Betula pendula II -/ / / /0.6 III -/ / / /0.7 * - there are 5 classes of quality of locality, the 1 class means the best growth condition and the 5 means the worst. The inventory of thinning plots is carried out in accordance with the Nastavleniya po otvody The volume of timber removal is calculated in conformity with standards of the intermediate felling on basis of measuring of absolute density. Intensity of cutting of timber during the intermediate felling can not exceed 40% of the wood stock in pure forests, 50% in mixed forests and 30% for selective cutting Organization of cutting area Borders of plots and scheme of road network are marked up on a territory of cutting area before implementation of intermediate felling. It is desirable to use old roads and free space between trees during creation of road and strip road network to reduce negative impact on a forest. A system of forest roads and strip roads have to be built so as to assure uniform intensity of the intermediate felling on the whole territory of cutting area Selection of trees for intermediate felling Selection of trees for the cutting is carried out in advance on basis of demonstration areas, which are examples for performers of the thinning. Selection of trees on the demonstration areas is performed under guide of a high-professional expert. Square of the demonstration areas is 2 5% of cutting area. Further, intermediate felling can carry 10

11 11 out without presence of experts if performers of the cutting have a sufficient qualification. Before a beginning of the cutting, a plan of the intermediate felling and technological scheme, which regulates all aspects of the cuttings have to be done Technology First of all, selection of technology for the intermediate felling in conditions of Russian forestry depends on amount of allotted money for the cuttings and availability of forestry machinery as well as on characteristics of forests and development of road network. The instructions recommend choose such kind of cutting technology that allows achieve a task of the intermediate felling with minimal inputs. The instructions advice use for the intermediate felling and accretion cutting cut-to-length or tree-length technologies. A feller plus a forwarder is the most used scheme for cut-to-length technology and a brigade of chain-saw operators plus a skidder is commonly used for tree-length technology. In most cases, a feller with a chain-saw is necessary on a cutting area to perform pruning and to remove trees, which are unavailable for machinery, even if a harvester is used for cutting. Timber has to be cut and skidded with the minimal possible damage of remaining trees, root systems and plant ground cover. Cutting area is cleaned according to used cutting technology, forest conditions, at the same time with felling and logging. There are four recommended methods of cleaning: Piling the branches on strip road; Piling the branches on cutting area: Collection and incineration the branches on glades Pounding and dispersion the branches on plots Terms of performance the intermediate felling According to demands of the instructions, the intermediate felling has to be implemented during twelve months after allotment of the forest area for the cutting. Young stand s tending can be carried out during the whole vegetation season. The intermediate felling can be performed during the whole a year. The exception for this is the intermediate felling in spruce forests, where it is forbidden during the first half of summer.

12 Control of effectiveness and quality of the intermediate felling Consequences about effectiveness of the intermediate felling are made on basis of comparison inventory data of plots where the cutting was not performed and inventory of the whole cutting area. The control of quality is carried out during a visual inspection of a cutting area. It includes an evaluation of current density of the forest, accuracy of selection of trees for the cuttings and estimation of caused damage to forest during the felling Current situation with intermediate felling in Russian Federation In view of several reasons, as lack of money and low quality of timber, intermediate felling in Russia has no such wide application compare to Fenno-Scandinavian countries. Only 12 percents of total cut timber volume were stoked by intermediate felling during 2002 year (The state report, 2004), but because of large size of annual allowed cutting, that volume is big enough. Volumes of timber, which were cut by intermediate felling during 2002, are presented in the table 2 (The state report, 2004). Table 2. The volume of intermediate felling in Russian Federation during 2002 year Cutting Area, 1000 ha Volume of commercial timber, 1000 m 3 The timber volume, % of total stocked timber Young stand tending Thinning Accretion cutting Selective sanitary felling Renewal and reforming cutting Total In generally, Russian forestry is based on forest methods and technologies, which have been worked up in the former USSR, and therefore Russian forestry has all traits, which were peculiar to forestry of USSR.

13 13 Creation of economically high-value forests to get the maximal profit was the main aim of forestry in former USSR and now it is the supreme aim of Russian forestry, because of the economical situation. Maintenance and improvement of social, ecological and protective functions of forests are secondary aims. In the former USSR, a system of intermediate felling was developed to increase an economic value of forests. It has been obtained by forming of forests, which included only economically valuable tree species. Very often, such forests consisted of one tree species only and had equable age-class distribution. The same kind of thinning system is used now in Russia. Instructions on intermediate felling (Nastavleniya po rubkam ukhoda 1995) of the Republic of Karelia define aims of thinning as directed on improvement of species composition, increasing quality and stability of forests, maintenance and strengthening forests ecological functions and increasing of forests productivity. These demands are close to some common international regulations of sustainable forestry, but the instructions on intermediate felling have no practical recommendations, which are directed to improving of ecological, social and protection function of forests. For different forests groups, which have different aims in forestry, the same instructions of intermediate felling are used. Moreover the same methods are used for different aims. However, if in the former USSR intermediate felling was performed with observance of instructions and during these cuttings low-quality, damaged and low valuable trees were removed. Due to of it, profitability of future cuttings was increased. Nowadays in modern Russia thinning often is used not according to the instructions and the best, high quality trees are removed in the first place. It is possible to confirm by following. In USSR yield of thinning included less than 40% of commercial timber, but nowadays in Russia this index can reach 90%, which is greatly more than for clear cutting (Yaroshenko 1999) Such kind of cutting causes substantial harm to Russian forests, because thinning is permitted in all groups of forest. Under the guise of thinning, cuttings are directed on harvesting the most valuable timber are used to cut timber in water protection, soil protection and recreation forests where final felling is prohibited. These cuttings lead to significant decreasing of forest quality, deterioration of stability of forest ecosystems and lessening of protection functions of forests (Yaroshenko 1999). Such application of intermediate felling spreads widely not only in the Republic of Karelia, but also on the all territory of Russia. A striking example of results of such cutting is the experimental plot

14 14 no. 1 of the Taiga Model Forest Project ; where a Russian harvesting company performed thinning mainly as corridor thinning and by removal of the best quality pine trees between the strip roads in defiance of the instructions on intermediate felling (Kiljunen et al. 2000). Application of Scandinavian technologies of intermediate felling by Russian performers cannot improve the situation, because of their low qualification. It was confirmed by the thinning on the plot no. 2 during the Taiga Model Forest Project. It is possible to show many reasons, why intermediate felling is not efficient in Russian forestry now. The first reason and maybe the main one are imperfection of Russian forestry legislation and absence of effective control system for implementation of thinning. Second problem follows from the first one. Russian forestry legislation provides only two possibilities for harvesting companies to get forest areas in use. It is lease of forests and a forest auction. The most of harvesting companies lease forest areas from the state. The maximal duration of lease contract is 49 years, but the most of the contract is concluded for several years only, as a result of it, many Russian harvesting companies are interested in profit earning as soon as possible. They have no reasons to make long-term investments in forests. Therefore they are not interested using of different models of sustainable forestry and in correct application of intermediate felling. The solution to this problem is to improve the forestry legislation and to create an independent system of forest control. Next problem is imperfection of instructions on intermediate felling. It was developed in the former USSR only to increase timber quality and timber volume before clear-cutting. Maintenance biodiversity, protection functions of forests and stability of forest ecosystem are proclaimed, but in reality it is not an important aim of thinning (Grigor ev 2001). One of the most significant problems is not related to intermediate felling only, but it concerns to all Russian forestry. It is a question of low level of forestry education of forest workers in Russia. Foresters often have no forest higher education, for instance, in one of the most developed forestry region of Russia the Republic of Komi, less than a half of foresters have forest higher education (Problems of sustainable development of forest ) These problems have to be solved as soon as possible, because successful development of forestry in Russia is impossible without solutions of these

15 15 problems. To increase level of forestry education it is necessary to widen international cooperation in field of forestry. For Russian forestry it is very important to improve quality of education and to develop international forest research projects such as Taiga Model Forest Project The Finnish instructions on intermediate felling General regulations The thinning cuttings were performed on two experimental plots of the Taiga Model Forest Project in accordance with instructions of Finnish Company Enso Ltd.. These instructions are based on the recommendations of the Tapio Centre on development of Forestry (The recommendation on silviculture in North Finland) and Forest Act of the Finnish Ministry of Agriculture and Forestry (The Forest Act, 1997). These documents define intermediate felling as cuttings, which are directed on increasing of timber quality and increment to raise profitability of future cuttings. The recommendations place high emphasis on problems of conservation of biodiversity during implementation of intermediate felling. Also it is recommended to perform thinning to use forests not only for timber harvesting, but for ecological and sociological purposes as well. Therefore, old trees, deciduous trees and brushes, which do not prevent good growth of main tree species, have not to be cut during a cutting Terms and kinds of cutting Finnish system of intermediate felling includes several kinds of cuttings. The cuttings subdivide into young stand s tending (clarification and thinning), pruning, thinning and sanitary cutting depend upon age of a stand and aims of thinning. Intermediate felling is carried out accordingly to the standard models are based on density of forest. Depending on local forest condition, thinning can be performed with different intensity of cutting. For instance, it is recommended to implement thinning with the minimal intensity in pine and spruce forest plantations or in forests, which were damaged by a storm. There are several thinning models for different part of Finland, that allows fulfil thinning at the most appropriate time for local conditions. During the cutting, principal concern has to be given to preservation of understory trees. Terms of thinning are defined on models of thinning. The models have been worked up depending on tree species and

16 16 types of forest soils. On basis of the models it is possible to estimate necessity in thinning and determine intensity of thinning. Feature of these models is they are more suitable for managed forests than for forests are thinned never. There are five models three for pine forests, one for spruce forests and one for birch forests. Depending on current conditions, implementation of intermediate felling can begin when a young stand only starts to form. The first cutting is a cutting of overstory, if it has old trees, which prevent to normal development of young trees. It is recommended to perform tending of young stands. The aim of it is removing all barriers for normal growing of young trees. During the cutting deciduous understory trees have to be cut if it prevents to develop of chief species. At the same time some quantity of deciduous trees can to be left for maintenance of biodiversity. Thinning of young stands is directed on speeding-up of growth of perspective trees. During implementation of thinning in young stand the best trees are left for subsequent cuttings, damaged and unpromising trees are cut. To decrease costs of intermediate felling in young stands, it is recommended to leave low productive plots of forests without treatment. When young stands have achieved appointed height, the cuttings are carried out. Each tree species are thinned to the recommended density for. Observance of terms of thinning and isolation is important because growing of trees in a dense young stand increases quality of trees until appointed time and early thinning can damage young trees. However, it is recommended to curry out the cuttings even if the pointed at the instructions time is passed. The next stage of intermediate felling is especially important from production point of view. When upper height of forests is m for spruce and m for birch forest, it is recommended by the instructions, to carry out thinning of the forests. At this age, forming of forests ecosystems is going and therefore, to leave admixture of other trees species and to keep old trees, to damage ground vegetation cover as less as possible are particularly important during thinning to maintenance biodiversity. The aim of thinning is to give more possibilities to the best trees for its growth. Thinning allows increase the quality and increment of timber. During thinning slowly grown trees, low quality, damaged and sick trees have to be cut. The cutting can be profitable if previous intermediate felling was performed.

17 The Swedish instructions on intermediate felling On two experimental plots of the Taiga Forest Model Project thinning cuttings were performed in accordance with instructions of Swedish Company Stora Ltd., which are based on Swedish thinning models and on recommendations and principles of the Swedish Forest Stewardship Council Working Group. These instructions are worked up in accordance with standards of the Forest Stewardship Council (FSC) ( For more detail information about principals of FSC see the Appendix 2. Swedish thinning models have no principal distinction with the Finnish one. FSC is an independent international organization. Its aim is to support ecological responsible, social efficient and economical stable forest management. The Swedish FSC Working Group is a local representative office of the FSC, which adapting standards of the FSC for Sweden. Recommendations and criteria of the Swedish FSC Working Group have been worked up in Sweden since 1996 with the aim to develop and to support sustainable forestry by voluntary forest certification. FSC certificate is given to a timber company or a forest owner, which activity meets the requirements of FSC Aim of the study Studies, which have been done during the Taiga Model Forest project is a very suitable base for comparison of the intermediate felling. Implementation of the project has allowed collect a lot of information, which has to be processed and analysed to get valuable knowledge about effectiveness of thinning and its influence on forests. Some data were not processed and analysed earlier. The timber volumes before the treatments and timber assortment structure of timber removals were not calculated and analysed then, although that information is quite valuable, because it allows draw some conclusions about the structure and quality of forests. Moreover, the management plan of the project provides for re-measure of the experimental plots in autumn 2004 spring 2005 to see results of impacts of the different thinning systems on the forest in 5 6 years after the treatment. These data could be used efficiently only if available now information will be processed.

18 18 The main aims of the study are: 1. to compare three thinning operation systems, which are: Finnish forest certification system and silvicultural recommendations of Enso Ltd.; Russian rules of thinning cutting; Cutting instructions of Stora Ltd. and standards of the Swedish Forest Stewardship Council Work Group; 2. to calculate timber volumes by tree species before treatments 3. to analyse timber assortment structure of thinnings; The additional aims of the study are: 4. to compare prime costs of cuttings in the Russian Federation and Finland 5. to evaluate influence of thinning on ground vegetation cover of the experimental plots; 6. to compare results of the evaluation with another study on changes of ground vegetation cover; 7. to suggest the follow-up and utilization of the experimental plots.

19 19 2. MATERIALS AND METHODS Location of the experimental territory The territory of the Taiga Model Forest Area is located on a forest area, which was rented for 20 years by the Petrozavodsk State University. Total area of the rent plot is 2447 ha out of which 2235 ha are forestlands (Leinonen et al. 2000). The area is located close to the village Motrosy in Pryazha district, the Republic of Karelia (Fig. 2). Fig. 2. Map of the Taiga Model Forest (Leinonen et al 2000) Inventory of the model forest The inventory of the experimental forest was performed twice. In undergraduate students from Evo Forest College (Finland) implemented the inventory.

20 20 No aerial photographs were available at the time of the inventory. Therefore, inventory method of linewise relascope plots was chosen to carry out the inventory. Inventory was done on basis of inventory areas. An inventory area had size m and they were divided on 6 inventory lines of 5 m of width (Fig. 3). 30 m 25 m Line Y, 30 m 20 m 15 m 10 m 5 m 0 m Fig 3. An inventory area Line X, 30 m On the inventory lines, height and diameters of a stem on height of 1.3 m and 6.0 m were measured for all trees. Geographical coordinates of trees were determined by tools of the Global Positioning System to make maps of the model area. In 1998 the inventory was carried out by Russian inventory methods according to the 1 1a rank of forest inventory. Results of the both inventories are presented in (Leinonen et al. 2000) Processing of the inventory data The computer programs were used widely to process the inventory data and to analyze it. The stand characteristics were transformed into a planning program Monsu (Pukkala 1998) to work up a forest management plan. The XFOREST mapping program was used to draw the forestry maps.

21 The inventory results Some results of the Finnish inventory are presented below. Timber volume per 1 hectare is quite high and it allows thin intensively the stands. Table 3. Quantitative characteristics of the experimental forest Quantitative characteristics, m 3 Per 1 hectare of Total forestland Total stem volume Annual gross growth Natural mortality Net annual increment Natural origin forests of middle age class are presented the biggest part of forests on the experimental area (Fig. 4) , Area, ha ,6 249,4 Stages of stand 337,3 Open area Sapling stand Pole stand Middle-aged Mature forest Fig. 4. Age structure of the forests, ha

22 22 The rented forest area has uneven age distribution. However, this forest area meets the requirements of the experiment very well, as middle age forests occupy the biggest part of the forest area. This age is the most convenient for implementation of thinning, because at that age it allows to achieve significant positive results (Sennov 1993). Spruce and birch are the dominant tree species of the area (Fig. 5). The stands have quiet low quality, share of pulpwood amounts for 65% of total volume (Fig. 6) Pinus Picea Betula Other Fig. 5. Distribution of timber volume by tree species, m 3

23 Sawlog Pulpwood Other wood Fig. 6. Timber assortment structure, m The experimental method The approach Before After Control Impact was used in the experiment to compare the different thinning systems (Leinonen et al. 2000). To define exactly influence of the different systems of intermediate felling the experiment requires that no action be taken in the experimental areas. Also, this method needs careful inventory of the forest area before and after thinning. Comparison of results of the inventory before and after cutting will allow determine influence of the thinning on the forest.

24 Scheme of an experimental plot The main structural element of the experiment was an experimental plot of thinning. The size of the experimental plots was 4 9 ha, but area of actual impact was only 1 ha. The rest is a border zone and a buffer zone, which protect the impact zone from other treatments. The structure of experimental plots is presented on Fig Buffer zone - Experimental area - Area of actual impact m Fig. 7. The scheme of an experimental plot

25 Structure of the experiment On the experimental area 31 experimental plots were established, of which 21 plots had to be thinned. Coniferous tree species are dominant on 16 plots and deciduous species dominate on 12 plots of 26. Such number of the experimental plots was established to guarantee reliability of results of the experiment. The graphical scheme of the experiment is presented in Fig. 8. Four treatments Russian Finnish Swedish Control 1 Replications of coniferous plots 2 meat meat Replications of deciduous plots 2 3 Fig. 8. The scheme of the experiment

26 Problems In the experiment on thinning accordingly to the Finnish and Swedish recommendations the research team met difficulties. The most important problem, from the point of view of accuracy of the experiment, was that the recommendations include thinning models, which have been worked up for managed forests. However, in the Taiga Model Forest area, at least some of the thinned experimental plots were managed never. Therefore there were several plots with a large number of rather tall but small-diameter trees growing by compact groups. In these conditions, it was difficult to use the thinning models, because average height of the trees did not correspond to the basal area of the thinning models. In such cases a feller had to use his knowledge to decide how much to cut. It could introduce some subjectivity in the experiment Implementation of the thinning Thinning operations were performed on eight experimental plots on the model forest area during 1998 and 1999 and on three plots in 2000 (Kiljunen et al. 2000). Different cutting methods were used in the course of implementing of the thinning. Inventory of damages due to the thinning was performed in August 1999 in accordance with instructions of Tapio, Finnish Forest Centre. The intermediate felling was done by Russian performers on logging area 1 and 2 without supervision of the Taiga Model Forest experts and it gave important data from practical point of view, because it allows draw some conclusion about actual quality of implementation of thinning in the Republic of Karelia. Some characteristics of the logging areas are shown at the table 4. Logging area 1. The thinning cutting was performed by a Russian logging company procuring timber for a local sawmill. Tree-length technology and chain-saws were applied to implement the cutting. A Russian skidder TDT-55 executed logging of timber to a loading site. On the loading site bucking of trees was performed. Distance between skid roads was 40 meters. It was detected during the inventory of damages on the cutting area that on the thinning was done mainly as corridor thinning and by removing the best-quality pine trees on swaths. Essentially it was a selective cutting of the best-quality trees but not thinning. It is possible to say that influence of implemented cutting on the forest will be negative.

27 27 Removal of the best pine trees will cause decreasing of potential quality and productivity of the forest on this plot. Logging area 2. Forest workers of a local forestry school performed the thinning. The selection of trees for thinning was done evenly on all diameter classes. During the inventory after the cutting, it was found out that the felling was implemented unevenly and the most of cut trees have big diameters, though the plan of the thinning assumed the more intensive cutting of trees of small diameter classes. At the same time, many selected trees for the cutting, were not cut. Performers of the cutting asserted that Scandinavian cut-to-length method was used to thinning the plot. However, no typical features of this technology were found. Trees were cut toward the strip road with following branching and bucking. Pilling of bolts was not done. Skidding was difficult because of hard landscape, gathering of wood-waste on the skid roads and mixture of cut tree species. Logging area 50/6 and 50/8. The thinning on these experimental plots were performed in compliance with the instructions on intermediate felling of Swedish Stora Ltd., which meet requirements of the Swedish forest certification system of Forest Stewardship Council. The difference between the two experimental plots is methods of selection of trees. A forwarder was used for skidding of bolts to the loading site. Logging area 50/6 was quite wet on some parts of the area and as the skidding was performed after the frost season, a wheel gauge appeared on the strip roads. It could have been avoided by operation at wintertime. Logging area 50/10. The thinning operation was implemented in compliance with the Russian instruction of intermediate felling. The cutting was performed under the supervision of a forest institute researchers. Chainsaws were used to fell trees and a Russian skidder TDT-55 was used to skid. Distance between the skid roads was 40 meters. All wood-waste was cut to 1-meter pieces after the cutting and bunched or carried to the strips roads. Logging area 50/3 and 50/4. A Finnish contractor of the project performed thinning of plot 50/4 by Kindai H8 harvester and Kindai S12 forwarder. The cutting was performed in accordance with the same instructions as the thinning on the plot 50/6. On area 50/3 the same machinery and the Finnish instructions were applied.

28 28 Logging area 50/1. Russian logging brigade of the Petrozavodsk State University thinned the plot in compliance with the Russian instructions. Quantitative characteristics of the two plots are presented in the table Distinctions between the Swedish and Finnish thinning The plots no. 50/4 and 50/6 were thinned on basis of Swedish system of intermediate felling in the same way as the Finnish thinning, with only some distinctions. So, for these plots it was permitted to build a strip road through a centre of the sampling areas, but a main skid road was built outside of a centre of the sample areas. The recommendations of the FSC, did not allow cut the biggest trees on the experimental plots. Big cedars (Juniperus), hollow trees, burned trees and significant as cultural heritage trees were left on the plots. Biotopes were marked out in protection belts. In the areas dominated by deciduous tree species, it was not recommended to thin plots, where a share of Populus tremula is big and to thin stand, where a part of coniferous is less than 50%. For coniferous forests with admixture of deciduous it was recommended to leave less than 20% of deciduous trees in species composition of the stand after thinning Quality of the performed intermediate felling The table 4 presents qualitative characteristics of the performed thinning. The data of the table is good regard to some previous research. Investigation of Frödig A. (1992) showed that for different methods of thinning the average damage frequency is 5.3%. For the chain-saw method it is 3.0%, in forests where a processor was used the average damage frequency is 7.5%, the average damage frequency is 5.9% in stands where grapple-harvesters and the tree-selections method was used.

29 29 Table 4. Some characteristics of the cuttings (Kiljunen et al. 2000) Numbers of the cutting plots System of thinning Logging methods* /6 50/8 50/10 50/4 50/3 50/1 Russian Scandinavian Swedish Finnish Russian Swedish Finnish Russian TL CTL CTL CTL TL CTL CTL TL Machinery TDT-55 TJ 1010 Average width of strip roads Standard deviation Percentage of damaged remaining trees Valmet 862 Valmet 862 TDT-55 Kindai H8, S12 Kindai H8, S12 TDT Average size of stem damages, cm 2 Average height of stem damages, dm * TL tree-length method; CTL cut-to-length method On the experimental plots during the analysis of the implemented cutting it was found out that the remaining trees had damages in different parts of the stems depending on the applied technology of cutting and machinery. When the tree-length method was used, the remaining trees were damaged in the lower parts of the stems and on the contrary the remaining trees had damages on the higher parts of the stems when the cut-to-length methods was used, especially it was visible well on the plots where the cut was performed by a harvester. The remaining trees had the maximum average size of damage on the plots no. 50/6 and 50/8. The plot no. 1 has the least percentage of damage of the remaining trees due to very wide skidding roads. On this plot was shown one of the most-used nowadays methods of harvesting in the Republic of Karelia (Yaroshenko 1999). It confirms that sometimes, Russian logging companies use thinning to get profit by the cutting of the best trees to the prejudice of future final cutting.

30 Productivity of the intermediate felling Intermediate felling is one of ways to organize continuous use of forest resources and organization of an efficient forest management was one of the main aims of the Taiga Model Forest Project. To solve the task, first of all was necessary to find an appropriate technology of intermediate felling, which will meet the requirements of current conditions and will assure the best economical, social and ecological effect. On the experimental plots intermediate felling was fulfilled in accordance with Finnish, Swedish and Russian instructions to compare the systems and to choose an appropriate technology. In the course of the implementation of the thinning, information about productivity of the cutting was obtained. As number and area of the experimental plots were quite small, it is impossible to draw conclusions about influence of the cutting areas characteristics on productivity of the cutting on basis of the obtained data. Comparison of productivity of the thinning was performed for two technologies: cut-tolength and tree-length ones. Chainsaws were used to cut trees in the course of the treelength technology. Productivity of the logging work in this case was about 3.5 m 3 per an hour that is almost two time less in comparison with productivity of a harvester for the same condition (Kiljunen et al. 2000). Obviously harvester cuttings are more productive, but at the same time it is more expensive in comparison with saw cuttings. The productivity of forwarding operations was the same Calculation of stock of timber on the sample areas of the Taiga Model Forest Volumes of timber were calculated for the 39 sample areas. For each tree species separately. A sample area has size m 2. On the sample areas height of a stem and diameter of a stem on height of 1.3 m were measured for all trees are higher 4 m, diameter on height of 6 m was measured also for trees are higher than 6 m. The diameters of trees were measured in accuracy of 1 mm and height in 1 decimetre. The following equations, which are commonly used in Finland, were used to calculate volumes of timber: for Pinus silvestris (Laasasenaho 1982): V = f (d 1.3, h) V = d ( ) d1.3 h (h 1.3) (1)

31 31 V = f (d 1.3, d 6, h) V = d d h d h d h (d d 1.3 d 6 + d 2 6 ) d 2 6 (h- 6) (2) for Picea Abies (Laasasenaho 1982): V = f (d 1.3, h) V = d ( ) d1.3 h (h 1.3) (3) V = f (d 1.3, d 6, h) V = d d h d h d h (d d 1.3 d 6 + d 2 6 ) d 2 6 (h-6) (4) for Betula pendula, B. pubescens, Sorbus, Salix and Padus (Laasasenaho 1982): V = f (d 1.3, h) V = d ( ) d1.3 h (h 1.3) (5) V = f (d 1.3, d 6, h) V = d d h d h d h (d d 1.3 d 6 + d 2 6 ) d 2 6 (h-6) (6) for Populus tremula (the equations are not published): V = f (d 1.3, h) V = EXP ( Ln(d 1.3 ) Ln(h) Ln(h - 1.3) Ln( d 1.3 )) (7) V = f (d 1.3, d 6, h) V = d d h (d d 1.3 d 6 + d 2 6 ) d 2 6 (h - 6) (8) for Alnus (Mäkinen 1984): V = f (d 1.3, h) V = EXP ( Ln(d 1.3 ) Ln(h) Ln(h - 1.3) Ln( d 1.3 )) (9) V = f (d 1.3, d 6, h) V = d h d (d d 1.3 d 6 + d 2 6 ) d 2 6 (h - 6) (10)