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  • Author: Henn Korjus x
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Abstract

Changes in the society have created a need for a systematic approach in forestry combining forest management, timber harvest analysis, research and demonstration of new technologies. A research and demonstration area is an option for explaining and visualising frameworks of forest design, modelling and planning in the real nature. A research and demonstration area of forest management planning can be defined as a forested landscape that combines various forest uses and aims to ensure and explain forest management strategies as well as conservation of ecosystems and natural resources. A suitable area for creating the research and demonstration area of forest management planning is at Järvselja Training and Experimental Forest Centre in Estonia. It has naturally diverse forests and these include also habitats of several rare and endangered species and already comprise different sets of nature conservation areas. The centre has been used for forestry higher education and research for over 90 years and therefore all essential infrastructure has been developed including dormitories and lecture rooms for field training as well as different nature paths, old field experiments (e.g. initial spacing and thinning experiments) and new modern research facilities. Forest management plans and inventory data since 1922 still exist for the area. The area at Järvselja is expected to demonstrate present studies and research work in the most comprehensive way as well as the implications to forest management and the newest technologies in forest management and planning. Different systems and techniques of forest management can be studied and demonstrated to the wider public by establishing the research and demonstration area of forest management planning at Järvselja.

Abstract.

Estonian forest management is based traditionally on long rotations. Recent trends in wood industry and wood consumption promote also production of small-size timber for bioenergy and timber products. This opens a discussion about shorter rotations and intensive forest management again in Estonia. In current study, profitability of Scots pine, Norway spruce and silver birch stand management on fertile soils was analyzed according to three different rotation lengths: traditional long rotation, short rotation and economically optimal rotation according Finnish TAPIO rules. Stand simulation software MOTTI was used to simulate and optimize forest growth and management. Simulation results were compared with actual data on forest growth and yield in Estonia. Economically optimal rotations were for Scots pine stand 58 years, Norway spruce stand 53 years and silver birch stand 41 years. Short and optimal rotation length enable 5.9-6.5% profitability for forest owner, traditional long rotation length enables 4.8-5.4% profitability. Rotation forestry is challenging task. Based on our analysis, it is likely that applied practices can intensify wood production and reduce forest management risks. However, theoretical approach is not enough for assessing practical feasibility of short rotations. Thus further studies and experiments are needed for careful analysis and recommendations

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Abstract

Private forest owners are increasingly responsible for providing an extensive range of goods and services from their forests, as there are around 100,000 forest owners in Estonia. In order to support forest owners in providing these services, the state has continuously backed the forestry sector and established a public-private partnership with forest owners’ associations as well as their umbrella organisations and cooperatives. The aim of this paper is to identify the service and information needs of private forest owners in the context of this established support system. Using a survey sample of 757 respondents, we found that in regard to informational needs more focus should be put on forest management activities, i.e. on available information about service providers’ contacts, prices, options and principles for selling harvesting rights and timber. Furthermore, joint timber sales as a service should be further developed and focused on. While forest owners ranked highly both the information about financial support and the specific measures, they found the system sometimes too complicated. Both in terms of information and service importance-performance, forest owners indicated certification as a low-priority topic. Whilst interest representation in policy processes was indicated as a very important service, its performance was rated quite modestly indicating slight dissatisfaction with the current arrangements. There are also several socio-demographic attributes of forest owners that influence their needs for information and services about forest management. However, a better understanding of these attributes might help develop the system further.

Abstract

A new paradigm in forest management using a streaming input of public participation needs effective online solutions. The process should be real-time, secure, effective and efficient. People are expected to share their data and thoughts on forest management with forest owners for improving forest management and planning. The participatory approach supports communication within society and can be designed as an interactive web-based solution. Many pre-requisites have already been met and society is ready for a successful start of an interactive participatory forest planning system in Estonia. People use digital identification for various purposes and the state already maintains an online public forest register. Motivating people to participate in the planning process is always challenging yet important for the successful implementation of the system. The system should allow simulating the development and management of forest stands following the participatory input and using ecosystem models and economic calculations. The outputs from the system include management alternatives, risk assessments and financial reports. The system requires a reliable financial compensation scheme to ensure overall long-term stability of the system and agreements between interested persons or groups and forest owners.

Abstract

The properties of biomass-based fuel and combustion tests showed that logging residues are promising renewable energy sources. The data used in this study were collected from four clear-felling areas in Järvselja Training and Experimental Forest Centre, Southeast Estonia in 2013–2014. Logging was carried out by harvesters in Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies [L.] Karst.), silver birch (Betula pendula Roth.) and black alder (Alnus glutinosa L. Gaertn.) dominated stands with a small admixture of other tree species according to the cut-to-length method and logging residues were placed in heaps. The aim of this research is to assess different characteristics of logging residues (quantity, moisture content, energetic potential, ash content and amount) in clear-felling areas. The highest load of slash was measured on the birch dominated study site, where the dry weight of the logging residues was 29 t ha−1. Only the branch fraction moisture content on the black alder dominated site (35.4%) was clearly different from respective values on other sites (21.6–25.4%). The highest calorific value of the residues was assessed with the residues from the birch dominated site, where in moist sample it was 365 GJ ha−1 and in dry matter 585 GJ ha−1. The heating value of the fresh residues is highest in coniferous trees. The highest ash content in branch segments was registered for the black alder dominated site. Järvselja data indicate higher quality in conifer dominated sites, yet a higher load of logging residues in broadleaf dominated stands.

Abstract

Assessment of tree mortality provides deeper understanding of forest structure and functioning. This enables evaluation of stand sustainability and provides information on stand productivity, diversity and health condition. Tree mortality can be assessed by spatiotemporal patterns as well as by studying the processes and causes of mortality. Tree mortality is caused by specific disturbance agents or by the complex effect of various disturbances. The purpose of this study is to examine tree mortality in Estonian forests, determine the causes of tree death, and estimate how different management regimes affect tree mortality and its causes. This study is based on 360 sample plots measured in 2003-2005 and re-measured in 2008-2010. The sample plots were divided into recently managed (RM, 146 plots) and low intensity/unmanaged (LU, 214 plots) plots based on forest management regime. In total, 53,990 trees were measured, of which 20,020 were located on RM and 33,970 on LU plots. The tree mortality for 5-year period was 3.4% on RM plots and 8.0% on LU plots. The main cause of tree mortality in RM stands was insect damage, which attributes to 29.8% of tree mortality, whereas in LU stands the main cause was tree competition, which attributes to 45.4% of tree mortality. The analysis of tree mortality indicated that an increase in relative tree diameter in both stand types contributes to an increase in mortality due to insect, wind or fungal damage and diseases. Opposite results were received with respect to competition - the smaller the tree relative diameter, the more probable it is that a tree will die because of competition with neighbouring trees. The analysis of game damage and other causes of tree mortality showed that these were not dependent on the relative diameter of trees. The analysis of the overall probability of tree mortality revealed that relatively smaller trees have a higher probability of mortality than larger trees.

Abstract

Diverse structural elements play an important role in sustaining biodiversity in old-growth forests. Therefore, it is important to have thorough knowledge about these habitats and their condition in protected areas. Metsakorralduse Büroo OÜ conducted a large-scale Natura 2000 forest habitat inventory that covered 60% of Lahemaa National Park (LNP) area. Western taiga habitat data (7,191 ha) from this inventory was used for analysis of forest stages. The data was grouped according to stand classes by total area and these classes were compared by deadwood occurrence and relative density. For more precise evaluation of coarse woody debris (CWD) we used 27 sample plots from the Estonian Network of Forest Research Plots (ENFRP) located in LNP. The biggest areas of Western taiga habitat were covered by mature and old stages. CWD occurrence (over 5 m3ha−1 of snags and logs) by habitat representativeness is higher in old and natural forest classes. This logical result is overshadowed by the outcome that the CWD was not substantially present on 32% of the area in the old-growth forest class. This indicates that these areas lack the potential of biological legacies to provide critical niche habitats for different species. The study shows that the CWD quantity in Estonian conditions is similar to that reported in previous studies in this region, but because many of the older forest stage classes do not have any CWD present, these areas should include ecological restoration practices in their conservation planning. By creating snags, logs and gaps in these areas, we are able to create better structural variability and include wood into different decay processes.

Abstract

Forest research has long traditions in Estonia that can be traced back to the 19th century. Data from long-term forest experiments are available since 1921. The first studies mainly focused on silvicultural treatments and application of such data for understanding and modeling ecological processes was limited. The Department of Forest Management of the Estonian University of Life Sciences started to develop the Estonian Network of Forest Research Plots (ENFRP) in 1995. Since then, plots have been continuously re-measured with 5-year interval. Approximately 100-150 permanent sample plots were measured annually. In 2014, the long-term research network consisted of 729 permanent sample plots, of which 699 have been re-measured at least once, 667 plots - twice and 367 plots - three times. The total number of trees recorded in the network database amounts to 130,479. The plots are systematically distributed throughout the country. Detailed dendrometric measurements including tree spatial distribution are part of the survey protocol. Initially the network was set up to produce suitable data for development of individual tree growth models for Estonia. The significance of the network for the Estonian forest research is continuously increasing and nowadays ENFRP is recognized as an important national research infrastructure.