Total Forest Land Area Research Articles

State of forest fund and planning in forestry

State of forest fund and planning in forestry

Assessing the Impact of Confirmation of Rights and Collective Trust on Farmer’s Forestry Management and Protection Behaviour—A Case of Collective Forest Areas in Zhejiang and Jiangxi Provinces, China

Confirmation of rights and collective trust (interpersonal and institutional) can act as primary factors for facilitating effective forest management and conservation. Collective forests are lands held collectively by either rural or indigenous communities based on a shared history, language, culture, or lineage. It is an institutional arrangement in which communities are involved wholly or partly in decision-making and contribute knowledge and labour to achieve healthy forests and social well-being. Based on the existing literature, the nature of collective forest rights and trust can be derived from social, rather than economic, prospects. Therefore, based on the institutional theory, this study constructs a theoretical framework to verify the impact of the confirmation of rights and trust on farmers’ forestry management conservation behaviour. The empirical setup of the study was comprised of a data set of 682 collective forest farmers in Zhejiang and Jiangxi provinces, China. We utilized the negative binomial regression model to quantify the proposed framework. The main conclusions were as follows. Confirmation of rights and collective trust had a significant positive role in promoting farmers’ forestry management and protection behaviour. Increasing the confirmation of rights and trusts by one unit increased the number of farmers’ forest management and protection by 1.846 and 2.631 times, respectively. The interaction between confirmation and trust did not substantially affect farmers’ behaviour. The diverse forest labour force, the total area of forest land, and the number of forest plots had a significant positive impact, while the head of the village and the number of migrant workers significantly and negatively impacted farmers’ behaviour. Therefore, it is necessary to further improve the forestry land rights system and strengthen the trust mechanism so that it can become an effective institutional incentive for farmers to manage and protect forests.

Mapping LULC Dynamics and Its Potential Implication on Forest Cover in Malam Jabba Region with Landsat Time Series Imagery and Random Forest Classification

Pakistan has an annual deforestation rate of 4.6% which is the second highest in Asia. It has been described by the Food and Agriculture Organization (FAO) that the deforestation rate increased from 1.8–2.2% within two decades (1980–2000 and 2000–2010). KPK (Khyber Pakhtunkhwa), Pakistan’s northwestern province, holds 31% of the country’s total forest resources, the majority of which are natural forests. The Malam Jabba region, known for its agro-forestry practices, has undergone significant changes in its agricultural, forestry, and urban development. Agricultural and built-up land increased by 77.6% in the last four decades, and significant changes in land cover especially loss in forest, woodland, and agricultural land were observed due to flood disasters since 1980. For assessing and interpreting land-cover dynamics, particularly for changes in natural resources such as evergreen forest cover, remote sensing images are valuable assets. This study proposes a framework to assess the changes in vegetation cover in the Malam Jabba region during the past four decades with Landsat time series data. The random forest classifier (RF) was used to analyze the forest, woodland, and other land cover changes over the past four decades. Landsat MMS, TM, ETM+, and OLI satellite images were used as inputs for the random forest (RF) classifier. The vegetation cover change for each period was calculated from the pixels using vegetation indices such as NDVI, SAVI, and VCI. The results show that Malam Jabba’s total forest land area in 1980 was about 236 km2 and shrank to 152 km2 by 2020. The overall loss rate of evergreen forests was 35.3 percent. The mean forest cover loss rate occurred at 2.1 km2/year from 1980 to 2020. The area of woodland forest decreased by 87 km2 (25.43 percent) between 1980 and 2020. Other landcover increased by 121% and covered a total area of 178 km2. The overall accuracy was about 94% and the value of the kappa coefficient was 0.92 for the change in forest and woodland cover. In conclusion, this study can be beneficial to researchers and decision makers who are enthusiastic about using remote sensing for monitoring and planning the development of LULC at the regional and global scales.

Increased levels of forestry best management practices reduce sediment delivery from Piedmont and Upper Coastal Plain clearcut harvests and access features, southeastern states, USA

A land use history of intensive agricultural practices, combined with highly erodible soils, have made erosion control and water quality protection essential for forest management in the Piedmont and Upper Coastal Plain of the southeastern U.S. Forestry Best Management Practices (BMPs), which include sustainable harvesting guidelines approved by state forestry agencies, are utilized in these regions to mitigate potential impacts to water quality. In this study, the relationship between three levels of BMP implementation ranging from < 80% (BMP–), 80–90% (BMP-standard) and > 90% (BMP+ ), estimated erosion (Mg ha-1 yr-1) based on the USLE-Forest empirical model, and sediment delivery ratios was explored to better understand impacts to forest water quality. Erosion and sediment delivery estimates by BMP level were multiplied by estimates of area occupied by each operational feature (e.g., decks, harvest areas only, haul roads, skid trails, stream crossings) and annual clearcut timberland (ha-1 yr-1) provided by the U.S. Forest Service FIA Program. The overall goal was to estimate total annual masses of erosion and sediment (Mg yr-1) by BMP level for twelve states with timberland located in either the Piedmont or Upper Coastal Plain. Forty-four clearcut harvest sites were assessed in the region. Over 431,000 ha yr−1 are clearcut in the Piedmont and Upper Coastal Plain, which represents approximately 2% of total forestland area in the regions. The BMP+ (0.5 Mg ha−1 yr−1) and BMP-standard (0.9 Mg ha−1 yr−1) levels of implementation provide considerably more water quality protection than BMP– (2.0 Mg ha−1 yr−1) based on average sedimentation rates for the overall harvest. Overall sediment removal efficiencies at the BMP-standard (54%) and BMP+ (74%) levels indicate that current BMPs are highly effective at mitigating potential sediment delivery from clearcut operations in the regions. The BMP+ level most efficiently limited potential sediment from skid trails (80%), harvest areas (75%), and haul roads (61%), which were also the primary contributors of sediment. Over 93% of clearcut harvests sampled were classified as either BMP-standard or BMP+. These findings indicate that current BMPs are implemented at high levels across the southeastern Piedmont and Upper Coastal Plain, and that BMP effectiveness has improved substantially over time in the regions.

Landscape pattern simulation for ecosystem service value regulation of Three Gorges Reservoir Area, China

Landscape pattern regulation would alter regional ecosystem structure, thus affecting ecosystem function and service provision. We analyzed the impact of landscape pattern change on ecosystem service value (ESV) of the Three Gorges Reservoir Area (TGRA). The CA-Markov model was used to map three future (ecological, economic, and eco-economic) scenarios of the TGRA in 2030, then we predicted and compared ESV changes among three scenarios. Our results documented that the total forestland area increased significantly in the ecological scenario, but decreased in the economic scenario. Meanwhile, the construction land area increased in the economic scenario. For the eco-economic scenario, the forestland area change was consistent with the ecological scenario, while the construction land area change was similar to the economic scenario. The ESV of TGRA in 2030 is the highest in the ecological scenario, followed by the eco-economic scenario. Compared to 2015, the total ESV increased in 2030 for both the ecological and eco-economic scenarios, while decreased in the economic scenario. Eco-economic scenario focuses on the coordinated development of ecological protection and economic construction, meeting the needs of economic construction in ecologically fragile areas. This development model will be greatly welcomed by policy makers and effectively promotes sustainable land use in the region. So, we proposed a landscape planning scheme for ecological restoration and economic construction of the TGRA, providing valuable information for decision and policy making and minimizing negative impacts through targeted management measures. Our findings can provide a scientific basis and theoretical practice for environmentally friendly land management.

Uncovering the patterns and driving forces of virtual forestland flows in China

Nowadays, virtual land use related to consumption and trade flows has become an important part of land use. However, there has been little discussion about virtual forestland use. Therefore, this study performs the multi-regional input-output model on virtual forestland use and its changes in thirty provinces in China. And the influencing factors behind the dynamics of virtual forestland have been explored through the structural decomposition analysis. The results show that the area of virtual forestland embodied in trade was 673,277 km2 and 566,791 km2 in 2007 and 2012, equivalent to 32.14% and 27.03% of the total forestland area in China, respectively. There was north to east coast virtual forestland trade mode in China. The developed provinces or cities in China such as Shanghai, Beijing, Tianjin and Guangdong have a disproportionate share of virtual forestland imports (over 90%) from least developed provinces and forest-rich provinces. In addition, 11.06% and 7.47% of China's total forestland in 2007 and 2012 was used to supply consumption of foreign countries and regions. In addition, forestland use intensity and consumption volume were the main reasons for the dynamic changes of virtual forestland in most provinces. Through the exploration of the virtual forestland flow pattern helps to develop forestland conservation and restoration policies from the consumer side and achieve sustainable development of China's forest land.

Ecological and economic aspects of forestry in Ukraine in the context of sustainable land using

Over the last half a century, the total area of forests in the world has decreased significantly. Ukraine belongs to countries with low quantity of forests and deficient of woods, because the level of forest cover is 15.9% with the required optimal value of 25-30%. Steppe areas are characterized by 1.9–4.8% of forest cover. The current total area of forest land belonging to the forest fund of Ukraine is 10.4 million hectares, including 9.6 million hectares of forested vegetation, about 3.5 million hectares of forests have restrictions in forest management. In 2008–2017, 4.03 million hectares of forests were cut down in Ukraine and additionally destroyed by fire, pests, storms, and by poachers about 170.7 thousand hectares, only 16.3% of this area was recovered. In order to ensure optimal forest cover, it is necessary to differentially restore the forest area in Ukraine by 6.0–9.2 million hectares. The average field protective forest cover in some physical-geographical zones of Ukraine varies within 1.3–1.5%, the optimal should be 3.0–4.5%. In particular, about 76.0% of the territory of the steppe zone of Ukraine has insufficient forest cover, which causes systematic negative manifestations of water and wind erosion. This situation is complicated by the high level of agricultural development of the southern regions - up to 97%, which causes a low degree of environmental sustainability of landscapes to preserve soil fertility. Retrospective analysis showed a significant decrease in the area of forest protection strips over the past 60 years by 1.9–2.3 times. The total loss of protective forest strips in Ukraine over the last 10 years is 10 071 hectares, which has weakened the nature protection function of the forest plantation and caused the scale of water and wind erosion. The survey uses data from the State Statistics Service and the State Geo-cadastre of Ukraine during 2008–2017. Decryption of Earth remote sensing data and use of a series of correctly calibrated MODIS satellite images (geometric resolution 230 × 230 m) made it possible to determine the ratio of the spatial distribution of the forest fund to the agricultural land on the territory of Ukraine. Using the Zonal Statistics of Spatial Analyst Tools module, of the ArcGIS program was determined forested and plowed lands within separate administrative and territorial units. The difficult situation in Ukraine, in which the state of forest ecosystems does not meet the ecological and economic requirements, is caused by the complexity of management decisions in the field of forestry. The obtained results make it possible to substantiate the need for spatial-differential measures of forest restoration and implementation of land and water preservation measures for optimization of the land fund on the basis of adaptive-landscape principles, which allows to create preconditions for rational use and rehabilitation of forest and land resources of Ukraine. Keywords: ecological and economic aspects, forest fund, protective forest strips, forest cover, plowing, ecological sustainability, sustainable land use, Ukraine, geomodeling.

Spatiotemporal changes and fragmentation of forest land in Jiangxi Province, China

Habitat loss and fragmentation resulting mainly from increased human impacts related to land use represent considerable threats to biodiversity. When regional ecological security is threatened, governments attempt to regulate unreasonable behavior via policies and laws. China has a dominant forestry industry, and the country is attempting to implement the dual goals of economic development and ecological security; therefore, the Chinese government has formulated a series of policies and regulations to balance these goals. This study presents the main forest policies in China and implements a logistic regression model to analyze the changes in forest land in the study area (Jiangxi Province) and the primary influencing factors for these changes under the forest policies from 1990 to 2010. Subsequently, a forest fragmentation model (non-traditional forest landscape pattern index) was built to analyze the forest fragmentation patterns and interference modes. The results indicated that the total forest land area increased by more than 40,000ha during the study period; however, the logistic model showed that a large amount of high-quality forest land was replaced by poor-quality forest land because forest land areas that present rich soil organic matter (SOM) content are more easily converted to other land types, whereas areas with poor SOM are more easily converted to forest land. Between 1990 and 2010, forest fragmentation improved because the proportion of interior forests increased and the proportions of patch and perforated forests decreased. The paper concludes by proposing some policy recommendations for the conservation of biodiversity.

Spatial and temporal patterns of plantation forests in the United States since the 1930s: an annual and gridded data set for regional Earth system modeling

Abstract. Plantation forest area in the conterminous United States (CONUS) ranked second among the world's nations in the land area apportioned to forest plantation. As compared to the naturally regenerated forests, plantation forests demonstrate significant differences in biophysical characteristics, and biogeochemical and hydrological cycles as a result of more intensive management practices. Inventory data have been reported for multiple time periods on plot, state, and regional scales across the CONUS, but the requisite annual and spatially explicit plantation data set over a long-term period for analysis of the role of plantation management on regional or national scales is lacking. Through synthesis of multiple inventory data sources, this study developed methods to spatialize the time series plantation forest and tree species distribution data for the CONUS over the 1928–2012 time period. According to this new data set, plantation forest area increased from near zero in the 1930s to 268.27 thousand km2 in 2012, accounting for 8.65 % of the total forestland area in the CONUS. Regionally, the South contained the highest proportion of plantation forests, accounting for about 19.34 % of total forestland area in 2012. This time series and gridded data set developed here can be readily applied in regional Earth system modeling frameworks for assessing the impacts of plantation management practices on forest productivity, carbon and nitrogen stocks, and greenhouse gases (e.g., CO2, CH4, and N2O) and water fluxes on regional or national scales. The gridded plantation distribution and tree species maps, and the interpolated state-level annual tree planting area and plantation area during 1928–2012, are available from https://doi.org/10.1594/PANGAEA.873558.

黑河中上游地区2000—2010年土地利用变化及水土保持服务功能分析

基于遥感影像数据,分析了黑河中上游地区2000年到2010年土地利用变化,在此基础上,从上游、中游以及整个区域的角度综合评价了该区域的水源涵养和土壤保持生态系统服务功能物质量变化。研究结果表明:①研究区60%以上为未利用地,2000-2010年,耕地、林地和未利用地面积大量增加,草地和水域面积减少。②耕地增加以荒漠和草地转入为主;林地转入表现为草地和荒漠造林,转出主要为林地荒漠化;草地转出主要去向为造林和荒漠化,而增加主要来源于冰雪覆盖地和荒漠;未利用地增加主要来源于草地的退化。③研究区土地利用程度较低,由东南向西北递减,2000-2010年,上游土地利用程度有所降低,中游大部分地区呈上升趋势。④由于上游山区林地面积的增加,植被覆盖下土壤的水源涵养量显著增加,土壤贮水量增加了0.764×10⁸ t。⑤土壤保持量由1.860×10⁸t增加到1.899×10⁸t,主要原因为草地转化为林地。在气候变化背景下,黑河流域应控制上游地区人工林面积,减少林地蒸腾量,以增加下游可用水量;适当控制中游地区耕地面积的扩张趋势,保证湿地、草地等自然生态系统生态用水量,维持流域山地-绿洲-荒漠系统的稳定,进而持续发挥生态系统土壤保持等功能。;Based on Landsat TM/ETM image data and some other survey materials, this paper analyzed the land use change in the upper and middle reaches of Heihe river basin during 2000-2010. Subsequently, two prominent functions of ecosystem service: water conservation and soil retention were evaluated, from upstream, midstream, as well as the whole region. The findings of this study are summarized as following: (1) The main types of land use is unused land accounting for more than 60% of the total area. In recent ten years, cultivated land, forest land and unused land increased dramatically. By contrast, grassland, water area and snow cover land decreased. (2) The increase of cultivated land was chiefly derived from the conversion of desert and grassland. Desertification on forest land, afforestation on desert and grassland happened at the same time. The total area of forest land showed an ascending trend. The loss of grassland was attributed to the afforestation and desertification, whereas the increment of grassland was ascribed to the conversion from snow cover land and desert. The increase of unused land mainly came from the degradation on grassland. (3) On the whole, the degree of land use was relatively low and displayed a descending trend from the southeast to the northwest. In recent 10 years, the degree of land use dropped in upstream area and ascends in most of the middle reaches of Heihe basin. (4) Owing to the increase of forest land of the upper reaches, water conservation for soil improved significantly. Water storage in soil increased by 0.746×10⁸ t. (5) The total amount of soil retention raised from 1.860×10⁸ t to 1.899×0⁸ t as grassland conversion to forest. Under the background of climate change, some measures should be implemented in order to maintain the stability of the mountain-oasis-desert system and the sustainable of the ecosystem services like soil retention. Firstly, the area of artificial forest should be controlled in the upper reaches which can reduce transpiration and increase the amount of water available. Secondly, in the middle reaches, cultivated land area should be under control to ensure the ecological water consumption, such as grassland and wetlands.

Fragmentation of forest communities in the eastern United States

Forest fragmentation threatens the sustainability of forest communities in the eastern United States. Forest communities exhibiting either a low total area or low percentage of intact forest are subject to relatively higher risk of shifts in stand composition towards edge-adapted and invasive species. Such changes in stand composition could result in local extirpation of communities, homogenization of forest communities at broader spatial scales, and a consequential reduction of the biodiversity values of forestland. To evaluate current conditions, we combined forest inventory data with land cover data to compare 70 forest communities in terms of the amount and ownership of intact (i.e., not fragmented) forest, and the proximate causes (i.e., adjacent land cover) of fragmentation. Only 45% of total forestland area was intact in 4.41-ha neighborhoods, but that varied from 13% to 78% among forest communities. Among 10 community groups, the proximate causes of fragmentation reflected their typical geographic context, and the relative importance of fragmentation by development was higher in mostly-forested neighborhoods than in less-forested neighborhoods. Fragmentation was also higher on privately owned forestland than on public forestland. Because of the regional dominance of only a few forest communities and private land ownership, the total regional area of intact forest was driven more by the total area of those strata than by their fragmentation characteristics. The results provide insight for targeting land management strategies to maintain the diversity and regional distributions of intact forest communities.

Assessing landscape change and biodiversity values of the Middle Vistula river valley, Poland, using BIO-SAFE

This paper deals with the relation between legally protected biodiversity and riverine ecotopes and with the assessment of biodiversity values of the Middle Vistula river valley (Poland). Furthermore, it describes the effects of landscape change on spatial distribution of ecotope patches and biodiversity values in Kazimierski Landscape Park. Biodiversity values were calculated using BIO-SAFE, a model meant to quantify biodiversity and to value ecotopes based on legally protected species. Dissimilarity indices depict high uniqueness of ecotope types regarding their species assemblages (e.g., river dunes, banks and bars). The actual biodiversity values of the river valley in Kazimierski Landscape Park are high in comparison with floodplains of lowland rivers in Western Europe. GIS analyses of remotely sensed ecotope maps show remarkable differences in number, acreage and patchiness of ecotopes for the years 1953 and 2003. The total number of patches increased by almost 44%. Side channels and floodplain lakes became fragmented. The average and total surface area of bush, forest and arable land increased, but decreased for bare soil, pioneer vegetation and grassland. These landscape changes indicate natural vegetation succession, intensification of agriculture and progressive impacts of river regulation. The Vistula river valley still represents high biodiversity values for higher plants, birds, herpetofauna and fish. However, current landscape changes negatively affect potential values for protected and endangered species. Assessments with BIO-SAFE can help to balance biodiversity conservation, river management and landscape planning.

Trends Among Family Forest Owners in Alabama, 1994–2004

Abstract There are an estimated 432,000 family forest owners in Alabama and they control 67% of the State's forestland. About two-thirds owned less than 10 ac. and about 88% of the family forest owners have holdings of less than 50 ac; collectively, this group of owners with 1–49 ac of forestland own 15% of Alabama's family forestland. The corollary to this finding is that a majority (85%) of the state's family forestland is owned by the minority (12%) of owners who own 50 ac or more. Between 1994 and 2004, the amount of forestland owned by family forest owners with small (less than 10 ac) and large (more than 500 ac) forest holdings increased, while the total area of forestland owned by people with intermediate-size holdings, in general, decreased. Compared with 10 years ago, the number of family forest owners 45–54 years old is higher but they tend to own smaller parcels of forestland. During the same period, the number of owners 65 years or older decreased, but, on average, the size of their holdings increased. Recreation and investments have become more important objectives of ownership, whereas timber production as a primary ownership objective decreases. The probability of an owner having harvested trees, having a management plan, or having sought forest management advice increased as the size of the forest holding increased.

Regionally optimized forest management under changing climate

The purpose of this study was to optimize forest management for a forest region (the total area of forest and scrub land 1.54 mill. ha) under changing climate by using the large-scale forestry scenario model MELA and sample plot data from the geo-referenced National Forest Inventory (NFI). The MELA model is based on integrated simulation and optimisation; in the simulation it utilises empirical tree-level models into which the impacts of climate change were introduced by transfer variables derived by using the physiological model FinnFor. Six scenarios with differences in climate and forest management were defined. In simulations, the accelerating tree growth caused by climate change resulted in an increase in maximum sustainable removal of trees at regional level. Changes in regionally optimized forest management were also detected during the analysis period of 30 years; the proportion of thinnings increased because the stands fulfilled the thinning requirements earlier than in the current climate. This study was the first attempt to solve endogenously maximum sustainable timber production and corresponding forest management at the regional level under different climate scenarios. When implemented in the MELA system, which is widely used in Finnish forestry, the transfer variables offer means of disseminating the results from physiological studies to planning of adjustment and mitigation measures under changing climate.

Forest distribution and site quality in southern Lower Michigan, USA

AbstractAim The primary objectives of this research were to determine whether current forest patches in southern Lower Michigan are a proportionate sample of forest types present in the pre‐settlement cover and, if not, to establish the degree to which certain types are over‐ or under‐represented in the contemporary landscape. This determination is useful not only because any conservation policy designed to restore the present forest to pre‐settlement biodiversity through preservation of existing stands requires an accurate understanding of the degree to which these stands in sum mirror past forest diversity, but also because it fills a gap in the existing ecological literature.Location The research was conducted within four counties in southern Lower Michigan, USA (Ionia, Livingston, Tuscola and Van Buren).Methods Soil survey data were used to characterize the range of site quality across the study area and the areal extent of each quality category. The geographic locations of all current forest patches in each county were then determined from land use maps and were overlaid on the site quality classification. This procedure yielded the observed distribution of forest relative to site quality. The expected areal extent of forest within each category of site quality on the landscape was determined by assuming a random distribution and multiplying the total area of forestland by the proportion of landscape within each category of site quality. This procedure calculated the expected distribution of forest in terms of site quality by dividing the total forestland among the landscape types, relative to how well represented the landscape types were. The observed and expected distributions were then compared both in terms of absolute difference and normalized difference.Results Overall results indicate that categories of site quality that support a large proportion of the present‐day forest patches are generally composed of agriculturally inferior soil and are over‐represented with forest. Surviving or reforested tracts are concentrated on inferior types of habitat.Main conclusions Results suggest that the present‐day forest patches may not be a proportionate sample of the primeval forest. Rather, they are concentrated on agriculturally‐inferior (coarse‐textured, steeply‐sloped, or poorly‐drained) types of habitat. Unless these stands are for some unknown reason compositionally richer than their pre‐settlement counterparts, these results suggest that the existing forest resource in southern Lower Michigan is an inferior (biased) sample of the primeval cover. Furthermore, because forest types associated with the most heavily‐developed agricultural sites have apparently suffered the most loss of habitat, species more characteristic of these types may have experienced a greater decline in overall importance across the landscape. This study suggests that policy aimed at increasing the potential biodiversity of the area should include provisions that encourage the redevelopment of forest habitat on those sites no longer supporting their equal share of forest.

The private cost and timber market implications of increasing strict forest conservation in Finland

Abstract In this paper the private costs of strict forest conservation are studied using Finnish data. First, the conservation-induced changes in the net present value of forest land are estimated together with the consequent compensation needs. Second, a dynamic reduced-form econometric model is estimated to derive the dynamic impacts of forest protection on the Finnish timber markets and forest sector. The estimations show that a conservation program that sets aside up to 3% (an additional 270 000 ha) of the total productive forest land area in southern Finland could result in up to 1 milliard euros in compensation to private landowners. The results of the dynamic analysis of the forest sector indicate that conservation has a price-increasing and quantity-decreasing effect on the timber markets. However, the raw material supply effects on the forest industry's output and raw timber imports are less than expected.

Biosims — a method for the calculation of woody biomass for fuel in Sweden

A planning model and a computer programme, ‘Biosims’, have been developed. A test of the model was conducted in Dalarna (Kopparberg), Sweden, in 1994. Modified ecological restrictions were tested using the current ecological restrictions as a reference. Recycling of wood ash was assumed to be a standard method. The results show that 24–56% of the total forest land area is affected by the ecological restrictions in the county of Dalarna. Translation of these results to woody biomass quantities shows that the total ecological potential of woody biomass for fuel is 20.5 PJ per year. The total use of woody biomass for fuel is 3.3 PJ per year. The remaining potential of woody biomass for fuel in the county of Dalarna is 17.2 PJ per year. The method uses stand data or sample plot data from the National Forest Survey (NFS). A method for application of ecological restrictions has been used. These restrictions are based on variables, e.g. soil and vegetation classes, included in the NFS-data. Two methods for woody biomass calculations are used: (1) the biomass functions for the main domestic tree species ( Pinus silvestris, Picea abies, Betula pubescens, Betula verrucosa); and (2) the ratio method based on forest inventory data and conversion factors or functions between stand variables. The woody biomass is measured as oven dry weight per unit area. The results can be transformed, e.g. into energy equivalents and biomass nitrogen content. Different assumptions, such as heat value and moisture content, can be programmed and various technical and ecological restrictions can be imposed. The results can be presented in the GIS.

Future development of the Leningrad region forests under nature-oriented forest management

Russian forests are of high importance for the Russian economy, the European wood market, for nature conservation, and for carbon sequestration. However, the ongoing changes in forest management and administration in Russia led to uncertainty about forest ownership, wood harvesting levels, and long-term impacts of alternative management plans. Therefore, better insight in their current and future state is highly desirable. We present a study for the Leningrad region forests in which alternative management regimes for wood production and nature conservation values are balanced in varying ways. The total forest land area in the Leningrad region forest fund is 4.8 million ha. Coniferous species dominate and due to the natural succession occurring, the forests are divers in vertical structurally. A timber assessment model was used to project the forest until 2040. Five forest management scenarios were run. Special attention was paid to a scenario that simulates recovery of the Russian forest sector in combination with the incorporation of a ‘set-aside for nature conservation’ policy. All scenarios showed that recovery of the forest sector in the Leningrad region is biologically feasible. A sustainable continuous annual production of 10.6 million m 3 per year (2.8 m 3 ha −1 per year) by 2040 was found. The ‘Recovery with Nature Conservation’ scenario showed that recovery of the forest sector in combination with the establishment of set-aside areas is very well feasible. It was possible to set aside 28% of the forest area for nature conservation while still developing a forest sector to a production level higher than that achieved in the late eighties. The timber assessment model applied was not specifically designed to incorporate nature-oriented forest management. We, therefore, discuss ways of improving the required methodology to analyse long-term effects of nature-oriented forest management in Europe.

The Quebracho Region of Argentina

The quebracho forests of northern Argentina and southern Paraguay have the distinction of being the only forests of their kind in existence. Here and here only, between the 20th and 3ist parallels, quebracho is found in sufficient quantities to permit commercial exploitation. Quebracho as a botanical species is not entirely confined to this particular region, but in no other portion of the globe has it been found to be so abundant and of so desirable quality. The heartwood of the quebracho yields a valuable extract highly desired in the tanning of high-grade leathers and in such demand in both Europe and the United States for the last thirty or more years that this forest product has become of great economical importance. Foreign and domestic companies, principally the former, have invested large sums of money in forest holdings and in the establishment of tannic acid factories. The industry has assumed such dimensions that it is the leading factor in the development and colonization of northern Argentina. Besides being utilized in the manufacture of tannin, the quebracho tree is converted into many other wood products consumed domestically. Chief among these are railroad ties, boards, beams, poles, piles, fence posts, and cross arms. It is also a desirable wood for certain general construction purposes but is limited in these uses because of its heavy weight and short lengths. It is fine-grained and takes a beautiful polish as well as being the hardest, heaviest, and most durable wood known. In fact in Argentina, especially in the quebracho region, this wood is put to almost every use for which wood can be employed. According to official statistics' the total area of forest land in Argentina is 264,0I2,000 acres, which is 36.I per cent of the land surface. This, however, includes some burned-over forest land and also a good deal of woodland, open and scrublike. The great bulk of the forest is located in the northern part of the country. The quebracho region alone is estimated to cover Ioo,ooo,ooo acres, or I3.7 per cent of the total land surface of the republic; but only 45 to 60 per cent of the region is actually timbered. The term quebracho is of Portuguese derivation, literally meaning break Unfortunately, in parts of South America the term has been indiscriminately used, being applied to any wood having sufficient hardness to turn an ax. In the quebracho region, however, quebracho has a definite meaning, for the reason that it is practically the only wood accepted and