Areas Of Mature Forest Research Articles

Nest reuse by Goshawks after timber harvesting: Importance of distance to logging, remaining mature forest area and tree species composition

We studied reuse of Goshawk Accipiter gentilis nests after timber harvesting within 50m from the nest in 31 territories in southeastern Norway. The proportion of nests used in the second or third breeding season after logging (55%) did not differ significantly from that of 27 control nests (67%). Both for all nests (N=58), and for nests with logging closer than 50m (N=31), reused nests differed from those not reused by being situated in a larger area of mature forest, and in forests with a higher proportion of Norway Spruce Picea abies, which gives better cover than Scots Pine Pinus silvestris and deciduous trees. However, a higher proportion of nesting territories with the target nest situated in a Spruce-dominated forest stand seemed to lack alternative nests, probably due to the more intensive timber harvesting in Spruce-dominated landscapes. Hence, Goshawks’ tolerance towards logging may be overestimated in Spruce-dominated forests. We recommend that foresters planning timber harvesting near Goshawk nests focus on the remaining mature forest stand and its structure. In order to maximise the chance of nest reuse, a patch of at least 2ha of suitable mature forest around the nest should be retained.

Browsing Patterns of White-Tailed Deer Following Increased Timber Harvest and a Decline in Population Density

We examined browsing patterns of white-tailed deer (Odocoileus virginianus) on a site in the central Appalachians that experienced a substantial (>50%) reduction in deer population density and an increase in the amount of timber harvest since 2001. We sampled woody browse in and immediately adjacent to 12 clearcuts ranging in age from 0–5 years postharvest in summer 2007. Clearcut-interior areas had higher woody browse abundance and browsing rates than clearcut-edge or mature forest areas. Woody browse abundance was slightly higher within individual clearcuts than in 2001 at higher population densities and lower timber harvest rates. Overall browsing rates declined from approximately 17% in 2001 to less than 5% during our study, suggesting that the combination of deer population control, and increasing the amount of timber harvest across the landscape can reduce herbivory to levels that may not impede growth and survival of forest vegetation.

Nonfrontier Deforestation in the Eastern Amazon

AbstractWhile interest in Amazonian deforestation mostly focuses on frontier areas, the amount of forest cover in areas already dominated by human settlement is also changing. Secondary forests play an increasingly important role for maintaining genetic diversity, hydrological functioning, and greenhouse gas emissions of altered landscapes, but secondary forests are also being converted to more intensive agricultural uses. Five dates of Landsat imagery from 1984 to 2002 were analyzed, covering 8000 km2 of the Zona Bragantina of the eastern part of the Brazilian state of Pará, which underwent its most intensive wave of deforestation several decades ago. However, even in this area of relatively long-term human occupation, ongoing decreases of forest cover were found, both in the small remaining areas of mature forest and in the more widespread areas of secondary forests, as human population increased and land use intensified. Although there was an initial increase in the area of secondary forest from 1984 to 1994, there has been a steady decline since then, from 75% secondary forest cover in 1994 to 54% in 2002. The amount of pasture was relatively stable from 1984 to 1994 but more recently has shown a steady increase, reaching 37% cover in 2002. The average rate of carbon loss over the 18-yr study period was 0.9 Mg C ha−1 yr−1 for the 8000 km2 study area. Forests in this long-settled region of eastern Amazonia continue to be degraded, resulting in the loss of ecosystem services and carbon stocks due to continued land-use change.

Geoestatística aplicada ao estudo das características físico-químicas do solo em áreas de Floresta Estacional Decidual

Utilizaram-se métodos da geoestatística na identificação do tamanho e da estrutura da variabilidade espacial de alguns atributos físico-químicos do solo em áreas de Floresta Estacional Decidual as quais foram denominadas floresta madura, floresta secundária e capoeirão. As áreas, localizadas no município de Santa Tereza, RS, foram amostradas durante o período de 2002 a 2003, compreendendo as classes de solo: Chernossolo Argilúvico, Cambissolo Ta e Neossolo Litólico. Realizou-se amostragem sistemática com grid de espaçamento regular entre os pontos variando de 30 m para o capoeirão e 40 m para floresta madura e secundária, totalizando oitenta pontos amostrais em uma área total de 7,34 ha. Foram coletadas amostras de solo "in situ" para análise em laboratório dos atributos densidade do solo, argila, pH, potássio, matéria orgânica e fósforo. A estrutura da variabilidade espacial foi identificada por meio dos semivariogramas, definindo-se os parâmetros necessários para a krigagem. O atributo mais variável foi a matéria orgânica, não obtendo ajuste a nenhum modelo teórico de semivariograma, enquanto que o pH foi o menor. Na análise de estrutura da variabilidade espacial por meio da geoestatística, a argila e densidade, ambas em área de floresta secundária, e o pH nas áreas experimentais apresentaram a maior dependência espacial. O modelo gaussiano para o atributo argila obteve o maior alcance da dependência espacial, sendo 400 e 388 m, nas áreas de floresta secundária e madura respectivamente. A validação cruzada mostrou acuracidade no ajuste dos modelos variográficos, tendo a variável pH apresentado o melhor desempenho, 0,87; 0,94 e 0,92 nas áreas de floresta madura, secundária e capoeirão respectivamente.

Macro-nutrientes no lençol freático em Floresta Intacta, Floresta de Manejo e Pastagem no norte de Mato Grosso

A remoção de uma cobertura florestal e sua substituição por outras formas de uso do solo tem sido uma constante no norte do estado de Mato Grosso podendo alterar os ciclos hidrológicos e biogeoquímicos dos ecossistemas. Neste contexto, o presente trabalho visou identificar a variação do fósforo e nitrogênio das águas do lençol freático em áreas de Floresta de Transição madura e intacta (Floresta Intacta), Floresta de Transição Manejada (Floresta Manejada) e Pastagem localizadas no norte de Mato Grosso. Foram realizadas mensalmente medidas do nível do lençol freático, de coletas de amostras de água para análises físico-químicas e medições de precipitação e temperatura do ar, no período de janeiro/2005 a novembro/2006. Verificou-se uma sazonalidade na precipitação e na temperatura do ar. No período de estiagem as águas do lençol freático apresentaram maiores teores de nitrogênio e de fósforo total nas três áreas em estudo. Os maiores valores de nitrogênio e fósforo foram detectados nos ecossistemas florestais (Florestas Intacta e Manejada) como indicativo da função da cobertura vegetal na ciclagem dos nutrientes.

Thresholds in nesting habitat requirements of an old forest specialist, the Brown Creeper (Certhia americana), as conservation targets

Many bird species respond to forestry, even at moderate intensities. In New Brunswick, Canada, the Brown Creeper exhibits a negative, threshold response to harvesting intensity. This study aimed to determine whether (a) the threshold found in Brown Creeper occurrence is lower than eventual thresholds in its nesting requirements, and whether (b) the conservation of this species could be achieved through moderate-intensity harvest systems. Creepers are particularly sensitive to forestry because they nest on snags with peeling bark and they mainly forage on large-diameter trees. In northern hardwood stands, we compared habitat structure at local- (r=80m) and neighbourhood-scales (r=250m) around nest sites and sites not used by creepers. Over two years, we found 76 nests, 66 of which were paired with unused sites for comparison. At the local scale, densities of trees ⩾30 cm dbh and snags ⩾10cmdbh, and the probability of presence of potential nest sites were significantly higher near nests than at sites where no creepers were detected. At the neighbourhood scale, the area of untreated mature forest was significantly higher around nests. Variance decomposition indicated that habitat variables at the local scale accounted for the majority of explained variation in nest site selection. We also found significant thresholds in the densities of large trees (127/ha) and snags (56/ha), and in the area of mature forest (10.4ha). The conservation of breeding populations of Brown Creepers may thus require densities of large trees nearly twice as high as those associated with its probability of presence. Such a target seems to be incompatible even with moderate-intensity harvesting.

Regrowth forests on abandoned agricultural land: A review of their habitat values for recovering forest fauna

Human land use has modified the structure and function of terrestrial landscapes throughout much of the world, with cropping and livestock grazing the major drivers of landscape change. In many tropical, sub-tropical, temperate and Mediterranean regions, regrowth forests regenerate naturally on abandoned agricultural land if human disturbance declines. With the exception of some tropical forest literature, the broader ecological and conservation literature has largely ignored the potential of regrowth forests to facilitate passive landscape restoration and the recovery of fauna communities in fragmented agricultural landscapes. This paper addresses this deficiency by reviewing the available global evidence of fauna recovery in regrowth forest from 68 papers, identifying the main gaps in current knowledge, and providing directions for further research. The majority of reviewed studies focus on regrowth in tropical regions, which often contain large areas of mature forest. Species’ utilisation of regrowth forest is highly variable and is particularly influenced by land-use history, an important determinant of the structural and compositional characteristics of regrowth forests. While site-scale (<1 ha) forest structure and floristic diversity were frequently studied, only 11 studies considered the spatial configuration and context of habitat patches and just two studies explicitly considered landscape structure. Based on this review, six key research questions are posed to direct future research on this important issue. We conclude that a broader perspective of the role of regrowth forest in the landscape is required if we are to realise the potential benefits of regrowth forest for passive landscape restoration and fauna conservation and recovery.

Scheduling forest core area production using mixed integer programming

Core area, the area of mature forest protected by a buffer area from edge effects of surrounding habitats, is an important spatial measure describing forest ecological conditions. Three alternative mixed integer programming (MIP) formulations are presented for explicitly scheduling core area production in a forest management scheduling model. Formulations utilize detailed data preprocessing that develops a set of influence zones. Each influence zone identifies an area of the forest that can produce core area. Each zone is influenced by a unique combination of management units (stands) of the forest. The assumed width of the buffer surrounding core area affects both the number of zones in the forest and the number of stands associated with each zone. Numerous test cases were applied, varying the MIP formulation used to describe core area production, the assumed buffer for core area (50 or 100 m), and the set of additional forest-wide constraints to control harvest levels and core area production levels over time. Solution times varied substantially between the alternative MIP formulations. Solution times were substantially less for the formulation that used more, but simpler, spatial constraints. Solution times for large test cases suggest that real-world applications are likely feasible.

Abundance, Density, and Diversity of Neotropical Migrants at the Lula Lake Land Trust, GA

I used point counts and mist netting at the Lula Lake Land Trust, GA, a reclaimed mining area, to assess its suitability for migrating and breeding long-distance migratory landbirds. The results suggest that the property is suitable for migrants. The proportion of migrants is similar to other areas of the southeastern United States, as well as other reclaimed forestland. In addition, migrant populations were either stable or increased over the three years of monitoring, and 4% of migrants banded returned in subsequent years. Management of the Trust properties should continue to emphasize maintaining large areas of mature forest, and Trust managers should take measures to ensure that increased human recreational activity on the property does not degrade habitat quality.

Evergreen broad-leaved forest in Eastern China: Its ecology and conservation and the importance of resprouting in forest restoration

Biogeographical and ecological research on the evergreen broad-leaved forests (EBLF) of the Far East, which have been reduced to remnant fragments over the historical period has, until now, been very limited. To inform forest conservation and management, this paper describes research into major plant community types and underlying environmental gradients of degraded EBLF in Eastern China and examines the importance of resprouting as a key mechanism in secondary succession following forest clearance. Species composition was described from 199 10 m × 10 m plots and analysed using two-way indicator species analysis and canonical correspondence analysis ordination. Some 22 degraded and mature forest community types were identified, while CCA indicated that a primary vegetation gradient was related to distance of sample plot from mature forest, which was closely linked to altitude and slope. The secondary gradient corresponded to successional stage and disturbance. The roles of resprouting and reseeding characteristics in forest regeneration were researched firstly by 10 m × 10 m plots from selected TWINSPAN groups and secondly by 20 m × 20 m plots in representative areas of forest at 1, 20, 43 and 60 years and in an area of mature forest. The importance of resprouting in the regeneration of many EBLF tree and shrub species is demonstrated, a process linked to ideas of the persistence niche. Existing remnant forests should be conserved but forest restoration is also essential and will benefit from understanding of the importance of tree/shrub resprouting, as well as seedling recruitment in forest regeneration. Further work is required on seedbanks, germination success and both inter- and intra-specific competition within Chinese EBLF to assist with successful forest conservation and management.

Reduced ant diversity along a habitat regeneration gradient in the southern Brazilian Atlantic Forest

This study evaluates the response of the ant communities along a habitat regeneration gradient in the south Atlantic Forest comparing it with the ant fauna from a mature forest at the same biome. The survey was conducted according to standard collecting protocols, employing sardine baits and mini-Winkler apparatuses. The structure of the ground and litter-foraging ant community was compared in five habitats, representing a regeneration gradient within the Atlantic Forest. Furthermore, the composition of the leaf-litter ant fauna and the species richness were compared between the regeneration gradient and an area of mature forest. The results showed a higher number of leaf-litter ant species in the mature forest in comparison with the regeneration gradient habitat, as well a distinct species composition. There was a significant loss of ant diversity in the regrowth forest, compared to the mature Atlantic Forest. The composition of the ground-dwelling ant fauna does not consistently separate the sites of forest succession; but a gradient of ant species richness and composition was revealed when the leaf-litter ant fauna data set was included in the analysis. In this sense, the leaf-litter ant fauna is an important segment to characterize habitats also playing an important rule as bio-indicators. The data suggest that only primary forests (our data) and old secondary forests ( in litt.) are capable of maintaining a substantial proportion of the biodiversity in areas of the Atlantic Forest.

Substratum diversity explains landscape-scale co-variation in the species-richness of bryophytes and lichens

Though the habitats and substrata of bryophytes and lichens overlap, their diversity has not been comparatively explored at large scales. We studied lichens and bryophytes on 30 random 2-km transects in a forest landscape in Estonia. For each vegetation type on each transect, large broad-leaved trees, decorticate snags, logs and windthrows were randomly sampled and their species composition recorded. A total of 108 bryophyte and 127 lichen species were found in 781 sample plots. At the transect scale, larger numbers of lichen species were accompanied with more bryophyte species ( r = 0.49; P = 0.006). Substratum diversity explained 38% of the variation in species-richness for lichens and 44% for bryophytes; when this effect was taken into account, the transect-scale co-variance of the species-richness of the two taxa disappeared. Indeed, other diversity-promoting factors differed for these species groups: the residual species-richness of lichens depended strongly on the relative area of mature forest on transects, while the residual species-richness of bryophytes was higher in commercial than protected forests. The latter was due to the lack of bryophyte-rich substrata in the reserve, since the small-scale richness of the same substrata there was similar to that in commercial forests. For cryptogam conservation, direct consideration of substratum diversity and co-occurrence is extremely important. If the substrata have scattered distributions or the substrata of different taxa are aggregated to different sites, conservation measures should not be based on one surrogate species group only.

06/01982 Biomass resources present in Japan — annual quantities grown, unused and wasted: Minami, E. and Saka, S. Biomass and Bioenergy, 2005, 29, (5), 310–320

The purpose of this study is to evaluate the global bioenergy potential in the future using a multi-regional global-land-use-and-energy model (GLUE-11). The model covers a wide range of biomass flow including food chains from feed to meat, paper recycling, and discharge of biomass residues.Through a set of simulations, the following results are obtained. (1) Supply potential of energy crops produced from surplus arable land will be available in North America, Western Europe, Oceania, Latin America, former USSR and Eastern Europe. However, the potential of energy crops will be strongly affected by the variation of parameters of food supply and demand such as animal food demand. (2) Bioenergy supply potential of biomass residues will be stable against a change of a food demand parameter. The ultimate bioenergy supply potential of biomass residues will be 265EJ/year in the world in 2100. The practical potential of biomass residues in the world will be 114EJ/year, which is equivalent to one-third of the commercial energy consumption in the world in 1990. (3) Concerning land uses, the global mature forest area will decrease by 24% between 1990 and 2100, because of growth of both population and wood biomass demand per capita in the developing regions. The mature forest, especially, will disappear by 2100 in some developing regions, such as Centrally Planned Asia, Middle East and North Africa, and South Asia.

Landscape impacts from valuing core area in national forest planning

Forest core area was valued in a mathematical programming model to support decision-making for the most recent USDA Forest Service plans for national forests in Minnesota. A comparison of management schedules developed by the model to a strategy of simply designating pre-allocated areas for large patch production shows that valuing core area substantially increases the average patch size of mature forest. Analyses of maps of management schedules over the 100-year planning horizon using Fragstats, a computer program for spatial analysis, show substantial differences in spatial measures such as the overall distribution of patch sizes and edge-to-patch-area ratios. Model results reflect the fact that increasing patch sizes improves the efficiency of producing core area because less area of mature forest is then needed for buffer area to protect core area. Although the model cannot address patch size directly, results point to locations where large patches can likely be produced without large sacrifices in other objectives. Compared to other spatial modeling approaches, the approach is appealing because emphasis is on forest conditions rather than the size of harvested areas. Results demonstrate that multiple model runs can give forest planners insight regarding tradeoffs between spatial management objectives and other management objectives for areas as large as a national forest.

RIQUEZA Y DIVERSIDAD DE ESPECIES DE AVES EN UNA SELVA MEDIANA SUBPERENNIFOLIA EN EL CENTRO DE VERACRUZ, MÉXICO

Se registran la riqueza y diversidad de especies de aves en tres áreas distintas (pastizal ganadero, selva con regeneración y selva madura) en una selva mediana subperennifolia del Centro de Veracruz. Se registraron 171 especies, el 45% son abundantes, el 23% escasas y el 32% raras. Del total de especies registradas 112 son residentes y 59 migratorias. Se registraron 126 especies en el área de selva en regeneración, 99 en el pastizal ganadero y 45 en la selva madura. Cincuenta y un especies prefieren el área de selva en regeneración, 40 el pastizal ganadero y 4 la selva madura. Se determinó que existen diferencias estadísticamente significativas entre la abundancia de especies entre las tres áreas de estudio. La diversidad de especies de aves se estimó con el índice de Shannon-Wiener y fue de 4.24 el área con regeneración intermedia, 4.19 en potrero y de 3.44 en selva madura. Una prueba de t de Hutcheson indica que no existen diferencias significativas entre las áreas de selva con regeneración intermedia y pastizal ganadero, pero sí entre estas y el área de selva madura. El análisis para estimar la riqueza de especies indica que pueden registrarse alrededor de 18 especies más.

Amphibian Habitat Associations at Patch and Landscape Scales in the Central Oregon Coast Range

We examined capture rates of amphibians in 30 250-300-ha landscapes in the central Oregon Coast Range, Oregon, USA, to better understand multiscale habitat associations. We compared capture rates of 5 species that had 26-79 captures to expected capture rates based on sampling effort in 7 vegetation patch types and 4 species with 208-482 captures in 11 patch types. Capture rates of 8 amphibian species were higher (P< 0.05) in conifer and/or mixed large sawtimber patch types than in other patch types. We also examined associations between landscape-level capture rates and both percent area of patch-type and 8 pattern indices. The percent area of conifer and/or mixed large sawtimber patch types was associated with capture rates of 5 amphibian species, and various pattern metrics were associated with the capture rates of 4 amphibian species. We found that most amphibian species were associated with unique habitat conditions, making managing across amphibian species difficult. Applying the intermediate disturbance hypothesis at the landscape scale may provide a useful management concept for maintaining suitable habitat conditions for a wide diversity of amphibian species. Mature forest area, patch richness, pattern, and composition seemed to be key features associated with amphibian abundance and distribution that should be considered in management plans when biodiversity of amphibians is a management objective.

Nesting of the black stork ( Ciconia nigra) and white-tailed eagle ( Haliaeetus albicilla) in relation to forest management

Since 1957, 200 m zones around known nests of the black stork ( Ciconia nigra) and white-tailed eagle ( Haliaeetus albicilla) have been strictly protected in Estonia. Yet, the black stork population has recently suffered a large decline, which coincides with the intensification of forestry. To check whether higher disturbance levels could have caused the decline, we related the extent of forestry operations and mature forest near black stork nests to their occupancy, treating the increasing eagle population as a comparison. For both species, we studied 1 km zone around 38 nest sites and, for each nest site, around two random points 2 km away. The total annually cut and reforested area was used to quantify forestry activity, since this single variable explained most of the variability in the extent of different forestry operations. Management was significantly more extensive in the landscapes inhabited by black storks than those inhabited by white-tailed eagles, but the periods of nest occupancy and unoccupancy did not differ significantly in either species. There were neither species-specific nor occupancy-related differences in the total area of mature forest. We conclude that, compared with the white-tailed eagle, the black stork is more vulnerable to disturbance and landscape change due to forestry operations, but these processes are probably not responsible for the recent decline of the stork population.

LANDSCAPE-LEVEL PATTERNS OF AVIAN DIVERSITY IN THE OREGON COAST RANGE

We used a comparative mensurative landscape-level experiment to quantify the relative importance of mature forest area and fragmentation and differences among watersheds in influencing avian community diversity in the Oregon Coast Range, USA. Our study design included three large hydrological basins, two levels of fragmentation, and six levels of mature forest area. We recorded 82 species of birds in a total of 1046 plots in 30 landscapes. Our four response variables were species richness, species density, species evenness, and total bird density. We used a combination of factorial ANOVA and partial canonical variates analysis to quantify the relative importance of differences in mature forest area, fragmentation, and basin in influencing each response variable and community diversity overall. Bird community diversity was influenced by both the extent and fragmentation of mature forest at the landscape level. Species richness and density responded more strongly to mature forest area than to fragmentation and were significantly lower in landscapes that were completely dominated by mature forest than in landscapes with a mixture of seral stages. This reflected a selective loss of a number of early-seral species when mature forest completely blanketed the landscape. Species evenness was more strongly related to fragmentation than to area of mature forest at the landscape level. In fragmented landscapes, the most dominant species decreased in abundance, whereas moderately abundant species increased in relative abundance. This resulted in bird communities that were more even in fragmented landscapes. Unlike several other studies, we did not find that the relative strength of fragmentation effects increased as habitat area decreased. Total bird density, in contrast, was not related to either mature forest area or fragmentation, but it varied significantly among basins. In summary, although both area and fragmentation of mature forest at the landscape level were strongly related to bird community diversity, they had qualitatively different effects. These results must be interpreted within the scope of this study, which took place in a forest-dominated landscape. Our results provide an interesting view of the factors that are related to bird diversity in a spatially complex seral mosaic but may not reflect the patterns that would exist in a high-contrast forest–nonforest landscape. Corresponding Editor: N. C. Kenkel.

Using Radar to Estimate Populations and Assess Habitat Associations of Marbled Murrelets

I used high-frequency marine radar to count marbled murrelets (Brachyramphus marmoratus) entering 20 watersheds in Clayoquot Sound, Vancouver Island, British Columbia, Canada, in 1996-1998. My goal was to develop standard protocols for radar inventory and to explain landscape-level habitat associations of this threatened species. Dawn counts were consistently higher and less variable than dusk counts, but both sampling periods produced similar rankings of watersheds and proportionate numbers of murrelets. Most dawn surveys showed a unimodal pre-sunrise pulse of incoming murrelets, but a few dawn surveys showed post-sunrise pulses, likely caused by repeat visits by some birds. These post-sunrise pulses, although rare, inflated estimates of incoming murrelets and were avoided by restricting analyses to pre-sunrise counts. Dawn and dusk counts were higher on cloudy days (≥80% cloud cover) than on clear days, but among cloudy days there was no additional effect on counts caused by precipitation (thick fog or drizzle). Numbers of murrelets entering watersheds varied seasonally, reflecting the breeding chronology, but counts restricted to the core period covering incubation and chick-rearing (mid-May through mid-Jul) showed no significant seasonal effects. Counts varied among years at some stations, but when all stations were considered together, no significant inter-annual variation occurred. Murrelets sometimes flew over low ridges (200-600 m), taking shortcuts into watersheds or crossing from 1 watershed into another. I therefore adjusted the boundaries of some inland catchment areas (based on topography and likely flight paths) to match correctly counts made at the watershed mouths with the appropriate inland catchment area. Radar counts at 18 watersheds were significantly correlated with total watershed area, areas of mature (>140 year old) forest, and-most strongly-with areas of mature forest below 600 m. Logging produced negative impacts. Three of the 5 watersheds with extensive logging of low-elevation forest had fewer murrelets per area than unlogged watersheds or those that were <10% logged, but these differences disappeared once remaining low-elevation mature forests were considered. With the removal of old-growth forests, murrelets evidently moved elsewhere and did not pack into the remaining old-growth patches in higher densities.

Evaluation of bioenergy potential with a multi-regional global-land-use-and-energy model

The purpose of this study is to evaluate the global bioenergy potential in the future using a multi-regional global-land-use-and-energy model (GLUE-11). The model covers a wide range of biomass flow including food chains from feed to meat, paper recycling, and discharge of biomass residues. Through a set of simulations, the following results are obtained. (1) Supply potential of energy crops produced from surplus arable land will be available in North America, Western Europe, Oceania, Latin America, former USSR and Eastern Europe. However, the potential of energy crops will be strongly affected by the variation of parameters of food supply and demand such as animal food demand. (2) Bioenergy supply potential of biomass residues will be stable against a change of a food demand parameter. The ultimate bioenergy supply potential of biomass residues will be 265 EJ/year in the world in 2100. The practical potential of biomass residues in the world will be 114 EJ/year , which is equivalent to one-third of the commercial energy consumption in the world in 1990. (3) Concerning land uses, the global mature forest area will decrease by 24% between 1990 and 2100, because of growth of both population and wood biomass demand per capita in the developing regions. The mature forest, especially, will disappear by 2100 in some developing regions, such as Centrally Planned Asia, Middle East and North Africa, and South Asia.