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Sample records for forest fragmentation reduces

  1. Targeted habitat restoration can reduce extinction rates in fragmented forests.

    Science.gov (United States)

    Newmark, William D; Jenkins, Clinton N; Pimm, Stuart L; McNeally, Phoebe B; Halley, John M

    2017-09-05

    The Eastern Arc Mountains of Tanzania and the Atlantic Forest of Brazil are two of the most fragmented biodiversity hotspots. Species-area relationships predict that their habitat fragments will experience a substantial loss of species. Most of these extinctions will occur over an extended time, and therefore, reconnecting fragments could prevent species losses and allow locally extinct species to recolonize former habitats. An empirical relaxation half-life vs. area relationship for tropical bird communities estimates the time that it takes to lose one-half of all species that will be eventually lost. We use it to estimate the increase in species persistence by regenerating a forest connection 1 km in width among the largest and closest fragments at 11 locations. In the Eastern Arc Mountains, regenerating 8,134 ha of forest would create >316,000 ha in total of restored contiguous forest. More importantly, it would increase the persistence time for species by a factor of 6.8 per location or ∼2,272 years, on average, relative to individual fragments. In the Atlantic Forest, regenerating 6,452 ha of forest would create >251,000 ha in total of restored contiguous forest and enhance species persistence by a factor of 13.0 per location or ∼5,102 years, on average, relative to individual fragments. Rapidly regenerating forest among fragments is important, because mean time to the first determined extinction across all fragments is 7 years. We estimate the cost of forest regeneration at $21-$49 million dollars. It could provide one of the highest returns on investment for biodiversity conservation worldwide.

  2. Changes in tree reproductive traits reduce functional diversity in a fragmented Atlantic forest landscape.

    Science.gov (United States)

    Girão, Luciana Coe; Lopes, Ariadna Valentina; Tabarelli, Marcelo; Bruna, Emilio M

    2007-09-19

    Functional diversity has been postulated to be critical for the maintenance of ecosystem functioning, but the way it can be disrupted by human-related disturbances remains poorly investigated. Here we test the hypothesis that habitat fragmentation changes the relative contribution of tree species within categories of reproductive traits (frequency of traits) and reduces the functional diversity of tree assemblages. The study was carried out in an old and severely fragmented landscape of the Brazilian Atlantic forest. We used published information and field observations to obtain the frequency of tree species and individuals within 50 categories of reproductive traits (distributed in four major classes: pollination systems, floral biology, sexual systems, and reproductive systems) in 10 fragments and 10 tracts of forest interior (control plots). As hypothesized, populations in fragments and control plots differed substantially in the representation of the four major classes of reproductive traits (more than 50% of the categories investigated). The most conspicuous differences were the lack of three pollination systems in fragments--pollination by birds, flies and non-flying mammals--and that fragments had a higher frequency of both species and individuals pollinated by generalist vectors. Hermaphroditic species predominate in both habitats, although their relative abundances were higher in fragments. On the contrary, self-incompatible species were underrepresented in fragments. Moreover, fragments showed lower functional diversity (H' scores) for pollination systems (-30.3%), floral types (-23.6%), and floral sizes (-20.8%) in comparison to control plots. In contrast to the overwhelming effect of fragmentation, patch and landscape metrics such as patch size and forest cover played a minor role on the frequency of traits. Our results suggest that habitat fragmentation promotes a marked shift in the relative abundance of tree reproductive traits and greatly reduces

  3. Changes in tree reproductive traits reduce functional diversity in a fragmented Atlantic forest landscape.

    Directory of Open Access Journals (Sweden)

    Luciana Coe Girão

    Full Text Available Functional diversity has been postulated to be critical for the maintenance of ecosystem functioning, but the way it can be disrupted by human-related disturbances remains poorly investigated. Here we test the hypothesis that habitat fragmentation changes the relative contribution of tree species within categories of reproductive traits (frequency of traits and reduces the functional diversity of tree assemblages. The study was carried out in an old and severely fragmented landscape of the Brazilian Atlantic forest. We used published information and field observations to obtain the frequency of tree species and individuals within 50 categories of reproductive traits (distributed in four major classes: pollination systems, floral biology, sexual systems, and reproductive systems in 10 fragments and 10 tracts of forest interior (control plots. As hypothesized, populations in fragments and control plots differed substantially in the representation of the four major classes of reproductive traits (more than 50% of the categories investigated. The most conspicuous differences were the lack of three pollination systems in fragments--pollination by birds, flies and non-flying mammals--and that fragments had a higher frequency of both species and individuals pollinated by generalist vectors. Hermaphroditic species predominate in both habitats, although their relative abundances were higher in fragments. On the contrary, self-incompatible species were underrepresented in fragments. Moreover, fragments showed lower functional diversity (H' scores for pollination systems (-30.3%, floral types (-23.6%, and floral sizes (-20.8% in comparison to control plots. In contrast to the overwhelming effect of fragmentation, patch and landscape metrics such as patch size and forest cover played a minor role on the frequency of traits. Our results suggest that habitat fragmentation promotes a marked shift in the relative abundance of tree reproductive traits and

  4. Forest fragmentation reduces parasitism via species loss at multiple trophic levels.

    Science.gov (United States)

    Fenoglio, Maria Silvina; Srivastava, Diane; Valladares, Graciela; Cagnolo, Luciano; Salvo, Adriana

    2012-11-01

    Although there is accumulating evidence from artificially assembled communities that reductions of species diversity result in diminished ecosystem functioning, it is not yet clear how real-world changes in diversity affect the flow of energy between trophic levels in multi-trophic contexts. In central Argentina, forest fragmentation has led to species loss of plants, herbivore and parasitoid insects, decline in trophic processes (herbivory and parasitism), and food web contraction. Here we examine if and how loss of parasitoid species following fragmentation causes decreased parasitism rates, by analyzing food webs of leaf miners and parasitoids from 19 forest fragments of decreasing size. We asked three questions: Do reductions in parasitoid richness following fragmentation directly or indirectly affect parasitism rate? Are changes in community parasitism rate driven by changes in the parasitism rate of individual leaf miner species, or changes in leaf miner composition, or both? Which traits of species determine the effects of food web change on parasitism rates? We found that habitat loss initiated a bottom-up cascade of extinctions from plants to leaf miners to parasitoids, with reductions in parasitoid richness ultimately driving decreases in parasitism rates. This relationship between parasitoid richness and parasitism depended on changes in the relative abundance (but not occurrence) of leaf miners such that parasitoid-rich fragments were dominated by leaf miner species that supported high rates of parasitism. Surprisingly, we found that only a small subset of species in the food web could account for much of the increase in parasitism with parasitoid richness: lepidopteran miners that attained exceptionally high densities in some fragments and their largely specialist parasitoids. How specialized a parasitoid is, and the relative abundance of leaf miners, had important effects on the diversity-parasitism rate relationship, but not other leaf miner traits

  5. Regional Forest Fragmentation and the Nesting Success of Migratory Birds

    Science.gov (United States)

    Scott K. Robinson; Frank R. Thompson III; Therese M. Donovan; Donald R. Whitehead; John Faaborg

    1995-01-01

    Forest fragmentation, the disruption in the continuity of forest habitat, is hypothesized to be a major cause of population decline for, some species of forest birds because fragmentation reduces nesting (reproductive) success. Nest predation and parasitism by cowbirds increased with forest fragmentation in nine midwestern (United States)landscapes that varied from 6...

  6. Targeting incentives to reduce habitat fragmentation

    Science.gov (United States)

    David Lewis; Andrew Plantinga; Junjie Wu

    2009-01-01

    This article develops a theoretical model to analyze the spatial targeting of incentives for the restoration of forested landscapes when wildlife habitat can be enhanced by reducing fragmentation. The key theoretical result is that the marginal net benefits of increasing forest can be convex, in which case corner solutions--converting either none or all of the...

  7. Fragmentation of eastern United States forest types

    Science.gov (United States)

    Kurt H. Riitters; John W. Coulston

    2013-01-01

    Fragmentation is a continuing threat to the sustainability of forests in the Eastern United States, where land use changes supporting a growing human population are the primary driver of forest fragmentation (Stein and others 2009). While once mostly forested, approximately 40 percent of the original forest area has been converted to other land uses, and most of the...

  8. Forest fragmentation and its effects on birds

    Science.gov (United States)

    Robbins, C.S.; Johnson, James E.

    1988-01-01

    Fragmentation of forest land, whether by suburban development, highways, transmission lines, or poorly planned cutting regimes, seriously affects reproduction by the large numbers of obligate forest interior birds. Many of our warblers, vireos, thrushes, tanagers, and flycatchers are highly migratory insectivorous birds that spend more than half the year in the neotropics, but migrate north to the United States and Canada to rear their young. These tropical visitors are especially vulnerable to predation and cowbird parasitism and are unable to maintain their populations within 100-200 m of forest edge. Habitats for these declining species can be provided by managing forest lands in large blocks so as to maintain at all times extensive contiguous areas of successional stages as well as of mature forest. Avoiding scattered small cuts will also help by reducing edge, road construction, and other disturbance.

  9. The effects of forest fragmentation on forest stand attributes

    Science.gov (United States)

    Ronald E. McRoberts; Greg C. Liknes

    2002-01-01

    For two study areas in Minnesota, USA, one heavily forested and one sparsely forested, maps of predicted proportion forest area were created using Landsat Thematic Mapper imagery, forest inventory plot data, and a logistic regression model. The maps were used to estimate quantitative indices of forest fragmentation. Correlations between the values of the indices and...

  10. Seasonal use of remnant forest fragments by understorey forest ...

    African Journals Online (AJOL)

    While there is information on the distribution of forest bird species in most of the Eastern Arc Mountain forests, some forests, particularly the smaller fragments, have not been adequately surveyed. Using mist ... Keywords: altitudinal gradient, altitudinal migration, bird distribution, conservation, fragmentation, mist-netting ...

  11. Global-Scale Patterns of Forest Fragmentation

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    Kurt Riitters

    2000-12-01

    Full Text Available We report an analysis of forest fragmentation based on 1-km resolution land-cover maps for the globe. Measurements in analysis windows from 81 km 2 (9 x 9 pixels, "small" scale to 59,049 km 2 (243 x 243 pixels, "large" scale were used to characterize the fragmentation around each forested pixel. We identified six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions. At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe-Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types and Europe-Asia (four types, in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as "naturally patchy" (e.g., dry woodland. The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf.

  12. Fragmentation impairs the microclimate buffering effect of tropical forests.

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    Ewers, Robert M; Banks-Leite, Cristina

    2013-01-01

    Tropical forest species are among the most sensitive to changing climatic conditions, and the forest they inhabit helps to buffer their microclimate from the variable climatic conditions outside the forest. However, habitat fragmentation and edge effects exposes vegetation to outside microclimatic conditions, thereby reducing the ability of the forest to buffer climatic variation. In this paper, we ask what proportion of forest in a fragmented ecosystem is impacted by altered microclimate conditions driven by edge effects, and extrapolate these results to the whole Atlantic Forest biome, one of the most disturbed biodiversity hotspots. To address these questions, we collected above and below ground temperature for a full year using temperature sensors placed in forest fragments of different sizes, and at different distances from the forest edge. In the Atlantic forests of Brazil, we found that the buffering effect of forests reduced maximum outside temperatures by one third or more at ground level within a forest, with the buffering effect being stronger below-ground than one metre above-ground. The temperature buffering effect of forests was, however, reduced near forest edges with the edge effect extending up to 20 m inside the forest. The heavily fragmented nature of the Brazilian Atlantic forest means that 12% of the remaining biome experiences altered microclimate conditions. Our results add further information about the extent of edge effects in the Atlantic Forest, and we suggest that maintaining a low perimeter-to-area ratio may be a judicious method for minimizing the amount of forest area that experiences altered microclimatic conditions in this ecosystem.

  13. Effect of fragmentation on the Costa Rican dry forest avifauna.

    Science.gov (United States)

    Barrantes, Gilbert; Ocampo, Diego; Ramírez-Fernández, José D; Fuchs, Eric J

    2016-01-01

    Deforestation and changes in land use have reduced the tropical dry forest to isolated forest patches in northwestern Costa Rica. We examined the effect of patch area and length of the dry season on nestedness of the entire avian community, forest fragment assemblages, and species occupancy across fragments for the entire native avifauna, and for a subset of forest dependent species. Species richness was independent of both fragment area and distance between fragments. Similarity in bird community composition between patches was related to habitat structure; fragments with similar forest structure have more similar avian assemblages. Size of forest patches influenced nestedness of the bird community and species occupancy, but not nestedness of assemblages across patches in northwestern Costa Rican avifauna. Forest dependent species (species that require large tracts of mature forest) and assemblages of these species were nested within patches ordered by a gradient of seasonality, and only occupancy of species was nested by area of patches. Thus, forest patches with a shorter dry season include more forest dependent species.

  14. Distribution and Causes of Global Forest Fragmentation

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    Timothy G. Wade

    2003-12-01

    Full Text Available Because human land uses tend to expand over time, forests that share a high proportion of their borders with anthropogenic uses are at higher risk of further degradation than forests that share a high proportion of their borders with non-forest, natural land cover (e.g., wetland. Using 1-km advanced very high resolution radiometer (AVHRR satellite-based land cover, we present a method to separate forest fragmentation into natural and anthropogenic components, and report results for all inhabited continents summarized by World Wildlife Fund biomes. Globally, over half of the temperate broadleaf and mixed forest biome and nearly one quarter of the tropical rainforest biome have been fragmented or removed by humans, as opposed to only 4% of the boreal forest. Overall, Europe had the most human-caused fragmentation and South America the least. This method may allow for improved risk assessments and better targeting for protection and remediation by identifying areas with high amounts of human-caused fragmentation.

  15. Global patterns of tropical forest fragmentation

    Science.gov (United States)

    Taubert, Franziska; Fischer, Rico; Groeneveld, Jürgen; Lehmann, Sebastian; Müller, Michael S.; Rödig, Edna; Wiegand, Thorsten; Huth, Andreas

    2018-02-01

    Remote sensing enables the quantification of tropical deforestation with high spatial resolution. This in-depth mapping has led to substantial advances in the analysis of continent-wide fragmentation of tropical forests. Here we identified approximately 130 million forest fragments in three continents that show surprisingly similar power-law size and perimeter distributions as well as fractal dimensions. Power-law distributions have been observed in many natural phenomena such as wildfires, landslides and earthquakes. The principles of percolation theory provide one explanation for the observed patterns, and suggest that forest fragmentation is close to the critical point of percolation; simulation modelling also supports this hypothesis. The observed patterns emerge not only from random deforestation, which can be described by percolation theory, but also from a wide range of deforestation and forest-recovery regimes. Our models predict that additional forest loss will result in a large increase in the total number of forest fragments—at maximum by a factor of 33 over 50 years—as well as a decrease in their size, and that these consequences could be partly mitigated by reforestation and forest protection.

  16. Forest fragmentation and Lyme disease

    Science.gov (United States)

    Lyme disease is the most commonly reported vectorborne disease in the United States. It is associated with human exposure to infected Ixodes ticks which exist even in degraded forest and herbaceous habitat. We provide an overview of the epidemiology, ecology and landscape charact...

  17. Avian guild assemblages in forest fragments around Budongo ...

    African Journals Online (AJOL)

    Remnant forest fragments provide an opportunity for conservation in fragmented landscapes but some patches are more useful than others. Forest fragments around Budongo Forest Reserve, an Important Bird Area in western Uganda, were surveyed to explore the effects of different aspects of habitat fragmentation on bird ...

  18. Fragmentation of forest, grassland, and shrubland

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    Kurt H. Riitters

    2013-01-01

    As humans introduce competing land uses into natural landscapes, the public concerns regarding landcover patterns are expressed through headline issues such as urban sprawl, forest fragmentation, water quality, and wilderness preservation. The spatial arrangement of an environment affects all human perceptions and ecological processes within that environment, but this...

  19. Life-history traits and landscape characteristics predict macro-moth responses to forest fragmentation.

    Science.gov (United States)

    Slade, Eleanor M; Merckx, Thomas; Riutta, Terhi; Bebber, Daniel P; Redhead, David; Riordan, Philip; Macdonald, David W

    2013-07-01

    How best to manage forest patches, mitigate the consequences of forest fragmentation, and enable landscape permeability are key questions facing conservation scientists and managers. Many temperate forests have become increasingly fragmented, resulting in reduced interior forest habitat, increased edge habitats, and reduced connectivity. Using a citizen science landscape-scale mark-release-recapture study on 87 macro-moth species, we investigated how both life-history traits and landscape characteristics predicted macro-moth responses to forest fragmentation. Wingspan, wing shape, adult feeding, and larval feeding guild predicted macro-moth mobility, although the predictive power of wingspan and wing shape depended on the species' affinity to the forest. Solitary trees and small fragments functioned as "stepping stones," especially when their landscape connectivity was increased, by being positioned within hedgerows or within a favorable matrix. Mobile forest specialists were most affected by forest fragmentation: despite their high intrinsic dispersal capability, these species were confined mostly to the largest of the forest patches due to their strong affinity for the forest habitat, and were also heavily dependent on forest connectivity in order to cross the agricultural matrix. Forest fragments need to be larger than five hectares and to have interior forest more than 100 m from the edge in order to sustain populations of forest specialists. Our study provides new insights into the movement patterns of a functionally important insect group, with implications for the landscape-scale management of forest patches within agricultural landscapes.

  20. Techniques and Considerations for FIA forest fragmentation analysis

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    Andrew J. Lister; Tonya W. Lister; Rachel Riemann; Mike Hoppus

    2002-01-01

    The Forest Inventory and Analysis unit of the Northeastern Research Station (NEFIA) is charged with inventorying and monitoring the Nation's forests. NEFIA has not gathered much information on forest fragmentation, but recent developments in computing and remote sensing technologies now make it possible to assess forest fragmentation on a regional basis. We...

  1. FLORULA URBAN FRAGMENT OF TROPICAL DRY FOREST

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    Willington Barranco-Pérez

    2016-01-01

    Full Text Available The aim of this study was to record the composition of plant species in an urban fragment of tropical dry forest of secondary regeneration (bs-T to generate information that can be used in the planning and management of green spaces in the city of Santa Marta. Transects of 2 x 50 m were established equivalent to 0.1 ha and all species were counted >1.0 cm DBH (Diameter at Breast Height: 1.3m. 100 species of angiosperms were recorded of which 47% have herbaceous habit. The number of species recorded in this study represents 39.6% of the species reported for the hills of Santa Marta and 3.8% for the dry forests of Colombia. It is suggested to isolate this type of secondary formations of any intervention and contemplate the reintroduction of individuals and conservation strategies.

  2. Genetic consequences of forest fragmentation for a highly specialized arboreal mammal--the edible dormouse.

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    Joanna Fietz

    Full Text Available Habitat loss and fragmentation represent the most serious extinction threats for many species and have been demonstrated to be especially detrimental for mammals. Particularly, highly specialized species with low dispersal abilities will encounter a high risk of extinction in fragmented landscapes. Here we studied the edible dormouse (Glis glis, a small arboreal mammal that is distributed throughout Central Europe, where forests are mostly fragmented at different spatial scales. The aim of this study was to investigate the effect of habitat fragmentation on genetic population structures using the example of edible dormouse populations inhabiting forest fragments in south western Germany. We genotyped 380 adult individuals captured between 2001 and 2009 in four different forest fragments and one large continuous forest using 14 species-specific microsatellites. We hypothesised, that populations in small forest patches have a lower genetic diversity and are more isolated compared to populations living in continuous forests. In accordance with our expectations we found that dormice inhabiting forest fragments were isolated from each other. Furthermore, their genetic population structure was more unstable over the study period than in the large continuous forest. Even though we could not detect lower genetic variability within individuals inhabiting forest fragments, strong genetic isolation and an overall high risk to mate with close relatives might be precursors to a reduced genetic variability and the onset of inbreeding depression. Results of this study highlight that connectivity among habitat fragments can already be strongly hampered before genetic erosion within small and isolated populations becomes evident.

  3. Who wants to conserve remaining forest fragments in the ...

    African Journals Online (AJOL)

    An increasing number of international projects are therefore trying to preserve remaining forests and to transfer the management of these for- ests to local communities. However, it is not known how impor- tant the preservation of forest fragments are to local people. We therefore explore the importance of forest fragments as ...

  4. Discerning Fragmentation Dynamics of Tropical Forest and Wetland during Reforestation, Urban Sprawl, and Policy Shifts

    Science.gov (United States)

    Gao, Qiong; Yu, Mei

    2014-01-01

    Despite the overall trend of worldwide deforestation over recent decades, reforestation has also been found and is expected in developing countries undergoing fast urbanization and agriculture abandonment. The consequences of reforestation on landscape patterns are seldom addressed in the literature, despite their importance in evaluating biodiversity and ecosystem functions. By analyzing long-term land cover changes in Puerto Rico, a rapidly reforested (6 to 42% during 1940–2000) and urbanized tropical island, we detected significantly different patterns of fragmentation and underlying mechanisms among forests, urban areas, and wetlands. Forest fragmentation is often associated with deforestation. However, we also found significant fragmentation during reforestation. Urban sprawl and suburb development have a dominant impact on forest fragmentation. Reforestation mostly occurs along forest edges, while significant deforestation occurs in forest interiors. The deforestation process has a much stronger impact on forest fragmentation than the reforestation process due to their different spatial configurations. In contrast, despite the strong interference of coastal urbanization, wetland aggregation has occurred due to the effective implementation of laws/regulations for wetland protection. The peak forest fragmentation shifted toward rural areas, indicating progressively more fragmentation in forest interiors. This shift is synchronous with the accelerated urban sprawl as indicated by the accelerated shift of the peak fragmentation index of urban cover toward rural areas, i.e., 1.37% yr−1 in 1977–1991 versus 2.17% yr−1 in 1991–2000. Based on the expected global urbanization and the regional forest transition from deforested to reforested, the fragmented forests and aggregated wetlands in this study highlight possible forest fragmentation processes during reforestation in an assessment of biodiversity and functions and suggest effective laws/regulations in

  5. Discerning fragmentation dynamics of tropical forest and wetland during reforestation, urban sprawl, and policy shifts.

    Science.gov (United States)

    Gao, Qiong; Yu, Mei

    2014-01-01

    Despite the overall trend of worldwide deforestation over recent decades, reforestation has also been found and is expected in developing countries undergoing fast urbanization and agriculture abandonment. The consequences of reforestation on landscape patterns are seldom addressed in the literature, despite their importance in evaluating biodiversity and ecosystem functions. By analyzing long-term land cover changes in Puerto Rico, a rapidly reforested (6 to 42% during 1940-2000) and urbanized tropical island, we detected significantly different patterns of fragmentation and underlying mechanisms among forests, urban areas, and wetlands. Forest fragmentation is often associated with deforestation. However, we also found significant fragmentation during reforestation. Urban sprawl and suburb development have a dominant impact on forest fragmentation. Reforestation mostly occurs along forest edges, while significant deforestation occurs in forest interiors. The deforestation process has a much stronger impact on forest fragmentation than the reforestation process due to their different spatial configurations. In contrast, despite the strong interference of coastal urbanization, wetland aggregation has occurred due to the effective implementation of laws/regulations for wetland protection. The peak forest fragmentation shifted toward rural areas, indicating progressively more fragmentation in forest interiors. This shift is synchronous with the accelerated urban sprawl as indicated by the accelerated shift of the peak fragmentation index of urban cover toward rural areas, i.e., 1.37% yr-1 in 1977-1991 versus 2.17% yr-1 in 1991-2000. Based on the expected global urbanization and the regional forest transition from deforested to reforested, the fragmented forests and aggregated wetlands in this study highlight possible forest fragmentation processes during reforestation in an assessment of biodiversity and functions and suggest effective laws/regulations in land

  6. Discerning fragmentation dynamics of tropical forest and wetland during reforestation, urban sprawl, and policy shifts.

    Directory of Open Access Journals (Sweden)

    Qiong Gao

    Full Text Available Despite the overall trend of worldwide deforestation over recent decades, reforestation has also been found and is expected in developing countries undergoing fast urbanization and agriculture abandonment. The consequences of reforestation on landscape patterns are seldom addressed in the literature, despite their importance in evaluating biodiversity and ecosystem functions. By analyzing long-term land cover changes in Puerto Rico, a rapidly reforested (6 to 42% during 1940-2000 and urbanized tropical island, we detected significantly different patterns of fragmentation and underlying mechanisms among forests, urban areas, and wetlands. Forest fragmentation is often associated with deforestation. However, we also found significant fragmentation during reforestation. Urban sprawl and suburb development have a dominant impact on forest fragmentation. Reforestation mostly occurs along forest edges, while significant deforestation occurs in forest interiors. The deforestation process has a much stronger impact on forest fragmentation than the reforestation process due to their different spatial configurations. In contrast, despite the strong interference of coastal urbanization, wetland aggregation has occurred due to the effective implementation of laws/regulations for wetland protection. The peak forest fragmentation shifted toward rural areas, indicating progressively more fragmentation in forest interiors. This shift is synchronous with the accelerated urban sprawl as indicated by the accelerated shift of the peak fragmentation index of urban cover toward rural areas, i.e., 1.37% yr-1 in 1977-1991 versus 2.17% yr-1 in 1991-2000. Based on the expected global urbanization and the regional forest transition from deforested to reforested, the fragmented forests and aggregated wetlands in this study highlight possible forest fragmentation processes during reforestation in an assessment of biodiversity and functions and suggest effective laws

  7. Forest habitat loss, fragmentation, and red-cockaded woodpecker populations

    Science.gov (United States)

    Richard N. Conner; D. Craig Rudolph

    1991-01-01

    Loss of mature forest habitat was measured around Red-cockaded Woodpecker (Picoides borealis) cavity tree clusters (colonies) in three National Forests in eastern Texas. Forest removal results in a loss of foraging habitat and causes habitat fragmentation of the remaining mature forest. Habitat loss was negatively associated with woodpecker group size in small...

  8. Forest Fragmentation and Driving Forces in Yingkou, Northeastern China

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    Lei Zhang

    2017-03-01

    Full Text Available Forest fragmentation, the process of changing original large and intact forest patches into smaller and isolated areas, significantly influences the balance of surface physical environment, biodiversity, and species richness. Sufficient knowledge of forest fragmentation is necessary to maintain ecological balance and promote sustainable resource utilization. This study combines remote sensing, geographical information systems, and landscape metrics to assess forest fragmentation at landscape and pixel levels during different time periods (2000–2005, 2005–2010, and 2010–2015 in the Yingkou region. Spatial statistical analysis is also used to analyze the relationship between forest landscape fragmentation and its determinants (e.g., natural factors, socioeconomic factors, and proximity factors. Results show that forest patches became smaller, subdivided, and isolated during 2010–2015 at the total landscape level. Local changes occurred in the southwest of the study region or around the development area. Our data also indicate that shrinkage and subdivision were the main forest fragmentation processes during three times, and attrition became the main forest fragmentation process from 2010 to 2015. These changes were significantly influenced by natural factors (e.g., elevation and slope, proximity factors (e.g., distance to city and distance to province roads, and socioeconomic factors (e.g., gross domestic product. Results presented in this study provide valuable insights into the pattern and processes of forest fragmentation and present direct implications for the protection and reasonable utilization of forest resources.

  9. Characterizing the forest fragmentation of Canada's national parks.

    Science.gov (United States)

    Soverel, Nicholas O; Coops, Nicholas C; White, Joanne C; Wulder, Michael A

    2010-05-01

    Characterizing the amount and configuration of forests can provide insights into habitat quality, biodiversity, and land use. The establishment of protected areas can be a mechanism for maintaining large, contiguous areas of forests, and the loss and fragmentation of forest habitat is a potential threat to Canada's national park system. Using the Earth Observation for Sustainable Development of Forests (EOSD) land cover product (EOSD LC 2000), we characterize the circa 2000 forest patterns in 26 of Canada's national parks and compare these to forest patterns in the ecological units surrounding these parks, referred to as the greater park ecosystem (GPE). Five landscape pattern metrics were analyzed: number of forest patches, mean forest patch size (hectare), standard deviation of forest patch size (hectare), mean forest patch perimeter-to-area ratio (meters per hectare), and edge density of forest patches (meters per hectare). An assumption is often made that forests within park boundaries are less fragmented than the surrounding GPE, as indicated by fewer forest patches, a larger mean forest patch size, less variability in forest patch size, a lower perimeter-to-area ratio, and lower forest edge density. Of the 26 national parks we analyzed, 58% had significantly fewer patches, 46% had a significantly larger mean forest patch size (23% were not significantly different), and 46% had a significantly smaller standard deviation of forest patch size (31% were not significantly different), relative to their GPEs. For forest patch perimeter-to-area ratio and forest edge density, equal proportions of parks had values that were significantly larger or smaller than their respective GPEs and no clear trend emerged. In summary, all the national parks we analyzed, with the exception of the Georgian Bay Islands, were found to be significantly different from their corresponding GPE for at least one of the five metrics assessed, and 50% of the 26 parks were significantly

  10. Semi-forest coffee cultivation and the conservation of Ethiopian Afromontane rainforest fragments

    OpenAIRE

    Aerts, Raf; Hundera, K; Berecha, G; Gijbels, Pieter; Baeten, Marieke; Van Mechelen, Maarten; Hermy, Martin; Muys, Bart; Honnay, Olivier

    2011-01-01

    Coffea arabica shrubs are indigenous to the understorey of the moist evergreen montane rainforest of Ethiopia. Semi-forest coffee is harvested from semi-wild plants in forest fragments where farmers thin the upper canopy and annually slash the undergrowth. This traditional method of coffee cultivation is a driver for preservation of indigenous forest cover, differing from other forms of agriculture and land use which tend to reduce forest cover. Because coffee farmers are primarily interes...

  11. Effects of habitat fragmentation on bird communities of sand forests ...

    African Journals Online (AJOL)

    We investigated the influence of forest fragment size and isolation on the bird assemblages in the species- and endemic-rich sand forests of the Maputaland Centre of Endemism, southern Mozambique. Point-centre surveys were conducted across 12 sand forest patches that varied in size and isolation. Patch size and ...

  12. Geospatial analysis of forest fragmentation in Uttara Kannada District, India

    Directory of Open Access Journals (Sweden)

    Ramachandra T V

    2016-04-01

    Full Text Available Background: Landscapes consist of heterogeneous interacting dynamic elements with complex ecological, economic and cultural attributes. These complex interactions help in the sustenance of natural resources through bio-geochemical and hydrological cycling. The ecosystem functions are altered with changes in the landscape structure. Fragmentation of large contiguous forests to small and isolated forest patches either by natural phenomena or anthropogenic activities leads to drastic changes in forest patch sizes, shape, connectivity and internal heterogeneity, which restrict the movement leading to inbreeding among Meta populations with extirpation of species. Methods: Landscape dynamics are assessed through land use analysis by way of remote sensing data acquired at different time periods. Forest fragmentation is assessed at the pixel level through computation of two indicators, i.e., Pf (the ratio of pixels that are forested to the total non-water pixels in the window and Pff (the proportion of all adjacent (cardinal directions only pixel pairs that include at least one forest pixel, for which both pixels are forested. Results: Uttara Kannada District has the distinction of having the highest forest cover in Karnataka State, India. This region has been experiencing changes in its forest cover and consequent alterations in functional abilities of its ecosystem. Temporal land use analyses show the trend of deforestation, evident from the reduction of evergreen - semi evergreen forest cover from 57.31 % (1979 to 32.08 % (2013 Forest fragmentation at the landscape level shows a decline of interior forests 64.42 % (1979 to 25.62 % (2013 and transition of non-forest categories such as crop land, plantations and built-up areas, amounting now to 47.29 %. PCA prioritized geophysical and socio variables responsible for changes in the landscape structure at local levels. Conclusion: Terrestrial forest ecosystems in Uttara Kannada District of Central

  13. Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient.

    Science.gov (United States)

    Orihuela, Rodrigo L L; Peres, Carlos A; Mendes, Gabriel; Jarenkow, João A; Tabarelli, Marcelo

    2015-01-01

    We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide.

  14. Forest edge disturbance increases rattan abundance in tropical rain forest fragments.

    Science.gov (United States)

    Campbell, Mason J; Edwards, Will; Magrach, Ainhoa; Laurance, Susan G; Alamgir, Mohammed; Porolak, Gabriel; Laurance, William F

    2017-07-20

    Human-induced forest fragmentation poses one of the largest threats to global diversity yet its impact on rattans (climbing palms) has remained virtually unexplored. Rattan is arguably the world's most valuable non-timber forest product though current levels of harvesting and land-use change place wild populations at risk. To assess rattan response to fragmentation exclusive of harvesting impacts we examined rattan abundance, demography and ecology within the forests of northeastern, Australia. We assessed the community abundance of rattans, and component adult (>3 m) and juvenile (≤3 m) abundance in five intact forests and five fragments (23-58 ha) to determine their response to a range of environmental and ecological parameters. Fragmented forests supported higher abundances of rattans than intact forests. Fragment size and edge degradation significantly increased adult rattan abundance, with more in smaller fragments and near edges. Our findings suggest that rattan increase within fragments is due to canopy disturbance of forest edges resulting in preferential, high-light habitat. However, adult and juvenile rattans may respond inconsistently to fragmentation. In managed forest fragments, a rattan abundance increase may provide economic benefits through sustainable harvesting practices. However, rattan increases in protected area forest fragments could negatively impact conservation outcomes.

  15. Evaluating differences in forest fragmentation and restoration between western natural forests and southeastern plantation forests in the United States.

    Science.gov (United States)

    Ren, Xinyu; Lv, Yingying; Li, Mingshi

    2017-03-01

    Changes in forest ecosystem structure and functions are considered some of the research issues in landscape ecology. In this study, advancing Forman's theory, we considered five spatially explicit processes associated with fragmentation, including perforation, dissection, subdivision, shrinkage, and attrition, and two processes associated with restoration, i.e., increment and expansion processes. Following this theory, a forest fragmentation and restoration process model that can detect the spatially explicit processes and ecological consequences of forest landscape change was developed and tested in the current analysis. Using the National Land Cover Databases (2001, 2006 and 2011), the forest fragmentation and restoration process model was applied to US western natural forests and southeastern plantation forests to quantify and classify forest patch losses into one of the four fragmentation processes (the dissection process was merged into the subdivision process) and to classify the newly gained forest patches based on the two restoration processes. At the same time, the spatio-temporal differences in fragmentation and restoration patterns and trends between natural forests and plantations were further compared. Then, through overlaying the forest fragmentation/restoration processes maps with targeting year land cover data and land ownership vectors, the results from forest fragmentation and the contributors to forest restoration in federal and nonfederal lands were identified. Results showed that, in natural forests, the forest change patches concentrated around the urban/forest, cultivated/forest, and shrubland/forest interfaces, while the patterns of plantation change patches were scattered sparsely and irregularly. The shrinkage process was the most common type in forest fragmentation, and the average size was the smallest. Expansion, the most common restoration process, was observed in both natural forests and plantations and often occurred around the

  16. Tropical Forest Fragmentation Limits Movements, but Not Occurrence of a Generalist Pollinator Species.

    Directory of Open Access Journals (Sweden)

    Noelia L Volpe

    Full Text Available Habitat loss and fragmentation influence species distributions and therefore ecological processes that depend upon them. Pollination may be particularly susceptible to fragmentation, as it depends on frequent pollinator movement. Unfortunately, most pollinators are too small to track efficiently which has precluded testing the hypothesis that habitat fragmentation reduces or eliminates pollen flow by disrupting pollinator movement. We used radio-telemetry to examine space use of the green hermit hummingbird (Phaethornis guy, an important 'hub' pollinator of understory flowering plants across substantial portions of the neotropics and the primary pollinator of a keystone plant which shows reduced pollination success in fragmented landscapes. We found that green hermits strongly avoided crossing large stretches of non-forested matrix and preferred to move along stream corridors. Forest gaps as small as 50 m diminished the odds of movement by 50%. Green hermits occurred almost exclusively inside the forest, with the odds of occurrence being 8 times higher at points with >95% canopy cover compared with points having <5% canopy cover. Nevertheless, surprisingly. the species occurred in fragmented landscapes with low amounts of forest (~30% within a 2 km radius. Our results indicate that although green hermits are present even in landscapes with low amounts of tropical forest, movement within these landscapes ends up strongly constrained by forest gaps. Restricted movement of pollinators may be an underappreciated mechanism for widespread declines in pollination and plant fitness in fragmented landscapes, even when in the presence of appropriate pollinators.

  17. Edge-related loss of tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest.

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    Bráulio A Santos

    Full Text Available Deforestation and forest fragmentation are known major causes of nonrandom extinction, but there is no information about their impact on the phylogenetic diversity of the remaining species assemblages. Using a large vegetation dataset from an old hyper-fragmented landscape in the Brazilian Atlantic rainforest we assess whether the local extirpation of tree species and functional impoverishment of tree assemblages reduce the phylogenetic diversity of the remaining tree assemblages. We detected a significant loss of tree phylogenetic diversity in forest edges, but not in core areas of small (<80 ha forest fragments. This was attributed to a reduction of 11% in the average phylogenetic distance between any two randomly chosen individuals from forest edges; an increase of 17% in the average phylogenetic distance to closest non-conspecific relative for each individual in forest edges; and to the potential manifestation of late edge effects in the core areas of small forest remnants. We found no evidence supporting fragmentation-induced phylogenetic clustering or evenness. This could be explained by the low phylogenetic conservatism of key life-history traits corresponding to vulnerable species. Edge effects must be reduced to effectively protect tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest.

  18. Bird communities in two oceanic island forests fragmented by roads ...

    African Journals Online (AJOL)

    Although most studies on road effects on birds have been conducted on continental grounds, road fragmentation on oceanic islands is often heavier. We assessed variation in bird communities near (≤ 25 m) and far (>100 m) from forest roads dividing laurel and pine forests on Tenerife, Canary Islands. Line transects were ...

  19. Assessing the Effects of Forest Fragmentation Using Satellite Imagery and Forest Inventory Data

    Science.gov (United States)

    Ronald E. McRoberts; Greg C. Liknes

    2005-01-01

    For a study area in the North Central region of the USA, maps of predicted proportion forest area were created using Landsat Thematic Mapper imagery, forest inventory plot data, and a logistic regression model. The maps were used to estimate quantitative indices of forest fragmentation. Correlations between the values of the indices and forest attributes observed on...

  20. Meta-analysis of the effects of forest fragmentation on interspecific interactions.

    Science.gov (United States)

    Magrach, Ainhoa; Laurance, William F; Larrinaga, Asier R; Santamaria, Luis

    2014-10-01

    Forest fragmentation dramatically alters species persistence and distribution and affects many ecological interactions among species. Recent studies suggest that mutualisms, such as pollination and seed dispersal, are more sensitive to the negative effects of forest fragmentation than antagonisms, such as predation or herbivory. We applied meta-analytical techniques to evaluate this hypothesis and quantified the relative contributions of different components of the fragmentation process (decreases in fragment size, edge effects, increased isolation, and habitat degradation) to the overall effect. The effects of fragmentation on mutualisms were primarily driven by habitat degradation, edge effects, and fragment isolation, and, as predicted, they were consistently more negative on mutualisms than on antagonisms. For the most studied interaction type, seed dispersal, only certain components of fragmentation had significant (edge effects) or marginally significant (fragment size) effects. Seed size modulated the effect of fragmentation: species with large seeds showed stronger negative impacts of fragmentation via reduced dispersal rates. Our results reveal that different components of the habitat fragmentation process have varying impacts on key mutualisms. We also conclude that antagonistic interactions have been understudied in fragmented landscapes, most of the research has concentrated on particular types of mutualistic interactions such as seed dispersal, and that available studies of interspecific interactions have a strong geographical bias (arising mostly from studies carried out in Brazil, Chile, and the United States). © 2014 Society for Conservation Biology.

  1. Forest fragmentation in Vietnam : Effects on tree diversity, populations and genetics

    NARCIS (Netherlands)

    Ha, V.T.

    2015-01-01

    Millions of square kilometers of the Earth’s surface is covered by forest fragments, and a quarter of remaining tropical forest has been fragmented. In Southeast Asia, about 650,000 ha of natural forests are fragmented per year. Fragmentation of old growth forests is considered to be the greatest

  2. A 50-m forest cover map in Southeast Asia from ALOS/PALSAR and its application on forest fragmentation assessment.

    Directory of Open Access Journals (Sweden)

    Jinwei Dong

    Full Text Available Southeast Asia experienced higher rates of deforestation than other continents in the 1990s and still was a hotspot of forest change in the 2000s. Biodiversity conservation planning and accurate estimation of forest carbon fluxes and pools need more accurate information about forest area, spatial distribution and fragmentation. However, the recent forest maps of Southeast Asia were generated from optical images at spatial resolutions of several hundreds of meters, and they do not capture well the exceptionally complex and dynamic environments in Southeast Asia. The forest area estimates from those maps vary substantially, ranging from 1.73×10(6 km(2 (GlobCover to 2.69×10(6 km(2 (MCD12Q1 in 2009; and their uncertainty is constrained by frequent cloud cover and coarse spatial resolution. Recently, cloud-free imagery from the Phased Array Type L-band Synthetic Aperture Radar (PALSAR onboard the Advanced Land Observing Satellite (ALOS became available. We used the PALSAR 50-m orthorectified mosaic imagery in 2009 to generate a forest cover map of Southeast Asia at 50-m spatial resolution. The validation, using ground-reference data collected from the Geo-Referenced Field Photo Library and high-resolution images in Google Earth, showed that our forest map has a reasonably high accuracy (producer's accuracy 86% and user's accuracy 93%. The PALSAR-based forest area estimates in 2009 are significantly correlated with those from GlobCover and MCD12Q1 at national and subnational scales but differ in some regions at the pixel scale due to different spatial resolutions, forest definitions, and algorithms. The resultant 50-m forest map was used to quantify forest fragmentation and it revealed substantial details of forest fragmentation. This new 50-m map of tropical forests could serve as a baseline map for forest resource inventory, deforestation monitoring, reducing emissions from deforestation and forest degradation (REDD+ implementation, and

  3. Carbon emissions from deforestation and forest fragmentation in the Brazilian Amazon

    International Nuclear Information System (INIS)

    Numata, Izaya; Cochrane, Mark A; Souza, Carlos M Jr; Sales, Marcio H

    2011-01-01

    Forest-fragmentation-related edge effects are one of the major causes of forest degradation in Amazonia and their spatio-temporal dynamics are highly influenced by annual deforestation patterns. Rapid biomass collapse due to edge effects in forest fragments has been reported in the Brazilian Amazon; however the collective impacts of this process on Amazonian carbon fluxes are poorly understood. We estimated biomass loss and carbon emissions from deforestation and forest fragmentation related to edge effects on the basis of the INPE (Brazilian National Space Research Institute) PRODES deforestation data and forest biomass volume data. The areas and ages of edge forests were calculated annually and the corresponding biomass loss and carbon emissions from these forest edges were estimated using published rates of biomass decay and decomposition corresponding to the areas and ages of edge forests. Our analysis estimated carbon fluxes from deforestation (4195 Tg C) and edge forest (126-221 Tg C) for 2001-10 in the Brazilian Amazon. The impacts of varying rates of deforestation on regional forest fragmentation and carbon fluxes were also investigated, with the focus on two periods: 2001-5 (high deforestation rates) and 2006-10 (low deforestation rates). Edge-released carbon accounted for 2.6-4.5% of deforestation-related carbon emissions. However, the relative importance of carbon emissions from forest fragmentation increased from 1.7-3.0% to 3.3-5.6% of the respective deforestation emissions between the two contrasting deforestation rates. Edge-related carbon fluxes are of increasing importance for basin-wide carbon accounting, especially as regards ongoing reducing emissions from deforestation and forest degradation (REDD) efforts in Brazilian Amazonia.

  4. Would protecting tropical forest fragments provide carbon and biodiversity cobenefits under REDD+?

    Science.gov (United States)

    Magnago, Luiz Fernando S; Magrach, Ainhoa; Laurance, William F; Martins, Sebastião V; Meira-Neto, João Augusto A; Simonelli, Marcelo; Edwards, David P

    2015-09-01

    Tropical forests store vast amounts of carbon and are the most biodiverse terrestrial habitats, yet they are being converted and degraded at alarming rates. Given global shortfalls in the budgets required to prevent carbon and biodiversity loss, we need to seek solutions that simultaneously address both issues. Of particular interest are carbon-based payments under the Reducing Emissions from Deforestation and Forest Degradation (REDD+) mechanism to also conserve biodiversity at no additional cost. One potential is for REDD+ to protect forest fragments, especially within biomes where contiguous forest cover has diminished dramatically, but we require empirical tests of the strength of any carbon and biodiversity cobenefits in such fragmented systems. Using the globally threatened Atlantic Forest landscape, we measured above-ground carbon stocks within forest fragments spanning 13 to 23 442 ha in area and with different degrees of isolation. We related these stocks to tree community structure and to the richness and abundance of endemic and IUCN Red-listed species. We found that increasing fragment size has a positive relationship with above-ground carbon stock and with abundance of IUCN Red-listed species and tree community structure. We also found negative relationships between distance from large forest block and tree community structure, endemic species richness and abundance, and IUCN Red-listed species abundance. These resulted in positive congruence between carbon stocks and Red-listed species, and the abundance and richness of endemic species, demonstrating vital cobenefits. As such, protecting forest fragments in hotspots of biodiversity, particularly larger fragments and those closest to sources, offers important carbon and biodiversity cobenefits. More generally, our results suggest that macroscale models of cobenefits under REDD+ have likely overlooked key benefits at small scales, indicating the necessity to apply models that include finer

  5. The paradox of forest fragmentation genetics

    Science.gov (United States)

    Andrea T. Kramer; Jennifer L. Ison; Mary V. Ashley; Henry F. Howe

    2008-01-01

    Theory predicts widespread loss of genetic diversity from drift and inbreeding in trees subjected to habitat fragmentation, yet empirical support of this theory is scarce. We argue that population genetics theory may be misapplied in light of ecological realities that, when recognized, require scrutiny of underlying evolutionary assumptions. One ecological reality is...

  6. Spatial metrics effect of forest fragmentation on forest bird ...

    African Journals Online (AJOL)

    In this study, relationship between forest patch size and isolation with abundance and occupancy probability of forest-dependent birds was investigated. This study was based within a coastal landscape that faces deleterious human activities such as clearing for agriculture. The study aimed to answer the question of ...

  7. Artificial nest experiments in a fragmented neotropical cloud forest

    Science.gov (United States)

    Trujillo, G.; Ahumada, J.A.

    2005-01-01

    We conducted artificial nest experiments in a Neotropical montane forest in the eastern Andes, Colombia, in order to test the effect of placing the nests in forest fragments or continuous forests, at two nest heights and for two different climatic seasons. Predation was not consistently different between nests placed in fragments and controls. However, we found that nests on the ground had a higher daily probability of being predated than nests in the understory. Also, daily nest mortality rate (DNM) was higher in the wet season than in the dry season. Most of the predated nests were attributed to mammals (56%), and predation occurred mostly on the ground (78%). Our estimates of DNM are quite low (= 0.023) and similar to another Neotropical montane forest and other Neotropical sites. Comparisons of DNM between Neotropical and temperate sites suggests that predation rates are similar. Our results suggest that fragmentation may not have a large negative impact in nest predation for bird populations breeding in fragments compared to other sites in tropical and temperate regions. ?? The Neotropical Ornithological Society.

  8. Responses of bats to forest fragmentation at Pozuzo, Peru

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    José Luis Mena

    2011-05-01

    Full Text Available Forest fragmentation and deforestation are among the major threats to Peruvian bats conservation. Unfortunately,information about the effects of these threats above 500 m elevation is lacking. In this study, I assessedbat responses to fragmentation in Pozuzo (Pasco at a landscape scale approach. I evaluate two hypothesesregarding the role of bats as indicators of habitat disturbance. The first prediction says that landscapes highlydisturbed will show higher abundances of habitat generalist species such as frugivorous bats belonging to thesubfamilies Stenodermatinae and Carollinae. The second prediction regards that landscapes with greater forestcover will show higher abundance of habitat specialist species such as animalivorous bat species belongingto the subfamily Phyllostominae, a guild sensitive to forest disturbance. I found evidence supporting the animalivoroushypothesis but it was partial to the frugivorous hypothesis. This study highlights the importance offorest fragments to bat conservation in human-modified landscapes.

  9. Phylogenetic impoverishment of Amazonian tree communities in an experimentally fragmented forest landscape.

    Science.gov (United States)

    Santos, Bráulio A; Tabarelli, Marcelo; Melo, Felipe P L; Camargo, José L C; Andrade, Ana; Laurance, Susan G; Laurance, William F

    2014-01-01

    Amazonian rainforests sustain some of the richest tree communities on Earth, but their ecological and evolutionary responses to human threats remain poorly known. We used one of the largest experimental datasets currently available on tree dynamics in fragmented tropical forests and a recent phylogeny of angiosperms to test whether tree communities have lost phylogenetic diversity since their isolation about two decades previously. Our findings revealed an overall trend toward phylogenetic impoverishment across the experimentally fragmented landscape, irrespective of whether tree communities were in 1-ha, 10-ha, or 100-ha forest fragments, near forest edges, or in continuous forest. The magnitude of the phylogenetic diversity loss was low (forest isolation, irrespective of plot location. Analyses based on tree genera that have significantly increased (28 genera) or declined (31 genera) in abundance and basal area in the landscape revealed that increasing genera are more phylogenetically related than decreasing ones. Also, the loss of phylogenetic diversity was greater in tree communities where increasing genera proliferated and decreasing genera reduced their importance values, suggesting that this taxonomic replacement is partially underlying the phylogenetic impoverishment at the landscape scale. This finding has clear implications for the current debate about the role human-modified landscapes play in sustaining biodiversity persistence and key ecosystem services, such as carbon storage. Although the generalization of our findings to other fragmented tropical forests is uncertain, it could negatively affect ecosystem productivity and stability and have broader impacts on coevolved organisms.

  10. Factors affecting bird richness in a fragmented cork oak forest in Morocco

    Science.gov (United States)

    Cherkaoui, Imad; Selmi, Slaheddine; Boukhriss, Jihen; Hamid, Rguibi-Idrissi; Mohammed, Dakki

    2009-03-01

    The cork oak forest of Ma'amora in north-western Morocco was the largest cork oak forest in the world until the beginning of the 20th century. Due to growing land use for agriculture and urbanization, however, this forest has become fragmented into relatively small and isolated patches. The effects of this fragmentation on the diversity of wild animal communities have never been investigated despite the importance of such investigations in elaborating long-term conservation plans of the biodiversity of this forest system. In this study of a sample of 44 forest patches we assessed the relationships between species numbers of wintering, breeding and spring migrant birds and patch size, shape, isolation and vegetation structure. We found that species richnesses of the three studied bird assemblages were strongly related to local vegetation structure, namely to the diversity and abundance of trees and bushes. Patches with higher diversity and cover of trees and bushes support higher numbers of bird species. However, patch size, shape and isolation were not significant predictors of bird richness. These results suggest that bird communities in the studied forest patches were more likely shaped by local habitat suitability rather than the amount of habitat or patch isolation. The results also demonstrate negative effects of current human pressures, namely logging, grazing and disturbance, on the diversity of bird communities in this forest system. This emphasizes the need for urgent management efforts aiming at reducing the negative impacts of forest use by humans on bird diversity in this forest system.

  11. Quantifying forest fragmentation using Geographic Information Systems and Forest Inventory and Analysis plot data

    Science.gov (United States)

    Dacia M. Meneguzzo; Mark H. Hansen

    2009-01-01

    Fragmentation metrics provide a means of quantifying and describing forest fragmentation. The most common method of calculating these metrics is through the use of Geographic Information System software to analyze raster data, such as a satellite or aerial image of the study area; however, the spatial resolution of the imagery has a significant impact on the results....

  12. A multi-method analysis of forest fragmentation and loss: The case ...

    African Journals Online (AJOL)

    Forest fragmentation and loss seriously affect biodiversity. There is need to monitor and assess forest fragmentation and loss in communal areas for effective biodiversity management. In this study, we analysed the extent of forest fragmentation and loss in ward 11, Chiredzi district of Zimbabwe over a 14 year period (1989 ...

  13. Forest fragmentation and bird community dynamics: inference at regional scales

    Science.gov (United States)

    Boulinier, T.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Flather, C.H.; Pollock, K.H.

    2001-01-01

    With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North American Breeding Bird Survey (BBS) and the Land Use and Land Cover Classification data from the U.S. Geological Survey. We used methods that accounted for heterogeneity in the probability of detecting species to estimate species richness and temporal changes in the bird communities for BBS routes in three mid-Atlantic U.S. states. Forest breeding bird species were grouped prior to the analyses into area-sensitive and non-area-sensitive species according to previous studies. We tested predictions relating measures of forest structure at one point in time (1974) to species richness at that time and to parameters of forest bird community change over the following 22-yr-period (1975-1996). We used the mean size of forest patches to characterize landscape structure, as high correlations among landscape variables did not allow us to disentangle the relative roles of habitat fragmentation per se and habitat loss. As predicted, together with lower species richness for area-sensitive species on routes surrounded by landscapes with lower mean forest-patch size, we found higher mean year-to-year rates of local extinction. Moreover, the mean year-to-year rates of local turnover (proportion of locally new species) for area-sensitive species were also higher in landscapes with lower mean forest-patch size. These associations were not observed for the non-area-sensitive species group. These

  14. Geospatial Assessment of Forest Fragmentation and its Implications for Ecological Processes in Tropical Forests

    Directory of Open Access Journals (Sweden)

    Adepoju Kayode Adewale

    2017-11-01

    Full Text Available The study assessed the patterns of spatio-temporal configuration imposed on a forest landscape in Southwestern Nigeria due to fragmentation for the period 1986 – 2010 in order to understand the relationship between landscape patterns and the ecological processes influencing the distribution of species in tropical forest environment. Time-series Landsat TM and ETM satellite images and forest inventory data were pre-processed and classified into four landuse/landcover categories using maximum likelihood classification algorithm. Fragstats software was used for the computation of seven landscape and six class level metrics to provide indicators of fragmentation and landscape connectivity from the classified images.

  15. Spatial distribution of bird communities in small forest fragments in central Europe in relation to distance to the forest edge, fragment size and type of forest

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, Jeňýk; Hošek, J.; Brabec, Marek; Kočvara, R.

    2017-01-01

    Roč. 401, OCT (2017), s. 255-263 ISSN 0378-1127 Institutional support: RVO:67179843 ; RVO:67985807 Keywords : Clearing * Dryocopus martius * Forest bird * Forest management * Generalized additive model * Habitat fragmentation Subject RIV: GK - Forestry; BB - Applied Statistics, Operational Research (UIVT-O) OBOR OECD: Forestry; Statistics and probability (UIVT-O) Impact factor: 3.064, year: 2016

  16. Multiple successional pathways in human-modified tropical landscapes: new insights from forest succession, forest fragmentation and landscape ecology research.

    Science.gov (United States)

    Arroyo-Rodríguez, Víctor; Melo, Felipe P L; Martínez-Ramos, Miguel; Bongers, Frans; Chazdon, Robin L; Meave, Jorge A; Norden, Natalia; Santos, Bráulio A; Leal, Inara R; Tabarelli, Marcelo

    2017-02-01

    Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical biodiversity, and also as a source of essential ecosystem functions and services in HMTLs. Such critical roles are controversial, however, as they depend on successional, landscape and socio-economic dynamics, which can vary widely within and across landscapes and regions. Understanding the main drivers of successional pathways of disturbed tropical forests is critically needed for improving management, conservation, and restoration strategies. Here, we combine emerging knowledge from tropical forest succession, forest fragmentation and landscape ecology research to identify the main driving forces shaping successional pathways at different spatial scales. We also explore causal connections between land-use dynamics and the level of predictability of successional pathways, and examine potential implications of such connections to determine the importance of secondary forests for biodiversity conservation in HMTLs. We show that secondary succession (SS) in tropical landscapes is a multifactorial phenomenon affected by a myriad of forces operating at multiple spatio-temporal scales. SS is relatively fast and more predictable in recently modified landscapes and where well-preserved biodiversity-rich native forests are still present in the landscape. Yet the increasing variation in landscape spatial configuration and matrix heterogeneity in landscapes with intermediate levels of disturbance increases the uncertainty of successional pathways. In landscapes that have suffered extensive and intensive human disturbances, however, succession can be slow or arrested, with impoverished assemblages and reduced potential to deliver ecosystem functions and services. We conclude that: (i

  17. Diet and food availability of the Virginia northern flying squirrel (Glaucomys sabrinus fuscus): implications for dispersal in a fragmented forest

    Science.gov (United States)

    Stephanie E. Trapp; Winston P. Smith; Elizabeth A. Flaherty

    2017-01-01

    A history of timber harvest in West Virginia has reduced red spruce (Picea rubens) forests to < 10% of their historic range and resulted in considerable habitat fragmentation for wildlife species associated with these forests. The Virginia northern flying squirrel (Glaucomys sabrinus fuscus) has been described as a red...

  18. Plant diversity in hedgerows amidst Atlantic Forest fragments

    Directory of Open Access Journals (Sweden)

    Carolina C. C. Oliveira

    2015-06-01

    Full Text Available Hedgerows are linear structures found in agricultural landscapes that may facilitate dispersal of plants and animals and also serve as habitat. The aim of this study was to investigate the relationships among diversity and ecological traits of woody plants, hedgerow characteristics (size, age, and origin, and the structure of the surrounding Atlantic Forest landscape. Field data were collected from 14 hedgerows, and landscape metrics from 1000-m buffers surrounding hedgerows were recorded from a thematic map. In all sampled hedgerows, arboreal species were predominantly zoochoric and early-succession species, and hedgerow width was an important factor explaining the richness and abundance of this group of species. Connection with forest vegetation did not explain richness and abundance of animal-dispersed species, but richness of non-zoochoric species increased in more connected hedgerows. These results suggest that hedgerows are probably colonized by species arriving from nearby early-succession sites, forest fragment edges, and isolated trees in the matrix. Nonetheless, hedgerows provide resources for frugivorous animals and influence landscape connectivity, highlighting the importance of these elements in the conservation of biodiversity in fragmented and rural landscapes.

  19. Forest Fragments Surrounded by Sugar Cane Are More Inhospitable to Terrestrial Amphibian Abundance Than Fragments Surrounded by Pasture

    Directory of Open Access Journals (Sweden)

    Paula Eveline Ribeiro D’Anunciação

    2013-01-01

    Full Text Available In recent years, there has been increasing interest in matrix-type influence on forest fragments. Terrestrial amphibians are good bioindicators for this kind of research because of low vagility and high philopatry. This study compared richness, abundance, and species composition of terrestrial amphibians through pitfall traps in two sets of semideciduous seasonal forest fragments in southeastern Brazil, according to the predominant surrounding matrix (sugar cane and pasture. There were no differences in richness, but fragments surrounded by sugar cane had the lowest abundance of amphibians, whereas fragments surrounded by pastures had greater abundance. The most abundant species, Rhinella ornata, showed no biometric differences between fragment groups but like many other amphibians sampled showed very low numbers of individuals in fragments dominated by sugar cane fields. Our data indicate that the sugar cane matrix negatively influences the community of amphibians present in fragments surrounded by this type of land use.

  20. Analysis of Edge Effects on Fragmented Forests Using Forest Inventories in Southwestern Amazonia

    Science.gov (United States)

    Numata, I.; Silva, S.; Cochrane, M. A.

    2015-12-01

    Deforestation fragments contiguous forests into smaller and smaller pieces, inducing ecological and biological changes in forest ecosystems. Edge effects are spatial and temporal phenomena. The effects of forest fragmentation vary primarily as functions of edge penetration distance, spatial arrangements and time of persistence of forest edges. Across varying penetration distances in a forest edge, numerous changes occur including elevated tree mortality and canopy desiccation, changes in forest structure and species composition, alternation of hydrological and carbon cycles. We analyzed the effects of edge penetration distance and time of persistence of forest edges on forest biophysical characteristics based upon more than thirty 500m transects over highly fragmented forests in Acre, the southwestern Amazon. Spatial variability of tree data (diameter at breast height - DBH, above ground biomass, tree density, species composition and population) was measured along a penetration distance of 500m from forest edges. Different edge age classes (1-5yr, 6-10yr, > 10yr) and edge penetration distances were identified based upon a Landsat time-series analysis. The number of individual plants with DBH > 10cm tends to be greater near edge (largest in the first 100m), while larger biomass amounts are found at > 300m distance. The impact of penetration distance on biomass, however, is not statistically significant. In terms of the distribution of DBHs, while smaller trees with DBH trees, larger DBH trees tend to increase after 300m penetration distance. The effect of edge persistence period (edge age) is not significant for both the number of individual plants as well as the biomass, however it is more pronounced on secondary species' biomass such as Cecrcopia sp and bamboo, which increase as edges persist longer.

  1. Occupancy Pattern Of A Forest Dependent Bird Among Coastal Forest Fragments In Northeast Tanzania

    Directory of Open Access Journals (Sweden)

    Robert B. Modest

    2017-04-01

    Full Text Available The loss of biological resources in the coastal forests of eastern Tanzania is alarming. This is due to human related activities such as vegetation clearing for agriculture and intensive livestock grazing. By their nature these activities affect forest dependent birds through destroying habitat and or blocking migratory corridors and thus interrupting site occupancy pattern. The aim of this study therefore was to determine whether habitat degradation along the Tanzanias north eastern coast affects site occupancy patterns of forest dependent birds among forest fragments and the associated savannahs. Lowland Tiny Greenbul a forest dependent bird was used as a model. The data was collected along transects set inside the forest fragments and along the neighboring matrices. The collected data was then used to build site occupancy probability models using the software Presence. The results revealed that ideal undisturbed habitat positively influenced both the relative abundance and site occupancy probability of the model bird amp8213 indicating the significance of maintaining habitat in their natural state for the welfare of forest dependent species and the broader biodiversity. This study emphasizes minimizing human pressures in the forests and the matrices for the persistence of the species.

  2. Effects of forest fragmentation and habitat degradation on West African leaf-litter frogs

    NARCIS (Netherlands)

    Hillers, A.; Veith, M.; Rödel, M.-O.

    2008-01-01

    Habitat degradation alters the dynamics and composition of anuran assemblages in tropical forests. The effects of forest fragmentation on the composition of anuran assemblages are so far poorly known. We studied the joint influence of forest fragmentation and degradation on leaf-litter frogs. We

  3. Detecting fragmentation extinction thresholds for forest understory plant species in peninsular Spain.

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    Marta Rueda

    Full Text Available Ecological theory predicts that fragmentation aggravates the effects of habitat loss, yet empirical results show mixed evidences, which fail to support the theory instead reinforcing the primary importance of habitat loss. Fragmentation hypotheses have received much attention due to their potential implications for biodiversity conservation, however, animal studies have traditionally been their main focus. Here we assess variation in species sensitivity to forest amount and fragmentation and evaluate if fragmentation is related to extinction thresholds in forest understory herbs and ferns. Our expectation was that forest herbs would be more sensitive to fragmentation than ferns due to their lower dispersal capabilities. Using forest cover percentage and the proportion of this percentage occurring in the largest patch within UTM cells of 10-km resolution covering Peninsular Spain, we partitioned the effects of forest amount versus fragmentation and applied logistic regression to model occurrences of 16 species. For nine models showing robustness according to a set of quality criteria we subsequently defined two empirical fragmentation scenarios, minimum and maximum, and quantified species' sensitivity to forest contraction with no fragmentation, and to fragmentation under constant forest cover. We finally assessed how the extinction threshold of each species (the habitat amount below which it cannot persist varies under no and maximum fragmentation. Consistent with their preference for forest habitats probability occurrences of all species decreased as forest cover contracted. On average, herbs did not show significant sensitivity to fragmentation whereas ferns were favored. In line with theory, fragmentation yielded higher extinction thresholds for two species. For the remaining species, fragmentation had either positive or non-significant effects. We interpret these differences as reflecting species-specific traits and conclude that although

  4. Linear infrastructure drives habitat conversion and forest fragmentation associated with Marcellus shale gas development in a forested landscape.

    Science.gov (United States)

    Langlois, Lillie A; Drohan, Patrick J; Brittingham, Margaret C

    2017-07-15

    Large, continuous forest provides critical habitat for some species of forest dependent wildlife. The rapid expansion of shale gas development within the northern Appalachians results in direct loss of such habitat at well sites, pipelines, and access roads; however the resulting habitat fragmentation surrounding such areas may be of greater importance. Previous research has suggested that infrastructure supporting gas development is the driver for habitat loss, but knowledge of what specific infrastructure affects habitat is limited by a lack of spatial tracking of infrastructure development in different land uses. We used high-resolution aerial imagery, land cover data, and well point data to quantify shale gas development across four time periods (2010, 2012, 2014, 2016), including: the number of wells permitted, drilled, and producing gas (a measure of pipeline development); land use change; and forest fragmentation on both private and public land. As of April 2016, the majority of shale gas development was located on private land (74% of constructed well pads); however, the number of wells drilled per pad was lower on private compared to public land (3.5 and 5.4, respectively). Loss of core forest was more than double on private than public land (4.3 and 2.0%, respectively), which likely results from better management practices implemented on public land. Pipelines were by far the largest contributor to the fragmentation of core forest due to shale gas development. Forecasting future land use change resulting from gas development suggests that the greatest loss of core forest will occur with pads constructed farthest from pre-existing pipelines (new pipelines must be built to connect pads) and in areas with greater amounts of core forest. To reduce future fragmentation, our results suggest new pads should be placed near pre-existing pipelines and methods to consolidate pipelines with other infrastructure should be used. Without these mitigation practices, we

  5. NATURAL REGENERATION MECHANISMS IN A SEASONAL DECIDUOUS FOREST FRAGMENT

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    Marta Silvana Volpato Sccoti

    2011-09-01

    Full Text Available Due to the loss of biodiversity and natural habitat because of the forests fragmentation, it is the needed to find alternatives that allow the recovery of these environments. Thus, this study aimed to obtain information about the potential of natural regeneration mechanisms (seed rain, soil seed bank, seedling bank and established natural regeneration in a seasonal deciduous forest fragment in Santa Maria, RS state, in order to conserve and to recover these ecosystems. The study was conducted in a systematic way, having as a point of departure the demarcation of 14 sampling plots of 2000 sq m. From those plots, 70 subplots were randomly selected to evaluate the natural regeneration mechanisms. The seed rain was evaluated during one year based on the material that was monthly collected and analyzed from the collectors. To the study of the soil seed bank, soil samplings of 25cmx25cmx5cm were taken and the collected material was monitored during 7 months, observing the seed germination. The natural regeneration was evaluated in two classes: seedling bank and established The seed rain presented medium density of 1350 seeds m-², in which 73 species, predominantly arboreal, were observed. In the soil seed bank, 108 species were observed, in which 74 % were herbaceous. In the seedling bank, 48 species were found and they were heliophilous and sciaphilous species, while in the established natural regeneration, 37 species were found, prevailing sciaphilous. This study concluded that the species with the greatest potential to perpetuate in the studied area were Gymnanthes concolor, Soroceae bonplandii, Eugenia rostrifolia, Trichilia claussenii, Trichilia elegans and Dasyphylum spinescens, and they are highly indicated to the enrichment of the area. The species Myrocarpus frondosus, Cupania vernalis, Nectandra megapotamica and Syagrus rommanzoffiana showed certain restriction, depending on the silvicultural treatments in the forest to assure their

  6. Understory species richness in an urban forest fragment, Pernambuco, Brazil

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    Ana Cristina Ramos de Souza

    2009-09-01

    Full Text Available This study characterizes the floristic composition of the understory of Parque Estadual de Dois Irmãos, (08°01’15.1”S and 34°56’3.2”W, an area of about 370ha characterized as a lowland ombrophilous dense forest. The study included individuals with heights of up to 4.0m, such as treelets, shrubs, sub-bushes and terricolous herb plants, in fertile conditions. The collections were made every two weeks along a period of 24 months. A total of 108 species, belonging to 86 genera and 49 families, were recorded. The families with the highest number of species were Rubiaceae (14, Fabaceae (9 Melastomataceae (8, Asteraceae (8, Myrtaceae (6, and Poaceae (4. The Fabaceae, Melastomataceae, Myrtaceae and Rubiaceae presented the highest number of understory species in this fragment. Generally, among the studies made in the Atlantic forest areas in Pernambuco, the presence of a set of tree species common to these forests is evidenced.

  7. Reducing Emissions from Deforestation and Forest Degradation

    African Journals Online (AJOL)

    It combines a multi - temporal remote sensing approach incorporating satellite sensors from medium to very high resolution with a terrestrial cluster sampling design, which proved to be operational for the whole spectrum from highly fragmented to pristine forest areas. This combination was implemented by a multi - phase ...

  8. Deforestation and fragmentation of natural forests in the upper Changhua watershed, Hainan, China: implications for biodiversity conservation.

    Science.gov (United States)

    Zhai, De-Li; Cannon, Charles H; Dai, Zhi-Cong; Zhang, Cui-Ping; Xu, Jian-Chu

    2015-01-01

    Hainan, the largest tropical island in China, belongs to the Indo-Burma biodiversity hotspot. The Changhua watershed is a center of endemism for plants and birds and the cradle of Hainan's main rivers. However, this area has experienced recent and ongoing deforestation and habitat fragmentation. To quantify habitat loss and fragmentation of natural forests, as well as the land-cover changes in the Changhua watershed, we analyzed Landsat images obtained in 1988, 1995, and 2005. Land-cover dynamics analysis showed that natural forests increased in area (97,909 to 104,023 ha) from 1988 to 1995 but decreased rapidly to 76,306 ha over the next decade. Rubber plantations increased steadily throughout the study period while pulp plantations rapidly expanded after 1995. Similar patterns of land cover change were observed in protected areas, indicating a lack of enforcement. Natural forests conversion to rubber and pulp plantations has a general negative effect on biodiversity, primarily through habitat fragmentation. The fragmentation analysis showed that natural forests area was reduced and patch number increased, while patch size and connectivity decreased. These land-cover changes threatened local biodiversity, especially island endemic species. Both natural forests losses and fragmentation should be stopped by strict enforcement to prevent further damage. Preserving the remaining natural forests and enforcing the status of protected areas should be a management priority to maximize the watershed's biodiversity conservation value.

  9. Frugivory on Persea lingue in temperate Chilean forests: interactions between fruit availability and habitat fragmentation across multiple spatial scales.

    Science.gov (United States)

    Vergara, Pablo M; Smith, Cecilia; Delpiano, Cristian A; Orellana, Ignacio; Gho, Dafne; Vazquez, Inao

    2010-12-01

    Habitat degradation and fragmentation are expected to reduce seed dispersal rates by reducing fruit availability as well as the movement and abundance of frugivores. These deleterious impacts may also interact with each other at different spatial scales, leading to nonlinear effects of fruit abundance on seed dispersal. In this study we assessed whether the degradation and fragmentation of southern Chilean forests had the potential to restrict seed dispersal the lingue (Persea lingue) tree, a fleshy-fruited tree species. Of five frugivore bird species, the austral thrush (Turdus falcklandii) and the fire-eyed diucon (Xolmis pyrope) were the only legitimate seed dispersers as well as being the most abundant species visiting lingue trees. The results showed little or no direct effect of habitat fragmentation on seed dispersal estimates, possibly because the assemblage of frugivore birds was comprised habitat-generalist species. Instead, the number of fruits removed per focal tree exhibited an enhanced response to crop size, but only in the more connected fragments. In the fruit-richer fragment networks, there was an increased fragment-size effect on the proportion of fruits removed in comparison to fruit-poor networks in which the fragment size effect was spurious. We suggest that such nonlinear effects are widespread in fragmented forest regions, resulting from the link between the spatial scales over which frugivores sample resources and the spatial heterogeneity in fruiting resources caused by habitat fragmentation and degradation.

  10. Gene Flow of a Forest-Dependent Bird across a Fragmented Landscape.

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    Rachael V Adams

    Full Text Available Habitat loss and fragmentation can affect the persistence of populations by reducing connectivity and restricting the ability of individuals to disperse across landscapes. Dispersal corridors promote population connectivity and therefore play important roles in maintaining gene flow in natural populations inhabiting fragmented landscapes. In the prairies, forests are restricted to riparian areas along river systems which act as important dispersal corridors for forest dependent species across large expanses of unsuitable grassland habitat. However, natural and anthropogenic barriers within riparian systems have fragmented these forested habitats. In this study, we used microsatellite markers to assess the fine-scale genetic structure of a forest-dependent species, the black-capped chickadee (Poecile atricapillus, along 10 different river systems in Southern Alberta. Using a landscape genetic approach, landscape features (e.g., land cover were found to have a significant effect on patterns of genetic differentiation. Populations are genetically structured as a result of natural breaks in continuous habitat at small spatial scales, but the artificial barriers we tested do not appear to restrict gene flow. Dispersal between rivers is impeded by grasslands, evident from isolation of nearby populations (~ 50 km apart, but also within river systems by large treeless canyons (>100 km. Significant population genetic differentiation within some rivers corresponded with zones of different cottonwood (riparian poplar tree species and their hybrids. This study illustrates the importance of considering the impacts of habitat fragmentation at small spatial scales as well as other ecological processes to gain a better understanding of how organisms respond to their environmental connectivity. Here, even in a common and widespread songbird with high dispersal potential, small breaks in continuous habitats strongly influenced the spatial patterns of genetic

  11. Thermokarst rates intensify due to climate change and forest fragmentation in an Alaskan boreal forest lowland.

    Science.gov (United States)

    Lara, Mark J; Genet, Hélène; McGuire, Anthony D; Euskirchen, Eugénie S; Zhang, Yujin; Brown, Dana R N; Jorgenson, Mark T; Romanovsky, Vladimir; Breen, Amy; Bolton, William R

    2016-02-01

    Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse-scar bogs, low shrub/scrub, and forests growing on elevated ice-rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5 °C of thawing. Increased permafrost thaw in lowland boreal forests in response to warming may have consequences for the climate system. This study evaluates the trajectories and potential drivers of 60 years of forest change in a landscape subjected to permafrost thaw in unburned dominant forest types (paper birch and black spruce) associated with location on elevated permafrost plateau and across multiple time periods (1949, 1978, 1986, 1998, and 2009) using historical and contemporary aerial and satellite images for change detection. We developed (i) a deterministic statistical model to evaluate the potential climatic controls on forest change using gradient boosting and regression tree analysis, and (ii) a 30 × 30 m land cover map of the Tanana Flats to estimate the potential landscape-level losses of forest area due to thermokarst from 1949 to 2009. Over the 60-year period, we observed a nonlinear loss of birch forests and a relatively continuous gain of spruce forest associated with thermokarst and forest succession, while gradient boosting/regression tree models identify precipitation and forest fragmentation as the primary factors controlling birch and spruce forest change, respectively. Between 1950 and 2009, landscape-level analysis estimates a transition of ~15 km² or ~7% of birch forests to wetlands, where the greatest change followed warm periods. This work highlights that the vulnerability and resilience of

  12. Thermokarst rates intensify due to climate change and forest fragmentation in an Alaskan boreal forest lowland

    Science.gov (United States)

    Lara, M.; Genet, Helene; McGuire, A. David; Euskirchen, Eugénie S.; Zhang, Yujin; Brown, Dana R. N.; Jorgenson, M.T.; Romanovsky, V.; Breen, Amy L.; Bolton, W.R.

    2016-01-01

    Lowland boreal forest ecosystems in Alaska are dominated by wetlands comprised of a complex mosaic of fens, collapse-scar bogs, low shrub/scrub, and forests growing on elevated ice-rich permafrost soils. Thermokarst has affected the lowlands of the Tanana Flats in central Alaska for centuries, as thawing permafrost collapses forests that transition to wetlands. Located within the discontinuous permafrost zone, this region has significantly warmed over the past half-century, and much of these carbon-rich permafrost soils are now within ~0.5 °C of thawing. Increased permafrost thaw in lowland boreal forests in response to warming may have consequences for the climate system. This study evaluates the trajectories and potential drivers of 60 years of forest change in a landscape subjected to permafrost thaw in unburned dominant forest types (paper birch and black spruce) associated with location on elevated permafrost plateau and across multiple time periods (1949, 1978, 1986, 1998, and 2009) using historical and contemporary aerial and satellite images for change detection. We developed (i) a deterministic statistical model to evaluate the potential climatic controls on forest change using gradient boosting and regression tree analysis, and (ii) a 30 × 30 m land cover map of the Tanana Flats to estimate the potential landscape-level losses of forest area due to thermokarst from 1949 to 2009. Over the 60-year period, we observed a nonlinear loss of birch forests and a relatively continuous gain of spruce forest associated with thermokarst and forest succession, while gradient boosting/regression tree models identify precipitation and forest fragmentation as the primary factors controlling birch and spruce forest change, respectively. Between 1950 and 2009, landscape-level analysis estimates a transition of ~15 km² or ~7% of birch forests to wetlands, where the greatest change followed warm periods. This work highlights that the vulnerability and resilience of

  13. Human-sensitive bryophytes retreat into the depth of forest fragments in central European landscape

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, Jeňýk; Hošek, J.; Brabec, Marek; Tenčík, A.

    2016-01-01

    Roč. 135, č. 3 (2016), s. 539-549 ISSN 1612-4669 Institutional support: RVO:67179843 ; RVO:67985807 Keywords : colonization * forest continuity * fragmentation * forest management * fragment size Subject RIV: EH - Ecology, Behaviour; BB - Applied Statistics, Operational Research (UIVT-O) Impact factor: 2.017, year: 2016

  14. The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments.

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    Renata Calixto Campos

    Full Text Available Dung beetle community structures changes due to the effects of destruction, fragmentation, isolation and decrease in tropical forest area, and therefore are considered ecological indicators. In order to assess the influence of type of maize cultivated and associated maize management on dung beetle communities in Atlantic Forest fragments surrounded by conventional and transgenic maize were evaluated 40 Atlantic Forest fragments of different sizes, 20 surrounded by GM maize and 20 surrounded by conventional maize, in February 2013 and 2014 in Southern Brazil. After applying a sampling protocol in each fragment (10 pitfall traps baited with human feces or carrion exposed for 48 h, a total of 3454 individuals from 44 species were captured: 1142 individuals from 38 species in GM maize surrounded fragments, and 2312 from 42 species in conventional maize surrounded fragments. Differences in dung beetle communities were found between GM and conventional maize communities. As expected for fragmented areas, the covariance analysis showed a greater species richness in larger fragments under both conditions; however species richness was greater in fragments surrounded by conventional maize. Dung beetle structure in the forest fragments was explained by environmental variables, fragment area, spatial distance and also type of maize (transgenic or conventional associated with maize management techniques. In Southern Brazil's scenario, the use of GM maize combined with associated agricultural management may be accelerating the loss of diversity in Atlantic Forest areas, and consequently, important ecosystem services provided by dung beetles may be lost.

  15. Complementary seed dispersal by three avian frugivores in a fragmented Afromontane forest

    NARCIS (Netherlands)

    Lehouck, V.; Spanhove, T.; Demeter, S.; Groot, N.E.; Lens, L.

    2009-01-01

    Questions To what extent does species-specific variation in gut passage time (GPT), habitat use and mobility of three key avian frugivores synergistically affect the distribution of Xymalos monospora seeds within and among isolated forest fragments? Location Three fragments of a severely fragmented

  16. Structural Changes are More Important than Compositional Changes in Driving Biomass Loss in Ugandan Forest Fragments

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    C. Bulafu

    2014-01-01

    Full Text Available Aboveground biomass (AGB contained in privately-owned forests is less frequently measured than in forest reserves despite their greater likelihood of degradation. We demonstrate how density changes in contrast to species compositional changes have driven AGB changes in privately-owned fragments in Uganda over two decades. Data on tree assemblages in fragments were obtained by re-sampling a 1990 dataset in 2010 and AGB estimated using generalised allometric equation that incorporates diameter at breast height (DBH and species-specific wood density. AGB were highly variable between fragments and over time. Structural changes contributed a higher proportion of change in AGB than species compositional changes in all forests. Non-pioneer species constituted over 50% of AGB in reserve forest, in contrast to private forests where pioneer species dominated. Our study demonstrates the potential of private forests to hold comparable AGB to plantation. Reduction in exploitation pressure is required if fragments are to mitigate carbon emissions.

  17. SPATIAL DISTRIBUTION AND POPULATION STRUCTURE OF PALMS (ARECACEAE IN A FOREST FRAGMENT OF LOWLAND DENSE HUMID FOREST IN SOUTH BRAZIL

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    Laura Cappelatti

    2015-01-01

    Full Text Available In the state of Rio Grande do Sul, the Dense Humid Forest is reduced to less than 5% of its original cover. However, it still has the highest richness of palms in this state, which constitute an important and economically relevant group. Environmental and demographic aspects of plant populations in forest fragments are of great importance for their management and conservation. We conducted a study on the spatial distribution and age structure of five palm species in a forest fragment at the municipality of Três Cachoeiras, in the north coast of Rio Grande do Sul. We delimited 25 10×10 m plots and counted the number of individuals in the stages of seedling, juvenile and adult for each palm species. Aggregation Indices were calculated with software SADIEShell. We performed variation partitioning analyses among species distribution and environmental variables canopy openness and soil moisture. A total of 1,443 plants were counted and the most abundant species was Euterpe edulis. The average density was of 57.72 ind. 100 m-2. Three species showed a pattern of “inverse J”, which indicated that they have a potential for regenerating in that palm community. The predominant spatial pattern was aggregated (Ia>1 and canopy openness did not influence species abundances. Only the distribution of Bactris setosa and Geonoma gamiova, both understory species, was explained by soil moisture, suggesting that other abiotic or biotic factors may be influencing the spatial arrangement of the canopy species.

  18. Effect of habitat fragmentation on ranging behavior of white-headed langurs in limestone forests in Southwest China.

    Science.gov (United States)

    Huang, Zhonghao; Yuan, Peisong; Huang, Henglian; Tang, Xiaoping; Xu, Weijian; Huang, Chengming; Zhou, Qihai

    2017-07-01

    The critically endangered white-headed langur (Trachypithecus leucocephalus) is confined to fragmented karst forests of southwest Guangxi Province, China. A lack of information on the influence of habitat fragmentation on langur behavior has prevented a comprehensive understanding of their ranging behavior and the development of effective langur conservation strategies. We collected comparative data on time budgets, daily path lengths, home range and diets of four langur groups inhabiting the lightly fragmented Fusui forest (G1, G2) and the more heavily fragmented Chongzuo forest (G3, G4). The aim was to explore the effect of this fragmentation on langur ranging behavior. Our results showed that the Fusui groups spent more time on moving and less time on feeding and playing than the Chongzuo groups. Daily path lengths were 472.4-536.1 m for the Fusui groups and 449.6-480.7 m for the Chongzuo groups, indicating no marked inter-site variation. The Fusui groups occupied much larger home ranges (23.8-33.8 ha) than the Chongzuo groups (14.5-15.8 ha). However, all groups had similar monthly home ranges. Diets significantly differed among langur groups. The Fusui groups consumed more young leaves and had much lower diet diversity compared with the Chongzuo groups. Our findings indicate that habitat fragmentation is one of the crucial determinants of white-headed langur ranging behavior because fragmentation reduces and restricts the home range. Langurs in fragmented habitat adopt an energy conservation strategy characterized by devoting more time to feeding and less time to moving, with a smaller home range and consumption of more plant species. We argue that linking fragmented forests with corridors should be considered a priority in a wider and comprehensive longer term langur population conservation and habitat management strategy.

  19. Fragmentation increases wind disturbance impacts on forest structure and carbon stocks in a western Amazonian landscape.

    Science.gov (United States)

    Schwartz, Naomi B; Uriarte, María; DeFries, Ruth; Bedka, Kristopher M; Fernandes, Katia; Gutiérrez-Vélez, Victor; Pinedo-Vasquez, Miguel A

    2017-09-01

    Tropical second-growth forests could help mitigate climate change, but the degree to which their carbon potential is achieved will depend on exposure to disturbance. Wind disturbance is common in tropical forests, shaping structure, composition, and function, and influencing successional trajectories. However, little is known about the impacts of extreme winds on second-growth forests in fragmented landscapes, though these ecosystems are often located in mosaics of forest, pasture, cropland, and other land cover types. Indirect evidence suggests that fragmentation increases risk of wind damage in tropical forests, but no studies have found such impacts following severe storms. In this study, we ask whether fragmentation and forest type (old vs. second growth) were associated with variation in wind damage after a severe convective storm in a fragmented production landscape in western Amazonia. We applied linear spectral unmixing to Landsat 8 imagery from before and after the storm, and combined it with field observations of damage to map wind effects on forest structure and biomass. We also used Landsat 8 imagery to map land cover with the goals of identifying old- and second-growth forest and characterizing fragmentation. We used these data to assess variation in wind disturbance across 95,596 ha of forest, distributed over 6,110 patches. We find that fragmentation is significantly associated with wind damage, with damage severity higher at forest edges and in edgier, more isolated patches. Damage was also more severe in old-growth than in second-growth forests, but this effect was weaker than that of fragmentation. These results illustrate the importance of considering landscape context in planning tropical forest restoration and natural regeneration projects. Assessments of long-term carbon sequestration potential need to consider spatial variation in disturbance exposure. Where risk of extreme winds is high, minimizing fragmentation and isolation could increase

  20. Habitat fragmentation, tree diversity, and plant invasion interact to structure forest caterpillar communities.

    Science.gov (United States)

    Stireman, John O; Devlin, Hilary; Doyle, Annie L

    2014-09-01

    Habitat fragmentation and invasive species are two of the most prominent threats to terrestrial ecosystems. Few studies have examined how these factors interact to influence the diversity of natural communities, particularly primary consumers. Here, we examined the effects of forest fragmentation and invasion of exotic honeysuckle (Lonicera maackii, Caprifoliaceae) on the abundance and diversity of the dominant forest herbivores: woody plant-feeding Lepidoptera. We systematically surveyed understory caterpillars along transects in 19 forest fragments over multiple years in southwestern Ohio and evaluated how fragment area, isolation, tree diversity, invasion by honeysuckle and interactions among these factors influence species richness, diversity and abundance. We found strong seasonal variation in caterpillar communities, which responded differently to fragmentation and invasion. Abundance and richness increased with fragment area, but these effects were mitigated by high levels of honeysuckle, tree diversity, landscape forest cover, and large recent changes in area. Honeysuckle infestation was generally associated with decreased caterpillar abundance and diversity, but these effects were strongly dependent on other fragment traits. Effects of honeysuckle on abundance were moderated when fragment area, landscape forest cover and tree diversity were high. In contrast, negative effects of honeysuckle invasion on caterpillar diversity were most pronounced in fragments with high tree diversity and large recent increases in area. Our results illustrate the complex interdependencies of habitat fragmentation, plant diversity and plant invasion in their effects on primary consumers and emphasize the need to consider these processes in concert to understand the consequences of anthropogenic habitat change for biodiversity.

  1. Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Andréa O. Mesquita

    2012-09-01

    Full Text Available Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments.

  2. Resilient networks of ant-plant mutualists in Amazonian forest fragments.

    Science.gov (United States)

    Passmore, Heather A; Bruna, Emilio M; Heredia, Sylvia M; Vasconcelos, Heraldo L

    2012-01-01

    The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions. We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments. We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide.

  3. Resilient networks of ant-plant mutualists in Amazonian forest fragments.

    Directory of Open Access Journals (Sweden)

    Heather A Passmore

    Full Text Available The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions.We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments.We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide.

  4. Resilient Networks of Ant-Plant Mutualists in Amazonian Forest Fragments

    Science.gov (United States)

    Passmore, Heather A.; Bruna, Emilio M.; Heredia, Sylvia M.; Vasconcelos, Heraldo L.

    2012-01-01

    Background The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks. This is particularly true for biodiversity-rich tropical ecosystems, where the majority of plant species depend on mutualisms with animals and it is thought that changes in the structure of mutualist networks could lead to cascades of extinctions. Methodology/Principal Findings We evaluated effects of fragmentation on mutualistic networks by calculating metrics of network structure for ant-plant networks in continuous Amazonian forests with those in forest fragments. We hypothesized that networks in fragments would have fewer species and higher connectance, but equal nestedness and resilience compared to forest networks. Only one of the nine metrics we compared differed between continuous forest and forest fragments, indicating that networks were resistant to the biotic and abiotic changes that accompany fragmentation. This is partially the result of the loss of only specialist species with one connection that were lost in forest fragments. Conclusions/Significance We found that the networks of ant-plant mutualists in twenty-five year old fragments are similar to those in continuous forest, suggesting these interactions are resistant to the detrimental changes associated with habitat fragmentation, at least in landscapes that are a mosaic of fragments, regenerating forests, and pastures. However, ant-plant mutualistic networks may have several properties that may promote their persistence in fragmented landscapes. Proactive identification of key mutualist partners may be necessary to focus conservation efforts on the interactions that insure the integrity of network structure and the ecosystems services networks provide. PMID:22912666

  5. Species and structural diversity of church forests in a fragmented Ethiopian Highland landscape

    NARCIS (Netherlands)

    Wassie Eshete, Alemayehu; Sterck, F.J.; Bongers, F.

    2010-01-01

    Question: Thousands of small isolated forest fragments remain around churches (“church forests”) in the almost completely deforested Ethiopian Highlands. We questioned how the forest structure and composition varied with altitude, forest area and human influence. Location: South Gondar, Amhara

  6. Epiphyte biodiversity in the coffee agricultural matrix: canopy stratification and distance from forest fragments.

    Science.gov (United States)

    Moorhead, Leigh C; Philpott, Stacy M; Bichier, Peter

    2010-06-01

    Quality of the agricultural matrix profoundly affects biodiversity and dispersal in agricultural areas. Vegetatively complex coffee agroecosystems maintain species richness at larger distances from the forest. Epiphytes colonize canopy trees and provide resources for birds and insects and thus effects of agricultural production on epiphytes may affect other species. We compared diversity, composition, and vertical stratification of epiphytes in a forest fragment and in two coffee farms differing in management intensity in southern Mexico. We also examined spatial distribution of epiphytes with respect to the forest fragment to examine quality of the two agricultural matrix types for epiphyte conservation. We sampled vascular epiphytes in a forest fragment, a shade polyculture farm, and a shade monoculture farm at 100 m, 200 m, and 400 m from the forest. Epiphyte and orchid richness was greater in the forest than in the monoculture but richness was similar in the forest and polyculture farm. Epiphyte species composition differed with habitat type, but not with distance from the forest. In the forest, epiphytes were distributed throughout tree canopies, but in the farms, epiphytes were primarily found on trunks and larger branches. Epiphyte richness and species similarity to forest species declined with distance from the forest fragment in the monoculture, but richness and similarity to forest species did not decline with distance from forest in the polyculture. This suggests polyculture coffee has greater conservation value. In contrast, monoculture coffee is likely a sink habitat for epiphytes dispersing from forests into coffee. Coffee farms differ from forests in terms of the habitat they provide and species composition, thus protecting forest fragments is essential for epiphyte conservation. Nonetheless, in agricultural landscapes, vegetatively complex coffee farms may contribute to conservation of epiphytes more than other agricultural land uses.

  7. Higher climate warming sensitivity of Siberian larch in small than large forest islands in the fragmented Mongolian forest steppe.

    Science.gov (United States)

    Khansaritoreh, Elmira; Dulamsuren, Choimaa; Klinge, Michael; Ariunbaatar, Tumurbaatar; Bat-Enerel, Banzragch; Batsaikhan, Ganbaatar; Ganbaatar, Kherlenchimeg; Saindovdon, Davaadorj; Yeruult, Yolk; Tsogtbaatar, Jamsran; Tuya, Daramragchaa; Leuschner, Christoph; Hauck, Markus

    2017-09-01

    Forest fragmentation has been found to affect biodiversity and ecosystem functioning in multiple ways. We asked whether forest size and isolation in fragmented woodlands influences the climate warming sensitivity of tree growth in the southern boreal forest of the Mongolian Larix sibirica forest steppe, a naturally fragmented woodland embedded in grassland, which is highly affected by warming, drought, and increasing anthropogenic forest destruction in recent time. We examined the influence of stand size and stand isolation on the growth performance of larch in forests of four different size classes located in a woodland-dominated forest-steppe area and small forest patches in a grassland-dominated area. We found increasing climate sensitivity and decreasing first-order autocorrelation of annual stemwood increment with decreasing stand size. Stemwood increment increased with previous year's June and August precipitation in the three smallest forest size classes, but not in the largest forests. In the grassland-dominated area, the tree growth dependence on summer rainfall was highest. Missing ring frequency has strongly increased since the 1970s in small, but not in large forests. In the grassland-dominated area, the increase was much greater than in the forest-dominated landscape. Forest regeneration decreased with decreasing stand size and was scarce or absent in the smallest forests. Our results suggest that the larch trees in small and isolated forest patches are far more susceptible to climate warming than in large continuous forests pointing to a grim future for the forests in this strongly warming region of the boreal forest that is also under high land use pressure. © 2017 John Wiley & Sons Ltd.

  8. Birds communities of fragmented forest within highly urbanized landscape in Kuala Lumpur, Malaysia

    Science.gov (United States)

    Mohd-Taib, F. S.; Rabiatul-Adawiyah, S.; Md-Nor, S.

    2014-09-01

    Urbanization is one form of forest modification for development purposes. It produces forest fragments scattered in the landscape with different intensity of disturbance. We want to determine the effect of forest fragmentation towards bird community in urbanized landscapes in Kuala Lumpur, namely Sungai Besi Forest Reserve (FR), Bukit Nenas FR and Bukit Sungei Puteh FR. We used mist-netting and direct observation method along established trails. These forests differ in size, vegetation composition and land use history. Results show that these forests show relatively low number of species compared to other secondary forest with only 39 bird species recorded. The largest fragment, Sg. Besi encompassed the highest species richness and abundance with 69% species but lower in diversity. Bukit Nenas, the next smallest fragment besides being the only remaining primary forest has the highest diversity index with 1.866. Bkt. Sg. Puteh the smallest fragment has the lowest species richness and diversity with Shanon diversity index of 1.332. The presence of introduced species such as Corvus splendens (House crow) in all study areas suggest high disturbance encountered by these forests. Nonetheless, these patches comprised of considerably high proportion of native species. In conclusion, different intensity of disturbance due to logging activities and urbanization surrounding the forest directly influenced bird species richness and diversity. These effects however can be compensated by maintaining habitat complexity including high vegetation composition and habitat structure at the landscape level.

  9. Jaguars on the move: modeling movement to mitigate fragmentation from road expansion in the Mayan Forests

    DEFF Research Database (Denmark)

    Colchero, Fernando; Conde, Dalia Amor; Manterola, Carlos

    2011-01-01

    Road-induced habitat fragmentation is one of the greatest threats to large carnivores. Wildlife passes have been used to reduce fragmentation by mitigating the effects of roads as barriers to animal movement. However, direct observations of animals crossing roads are extremely rare and thus...... indirect methods are necessary to locate crossings. Yet, current methods fail to incorporate the animals' movement behavior and thus have little predictive power. Based on the principles of resource selection functions and state-space modeling, we developed a Bayesian movement model applied to radio......-telemetry and GPS data to infer the movement behavior of jaguars Panthera onca as a response to vegetation, roads and human population density in the Mayan Forests of Mexico and Guatemala. We used the results of the model to simulate jaguars moving along a road that bisects the major reserve system in the area...

  10. Use of FIA data and GIS to characterize the effects of fragmentation on the forests of New Hampshire

    Science.gov (United States)

    Randall S. Morin; Andrew Lister; James Doyle

    2009-01-01

    Urbanization, and the resulting fragmentation of forest land, are of great concern across the world and continues to affect many facets of natural ecosystems. Due to development pressure, this is especially true in the northeastern United States. Assessments of regional and national forest fragmentation highlight where forest fragmentation has occurred at one point in...

  11. PHYTOSOCIOLOGICAL AND CARBON STOCK ANALYSIS IN THE TREE LAYER OF A SEMIDECIDUOUS FOREST FRAGMENT

    Directory of Open Access Journals (Sweden)

    Ricardo de Oliveira Gaspar

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814569The studies directed to quantify the carbon fixed stocks by natural forests are in ample evidence, as well as discussion about the effectiveness of the recovery of degraded areas as a strategy to reduce atmospheric CO2 levels. In this sense, this study had two purposes: i quantify the carbon stocks present in the shoot biomass of a tropical semi-deciduous Montana fragment, which belongs to the Atlantic Forest biome in Minas Gerais state and; ii incorporate the variable carbon stock in the horizontal phytosociological analysis structure and compare the results to those obtained by the standard methodology without using the variable in the calculation of the species importance value. The results indicate that the carbon stock equals to the fragments found at the intermediate succession stage, and that the carbon variable use greatly influences the species importance value. This methodology serves as a support for the selection of species which present the greatest potential to sequester carbon and may support programs for the remnant restoration of the Atlantic Forest biome.

  12. Differences in seed rain composition in small and large fragments in the northeast Brazilian Atlantic Forest.

    Science.gov (United States)

    Knörr, U C; Gottsberger, G

    2012-09-01

    Tropical forests are seriously threatened by fragmentation and habitat loss. The impact of fragment size and forest configuration on the composition of seed rain is insufficiently studied. For the present study, seed rain composition of small and large forest fragments (8-388 ha) was assessed in order to identify variations in seed abundance, species richness, seed size and dispersal mode. Seed rain was documented during a 1-year period in three large and four small Atlantic Forest fragments that are isolated by a sugarcane matrix. Total seed rain included 20,518 seeds of 149 species of trees, shrubs, palms, lianas and herbs. Most species and seeds were animal-dispersed. A significant difference in the proportion of seeds and species within different categories of seed size was found between small and large fragments. Small fragments received significantly more very small-sized seeds (1.5 cm) that were generally very rare, with only one species in small and eight in large fragments. We found a negative correlation between the inflow of small-sized seeds and the percentage of forest cover. Species richness was lower in small than in large fragments, but the difference was not very pronounced. Given our results, we propose changing plant species pools through logging, tree mortality and a high inflow of pioneer species and lianas, especially in small forest fragments and areas with low forest cover. Connecting forest fragments through corridors and reforestation with local large-seeded tree species may facilitate the maintenance of species diversity. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Reproductive success of Cabralea canjerana (Meliaceae in Atlantic forest fragments, Brazil

    Directory of Open Access Journals (Sweden)

    Edivani Villaron Franceschinelli

    2015-06-01

    Full Text Available In Brazil, the Atlantic forest remnants have high biological diversity and a high level of endemism, but very little is known about the reproductive success of native species. Cabralea canjerana is a common tree in the Montane Atlantic forest, and its reproduction is highly dependent on pollinators. In order to contribute with the particular knowledge on this species, we collected data in three fragmented and three continuous forest sites, where the effects of fragmentation on both mutualistic (pollination and antagonistic (seed predation interactions were analysed. We determined fruit production and weight of 25 trees per site. The number of seeds and the percentage of predated and aborted seeds were also accessed for seven fruits of 10 trees per site. Pollinator visitation frequencies to flowers were recorded in two forest fragments and in two sites of the continuous forest. Our data showed that plants of C. canjerana produced more fruits (z-value=-8.24; p<0.0001 and seeds per fruit (z-value=-6.58; p=0.002 in the continuous than in the fragmented sites. This was likely due to differences in pollination, because the number of pollinator visits was higher in the continuous forest than in the fragments. Seed abortion (z-value=4.08, p<0.001 and predation (z-value=3.72, p=0.0002, on the other hand, were higher in the fragmented than in the continuous sites. Then, mutualistic and antagonistic interactions were affected by fragmentation, decreasing the reproductive success of the study tree. This study was the first to show a decrease in the reproductive output in forest fragments in an Atlantic forest tree species. This decrease may threaten the population structure and viability of C. canjerana in forest fragments. Rev. Biol. Trop. 63 (2: 515-524. Epub 2015 June 01.

  14. Gamebird responses to anthropogenic forest fragmentation and degradation in a southern Amazonian landscape

    Directory of Open Access Journals (Sweden)

    Fernanda Michalski

    2017-06-01

    Full Text Available Although large-bodied tropical forest birds are impacted by both habitat loss and fragmentation, their patterns of habitat occupancy will also depend on the degree of forest habitat disturbance, which may interact synergistically or additively with fragmentation effects. Here, we examine the effects of forest patch and landscape metrics, and levels of forest disturbance on the patterns of persistence of six gamebird taxa in the southern Brazilian Amazon. We use both interview data conducted with long-term residents and/or landowners from 129 remnant forest patches and 15 continuous forest sites and line-transect census data from a subset of 21 forest patches and two continuous forests. Forest patch area was the strongest predictor of species persistence, explaining as much as 46% of the overall variation in gamebird species richness. Logistic regression models showed that anthropogenic disturbance—including surface wildfires, selective logging and hunting pressure—had a variety of effects on species persistence. Most large-bodied gamebird species were sensitive to forest fragmentation, occupying primarily large, high-quality forest patches in higher abundances, and were typically absent from patches 10,000 ha, relatively undisturbed forest patches to both maximize persistence and maintain baseline abundances of large neotropical forest birds.

  15. A small mammal community in a forest fragment, vegetation corridor and coffee matrix system in the Brazilian Atlantic forest.

    Directory of Open Access Journals (Sweden)

    Mariana Ferreira Rocha

    Full Text Available The objective of our work was to verify the value of the vegetation corridor in the conservation of small mammals in fragmented tropical landscapes, using a model system in the southeastern Minas Gerais. We evaluated and compared the composition and structure of small mammals in a vegetation corridor, forest fragments and a coffee matrix. A total of 15 species were recorded, and the highest species richness was observed in the vegetation corridor (13 species, followed by the forest fragments (10 and the coffee matrix (6. The absolute abundance was similar between the vegetation corridor and fragments (F = 22.94; p = 0.064, and the greatest differences occurred between the vegetation corridor and the matrix (F = 22.94; p = 0.001 and the forest fragments and the matrix (F = 22.94; p = 0.007. Six species showed significant habitat preference possibly related to the sensitivity of the species to the forest disturbance. Marmosops incanus was the species most sensitive to disturbance; Akodon montensis, Cerradomys subflavus, Gracilinanus microtarsus and Rhipidomys sp. displayed little sensitivity to disturbance, with a high relative abundance in the vegetation corridor. Calomys sp. was the species least affected by habitat disturbance, displaying a high relative abundance in the coffee matrix. Although the vegetation corridors are narrow (4 m width, our results support the hypothesis in which they work as a forest extension, share most species with the forest fragment and support species richness and abundance closer to forest fragments than to the coffee matrix. Our work highlights the importance and cost-effectiveness of these corridors to biodiversity management in the fragmented Atlantic Forest landscapes and at the regional level.

  16. Forest area, fragmentation and loss in the Eastern Arc Mountains ...

    African Journals Online (AJOL)

    Based upon the estimates of various workers, approximately 1,447 km2 of closed forest remains in the Eastern Arc Mountains or 27 % of the remaining natural forest. Comparisons of the current to prehistoric forest cover suggest that 77 % of the original forest has been lost over the last approximately 2,000 years. Journal of ...

  17. Richness and Abundance of Ichneumonidae in a Fragmented Tropical Rain Forest.

    Science.gov (United States)

    Ruiz-Guerra, B; Hanson, P; Guevara, R; Dirzo, R

    2013-10-01

    Because of the magnitude of land use currently occurring in tropical regions, the local loss of animal species due to habitat fragmentation has been widely studied, particularly in the case of vertebrates. Many invertebrate groups and the ichneumonid wasps in particular, however, have been poorly studied in this context, despite the fact that they are one of the most species-rich groups and play an important role as regulators of other insect populations. Here, we recorded the taxonomic composition of ichneumonid parasitoids and assessed their species richness, abundance, similarity, and dominance in the Los Tuxtlas tropical rain forest, Mexico. We compared two forest types: a continuous forest (640 ha) and a forest fragment (19 ha). We sampled ichneumonids using four malaise traps in both forest types during the dry (September-October) and rainy (March-April) seasons. A total of 104 individuals of Ichneumonidae belonging to 11 subfamilies, 18 genera, and 42 species were collected in the continuous forest and 11 subfamilies, 15 genera, and 24 species were collected in the forest fragment. Species richness, abundance, and diversity of ichneumonids were greater in the continuous forest than in the forest fragment. We did not detect differences between seasons. Species rank/abundance curves showed that the ichneumonid community between the forest types was different. Species similarity between forest types was low. The most dominant species in continuous forest was Neotheronia sp., whereas in the forest fragment, it was Orthocentrus sp. Changes in the ichneumonid wasp community may compromise important tropical ecosystem processes.

  18. Edge effect on palm diversity in rain forest fragments in western Ecuador

    DEFF Research Database (Denmark)

    Baez, S.; Balslev, Henrik

    2007-01-01

      At the edges of tropical rain forest fragments, altered abiotic and biotic conditions influence the structure and dynamics of plant communities. In Neotropical rain forests, palms (Arecaceae) are important floristic and ecological elements. Palms' responses to edge effects appear...... effects influence the relative proportion of palm adults and juveniles, (2) how distance from the forest edge affects palm density and species richness, (3) how altered forest structure along edges affects palm density. We found that at edges (1) palm communities had a lower proportion of adults relative...... to juvenile individuals compared to continuous forests, (2) the density of two species of palms and the overall species richness of the palm community tended to decrease toward the edges within forest fragments, and, (3) altered forest structure decreased the density of adult palms. Hence, edge effects...

  19. Sequential Fragmentation of Pleistocene Forests in an East Africa Biodiversity Hotspot: Chameleons as a Model to Track Forest History

    OpenAIRE

    Measey, G. John; Tolley, Krystal A.

    2011-01-01

    Background The Eastern Arc Mountains (EAM) is an example of naturally fragmented tropical forests, which contain one of the highest known concentrations of endemic plants and vertebrates. Numerous paleo-climatic studies have not provided direct evidence for ancient presence of Pleistocene forests, particularly in the regions in which savannah presently occurs. Knowledge of the last period when forests connected EAM would provide a sound basis for hypothesis testing of vicariance and dispersal...

  20. Temporary and space dynamics of the fragmentation of the native forest in the south of Chile

    International Nuclear Information System (INIS)

    Montenegro Calderon, Leyla M

    2001-01-01

    The degree of fragmentation of the remainders of native vegetation is evaluated in the hydro graphical basin of the River Damas, through the time. The native forests are had among the ecosystems bigger degree of fragmentation in the world environment. The fragmentation has been defined as the transformation of an originally continuous forest, in smaller varieties, generally anthropics that are hostile for they; These fragments behave as islands virtual immerses in an anthropic ocean and frequently they are analyzed in the context of the theory of the isolation bio geographic. The result of the fragmentation is a landscape in which they mix managed areas and transformed by the man with fragments of native vegetation, that is to say patches of different sizes and forms

  1. Comparing forest fragmentation and its drivers in China and the USA with Globcover v2.2

    Science.gov (United States)

    Chen, Mingshi; Mao, Lijun; Zhou, Chunguo; Vogelmann, James E.; Zhu, Zhiliang

    2010-01-01

    Forest loss and fragmentation are of major concern to the international community, in large part because they impact so many important environmental processes. The main objective of this study was to assess the differences in forest fragmentation patterns and drivers between China and the conterminous United States (USA). Using the latest 300-m resolution global land cover product, Globcover v2.2, a comparative analysis of forest fragmentation patterns and drivers was made. The fragmentation patterns were characterized by using a forest fragmentation model built on the sliding window analysis technique in association with landscape indices. Results showed that China’s forests were substantially more fragmented than those of the USA. This was evidenced by a large difference in the amount of interior forest area share, with China having 48% interior forest versus the 66% for the USA. China’s forest fragmentation was primarily attributed to anthropogenic disturbances, driven particularly by agricultural expansion from an increasing and large population, as well as poor forest management practices. In contrast, USA forests were principally fragmented by natural land cover types. However, USA urban sprawl contributed more to forest fragmentation than in China. This is closely tied to the USA’s economy, lifestyle and institutional processes. Fragmentation maps were generated from this study, which provide valuable insights and implications regarding habitat planning for rare and endangered species. Such maps enable development of strategic plans for sustainable forest management by identifying areas with high amounts of human-induced fragmentation, which improve risk assessments and enable better targeting for protection and remediation efforts. Because forest fragmentation is a long-term, complex process that is highly related to political, institutional, economic and philosophical arenas, both nations need to take effective and comprehensive measures to mitigate

  2. Vegetation structure of four small forest fragments in Taita Hills, Kenya

    African Journals Online (AJOL)

    The structure of four small forest fragments, Kichuchenyi, Macha, Ndiwenyi and Yale, all situated in the Dabida massif of the Taita Hills, was analyzed. The study was based on sample plots of 400 m2 each. Basal area, stratification and disturbance data are presented. All fragments are heavily disturbed. Ndiwenyi and ...

  3. Tropical forest degradation and recovery in fragmented landscapes — Simulating changes in tree community, forest hydrology and carbon balance

    Directory of Open Access Journals (Sweden)

    M. Dantas de Paula

    2015-01-01

    Averages from ten four-hectare simulations show forest biomass degradation lasting around 100 years. If edge effects cease, recovery of biomass lasts around 150 years. Carbon loss is especially intense during the first five years after fragmentation, resulting in a decline of over 5 Mg ha−1y−1 C. Finally, edges of large fragments face an evapotranspiration loss of 43% and total runoff gains of 57% in relation to core areas of large fragments, suggesting that fragmented landscapes can be of significantly lower value in terms of ecosystem services.

  4. Assessment and monitoring of deforestation and forest fragmentation in South Asia since the 1930s

    Science.gov (United States)

    Sudhakar Reddy, C.; Saranya, K. R. L.; Vazeed Pasha, S.; Satish, K. V.; Jha, C. S.; Diwakar, P. G.; Dadhwal, V. K.; Rao, P. V. N.; Krishna Murthy, Y. V. N.

    2018-02-01

    The present study, first of its kind, has analyzed the land cover and investigated the spatial patterns of deforestation and forest fragmentation in South Asian region since the 1930's. This region comprises of eight countries: India, Bangladesh, Bhutan, Nepal, Pakistan, Afghanistan, Sri Lanka and Maldives. In South Asia, agricultural land is predominant constituting 43% of the total geographical area followed by barren land (19.99%) and forests (14.72%). The long-term change analysis using the classified maps of 1930 and 2014 indicated a loss of 29.62% of the forest cover. Higher annual net deforestation rates were observed in the period from 1930-1975 (0.68%) followed by 1975-1985 (0.23%), 1985-1995 (0.12%), 1995-2005 (0.06%) and 2005-2014 (0.04%) for the region. Forest fragmentation had significant spatio-temporal variation across the South Asian countries. In 1930, 88.91% of the South Asian forest was classified as large core forest, 8.18% as edge forest and 1.18% as perforated forest. The large core forest category has decreased significantly in area over last eight decades. The results of the present study are expected to serve as a reference for the evaluation of globally agreed Aichi biodiversity target 5 for South Asian countries. This study will be a valuable basis for developing management strategies and restoration programs as it tracks the spatial changes in deforestation and forest fragmentation.

  5. Influence of agricultural environment on the plant mite community in forest fragments

    Directory of Open Access Journals (Sweden)

    PR. Demite

    Full Text Available The mite community has been surveyed in Seasonal Semideciduous Forest with three types of surrounding agricultural environments to test the hypothesis that abundance and richness of mites in forest fragments are influenced by the type of agricultural environment. The survey has been carried out in six fragments, divided into sets of two fragments, each one neighboring one sort of agricultural environment: sugarcane crop (FS, orange crop (FO and pasture (FP. In each fragment, ten individuals of Actinostemon communis (Euphorbiaceae were selected, five at the edge and five within each fragment. Iphiseiodes zuluagai, often registered in orange crops, was more abundant in the fragments neighboring such crop, as well as some species of Tarsonemidae. In this study, the Phytoseiidae were more abundant in the fragments neighboring pasture, while sugarcane crops probably favored occurrence of phytophagous mites in the neighboring fragments. Tetranychidae were less abundant in FO, which can be explained by periodical use of pesticides in the orange crops. Forest fragments are important for colonies of predators in the neighboring crops, mainly for annual crops such as sugarcane, where the close perennial environment is very important for colonization of the crop. Maintenance of those areas, besides favoring preservation of wild species of mite, is very important to increase diversity of the neighboring agricultural ecosystems.

  6. Wildlife conservation in fragmented tropical forests: A case of South Garo Hills, Meghalaya, North East India

    Science.gov (United States)

    Ashish. Kumar; Bruce G. Marcot; Rohitkumar. Patel

    2017-01-01

    This volume presents findings on, and implications for, wildlife conservation in the tropical forests in Garo Hills of Meghalaya state in the North East India. A companion volume presented the findings on forest fragmentation due to practice of slash and burn agriculture in the region. Both of the volumes summarize work completed over more than a decade on...

  7. Species Richness and Phenology of Cerambycid Beetles in Urban Forest Fragments of Northern Delaware

    Science.gov (United States)

    K. Handley; J. Hough-Goldstein; L.M. Hanks; J.G. Millar; V. D' amico

    2015-01-01

    Cerambycid beetles are abundant and diverse in forests, but much about their host relationships and adult behavior remains unknown. Generic blends of synthetic pheromones were used as lures in traps, to assess the species richness, and phenology of cerambycids in forest fragments in northern Delaware. More than 15,000 cerambycid beetles of 69 species were trapped over...

  8. Regional forest fragmentation effects on bottomland hardwood community types and resource values

    Science.gov (United States)

    Victor A. Rudis

    1995-01-01

    In human-dominated regions, forest vegetation removal impacts remaining ecosystems but regional-scale biological consequences and resource value changes are not well known. Using forest resource survey data, I examined current bottomland hardwood community types and a range of fragment size classes in the south central United States. Analyses examined resource value...

  9. Effect of rock fragments on macropores and water effluent in a forest ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-05-15

    May 15, 2012 ... 2Key Laboratory of Forest Ecological Environment, Institute of Forest Ecology, Environment and Protection, Chinese. Academy of Forestry, Beijing 100091, China. Accepted 16 April, 2012. Rock fragments exert important effects on soil water movement and macropores.However,they are not well-studied in ...

  10. A multi-scale metrics approach to forest fragmentation for Strategic Environmental Impact Assessment

    International Nuclear Information System (INIS)

    Kim, Eunyoung; Song, Wonkyong; Lee, Dongkun

    2013-01-01

    Forests are becoming severely fragmented as a result of land development. South Korea has responded to changing community concerns about environmental issues. The nation has developed and is extending a broad range of tools for use in environmental management. Although legally mandated environmental compliance requirements in South Korea have been implemented to predict and evaluate the impacts of land-development projects, these legal instruments are often insufficient to assess the subsequent impact of development on the surrounding forests. It is especially difficult to examine impacts on multiple (e.g., regional and local) scales in detail. Forest configuration and size, including forest fragmentation by land development, are considered on a regional scale. Moreover, forest structure and composition, including biodiversity, are considered on a local scale in the Environmental Impact Assessment process. Recently, the government amended the Environmental Impact Assessment Act, including the SEA, EIA, and small-scale EIA, to require an integrated approach. Therefore, the purpose of this study was to establish an impact assessment system that minimizes the impacts of land development using an approach that is integrated across multiple scales. This study focused on forest fragmentation due to residential development and road construction sites in selected Congestion Restraint Zones (CRZs) in the Greater Seoul Area of South Korea. Based on a review of multiple-scale impacts, this paper integrates models that assess the impacts of land development on forest ecosystems. The applicability of the integrated model for assessing impacts on forest ecosystems through the SEIA process is considered. On a regional scale, it is possible to evaluate the location and size of a land-development project by considering aspects of forest fragmentation, such as the stability of the forest structure and the degree of fragmentation. On a local scale, land-development projects should

  11. Effects of forest fragmentation on the mating system of a cool-temperate heterodichogamous tree Acer mono

    Directory of Open Access Journals (Sweden)

    Satoshi Kikuchi

    2015-01-01

    Full Text Available Pollination is a key process for reproduction and gene flow in flowering plants. Anthropogenic habitat fragmentation, however, can disrupt plant–pollinator interactions, and may have a negative impact on the reproductive success and population viability of entomophilous plants. Heterodichogamous plants containing protandrous and protogynous individuals within a population may be susceptible to habitat fragmentation due to a lack of available mating partners. In this study, we investigated the effects of forest fragmentation on the mating system in the heterodichogamous plant Acer mono, a major constituent of cool-temperate deciduous forests in Japan. Microsatellite analysis was applied to 212 adult trees and 17 seed families from continuous and fragmented forests. Dispersal kernel modeling using the neighborhood model indicated that pollen dispersal of A. mono was highly fat-tailed. The estimated parameters of the model suggested that the siring success of a pollen donor increased approximately fivefold, with a 100 cm increase in its diameter at breast height (DBH, and that disassortative mating was five times more frequent than assortative mating. The mating system parameters of each mother tree, outcrossing rate (tm, biparental inbreeding (tm−ts, and paternity correlation (rpm varied among sites and conditions, depending on the local density of potential pollen donors. Whereas A. mono was effectively outcrossed (tm=0.901, tm−ts=0.052, and the number of effective sires was 1/rpm=14.93 in the continuous forest, clumped trees within the fragmented forest showed increased biparental inbreeding and reduced pollen pool genetic diversity (tm=0.959, tm−ts=0.245,1/rpm=1.742 as a result of localized mating combined with spatial genetic structures. In contrast, the isolated trees had a higher selfing rate, but the pollen pool diversity was maintained (tm=0.801, tm−ts=0.022, and 1/rpm=15.63 due to frequent long-distance pollination. These

  12. Effects of forest fragmentation on brood parasitism and nest predation in eastern and western landscapes

    Science.gov (United States)

    Cavitt, J.F.; Martin, T.E.

    2002-01-01

    The fragmentation of North American forests by agriculture and other human activities may negatively impact the demographic processes of birds through increases in nest predation and brood parasitism. In fact, the effects of fragmentation on demographic processes are thought to be a major underlying cause of long-term population declines of many bird species. However, much of our understanding of the demographic consequences of fragmentation has come from research conducted in North America east of the Rocky Mountains. Thus, results obtained from these studies may not be applicable to western landscapes, where habitats are often naturally heterogeneous due to topographic variation and periodic fire. We utilized data from a large database of nest records (>10,000) collected at sites both east and west of the Rocky Mountains to determine if the effects of fragmentation are consistent across broad geographic regions. We found that forest fragmentation tended to increase the frequency of brood parasitism by Brown-headed Cowbirds (Molothrus ater) east of the Rockies but we were unable to detect a significant difference in the West. Within the eastern United States, nest predation rates were consistently higher within fragmented sites relative to unfragmented sites. Yet, in the West, fragmentation resulted in a decrease in nest predation relative to unfragmented sites. This is perhaps accounted for by differential responses of the local predator community to fragmentation. Our results suggest that the effects of fragmentation may not be consistent across broad geographic regions and that the effects of fragmentation may depend on dynamics within local landscapes.

  13. Forests

    Science.gov (United States)

    Louis R. Iverson; Mark W. Schwartz

    1994-01-01

    Originally diminished by development, forests are coming back: forest biomass is accumulating. Forests are repositories for many threatened species. Even with increased standing timber, however, biodiversity is threatened by increased forest fragmentation and by exotic species.

  14. Does the afrotropical army ant Dorylus (Anomma) molestus go extinct in fragmented forests?

    DEFF Research Database (Denmark)

    Schöning, Caspar; Kinuthia, Wanja; Boomsma, Jacobus Jan

    2006-01-01

    or facultatively associated with them. Field observations and mathematical modelling suggest that deforestation and accompanying forest fragmentation cause local extinctions of the neotropical swarm-raiding army ant Eciton burchellii which in turn have negative effects on its associated fauna. The aim......Swarm-raiding army ants are extremely polyphagous nomadic predators inhabiting tropical forests. They are considered keystone species because their raids can regulate the population dynamics of their prey and because a plethora of both invertebrate and vertebrate species are obligatorily...... of this study was to examine whether afrotropical army ants are affected by forest fragmentation in the same way. Surveys of Dorylus (Anomma) molestus colonies were carried out in forest fragments of different sizes and in the matrix habitat at two sites in Eastern Kenya, along the Lower Tana River...

  15. Effects of Forest Fragmentation on Human Risk of Lyme Disease

    Science.gov (United States)

    Percent forest-herbaceous edge repeatedly explained most of the variability in reported Lyme disease rates within a rural-to-urban study gradient across central Maryland and southeastern Pennsylvania. A one-percent increase in forest-herbaceous edge was associated with an increas...

  16. Reducing social losses from forest fires

    Science.gov (United States)

    Gregory S. Amacher; Arun S. Malik; Robert G. Haight

    2006-01-01

    We evaluate two financial incentives to encourage nonindustrial forest landowners to undertake activities that mitigate fire losses: sharing of fire suppression costs by the landowner and sharing of fuel reduction costs by the government. First and second best outcomes are identified and compared to assess the effectiveness of these incentives in reducing social...

  17. Mitochondrial DNA diversity and population structure of a forest-dependent rodent, Praomys taitae (Rodentia: Muridae) Heller 1911, in the fragmented forest patches of Taita Hills, Kenya

    DEFF Research Database (Denmark)

    Nyakaana, S.; Tumusiime, C.; Oguge, N.

    2008-01-01

    The population genetic structure of the forest-dependent rodent, Praomys taitae, sampled from nine indigenous forest fragments sampled from nine indigenous forest fragments distributed over three ranges of the Taita Hills in Kenya, was determined using mitochondrial DNA (mtDNA) control region seq...

  18. Comparison of neotropical migrant landbird populations wintering in tropical forest, isolated forest fragments, and agricultural habitats

    Science.gov (United States)

    Robbins, C.S.; Dowell, B.A.; Dawson, D.K.; Colon, J.A.; Estrada, R.; Sutton, A.; Sutton, R.; Weyer, D.; Hagan, John M.; Johnston, David W.

    1992-01-01

    Neotropical migrant bird populations were sampled at 76 sites in seven countries by using mist nets and point counts during a six-winter study. Populations in major agricultural habitats were compared with those in extensive forest and isolated forest fragments. Certain Neotropical migrants, such as the Northern Parula, American Redstart, and the Black-throated Blue, Magnolia, Black-and-white, and Hooded warblers, were present in arboreal agricultural habitats such as pine, cacao, citrus, and shade coffee plantations in relatively large numbers. Many north temperate zone shrub-nesting species, such as the Gray Catbird, White-eyed Vireo, Tennessee Warbler, Common Yellowthroat, and Indigo Bunting, also used agricultural habitats in winter, as did resident hummingbirds and migrant orioles. Ground-foraging migrants, such as thrushes and Kentucky Warblers, were rarely found in the agricultural habitats sampled. Although many Neotropical migrants use some croplands, this use might be severely limited by overgrazing by cattle, by intensive management (such as removal of ground cover in an orchard), or by heavy use of insecticides, herbicides, or fungicides.

  19. Can proximity to roads influence forest fragmentation? A case study in northern Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Tiago Rezzadori

    2016-09-01

    Full Text Available The establishment and use of roads interfere with the atmosphere, soil, vegetation, fauna, and human communities surrounding them. One of the main effects caused by the implementation and operation of a road is fragmentation of natural landscapes, which consequently generates edge effects and isolation of populations. Thus, this study aimed to quantify and compare the distribution of vegetation cover in areas with and without ecological influence of roads in the Alto Uruguai region, northern Rio Grande do Sul, Brazil. To do this, a geo-relational database was created, where satellite images taken by Landsat V and CBERS 2b were entered. The size and amount of forest fragments were estimated in areas with and without influence of roads. The area with ecological influence of roads had less and smaller sized forest fragments when compared to the area without ecological influence. High forest fragmentation seems to be enhanced by proximity to roads in northern Rio Grande do Sul, contributing to isolate and reduce the size of native populations that occupy these areas.

  20. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants

    Science.gov (United States)

    Benítez-Malvido, Julieta; Dáttilo, Wesley; Martínez-Falcón, Ana Paola; Durán-Barrón, César; Valenzuela, Jorge; López, Sara; Lombera, Rafael

    2016-01-01

    Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators) and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages. PMID:26731271

  1. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants.

    Directory of Open Access Journals (Sweden)

    Julieta Benítez-Malvido

    Full Text Available Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages.

  2. Determining the dynamics of evapotranspiration from fragmented forests under drought in southwestern Amazonia using Landsat imagery

    Science.gov (United States)

    Numata, I.; Khand, K.; Kjaersgaard, J.; Cochrane, M. A.; Silva, S.

    2016-12-01

    Deforestation in the Amazon has resulted in massive amounts of forest biomass loss and also in extensive forest fragmentation across the region. Fragmented tropical forests are exposed to abrupt environmental changes and experience several biological and ecological changes across distances from forest edges. Extreme droughts in 2005 and 2010 have caused extensive tree mortality across this region. These events may exacerbate edge effects, where already water stressed forest fragments dry more rapidly potentially enabling other disturbances such as forest fire. We analyzed the effects of forest fragmentation and drought on forest evapotranspiration (ET) estimated using the energy balance-based model METRIC with Landsat imagery in Rondônia State in the southwestern Amazon. Forest ET estimates were produced for the dry seasons (June-August) of 2009-2011 thus including the 2010 drought event and pre- and post-event periods. METRIC ET data were combined with forest edge data with edge distances of 100m, 300m, 500m, 1000m, 5000m and >5000m (core forest), generated from Landsat land cover maps for spatiotemporal analysis of forest ET. METRIC ET estimates had an agreement with flux tower ET data from the field of R2 = 0.72. Within the study time period, the 2010 drought year showed the lowest average ET from core forest (2.5mm/day), followed by 2011 (3.0mm/day) and 2009 (3.6mm/day) in the month of August, the mid dry season, while no significant differences were noted among three study years earlier in the dry seasons. In terms of edge effects, the major changes in forest ET occur up to 300 m from the forest edges, with ET decreasees of 30 % at 100 m as compared to further distances. The magnitude of edge-related ET changes became even greater during August of the drought year (2010) and the post-drought year (2011). Annual (drought and non-drought) and seasonal (June-August) forest ET variations were highly significant (p<0.001), while the impact of distance from edge on

  3. Dung beetle (Coleoptera, Scarabaeidae assemblage of a highly fragmented landscape of Atlantic forest: from small to the largest fragments of northeastern Brazilian region

    Directory of Open Access Journals (Sweden)

    Renato P. Salomão

    2015-06-01

    Full Text Available Human activities in tropical forests are the main causes of forest fragmentation. According to historical factor in deforestation processes, forest remnants exhibit different sizes and shapes. The aim of the present study was to evaluate the dung beetle assemblage on fragments of different degree of sizes. Sampling was performed during rainy and dry season of 2010 in six fragments of Atlantic forest, using pitfall traps baited with excrement and carrion. Also, we used two larger fragments as control. We used General Linear Models to determine whether the fragments presented distinguished dung beetle abundance and richness. Analysis of Similarities and Non-Metric Multidimensional Scaling were used to determine whether the dung beetle assemblage was grouped according to species composition. A total of 3352 individuals were collected and 19 species were identified in the six fragments sampled. Dung beetle abundance exhibited a shift according to fragment size; however, richness did not change among fragments evaluated. Also, fragments sampled and the two controls exhibited distinct species composition. The distinction on abundance of dung beetles among fragments may be related to different amount of resource available in each one. It is likely that the dung beetle richness did not distinguish among the different fragments due to the even distribution of the mammal communities in these patches, and consequent equal dung diversity. We conclude that larger fragments encompass higher abundance of dung beetle and distinct species. However, for a clearer understanding of effects of fragmentation on dung beetles in Atlantic forest, studies evaluating narrower variations of larger fragments should be conducted.

  4. Human impacts affect tree community features of 20 forest fragments of a vanishing neotropical hotspot.

    Science.gov (United States)

    Pereira, José Aldo Alves; de Oliveira-Filho, Ary Teixeira; Eisenlohr, Pedro V; Miranda, Pedro L S; de Lemos Filho, José Pires

    2015-02-01

    The loss in forest area due to human occupancy is not the only threat to the remaining biodiversity: forest fragments are susceptible to additional human impact. Our aim was to investigate the effect of human impact on tree community features (species composition and abundance, and structural descriptors) and check if there was a decrease in the number of slender trees, an increase in the amount of large trees, and also a reduction in the number of tree species that occur in 20 fragments of Atlantic montane semideciduous forest in southeastern Brazil. We produced digital maps of each forest fragment using Landsat 7 satellite images and processed the maps to obtain morphometric variables. We used investigative questionnaires and field observations to survey the history of human impact. We then converted the information into scores given to the extent, severity, and duration of each impact, including proportional border area, fire, trails, coppicing, logging, and cattle, and converted these scores into categorical levels. We used linear models to assess the effect of impacts on tree species abundance distribution and stand structural descriptors. Part of the variation in floristic patterns was significantly correlated to the impacts of fire, logging, and proportional border area. Structural descriptors were influenced by cattle and outer roads. Our results provided, for the first time, strong evidence that tree species occurrence and abundance, and forest structure of Atlantic seasonal forest fragments respond differently to various modes of disturbance by humans.

  5. Deforestation and Forest Fragmentation in South Ecuador since the 1970s - Losing a Hotspot of Biodiversity.

    Science.gov (United States)

    Tapia-Armijos, María Fernanda; Homeier, Jürgen; Espinosa, Carlos Iván; Leuschner, Christoph; de la Cruz, Marcelino

    2015-01-01

    Deforestation and fragmentation are major components of global change; both are contributing to the rapid loss of tropical forest area with important implications for ecosystem functioning and biodiversity conservation. The forests of South Ecuador are a biological 'hotspot' due to their high diversity and endemism levels. We examined the deforestation and fragmentation patterns in this area of high conservation value using aerial photographs and Aster satellite scenes. The registered annual deforestation rates of 0.75% (1976-1989) and 2.86% (1989-2008) for two consecutive survey periods, the decreasing mean patch size and the increasing isolation of the forest fragments show that the area is under severe threat. Approximately 46% of South Ecuador's original forest cover had been converted by 2008 into pastures and other anthropogenic land cover types. We found that deforestation is more intense at lower elevations (premontane evergreen forest and shrubland) and that the deforestation front currently moves in upslope direction. Improved awareness of the spatial extent, dynamics and patterns of deforestation and forest fragmentation is urgently needed in biologically diverse areas like South Ecuador.

  6. Effects of climate and forest structure on palms, bromeliads and bamboos in Atlantic Forest fragments of Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    R. R. Hilário

    Full Text Available Abstract Palms, bromeliads and bamboos are key elements of tropical forests and understanding the effects of climate, anthropogenic pressure and forest structure on these groups is crucial to forecast structural changes in tropical forests. Therefore, we investigated the effects of these factors on the abundance of these groups in 22 Atlantic forest fragments of Northeastern Brazil. Abundance of bromeliads and bamboos were assessed through indexes. Palms were counted within a radius of 20 m. We also obtained measures of vegetation structure, fragment size, annual precipitation, precipitation seasonality and human population density. We tested the effects of these predictors on plant groups using path analysis. Palm abundance was higher in taller forests with larger trees, closed canopy and sparse understory, which may be a result of the presence of seed dispersers and specific attributes of local palm species. Bromeliads were negatively affected by both annual precipitation and precipitation seasonality, what may reflect adaptations of these plants to use water efficiently, but also the need to capture water in a regular basis. Bamboos were not related to any predictor variable. As climate and forest structure affected the abundance of bromeliads and palms, human-induced climatic changes and disturbances in forest structure may modify the abundance of these groups. In addition, soil properties and direct measurements of human disturbance should be used in future studies in order to improve the predictability of models about plant groups in Northeastern Atlantic Forest.

  7. Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina.

    Science.gov (United States)

    Frate, Ludovico; Acosta, Alicia T R; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

    2015-01-01

    The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979-2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (Pf) and structural connectivity (Pff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting Pf vs. Pff mean values and were compared across spatial extents. The distributions of Pf across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of Pf's variability along with the increment of the mean slope of the Pf 's scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and sustainable

  8. Incidence of plant cover over the autotrophic nitrifying bacteria population in a fragment of Andean forest

    International Nuclear Information System (INIS)

    Gonzalez, Xiomara; Gonzalez, L; Varela, A; Ahumada, J A

    1999-01-01

    It was determined the incidence of plant cover (forest vs. pasture), on the autotrophy nitrifying bacteria, through the effect of biotic factors (radical exudate) and abiotic factors (temperature, ph and humidity), in a high mountain cloud forest fragment. The site of study was located near La Mesa (Cundinamarca) municipality. The temperature of soil was measured in situ, and soil samples were collected and carried to the laboratory for pH and humidity percentage measurements. Serial soil dilution method was used for plating samples on a selective culture medium with ammonium sulphate as nitrogen source, in order to estimate the autotrophic nitrifying bacteria population levels. Grown colonies were examined macro and microscopically. The quantity of nitrates produced by bacteria cultured in vitro was determined spectra-photometrical. In relation to the abiotic factors, there was no significant differences of pH between both plant covers, but there were significant for soil humidity and temperature (p<0.05). There were highly significant differences with respect to the bacteria population levels (p<0.0001) and with respect to nitrate production. This suggests a higher bacterial activity in the under forest cover. The radical exudate from both types of plant cover reduced the viability of bacteria in vitro, from 1:1 to 1:30 exudate bacteria proportions. In the soils physical and chemical analysis, it was found a higher P and Al concentrations, and a higher CIC and organic matter content under the forest cover. It is suggested the importance of this functional group in this ecosystem

  9. Impacts of changes in land use and fragmentation patterns on Atlantic coastal forests in northern Spain.

    Science.gov (United States)

    Teixido, Alberto L; Quintanilla, Luis G; Carreño, Francisco; Gutiérrez, David

    2010-01-01

    Changes in forested landscapes may have important consequences for ecosystem services and biodiversity conservation. In northern Spain, major changes in land use occurred during the second half of the 20th century, but their impacts on forests have not been quantified. We evaluated the dynamics of landscape and forest distribution patterns between 1957 and 2003 in Fragas do Eume Natural Park (northwestern Spain). We used orthoimages and a set of standard landscape metrics to determine transitions between land cover classes and to examine forest distribution patterns. Eucalypt plantations showed the greatest increase in area (197%) over time. Furthermore, transitions to eucalypt plantations were found in all major land cover classes. Forest showed a net decline of 20% in total area and represented 30% of the landscape area in 2003. Forest losses were mainly due to eucalypt plantations and the building of a water reservoir, while forest gains were due to increases in shrubland, meadows and cultivated fields which had been recolonised. Forest patch size and core area decreased, and edge length increased over time. In turn, increases were obtained in mean distance between forest patches, and in adjacency to eucalypt plantations and to a water reservoir. These results suggest an increase in forest fragmentation from 1957 to 2003, as well as a change in the nature of the habitat surrounding forest patches. This study shows that land use changes, mostly from eucalypt plantation intensification, negatively affected forested habitats, although some regeneration was ongoing through ecological succession from land abandonment. Copyright 2009 Elsevier Ltd. All rights reserved.

  10. Barrier effects on vertebrate distribution caused by a motorway crossing through fragmented forest landscape

    Directory of Open Access Journals (Sweden)

    Tellería, J. L.

    2011-12-01

    Full Text Available We analysed the effects of a 25–year–old motorway on the distribution of five vertebrates inhabiting a fragmented forest landscape and differing in their ability to move across linear infrastructures. We found clear evidence of barrier effects on the distribution of the forest lizard Psammodromus algirus. The roe deer (Capreolus capreolus was also unequally distributed on both sides of the motorway, but this could also be due, at least in part, to fragmentation. The eyed lizard (Timon lepidus, that can move through open fields, showed no evidence of barrier effects. The distribution of two small birds (Erithacus rubecula and Phylloscopus bonelli was unaffected by the motorway. Our results show that a motorway may severely restrict the distribution of species which can withstand high levels of forest fragmentation but show limited dispersal ability, highlighting the role of linear infrastructures in shaping species’ ranges at regional scales.

  11. Association of pteridophyte species in two fragments of Atlantic Coastal Forest in the Brazilian Northeast

    Directory of Open Access Journals (Sweden)

    Iva Carneiro Leão Barros

    2006-09-01

    Full Text Available This study aims to investigate fern flora similarity and fern species relationships in the study areas, in terms of their substrates, habitat types, and life forms. The study was conducted in the Água Azul forest fragment, municipality of Timbaúba, Pernambuco, and the Maria Maior forest fragment, municipality of São José da Laje, Alagoas. The Jaccard similarity index was used for cluster analysis. The 112 species that occur in the two areas were used for numerical analysis. The floristic similarity was great (J=43.75%, principally due to similarities in the two areas vegetational types, as was expected due to their geographic proximity to one another and their similar climatic conditions. Five groups of associated species were determined for the Água Azul fragment and six groups for the Maria Maior fragment. In general, the ecological factors that determined fern species associations were habitat and type of substrate.

  12. Strategic rat control for restoring populations of native species in forest fragments.

    Science.gov (United States)

    Armstrong, Doug P; Gorman, Nic; Pike, Rhonda; Kreigenhofer, Brigitte; McArthur, Nikki; Govella, Susanne; Barrett, Paul; Richard, Yvan

    2014-06-01

    Forest fragments have biodiversity value that may be enhanced through management such as control of non-native predators. However, such efforts may be ineffective, and research is needed to ensure that predator control is done strategically. We used Bayesian hierarchical modeling to estimate fragment-specific effects of experimental rat control on a native species targeted for recovery in a New Zealand pastoral landscape. The experiment was a modified BACI (before-after-control-impact) design conducted over 6 years in 19 forest fragments with low-density subpopulations of North Island Robins (Petroica longipes). The aim was to identify individual fragments that not only showed clear benefits of rat control, but also would have a high probability of subpopulation growth even if they were the only fragment managed. We collected data on fecundity, adult and juvenile survival, and juvenile emigration, and modeled the data in an integrated framework to estimate the expected annual growth rate (λ) of each subpopulation with and without rat control. Without emigration, subpopulation growth was estimated as marginal (λ = 0.95-1.05) or negative (λ = 0.74-0.90) without rat control, but it was estimated as positive in all fragments (λ = 1.4-2.1) if rats were controlled. This reflected a 150% average increase in fecundity and 45% average increase in adult female survival. The probability of a juvenile remaining in its natal fragment was 0.37 on average, but varied with fragment connectivity. With juvenile emigration added, 6 fragments were estimated to have a high (>0.8) probability of being self-sustaining (λ > 1) with rat control. The key factors affecting subpopulation growth rates under rat control were low connectivity and stock fencing because these factors were associated with lower juvenile emigration and higher fecundity, respectively. However, there was also substantial random variation in adult survival among fragments, illustrating the importance of

  13. Dispersal of remnant endangered trees in a fragmented and disturbed forest by frugivorous birds.

    Science.gov (United States)

    Li, Ning; Bai, Bing; Li, Xin-Hai; An, Shu-Qing; Lu, Chang-Hu

    2017-07-01

    Most endangered plant species in a fragmented forest behave as a unique source population, with a high dependence on frugivorous birds for recruitment and persistence. In this study, we combined field data of dispersal behavior of birds and GIS information of patch attributes to estimate how frugivorous birds could affect the effective dispersal pattern of Chinese yew (Taxus chinensis) in a fragmented and disturbed forest. Nine bird species were observed to visit T. chinensis trees, with Urocissa erythrorhyncha, Zoothera dauma and Picus canus being the most common dispersers. After foraging, six disperser species exhibited different perching patterns. Three specialist species, P. canus, Turdus hortulorum, and Z. dauma stayed in the source patch, while three generalist species, U. erythrorhyncha, Hypsipetes mcclellandii, and H. castanonotus, could perch in bamboo patches and varied in movement ability due to body size. As a consequence of perching, dispersers significantly contributed to the seed bank, but indirectly affected seedling recruitment. Moreover, the recruitment of T. chinensis was also affected by patch attributes in a fragmented forest (distances to source patch, patch type, size). Our results highlighted the ability of unique source population regeneration of T. chinensis in a fragmented forest, with high dependence on both frugivorous birds and patch attributes, which should be considered in future planning for forest management and conservation.

  14. Corridors restore animal-mediated pollination in fragmented tropical forest landscapes.

    Science.gov (United States)

    Kormann, Urs; Scherber, Christoph; Tscharntke, Teja; Klein, Nadja; Larbig, Manuel; Valente, Jonathon J; Hadley, Adam S; Betts, Matthew G

    2016-01-27

    Tropical biodiversity and associated ecosystem functions have become heavily eroded through habitat loss. Animal-mediated pollination is required in more than 94% of higher tropical plant species and 75% of the world's leading food crops, but it remains unclear if corridors avert deforestation-driven pollination breakdown in fragmented tropical landscapes. Here, we used manipulative resource experiments and field observations to show that corridors functionally connect neotropical forest fragments for forest-associated hummingbirds and increase pollen transfer. Further, corridors boosted forest-associated pollinator availability in fragments by 14.3 times compared with unconnected equivalents, increasing overall pollination success. Plants in patches without corridors showed pollination rates equal to bagged control flowers, indicating pollination failure in isolated fragments. This indicates, for the first time, that corridors benefit tropical forest ecosystems beyond boosting local species richness, by functionally connecting mutualistic network partners. We conclude that small-scale adjustments to landscape configuration safeguard native pollinators and associated pollination services in tropical forest landscapes. © 2016 The Author(s).

  15. Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

    CSIR Research Space (South Africa)

    Cho, Moses A

    2013-10-01

    Full Text Available Eucalyptus trees tend to accumulate as much leaf nitrogen as the natural forest in the Dukuduku region. Acknowledgments The Council for Scientific and Industrial Research (CSIR) and the Department of Science and Technology (DST) provided the funding... forest fragmentation on leaf nitrogen distribution using remote sensing data Moses Azong Cho. Abel Ramoelo. Pravesh Debba. Onisimo Mutanga. Renaud Mathieu. Heidi van Deventer H., Nomzamo Ndlovu M.A. Cho. Council for Scientific and Industrial...

  16. Sequential fragmentation of Pleistocene forests in an East Africa biodiversity hotspot: chameleons as a model to track forest history.

    Directory of Open Access Journals (Sweden)

    G John Measey

    Full Text Available The Eastern Arc Mountains (EAM is an example of naturally fragmented tropical forests, which contain one of the highest known concentrations of endemic plants and vertebrates. Numerous paleo-climatic studies have not provided direct evidence for ancient presence of Pleistocene forests, particularly in the regions in which savannah presently occurs. Knowledge of the last period when forests connected EAM would provide a sound basis for hypothesis testing of vicariance and dispersal models of speciation. Dated phylogenies have revealed complex patterns throughout EAM, so we investigated divergence times of forest fauna on four montane isolates in close proximity to determine whether forest break-up was most likely to have been simultaneous or sequential, using population genetics of a forest restricted arboreal chameleon, Kinyongia boehmei.We used mitochondrial and nuclear genetic sequence data and mutation rates from a fossil-calibrated phylogeny to estimate divergence times between montane isolates using a coalescent approach. We found that chameleons on all mountains are most likely to have diverged sequentially within the Pleistocene from 0.93-0.59 Ma (95% HPD 0.22-1.84 Ma. In addition, post-hoc tests on chameleons on the largest montane isolate suggest a population expansion ∼182 Ka.Sequential divergence is most likely to have occurred after the last of three wet periods within the arid Plio-Pleistocene era, but was not correlated with inter-montane distance. We speculate that forest connection persisted due to riparian corridors regardless of proximity, highlighting their importance in the region's historic dispersal events. The population expansion coincides with nearby volcanic activity, which may also explain the relative paucity of the Taita's endemic fauna. Our study shows that forest chameleons are an apposite group to track forest fragmentation, with the inference that forest extended between some EAM during the Pleistocene 1

  17. Sequential fragmentation of Pleistocene forests in an East Africa biodiversity hotspot: chameleons as a model to track forest history.

    Science.gov (United States)

    Measey, G John; Tolley, Krystal A

    2011-01-01

    The Eastern Arc Mountains (EAM) is an example of naturally fragmented tropical forests, which contain one of the highest known concentrations of endemic plants and vertebrates. Numerous paleo-climatic studies have not provided direct evidence for ancient presence of Pleistocene forests, particularly in the regions in which savannah presently occurs. Knowledge of the last period when forests connected EAM would provide a sound basis for hypothesis testing of vicariance and dispersal models of speciation. Dated phylogenies have revealed complex patterns throughout EAM, so we investigated divergence times of forest fauna on four montane isolates in close proximity to determine whether forest break-up was most likely to have been simultaneous or sequential, using population genetics of a forest restricted arboreal chameleon, Kinyongia boehmei. We used mitochondrial and nuclear genetic sequence data and mutation rates from a fossil-calibrated phylogeny to estimate divergence times between montane isolates using a coalescent approach. We found that chameleons on all mountains are most likely to have diverged sequentially within the Pleistocene from 0.93-0.59 Ma (95% HPD 0.22-1.84 Ma). In addition, post-hoc tests on chameleons on the largest montane isolate suggest a population expansion ∼182 Ka. Sequential divergence is most likely to have occurred after the last of three wet periods within the arid Plio-Pleistocene era, but was not correlated with inter-montane distance. We speculate that forest connection persisted due to riparian corridors regardless of proximity, highlighting their importance in the region's historic dispersal events. The population expansion coincides with nearby volcanic activity, which may also explain the relative paucity of the Taita's endemic fauna. Our study shows that forest chameleons are an apposite group to track forest fragmentation, with the inference that forest extended between some EAM during the Pleistocene 1.1-0.9 Ma.

  18. Sequential Fragmentation of Pleistocene Forests in an East Africa Biodiversity Hotspot: Chameleons as a Model to Track Forest History

    Science.gov (United States)

    Measey, G. John; Tolley, Krystal A.

    2011-01-01

    Background The Eastern Arc Mountains (EAM) is an example of naturally fragmented tropical forests, which contain one of the highest known concentrations of endemic plants and vertebrates. Numerous paleo-climatic studies have not provided direct evidence for ancient presence of Pleistocene forests, particularly in the regions in which savannah presently occurs. Knowledge of the last period when forests connected EAM would provide a sound basis for hypothesis testing of vicariance and dispersal models of speciation. Dated phylogenies have revealed complex patterns throughout EAM, so we investigated divergence times of forest fauna on four montane isolates in close proximity to determine whether forest break-up was most likely to have been simultaneous or sequential, using population genetics of a forest restricted arboreal chameleon, Kinyongia boehmei. Methodology/Principal Findings We used mitochondrial and nuclear genetic sequence data and mutation rates from a fossil-calibrated phylogeny to estimate divergence times between montane isolates using a coalescent approach. We found that chameleons on all mountains are most likely to have diverged sequentially within the Pleistocene from 0.93–0.59 Ma (95% HPD 0.22–1.84 Ma). In addition, post-hoc tests on chameleons on the largest montane isolate suggest a population expansion ∼182 Ka. Conclusions/Significance Sequential divergence is most likely to have occurred after the last of three wet periods within the arid Plio-Pleistocene era, but was not correlated with inter-montane distance. We speculate that forest connection persisted due to riparian corridors regardless of proximity, highlighting their importance in the region's historic dispersal events. The population expansion coincides with nearby volcanic activity, which may also explain the relative paucity of the Taita's endemic fauna. Our study shows that forest chameleons are an apposite group to track forest fragmentation, with the inference that forest

  19. Plant diversity in hedgerows amidst Atlantic Forest fragments

    OpenAIRE

    Oliveira, Carolina C. C.; Pereira, Lya C. S. M.; Lima, André; Shimabukuro, Yosio E.; Torezan, José Marcelo D.

    2015-01-01

    Hedgerows are linear structures found in agricultural landscapes that may facilitate dispersal of plants and animals and also serve as habitat. The aim of this study was to investigate the relationships among diversity and ecological traits of woody plants, hedgerow characteristics (size, age, and origin), and the structure of the surrounding Atlantic Forest landscape. Field data were collected from 14 hedgerows, and landscape metrics from 1000-m buffers surrounding hedgerows were recorded fr...

  20. PRESERVATION OF PRIMARY FOREST CHARACTERISTICS DESPITE FRAGMENTATION AND ISOLATION IN A FOREST REMNANT FROM VIÇOSA, MG, BRAZIL1

    Directory of Open Access Journals (Sweden)

    Markus Gastauer

    2015-12-01

    Full Text Available According to its owners, the Forest of Seu Nico (FSN from the Viçosa municipality, Minas Gerais, Brazil, never has been logged and is therefore considered a primary forest. Nevertheless, the forest patch suffered impacts due to selective wood and non-timber extraction, fragmentation and isolation. Aim of this study was to test if the FSN, despite impacts, preserved characteristics of primary forests, which are elevated percentages of non-pioneer (>90%, animal-dispersed (>80 %, understory (>50% and endemic species (~40%. For that, all trees with diameter at breast height equal or major than 3.2 cm within a plot of 100 x 100 m were identified. With 218 tree species found within this hectare, the FSN's species richness is outstanding for the region. The percentages of non-pioneer (92 %, animal-dispersed (85 %, understory (55 % and endemic species (39.2 % from the FSN fulfill the criteria proposed for primary forest. Therefore, we conclude that the FSN maintained its characteristics as a primary forest which highlights its importance for the conservation of biotic resources in the region, where similar fragments are lacking or not described yet.

  1. Impact of Forest Fragmentation on Patterns of Mountain Pine Beetle-Caused Tree Mortality

    Directory of Open Access Journals (Sweden)

    Trisalyn A. Nelson

    2013-04-01

    Full Text Available The current outbreak of mountain pine beetle, Dendroctonus ponderosae Hopkins, has led to extensive tree mortality in British Columbia and the western United States. While the greatest impacts of the outbreak have been in British Columbia, ongoing impacts are expected as the outbreak continues to spread eastward towards Canada’s boreal and eastern pine forests. Successful mitigation of this outbreak is dependent on understanding how the beetle’s host selection behaviour is influenced by the patchwork of tree mortality across the landscape. While several studies have shown that selective mechanisms operate at the individual tree level, less attention has been given to beetles’ preference for variation in spatial forest patterns, namely forest fragmentation, and if such preference changes with changing population conditions. The objective of this study is to explore the influence of fragmentation on the location of mountain pine beetle caused mortality. Using a negative binomial regression model, we tested the significance of a fragmentation measure called the Aggregation Index for predicting beetle-caused tree mortality in the central interior of British Columbia, Canada in 2000 and 2005. The results explain that mountain pine beetle OPEN ACCESS Forests 2013, 4 280 exhibit a density-dependent dynamic behaviour related to forest patterns, with fragmented forests experiencing greater tree mortality when beetle populations are low (2000. Conversely, more contiguous forests are preferred when populations reach epidemic levels (2005. These results reinforce existing findings that bark beetles exhibit a strong host configuration preference at low population levels and that such pressures are relaxed when beetle densities are high.

  2. Geotechnology and landscape ecology applied to the selection of potential forest fragments for seed harvesting.

    Science.gov (United States)

    Santos, Alexandre Rosa Dos; Antonio Alvares Soares Ribeiro, Carlos; de Oliveira Peluzio, Telma Machado; Esteves Peluzio, João Batista; de Queiroz, Vagner Tebaldi; Figueira Branco, Elvis Ricardo; Lorenzon, Alexandre Simões; Domingues, Getulio Fonseca; Marcatti, Gustavo Eduardo; de Castro, Nero Lemos Martins; Teixeira, Thaisa Ribeiro; Dos Santos, Gleissy Mary Amaral Dino Alves; Santos Mota, Pedro Henrique; Ferreira da Silva, Samuel; Vargas, Rozimelia; de Carvalho, José Romário; Macedo, Leandro Levate; da Silva Araújo, Cintia; de Almeida, Samira Luns Hatum

    2016-12-01

    The Atlantic Forest biome is recognized for its biodiversity and is one of the most threatened biomes on the planet, with forest fragmentation increasing due to uncontrolled land use, land occupation, and population growth. The most serious aspect of the forest fragmentation process is the edge effect and the loss of biodiversity. In this context, the aim of this study was to evaluate the dynamics of forest fragmentation and select potential forest fragments with a higher degree of conservation for seed harvesting in the Itapemirim river basin, Espírito Santo State, Brazil. Image classification techniques, forest landscape ecology, and multi-criteria analysis were used to evaluate the evolution of forest fragmentation to develop the landscape metric indexes, and to select potential forest fragments for seed harvesting for the years 1985 and 2013. According to the results, there was a reduction of 2.55% of the occupancy of the fragments in the basin between the years 1985 and 2013. For the years 1985 and 2013, forest fragment units 2 and 3 were spatialized with a high potential for seed harvesting, representing 6.99% and 16.01% of the total fragments, respectively. The methodology used in this study has the potential to be used to support decisions for the selection of potential fragments for seed harvesting because selecting fragments in different environments by their spatial attributes provides a greater degree of conservation, contributing to the protection and conscious management of the forests. The proposed methodology can be adapted to other areas and different biomes of the world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Characterizing the spatial distribution of giant pandas (Ailuropoda melanoleuca) in fragmented forest landscapes

    NARCIS (Netherlands)

    Wang, T.; Ye, X.P.; Skidmore, A.K.; Toxopeus, A.G.

    2010-01-01

    Aim. To examine the effects of forest fragmentation on the distribution of the entire wild giant panda (Ailuropoda melanoleuca) population, and to propose a modelling approach for monitoring the spatial distribution and habitat of pandas at the landscape scale using Moderate Resolution Imaging

  4. Agaricales Fungi from atlantic rain forest fragments in Minas Gerais, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Henrique Rosa

    2009-12-01

    Full Text Available Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil.

  5. Agaricales Fungi from atlantic rain forest fragments in Minas Gerais, Brazil

    Science.gov (United States)

    Rosa, Luiz Henrique; Capelari, Marina

    2009-01-01

    Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil. PMID:24031432

  6. Herpetofauna of an urban fragment of Atlantic Forest in Paraíba State, Northeast Brazil

    OpenAIRE

    Yuri C. C. Lima; Fagner R. Delfim; Gentil A. Pereira-Filho; Washington L. S. Vieira; Gindomar Gomes Santana; Kleber S. Vieira

    2008-01-01

    The Herpetofauna of an urban fragment of Atlantic Forest was investigated in relation to species richness and habitat use. Fourteen species of amphibian anurans pertaining to the families Bufonidae, Brachycephalidae, Hylidae, Leptodactylidae, Leiuperidae, Microhylidae and Ranidae were recorded. The reptiles were represented by 37 species, distributed in the families Gekkonidae, Gymnophthalmidae, Polychrotidae, Scincidae, Teiidae, Tropiduridae, Amphisbaenidae, Boidae, Colubridae, Elapidae, Typ...

  7. Fragmentation of Araucaria Forests in the Chapecó Ecological Corridor, Santa Catarina

    Directory of Open Access Journals (Sweden)

    Gisele Garcia Alarcon

    2011-09-01

    Full Text Available In Brazil, only 2% of the Araucaria forest remains, and less than 1% of this forest is protected (as conservation units. In Santa Catarina, the Chapecó River sub-basin was evaluated for the creation of a state ecological corridor. Studies were developed within the Microbacias 2 Project between 2007 and 2009. Landscape metrics provided important data for evaluating the conservation status of the forest remnants for the zoning of the corridor. The Chapecó Ecological Corridor encompasses around 5,000km²; 50.5% of this area comprises remnants of natural ecosystems and 42.7% is used by agricultural activities. Fifteen fragments, which are each larger than 500ha, are Araucaria forests that contain elements of Floresta Estacional Decidual. Of the 83 watersheds studied in permanent preservation areas, 20.5% has more than 60% vegetation cover and 57.5% has between 10% and 30% vegetation cover. It is estimated that the sub-basin has 111,000km2 of forest on private properties, along with remnants in three conservation units and three indigenous areas. The forests of the Chapecó Ecological Corridor represent the last fragments of continuous Araucaria forest in western Santa Catarina.

  8. Termite assemblages in five semideciduous Atlantic Forest fragments in the northern coastland limit of the biome

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    Heitor Bruno de Araújo Souza

    2012-03-01

    Full Text Available Termites are abundant organisms in tropical ecosystems and strongly influence the litter decomposition and soil formation. Despite their importance, few studies about their assemblage structures have been made in Brazilian Atlantic Forest fragments, especially in the area located north of the São Francisco River. This study aims to analyze the assemblage composition of five Atlantic Forest fragments located in the northern biome limit along the Brazilian coast. A standardized sampling protocol of termites was applied in each fragment. Thirty-three termite species belonging to twenty genera and three families were found in the forest fragments. The wood-feeder group was dominant both concerning to species richness and number of encounters in all areas. In sites northern to 7°S, there is an evident simplification of the termite assemblage composition regarding species richness and number of encounters by feeding group. This fact is apparently due to a higher sandy level in soils and to semideciduous character of the vegetation in the northern fragments. Thus, even on the north of São Francisco River, termite biodiversity is heterogeneously spread with highest density of species in the portion between 07°S and São Francisco River mouth (10°29'S.

  9. Dynamic anthropogenic edge effects on the distribution and diversity of fungi in fragmented old-growth forests.

    Science.gov (United States)

    Ruete, Alejandro; Snäll, Tord; Jönsson, Mari

    2016-07-01

    Diversity patterns and dynamics at forest edges are not well understood. We disentangle the relative importance of edge-effect variables on spatio-temporal patterns in species richness and occupancy of deadwood-dwelling fungi in fragmented old-growth forests. We related richness and log occupancy by 10 old-growth forest indicator fungi and by two common fungi to log conditions in natural and anthropogenic edge habitats of 31 old-growth Picea abies forest stands in central Sweden. We compared edge-to-interior gradients (100 m) to the forest interior (beyond 100 m), and we analyzed stand-level changes after 10 yr. Both richness and occupancy of logs by indicator species was negatively related to adjacent young clear-cut edges, but this effect decreased with increasing clear-cut age. The occupancy of logs by indicator species also increased with increasing distance to the natural edges. In contrast, the occupancy of logs by common species was positively related or unrelated to distance to clear-cut edges regardless of the edge age, and this was partly explained by fungal specificity to substrate quality. Stand-level mean richness and mean occupancy of logs did not change for indicator or common species over a decade. By illustrating the importance of spatial and temporal dimensions of edge effects, we extend the general understanding of the distribution and diversity of substrate-confined fungi in fragmented old-growth forests. Our results highlight the importance of longer forest rotation times adjacent to small protected areas and forest set-asides, where it may take more than 50 yr for indicator species richness levels to recover to occupancy levels observed in the forest interior. Also, non-simultaneous clear-cutting of surrounding productive forests in a way that reduces the edge effect over time (i.e., dynamic buffers) may increase the effective core area of small forest set-asides and improve their performance on protecting species of special concern for

  10. Disentangling the drivers of reduced long-distance seed dispersal by birds in an experimentally fragmented landscape.

    Science.gov (United States)

    Uriarte, María; Anciães, Marina; da Silva, Mariana T B; Rubim, Paulo; Johnson, Erik; Bruna, Emilio M

    2011-04-01

    Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largest-bodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities

  11. Response of the agile antechinus to habitat edge, configuration and condition in fragmented forest.

    Science.gov (United States)

    Johnstone, Christopher P; Lill, Alan; Reina, Richard D

    2011-01-01

    Habitat fragmentation and degradation seriously threaten native animal communities. We studied the response of a small marsupial, the agile antechinus Antechinus agilis, to several environmental variables in anthropogenically fragmented Eucalyptus forest in south-east Australia. Agile antechinus were captured more in microhabitats dominated by woody debris than in other microhabitats. Relative abundances of both sexes were positively correlated with fragment core area. Male and female mass-size residuals were smaller in larger fragments. A health status indicator, haemoglobin-haematocrit residuals (HHR), did not vary as a function of any environmental variable in females, but male HHR indicated better health where sites' microhabitats were dominated by shrubs, woody debris and trees other than Eucalyptus. Females were trapped less often in edge than interior fragment habitat and their physiological stress level, indicated by the neutrophil/lymphocyte ratio in peripheral blood, was higher where fragments had a greater proportion of edge habitat. The latter trend was potentially due to lymphopoenia resulting from stress hormone-mediated leukocyte trafficking. Using multiple indicators of population condition and health status facilitates a comprehensive examination of the effects of anthropogenic disturbances, such as habitat fragmentation and degradation, on native vertebrates. Male agile antechinus' health responded negatively to habitat degradation, whilst females responded negatively to the proportion of edge habitat. The health and condition indicators used could be employed to identify conservation strategies that would make habitat fragments less stressful for this or similar native, small mammals.

  12. Response of the agile antechinus to habitat edge, configuration and condition in fragmented forest.

    Directory of Open Access Journals (Sweden)

    Christopher P Johnstone

    Full Text Available Habitat fragmentation and degradation seriously threaten native animal communities. We studied the response of a small marsupial, the agile antechinus Antechinus agilis, to several environmental variables in anthropogenically fragmented Eucalyptus forest in south-east Australia. Agile antechinus were captured more in microhabitats dominated by woody debris than in other microhabitats. Relative abundances of both sexes were positively correlated with fragment core area. Male and female mass-size residuals were smaller in larger fragments. A health status indicator, haemoglobin-haematocrit residuals (HHR, did not vary as a function of any environmental variable in females, but male HHR indicated better health where sites' microhabitats were dominated by shrubs, woody debris and trees other than Eucalyptus. Females were trapped less often in edge than interior fragment habitat and their physiological stress level, indicated by the neutrophil/lymphocyte ratio in peripheral blood, was higher where fragments had a greater proportion of edge habitat. The latter trend was potentially due to lymphopoenia resulting from stress hormone-mediated leukocyte trafficking. Using multiple indicators of population condition and health status facilitates a comprehensive examination of the effects of anthropogenic disturbances, such as habitat fragmentation and degradation, on native vertebrates. Male agile antechinus' health responded negatively to habitat degradation, whilst females responded negatively to the proportion of edge habitat. The health and condition indicators used could be employed to identify conservation strategies that would make habitat fragments less stressful for this or similar native, small mammals.

  13. The nexus between forest fragmentation in Africa and Ebola virus disease outbreaks

    Science.gov (United States)

    Rulli, Maria Cristina; Santini, Monia; Hayman, David T. S.; D'Odorico, Paolo

    2017-02-01

    Tropical forests are undergoing land use change in many regions of the world, including the African continent. Human populations living close to forest margins fragmented and disturbed by deforestation may be particularly exposed to zoonotic infections because of the higher likelihood for humans to be in contact with disease reservoirs. Quantitative analysis of the nexus between deforestation and the emergence of Ebola virus disease (EVD), however, is still missing. Here we use land cover change data in conjunction with EVD outbreak records to investigate the association between recent (2004-2014) outbreaks in West and Central Africa, and patterns of land use change in the region. We show how in these EVD outbreaks the index cases in humans (i.e. spillover from wildlife reservoirs) occurred mostly in hotspots of forest fragmentation.

  14. Herpetofauna of an urban fragment of Atlantic Forest in Paraíba State, Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Yuri C. C. Lima

    2008-03-01

    Full Text Available The Herpetofauna of an urban fragment of Atlantic Forest was investigated in relation to species richness and habitat use. Fourteen species of amphibian anurans pertaining to the families Bufonidae, Brachycephalidae, Hylidae, Leptodactylidae, Leiuperidae, Microhylidae and Ranidae were recorded. The reptiles were represented by 37 species, distributed in the families Gekkonidae, Gymnophthalmidae, Polychrotidae, Scincidae, Teiidae, Tropiduridae, Amphisbaenidae, Boidae, Colubridae, Elapidae, Typhlopidae, Chelidae, Testudinidae and Alligatoridae. Most of the recorded species presented wide geographic distribution, although some of them had distributions that were restricted to the Atlantic Forest. The species richness of Mata do Buraquinho is relatively high for an urban fragment of Atlantic Forest, and the observed anthropogenic impacts show the urgent necessity of conservation in order to guarantee the viability of populations of amphibians and reptiles.

  15. Reducing habitat fragmentation on minor rural roads through traffic calming

    NARCIS (Netherlands)

    Jaarsma, C.F.; Willems, G.P.A.

    2002-01-01

    The rural road network suffers continually from ambiguity. On the one hand, the presence of this network and its traffic flows offer accessibility and make a contribution to economic development. While on the other, its presence and its traffic flows cause fragmentation. The actual ecological impact

  16. Landscapes of Protection: Forest Change and Fragmentation in Northern West Bengal, India

    Science.gov (United States)

    Nagendra, Harini; Paul, Somajita; Pareeth, Sajid; Dutt, Sugato

    2009-11-01

    In the tropics and sub-tropics, where high levels of biodiversity co-exist with some of the greatest levels of population density, achieving complete exclusion in protected area contexts has proved close to impossible. There is a clear need to recognize that parks are significantly impacted by human-environment interactions in the larger landscape within which they are embedded, and to move the frontier of research beyond the boundaries of protected areas in order to examine larger landscapes where multiple forms of ownership and access are embedded. This research evaluates forest change and fragmentation between 1990 and 2000, in a landscape surrounding the Mahananda Wildlife Sanctuary in the Indian state of West Bengal. This protected forest is bounded to the south by a less intensively protected area, the Baikunthapur Reserve Forest, and surrounded by a mosaic of unprotected, largely private land holdings. Results indicate differences in the extent and spatial pattern of forest cover change in these three zones, corresponding to different levels of government protection, access and monitoring. The two protected areas experience a trend toward forest regrowth, relating to the cessation of commercial logging by park management during this period. Yet, there is still substantial clearing toward peripheral areas that are well connected to illegal timber markets by transportation networks. The surrounding landscape, although experiencing some forest regrowth within less intensively cultivated tea plantations, is also becoming increasingly fragmented, with potentially critical impacts on the maintenance of effective wildlife corridors in this ecologically critical region.

  17. Vertical distribution of epiphytic bryophytes in Atlantic Forest fragments in northeastern Brazil

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    Hermeson Cassiano de Oliveira

    Full Text Available ABSTRACT The microclimatic gradient established from the forest understory to the canopy provides a range of different conditions for the establishment of bryophytes along the height of a tree. We investigated epiphytic bryophyte communities of four fragments of Atlantic Forest with the aim of describing their vertical zonation and assessing differentiation among the communities of the different fragments. In each fragment, five host trees were selected from which bryophyte samples were collected in four height zones from the base to the canopy. Furthermore, 10 plots were demarcated in each fragment where bryophytes were collected from the understory. In total, 114 bryophyte species were found on the 20 sampled phorophytes, plus an additional 51 species in the understory, for a total of 165 species. Species composition of height zones differed significantly between communities of the trunk base and the canopy. The samples from the understory included 77% of all species. Among all species found, 10 showed a significant preference for a specific height. Around 70% of the bryophyte species grew as mats; this life form occurred in all trees and height zones. The results showed a weak, yet significant, vertical gradient, which differs from what is usually found in the Atlantic Forest.

  18. Landscape genetics indicate recently increased habitat fragmentation in African forest-associated chafers.

    Science.gov (United States)

    Eberle, Jonas; Rödder, Dennis; Beckett, Marc; Ahrens, Dirk

    2017-05-01

    Today, indigenous forests cover less than 0.6% of South Africa's land surface and are highly fragmented. Most forest relicts are very small and typically occur in fire-protected gorges along the eastern Great Escarpment. Yet, they hold a unique and valuable fauna with high endemism and ancient phylogenetic lineages, fostered by long-term climatic stability and complex microclimates. Despite numerous studies on southern African vegetation cover, the current state of knowledge about the natural extension of indigenous forests is rather fragmentary. We use an integrated approach of population-level phylogeography and climatic niche modeling of forest-associated chafer species to assess connectivity and extent of forest habitats since the last glacial maximum. Current and past species distribution models ascertained potential fluctuations of forest distribution and supported a much wider potential current extension of forests based on climatic data. Considerable genetic admixture of mitochondrial and nuclear DNA among many populations and an increase in mean population mutation rate in Extended Bayesian Skyline Plots of all species indicated more extended or better connected forests in the recent past (habitat succession scenarios suggests considerable loss of habitat connectivity. As major anthropogenic influence is likely, conservational actions need to be considered. © 2017 John Wiley & Sons Ltd.

  19. Robustness of plant-insect herbivore interaction networks to climate change in a fragmented temperate forest landscape.

    Science.gov (United States)

    Bähner, K W; Zweig, K A; Leal, I R; Wirth, R

    2017-10-01

    Forest fragmentation and climate change are among the most severe and pervasive forms of human impact. Yet, their combined effects on plant-insect herbivore interaction networks, essential components of forest ecosystems with respect to biodiversity and functioning, are still poorly investigated, particularly in temperate forests. We addressed this issue by analysing plant-insect herbivore networks (PIHNs) from understories of three managed beech forest habitats: small forest fragments (2.2-145 ha), forest edges and forest interior areas within three continuous control forests (1050-5600 ha) in an old hyper-fragmented forest landscape in SW Germany. We assessed the impact of forest fragmentation, particularly edge effects, on PIHNs and the resulting differences in robustness against climate change by habitat-wise comparison of network topology and biologically realistic extinction cascades of networks following scores of vulnerability to climate change for the food plant species involved. Both the topological network metrics (complexity, nestedness, trophic niche redundancy) and robustness to climate change strongly increased in forest edges and fragments as opposed to the managed forest interior. The nature of the changes indicates that human impacts modify network structure mainly via host plant availability to insect herbivores. Improved robustness of PIHNs in forest edges/small fragments to climate-driven extinction cascades was attributable to an overall higher thermotolerance across plant communities, along with positive effects of network structure. The impoverishment of PIHNs in managed forest interiors and the suggested loss of insect diversity from climate-induced co-extinction highlight the need for further research efforts focusing on adequate silvicultural and conservation approaches.

  20. The Relationship of Forest Fragmentation and Lyme Disease

    Science.gov (United States)

    There is increasing recognition that many aspects of human well-being are linked to functions of healthy ecosystems and the services they provide to society at local to global scales. Societal pressures can contaminate habitats, reduce their area, alter community composition, and...

  1. Assessment of Land-Use/Land-Cover Change and Forest Fragmentation in the Garhwal Himalayan Region of India

    Directory of Open Access Journals (Sweden)

    Amit Kumar Batar

    2017-04-01

    Full Text Available The Garhwal Himalaya has experienced extensive deforestation and forest fragmentation, but data and documentation detailing this transformation of the Himalaya are limited. The aim of this study is to analyse the observed changes in land cover and forest fragmentation that occurred between 1976 and 2014 in the Garhwal Himalayan region in India. Three images from Landsat 2 Multispectral Scanner System (MSS, Landsat 5 Thematic Mapper (TM, and Landsat 8 Operational Land Imager (OLI were used to extract the land cover maps. A cross-tabulation detection method in the geographic information system (GIS module was used to detect land cover changes during the 1st period (1976–1998 and 2nd period (1998–2014. The landscape fragmentation tool LFT v2.0 was used to construct a forest fragmentation map and analyse the forest fragmentation pattern and change during the 1st period (1976–1998 and 2nd period (1998–2014. The overall annual rate of change in the forest cover was observed to be 0.22% and 0.27% in the 1st period (1976–1998 and 2nd period (1998–2014, respectively. The forest fragmentation analysis shows that a large core forest has decreased throughout the study period. The total area of forest patches also increased from 1976 to 2014, which are completely degraded forests. The results indicate that anthropogenic activities are the main causes of the loss of forest cover and forest fragmentation, but that natural factors also contributed. An increase in the area of scrub and barren land also contributed to the accumulation of wasteland or non-forest land in this region. Determining the trend and the rate of land cover conversion is necessary for development planners to establish a rational land use policy.

  2. Edge effects and beta diversity in ground and canopy beetle communities of fragmented subtropical forest.

    Science.gov (United States)

    Stone, Marisa J; Catterall, Carla P; Stork, Nigel E

    2018-01-01

    Clearing of dry forests globally creates edges between remnant forest and open anthropogenic habitats. We used flight intercept traps to evaluate how forest beetle communities are influenced by distance from such edges, together with vertical height, spatial location, and local vegetation structure, in an urbanising region (Brisbane, Australia). Species composition (but not total abundance or richness) differed greatly between ground and canopy. Species composition also varied strongly among sites at both ground and canopy levels, but almost all other significant effects occurred only at ground level, where: species richness declined from edge to interior; composition differed between positions near edges ( 50 m); high local canopy cover was associated with greater total abundance and richness and differing composition; and greater distances to the city centre were associated with increased total abundances and altered composition. Analyses of individual indicator species associated with this variation enabled further biological interpretations. A global literature synthesis showed that most spatially well-replicated studies of edge effects on ground-level beetles within forest fragments have likewise found that positions within tens of metres from edges with open anthropogenic habitats had increased species richness and different compositions from forest interior sites, with fewer effects on abundance. Accordingly, negative edge effects will not prevent relatively small compact fragments (if >10-20 ha) from supporting forest-like beetle communities, although indirect consequences of habitat degradation remain a threat. Retention of multiple spatially scattered forest areas will also be important in conserving forest-dependent beetles, given high levels of between-site diversity.

  3. Edge effects and beta diversity in ground and canopy beetle communities of fragmented subtropical forest

    Science.gov (United States)

    Catterall, Carla P.; Stork, Nigel E.

    2018-01-01

    Clearing of dry forests globally creates edges between remnant forest and open anthropogenic habitats. We used flight intercept traps to evaluate how forest beetle communities are influenced by distance from such edges, together with vertical height, spatial location, and local vegetation structure, in an urbanising region (Brisbane, Australia). Species composition (but not total abundance or richness) differed greatly between ground and canopy. Species composition also varied strongly among sites at both ground and canopy levels, but almost all other significant effects occurred only at ground level, where: species richness declined from edge to interior; composition differed between positions near edges ( 50 m); high local canopy cover was associated with greater total abundance and richness and differing composition; and greater distances to the city centre were associated with increased total abundances and altered composition. Analyses of individual indicator species associated with this variation enabled further biological interpretations. A global literature synthesis showed that most spatially well-replicated studies of edge effects on ground-level beetles within forest fragments have likewise found that positions within tens of metres from edges with open anthropogenic habitats had increased species richness and different compositions from forest interior sites, with fewer effects on abundance. Accordingly, negative edge effects will not prevent relatively small compact fragments (if >10–20 ha) from supporting forest-like beetle communities, although indirect consequences of habitat degradation remain a threat. Retention of multiple spatially scattered forest areas will also be important in conserving forest-dependent beetles, given high levels of between-site diversity. PMID:29494680

  4. Behavioral and physiological responses to fruit availability of spider monkeys ranging in a small forest fragment

    OpenAIRE

    Rimbach, Rebecca; Link, Andrés; Montes-Rojas, Andrés; Di Fiore, Anthony; Heistermann, Michael; Heymann, Eckhard W

    2014-01-01

    Numerous animal species currently experience habitat loss and fragmentation. This might result in behavioral and dietary adjustments, especially because fruit availability is frequently reduced in fragments. Food scarcity can result in elevated physiological stress levels, and chronic stress often has detrimental effects on individuals. Some animal species exhibit a high degree of fission–fusion dynamics, and theory predicts that these species reduce intragroup feeding competition by modifyin...

  5. Clustering Timber Harvests and the Effects of Dynamic Forest Management Policy on Forest Fragmentation

    Science.gov (United States)

    Eric J. Gustafson

    1998-01-01

    To integrate multiple uses (mature forest and commodity production) better on forested lands, timber management strategies that cluster harvests have been proposed. One such approach clusters harvest activity in space and time, and rotates timber production zones across the landscape with a long temporal period (dynamic zoning). Dynamic zoning has...

  6. Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil

    OpenAIRE

    Silva,HM; Hernandes,FA; Pichorim,M

    2015-01-01

    AbstractThe present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fiftee...

  7. Continental divide: Predicting climate-mediated fragmentation and biodiversity loss in the boreal forest.

    Science.gov (United States)

    Murray, Dennis L; Peers, Michael J L; Majchrzak, Yasmine N; Wehtje, Morgan; Ferreira, Catarina; Pickles, Rob S A; Row, Jeffrey R; Thornton, Daniel H

    2017-01-01

    Climate change threatens natural landscapes through shifting distribution and abundance of species and attendant change in the structure and function of ecosystems. However, it remains unclear how climate-mediated variation in species' environmental niche space may lead to large-scale fragmentation of species distributions, altered meta-population dynamics and gene flow, and disrupted ecosystem integrity. Such change may be especially relevant when species distributions are restricted either spatially or to a narrow environmental niche, or when environments are rapidly changing. Here, we use range-wide environmental niche models to posit that climate-mediated range fragmentation aggravates the direct effects of climate change on species in the boreal forest of North America. We show that climate change will directly alter environmental niche suitability for boreal-obligate species of trees, birds and mammals (n = 12), with most species ranges becoming smaller and shifting northward through time. Importantly, species distributions will become increasingly fragmented, as characterized by smaller mean size and greater isolation of environmentally-suitable landscape patches. This loss is especially pronounced along the Ontario-Québec border, where the boreal forest is narrowest and roughly 78% of suitable niche space could disappear by 2080. Despite the diversity of taxa surveyed, patterns of range fragmentation are remarkably consistent, with our models predicting that spruce grouse (Dendragapus canadensis), boreal chickadee (Poecile hudsonicus), moose (Alces americanus) and caribou (Rangifer tarandus) could have entirely disjunct east-west population segments in North America. These findings reveal potentially dire consequences of climate change on population continuity and species diversity in the boreal forest, highlighting the need to better understand: 1) extent and primary drivers of anticipated climate-mediated range loss and fragmentation; 2) diversity of

  8. How forest marsupials are affected by habitat degradation and fragmentation? A meta-analysis.

    Science.gov (United States)

    Fontúrbel, Francisco E; Candia, Alina B; Salazar, Daniela A; Malebrán, Javiera; González-Browne, Catalina; Botto-Mahan, Carezza

    2014-07-01

    Habitat fragmentation and degradation are important biodiversity change drivers worldwide. Their effects have been described for many animal groups, but little is known about marsupials. We conducted a meta-analysis aiming to evaluate the actual effects of habitat fragmentation and degradation on forest marsupials. From a literature survey, we obtained 85 case studies reporting disturbance comparisons. We found a negative overall effect, as well as a negative effect for habitat fragmentation, but not for habitat degradation. Marsupials from Oceania were negatively affected by habitat disturbance, whereas there was no effect for those from South America. Arboreal marsupials were negatively affected, whereas terrestrial marsupials did not. Species from the families Dasyuridae (Antechinus spp.) and Microbiotheriidae (Dromiciops gliroides) showed to be sensitive to habitat disturbance.

  9. Time-Lag in Responses of Birds to Atlantic Forest Fragmentation: Restoration Opportunity and Urgency.

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    Alexandre Uezu

    Full Text Available There are few opportunities to evaluate the relative importance of landscape structure and dynamics upon biodiversity, especially in highly fragmented tropical landscapes. Conservation strategies and species risk evaluations often rely exclusively on current aspects of landscape structure, although such limited assumptions are known to be misleading when time-lag responses occur. By relating bird functional-group richness to forest patch size and isolation in ten-year intervals (1956, 1965, 1978, 1984, 1993 and 2003, we revealed that birds with different sensitivity to fragmentation display contrasting responses to landscape dynamics in the Brazilian Atlantic Forest. For non-sensitive groups, there was no time-lag in response: the recent degree of isolation best explains their variation in richness, which likely relates to these species' flexibility to adapt to changes in landscape structure. However, for sensitive bird groups, the 1978 patch area was the best explanatory variable, providing evidence for a 25-year time-lag in response to habitat reduction. Time-lag was more likely in landscapes that encompass large patches, which can support temporarily the presence of some sensitive species, even when habitat cover is relatively low. These landscapes potentially support the most threatened populations and should be priorities for restoration efforts to avoid further species loss. Although time-lags provide an opportunity to counteract the negative consequences of fragmentation, it also reinforces the urgency of restoration actions. Fragmented landscapes will be depleted of biodiversity if landscape structure is only maintained, and not improved. The urgency of restoration action may be even higher in landscapes where habitat loss and fragmentation history is older and where no large fragment remained to act temporarily as a refuge.

  10. Stuck in fragments: Population genetics of the Endangered collared brown lemur Eulemur collaris in the Malagasy littoral forest.

    Science.gov (United States)

    Bertoncini, Stefania; D'Ercole, Jacopo; Brisighelli, Francesca; Ramanamanjato, Jean-Baptiste; Capelli, Cristian; Tofanelli, Sergio; Donati, Giuseppe

    2017-07-01

    The Endangered collared brown lemur (Eulemur collaris) is the largest primate living in the littoral forest of southeastern Madagascar, a top priority habitat for biodiversity conservation on the island. Because this lemur is a key seed-disperser, an evaluation of the structure and connectivity of the populations surviving in the forest fragments is urgently needed to guide conservation plans. Genetic variability at autosomal microsatellites and mitochondrial DNA was investigated in a total of 49 collared brown lemurs sampled by non-invasive methods in three littoral forest fragments and in the nearby lowland humid forest. The overall genetic diversity of E. collaris in the southeastern coastal region of Madagascar was lower than in other populations, as well as in other lemur species. The population appears highly structured, with less variable and more inbred groups inhabiting the littoral forest fragments compared to the inland area. Major barriers to gene flow were identified isolating littoral forest fragments from each other and from the inland lowland humid forest. Medium to long-term drift and scarce gene flow is the scenario that best explains the current genetic distribution. Habitat discontinuities such as rivers and grassland between forest fragments played a major role in structuring the population. A common history of size contraction is pointed out by several genetic estimators, indicating a possible ecological crisis triggered around 1,300 years ago. The adoption of strategies aimed at facilitating gene flow and population growth appears crucial to delay further loss of genetic diversity. © 2017 Wiley Periodicals, Inc.

  11. Temporal Changes in Forest Contexts at Multiple Extents: Three Decades of Fragmentation in the Gran Chaco (1979-2010), Central Argentina

    Science.gov (United States)

    Frate, Ludovico; Acosta, Alicia T. R.; Cabido, Marcelo; Hoyos, Laura; Carranza, Maria Laura

    2015-01-01

    The context in which a forest exists strongly influences its function and sustainability. Unveiling the multi-scale nature of forest fragmentation context is crucial to understand how human activities affect the spatial patterns of forests across a range of scales. However, this issue remains almost unexplored in subtropical ecosystems. In this study, we analyzed temporal changes (1979–2010) in forest contexts in the Argentinean dry Chaco at multiple extents. We classified forests over the last three decades based on forest context amount (Pf) and structural connectivity (Pff), which were measured using a moving window approach fixed at eight different extents (from local, ~ 6 ha, to regional, ~ 8300 ha). Specific multi-scale forest context profiles (for the years 1979 and 2010) were defined by projecting Pf vs. Pff mean values and were compared across spatial extents. The distributions of Pf across scales were described by scalograms and their shapes over time were compared. The amount of agricultural land and rangelands across the scales were also analyzed. The dry Chaco has undergone an intensive process of fragmentation, resulting in a shift from landscapes dominated by forests with gaps of rangelands to landscapes where small forest patches are embedded in agricultural lands. Multi-scale fragmentation analysis depicted landscapes in which local exploitation, which perforates forest cover, occurs alongside extensive forest clearings, reducing forests to small and isolated patches surrounded by agricultural lands. In addition, the temporal diminution of Pf’s variability along with the increment of the mean slope of the Pf ‘s scalograms, indicate a simplification of the spatial pattern of forest over time. The observed changes have most likely been the result of the interplay between human activities and environmental constraints, which have shaped the spatial patterns of forests across scales. Based on our results, strategies for the conservation and

  12. Seed predation by mammals in forest fragments in Monteverde, Costa Rica

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    Federico A Chinchilla

    2009-09-01

    Full Text Available Few studies have evaluated seed predation in fragmented landscapes, in which lower species diversity is expected to modifying ecological interactions. The rates of seed removal by mammals were investigated in a continuous forest and two fragmented patches of Premontane Tropical Moist Forest, in Monteverde, Costa Rica. The composition of mammalian seed-predators in each site was recorded during 16 months. The removal of four native tree species of experimental seeds: Ocotea valeriana and Ocotea whitei (Lauraceae, Panopsis costaricensis (Proteaceae and Billia colombiana (Hippocastanaceae in forest understories was followed during two annual fruiting seasons for each species. Results indicated similar species composition of seed-predators between continuous forest, the largest fragment (350 ha. However the smaller fragment (20 ha, had fewer seed predators. In this fragment, the specialized seed predator Heteromys desmarestianus (Rodentia was more abundant. Unexpectedly, seed-predation in the two forest fragments and the continuous forest did not differ statistically for any of the seed species. Apparently, the higher abundance of small seed-predators in the fragments was compensated by the absence of medium and large seed-predators, like Agouti paca, Dasyprocta punctata (both Rodentia and Pecari tajacu (Artiodactyla recorded in continuous forest. Removal of experimentally-placed seeds was higher when the number of naturally occurring seeds in the sites was lower. This result could best be attributed to differential satiation of seed predators rather than differences in richness or abundance of seed predators. Rev. Biol. Trop. 57 (3: 865-877. Epub 2009 September 30.Pocos estudios han evaluado la depredación de semillas en ambientes fragmentados, en éstos la menor diversidad de especies debe estar modificando las interacciones ecológicas. Se investigó la remoción de semillas por mamíferos en un bosque continuo y dos fragmentos en Monteverde

  13. Fragmentation and Management of Ethiopian Moist Evergreen Forest Drive Compositional Shifts of Insect Communities Visiting Wild Arabica Coffee Flowers

    Science.gov (United States)

    Berecha, Gezahegn; Aerts, Raf; Muys, Bart; Honnay, Olivier

    2015-02-01

    Coffea arabica is an indigenous understorey shrub of the moist evergreen Afromontane forest of SW Ethiopia. Coffee cultivation here occurs under different forest management intensities, ranging from almost no intervention in the `forest coffee' system to far-reaching interventions that include the removal of competing shrubs and selective thinning of the upper canopy in the `semi-forest coffee' system. We investigated whether increasing forest management intensity and fragmentation result in impacts upon potential coffee pollination services through examining shifts in insect communities that visit coffee flowers. Overall, we netted 2,976 insect individuals on C. arabica flowers, belonging to sixteen taxonomic groups, comprising 10 insect orders. Taxonomic richness of the flower-visiting insects significantly decreased and pollinator community changed with increasing forest management intensity and fragmentation. The relative abundance of honey bees significantly increased with increasing forest management intensity and fragmentation, likely resulting from the introduction of bee hives in the most intensively managed forests. The impoverishment of the insect communities through increased forest management intensity and fragmentation potentially decreases the resilience of the coffee production system as pollination increasingly relies on honey bees alone. This may negatively affect coffee productivity in the long term as global pollination services by managed honey bees are expected to decline under current climate change scenarios. Coffee agroforestry management practices should urgently integrate pollinator conservation measures.

  14. CHARACTERIZATION OF THE ARBOREAL FLORA OF TWO FRAGMENTS OF GALLERY FOREST OF THE “PARQUE CANJERANA”, DF.

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    Laura Dietzsch

    2006-09-01

    Full Text Available This study was accomplished in two fragments of the gallery forest located in the Parque Canjerana in Brasília, DF, to characterize the structure and the floristic composition of the arboreal flora. Strips of 10 m of width, with varying lengths, depending on the limits of the forest, were systematically allocated perpendicularly to the water stream, distant 60 m from each other. Each strip was subdivided in continuous parcels of 10 x 20 m, so, in each fragment it was possible to allocate 14 parcels. The individuals with CHD ≥ 5 cm were identified and had their values of total height and CHD registered. It was sampled a total of 747 alive individuals distributed in 79 species and 43 botanical families. The estimated forest basal area was approximately 31.29 m2.ha-1 and the density was 1,475 ind.ha-1. There was low similarity among the fragments. One of the fragments, denominated of fragment II, was characterized as a inundated gallery forest and the species Protium spruceanum and Tapirira guianensis were considered the most important. The other fragment, denominated fragment IV, was characterized as a non-inundated gallery forest and the species Anadenanthera colubrina and Qualea dichotoma stood out with high importance. The diversity of the fragment IV was larger than the one of the fragment II (index of Shannon=3.698 and 2.571nats.ind-1, respectively. The specificity of identified species in each fragment can be used to define restoration and conservation strategies of the Gallery Forest of the Parque Canjerana.

  15. The effects of forest fragmentation on biodiversity under post-drought conditions

    Science.gov (United States)

    Lawrence, A.; Swei, A.

    2016-12-01

    Habitat fragmentation is the greatest threat to wildlife worldwide. Understanding the impact of habitat fragmentation on biodiversity can benefit from theories established in island biogeography. Landscapes surrounded by human development are analogous to oceanic islands in that the size of habitat fragment can determine biodiversity. For terrestrial ecosystems, species traits can influence how they respond to the disturbance of habitat fragmentation. We tested how habitat patch size correlates to species richness and abundance of mammals in northern California in a post-drought environment. Using GIS and Fragstat we established nine forest fragments of varying size, differing minimally in location, topography, climate, and vegetation cover. This allows us to minimize site differences to test the effects of patch size on biodiversity. We used wildlife cameras to estimate richness of medium and large mammals and mark-and-recapture analysis to estimate species richness and abundance of small mammals. We also collected ticks with standard dragging and flagging techniques to determine the relationship between habitat patch size and species richness on Lyme disease risk. Our preliminary results indicate that meso-and-large mammal richness increases significantly with patch area (P=0.024) as well as larval tick density (P=0.035). At the same time, small mammal richness, abundance and diversity peaks in intermediate sized fragments. Further we found invasive species such as house mouse, Norway rat, and black rat only in patches smaller than 50 ha. Our results support the theory that invasive species are better adapted to disturbed areas versus native habitat. The ways in which habitat destruction and fragmentation are acting upon species and communities has critical consequences for conservation, ecosystem services, landscape planning, and many fields of environmental change research.

  16. Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

    Science.gov (United States)

    Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

    2016-01-01

    Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

  17. Genetics of Euglossini bees (Hymenoptera in fragments of the Atlantic Forest in the region of Viçosa, MG

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    A. M. Waldschmidt

    Full Text Available With uncontrolled deforestation, forest fragments remain, which in most cases are in different stages of regeneration and present isolated populations. In the present study we analyzed the genetic patterns of Eulaema nigrita populations in seven Atlantic Forest fragments of different sizes and successional stages in the region of Viçosa, MG. This was done by RAPD molecular markers. We observed that the area of the fragments had no effect on the genetic variability of E. nigrita in the direction predicted by meta-population models. Medium-sized well-preserved woods presented the lowest variability, whereas large and small woods were statistically identical. The evidence supports the notion that rural areas present greater dispersal among fragments, implying greater similarity between the populations of fragments located in rural areas when compared to fragments in urban areas.

  18. Effects of soil, altitude, rainfall, and distance on the floristic similarity of Atlantic Forest fragments in the east-Northeast

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    Flávia de Barros Prado Moura

    2013-09-01

    Full Text Available This paper presents the results of a floristic survey conducted on an Atlantic Forest fragment in the state of Alagoas, Brazil. Besides, the results of a similarity analysis between ten rainforest fragments from the Brazilian east-Northeast are presented. The floristic comparison was based on binary data with regard to the presence/ absence criterion for tree species identified in the ten fragments by means of Sørensen’s similarity index. A dendrogram was prepared using cluster analysis (Jaccard’s index and canonical correspondence analysis (CCA to test the abiotic factors, which can differently influence the similarity of fragments. The fragments showed low similarity indices. The variations were due to the fact that each fragment is a patch of what once was a continuous and heterogeneous region. However, the diversity loss, including the disappearance of more demanding species, can lead, in large-scale, to homogeneity and simplification of the northeastern Atlantic Forest.

  19. Sleeping sites and latrines of spider monkeys in continuous and fragmented rainforests: implications for seed dispersal and forest regeneration.

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    Arturo González-Zamora

    Full Text Available Spider monkeys (Ateles geoffroyi use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively. Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations

  20. Sleeping sites and latrines of spider monkeys in continuous and fragmented rainforests: implications for seed dispersal and forest regeneration.

    Science.gov (United States)

    González-Zamora, Arturo; Arroyo-Rodríguez, Víctor; Oyama, Ken; Sork, Victoria; Chapman, Colin A; Stoner, Kathryn E

    2012-01-01

    Spider monkeys (Ateles geoffroyi) use sites composed of one or more trees for sleeping (sleeping sites and sleeping trees, respectively). Beneath these sites/trees they deposit copious amounts of dung in latrines. This behavior results in a clumped deposition pattern of seeds and nutrients that directly impacts the regeneration of tropical forests. Therefore, information on the density and spatial distribution of sleeping sites and latrines, and the characteristics (i.e., composition and structure) of sleeping trees are needed to improve our understanding of the ecological significance of spider monkeys in influencing forest composition. Moreover, since primate populations are increasingly forced to inhabit fragmented landscapes, it is important to assess if these characteristics differ between continuous and fragmented forests. We assessed this novel information from eight independent spider monkey communities in the Lacandona rainforest, Mexico: four continuous forest sites and four forest fragments. Both the density of sleeping sites and latrines did not differ between forest conditions. Latrines were uniformly distributed across sleeping sites, but the spatial distribution of sleeping sites within the areas was highly variable, being particularly clumped in forest fragments. In fact, the average inter-latrine distances were almost double in continuous forest than in fragments. Latrines were located beneath only a few tree species, and these trees were larger in diameter in continuous than fragmented forests. Because latrines may represent hotspots of seedling recruitment, our results have important ecological and conservation implications. The variation in the spatial distribution of sleeping sites across the forest indicates that spider monkeys likely create a complex seed deposition pattern in space and time. However, the use of a very few tree species for sleeping could contribute to the establishment of specific vegetation associations typical of the

  1. Species richness and relative abundance of birds in natural and anthropogenic fragments of Brazilian Atlantic forest

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    Luiz dos Anjos

    2004-06-01

    Full Text Available Bird communities were studied in two types of fragmented habitat of Atlantic forest in the State of Paraná, southern Brazil; one consisted of forest fragments that were created as a result of human activities (forest remnants, the other consisted of a set of naturally occurring forest fragments (forest patches. Using quantitative data obtained by the point counts method in 3 forest patches and 3 forest remnants during one year, species richness and relative abundance were compared in those habitats, considering species groups according to their general feeding habits. Insectivores, omnivores, and frugivores presented similar general tendencies in both habitats (decrease of species number with decreasing size and increasing isolation of forest fragment. However, these tendencies were different, when considering the relative abundance data: the trunk insectivores presented the highest value in the smallest patch while the lowest relative abundance was in the smallest remnant. In the naturally fragmented landscape, time permitted that the loss of some species of trunk insectivores be compensated for the increase in abundance of other species. In contrast, the remnants essentially represented newly formed islands that are not yet at equilibrium and where future species losses would make them similar to the patches.Comunidades de aves foram estudadas em duas regiões fragmentadas de floresta Atlântica no Estado do Paraná, sul do Brasil; uma região é constituída de fragmentos florestais que foram criados como resultado de atividades humanas (remanescentes florestais e a outra de um conjunto de fragmentos florestais naturais (manchas de floresta. Usando dados quantitativos (o método de contagens pontuais previamente obtidos em 3 manchas de floresta e em 3 remanescentes florestais durante um ano, a riqueza e a abundância relativa de aves foram comparadas naqueles habitats considerando as espécies pelos seus hábitos alimentares. Inset

  2. Model of Ecological Connectivity of Andean Forest Fragments in Santa Elena (Medellín, Colombia

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    Gabriel Jaime Colorado Zuluaga

    2017-09-01

    Full Text Available Forest fragmentation and the associated potential habitat loss is one of the main causes of biodiversity loss. One strategy that promotes its maintenance at a landscape scale is the establishment of biological corridors that enhance structural and functional connectivity of the biotic components. However, the applicability and functionality of this tool is limited due to the lack of planning at the moment of the design and establishment of corridors or connectivity networks that are guided by detailed and rigorous methods. In this research, we developed a theoretical proposal of ecological connectivity for the Santa Elena village, Medellin municipality, Colombia, using tools from landscape ecology. Initially, 21 forest fragments or nucleus were selected based on their minimum size (larger than 5 ha, core area (larger than 1 ha, and shape index (rounded or nearly rounded. Then, based on a friction matrix, we designed a potential network that would allow to connect 1356.35 ha of remnants forests through 31 ecological corridors of 100 m wide, comprising 208.33 ha in total. Finally, we discussed the importance of promoting this kind of strategies based on landscape ecology that enhance both habitat conservation and landscape connectivity in areas near large Latin-American cities.

  3. Do coyotesCanis latransinfluence occupancy of prey in suburban forest fragments?

    Science.gov (United States)

    Jones, Brandon M; Cove, Michael V; Lashley, Marcus A; Jackson, Victoria L

    2016-02-01

    With the extirpation of apex predators from many North American systems, coyotes Canis latrans have become the de facto top predator and are ubiquitous members of most ecosystems. Keystone predators aid in maintaining ecosystem function by regulating the mammal community through direct predation and instilling the landscape of fear, yet the value of coyotes regulating systems to this capacity is understudied and likely variable across environments. Since coyotes are common in the Midwestern United States, we utilized camera traps and occupancy analyses to assess their role in regulating the distribution of mammalian herbivores in a fragmented suburban ecosystem. Forest cover was a strong positive predictor of white-tailed deer Odocoileus virginianus detection, while coyote occurrence had a negative effect. Coyotes exerted a negative effect on squirrel ( Sciurus spp.) and eastern cottontail rabbit Sylvilagus floridanus occurrence, while urban cover was a positive predictor for the prey species' occurrence. These results suggest all 3 species behaviorally avoid coyotes whereby deer seek denser forest cover and squirrels and cottontails mitigate risk by increasing use of urban areas. Although previous studies reveal limited influence of coyote on the rest of the carnivore guild in suburban systems, we suggest coyotes play an important role in regulating the herbivorous mammals and hence may provide similar ecological benefits in urban/suburban forest fragments through trophic cascades. Furthermore, since hunting may not be allowed in urban and suburban habitats, coyotes might also serve as the primary regulator of nuisance species occurring at high abundance such as white-tailed deer and squirrels.

  4. An Experimental Test of Competition among Mice, Chipmunks, and Squirrels in Deciduous Forest Fragments.

    Directory of Open Access Journals (Sweden)

    Jesse L Brunner

    Full Text Available Mixed hardwood forests of the northeast United States support a guild of granivorous/omnivorous rodents including gray squirrels (Sciurus carolinensis, eastern chipmunks (Tamias striatus, and white-footed mice (Peromyscus leucopus. These species coincide geographically, co-occur locally, and consume similar food resources. Despite their idiosyncratic responses to landscape and patch variables, patch occupancy models suggest that competition may influence their respective distributions and abundances, and accordingly their influence on the rest of the forest community. Experimental studies, however, are wanting. We present the result of a large-scale experiment in which we removed white-footed mice or gray squirrels from small, isolated forest fragments in Dutchess County, New York, and added these mammals to other fragments in order to alter the abundance of these two species. We then used mark-recapture analyses to quantify the population-level and individual-level effects on resident mice, squirrels, and chipmunks. Overall, we found little evidence of competition. There were essentially no within-season numerical responses to changes in the abundance of putative competitors. Moreover, while individual-level responses (apparent survival and capture probability did vary with competitor densities in some models, these effects were often better explained by site-specific parameters and were restricted to few of the 19 sites we studied. With only weak or nonexistent competition among these three common rodent species, we expect their patterns of habitat occupancy and population dynamics to be largely independent of one another.

  5. Can Forest Transformation Help Reducing Floods in Forested Watersheds?

    DEFF Research Database (Denmark)

    Wahl, Niels Arne; Wöllecke, B.; Benz, O.

    2005-01-01

    populations and stand structure. It was found that infiltration capacity and hydraulic conductivity K exhibit overall low values nevertheless the tree species. This finding appears to be related to water repellency, the predominating texture, and a poor macroporosity. During the different stages of forest...

  6. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    Science.gov (United States)

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A; Habel, Jan C

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  7. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    Directory of Open Access Journals (Sweden)

    Werner Ulrich

    Full Text Available Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  8. Local population extinction and vitality of an epiphytic lichen in fragmented old-growth forest.

    Science.gov (United States)

    Ockinger, Erik; Nilsson, Sven G

    2010-07-01

    The population dynamics of organisms living in short-lived habitats will largely depend on the turnover of habitat patches. It has been suggested that epiphytes, whose host plants can be regarded as habitat patches, often form such patch-tracking populations. However, very little is known about the long-term fate of epiphyte individuals and populations. We estimated life span and assessed environmental factors influencing changes in vitality, fertility, abundance, and distribution of the epiphytic lichen species Lobaria pulmonaria on two spatial scales, individual trees and forest patches, over a period of approximately 10 years in 66 old-growth forest fragments. The lichen had gone extinct from 7 of the 66 sites (13.0%) where it was found 10 years earlier, even though the sites remained unchanged. The risk of local population extinction increased with decreasing population size. In contrast to the decrease in the number of occupied trees and sites, the mean area of the lichen per tree increased by 43.0%. The number of trees with fertile ramets of L. pulmonaria increased from 7 (approximately 1%) to 61 (approximately 10%) trees, and the number of forest fragments with fertile ramets increased from 4 to 23 fragments. The mean annual rate of L. pulmonaria extinction at the tree level was estimated to be 2.52%, translating into an expected lifetime of 39.7 years. This disappearance rate is higher than estimated mortality rates for potential host trees. The risk of extinction at the tree level was significantly positively related to tree circumference and differed between tree species. The probability of presence of fertile ramets increased significantly with local population size. Our results show a long expected lifetime of Lobaria pulmonaria ramets on individual trees and a recent increase in vitality, probably due to decreasing air pollution. The population is, however, declining slowly even though remaining stands are left uncut, which we interpret as an

  9. Mapping permanent preservation areas and natural forest fragments as subsidy to the registration of legal reserve areas in rural properties

    Directory of Open Access Journals (Sweden)

    Vicente Paulo Soares

    2011-12-01

    Full Text Available The major objective of this work was to identify and quantify forest fragments suitable to be used as private protected land in rural properties located in the São Bartolomeu creek watershed, State of Minas Gerais, Brazil. The methodological procedures included: mapping of 78 forest fragments through the visual interpretation of an Ikonos II satellite image; delineation of Permanent Preservation Areas (PPAs from a hydrographically conditioned digital elevation model and mapping of 292 rural properties through interviews with owners, with the aid of a printed Ikonos II image. The generated maps were overlapped (crossed, allowing the identification of forest fragments that could be used as private protected land in rural property. The result indicated that, from the total of properties evaluated, only 41 (14.04% have more than 20% of forest cover, and therefore, are in condition to attend the environmental law for private protected land.

  10. Phytosociology analysis of a fragment of Seasonal Deciduous Forest: Parque Estadual do Turvo, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Rafaelo Balbinot

    2016-06-01

    Full Text Available The ecosystem formed by the Seasonal Deciduous Forest (SDF predominates in the region of Alto Uruguay in Rio Grande do Sul State, Brazil. This study aimed to analyze descriptively the floristic composition and the phytosociology of trees from a fragment of SDF present in Parque Estadual do Turvo (PET located in the Municipality of Derrubadas, Rio Grande do Sul State (Yucumã forest. We used the method of fixed area, based on 18 sample units with 1,000 m2 installed randomly oriented by the main road of the park. All wood species with diameter at 1.3 m above ground level (DBH greater than 10 cm were measured and identified. It was observed the presence of 842 individuals belonging to 32 families, 67 genera and 83 species (12% were not identified. The families with the highest number of species were Fabaceae, Euphorbiaceae, Meliaceae, Myrtaceae and Sapindaceae. Shannon index estimated was 3.72.

  11. Mites associated with sugarcane crop and with native trees from adjacent Atlantic forest fragment in Brazil.

    Science.gov (United States)

    Duarte, Mércia E; Navia, Denise; dos Santos, Lucas R; Rideiqui, Pedro J S; Silva, Edmilson S

    2015-08-01

    In some Brazilian regions the Atlantic forest biome is currently restrict to fragments occurring amid monocultures, as sugarcane crops in the Northeast region. Important influence of forest remnants over mite fauna of permanent crops have been showed, however it has been poorly explored on annual crops. The first step for understanding ecological relationship in an agricultural systems is known its composition. The objective of this study was to investigate the plant-inhabiting mite fauna associated with sugarcane crop (Saccharum officinarum L.) (Poaceae) and caboatã (Cupania oblongifolia Mart.) (Sapindaceae) trees in the state of Alagoas, Brazil. Sugarcane stalks and sugarcane and caboatã apical, middle and basal leaves were sampled. A total of 2565 mites were collected from sugarcane and classified into seven families of Trombidiformes and Mesostigmata orders, with most individuals belonging to the Eriophyidae, Tetranychidae and Tarsonemidae families. Among predatory mites, the Phytoseiidae were the most common. A total of 1878 mites were found on C. oblongifolia and classified into 13 families of Trombidiformes and Mesostigmata orders. The most abundant phytophagous mite family on caboatã was also Eriophyidae. In contrast to sugarcane, Ascidae was the most common predatory mite family observed in caboatã. No phytophagous species were common to both sugarcane and C. oblongifolia. However two predatory mites were shared between host plants. Although mites associated with only one native species in the forest fragment were evaluated in this study, our preliminary results suggest Atlantic forest native vegetation can present an important role in the sugarcane agricultural system as a source of natural enemies.

  12. Habitat degradation and seasonality affect physiological stress levels of Eulemur collaris in littoral forest fragments.

    Science.gov (United States)

    Balestri, Michela; Barresi, Marta; Campera, Marco; Serra, Valentina; Ramanamanjato, Jean Baptiste; Heistermann, Michael; Donati, Giuseppe

    2014-01-01

    The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM) levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

  13. Habitat degradation and seasonality affect physiological stress levels of Eulemur collaris in littoral forest fragments.

    Directory of Open Access Journals (Sweden)

    Michela Balestri

    Full Text Available The littoral forest on sandy soil is among the most threatened habitats in Madagascar and, as such, it represents a hot-spot within a conservation hot-spot. Assessing the health of the resident lemur fauna is not only critical for the long-term viability of these populations, but also necessary for the future re-habilitation of this unique habitat. Since the Endangered collared brown lemur, Eulemur collaris, is the largest seed disperser of the Malagasy south-eastern littoral forest its survival in this habitat is crucial. In this study we compared fecal glucocorticoid metabolite (fGCM levels, a measure of physiological stress and potential early indicator of population health, between groups of collared brown lemurs living in a degraded forest fragment and groups occurring in a more preserved area. For this, we analysed 279 fecal samples collected year-round from 4 groups of collared brown lemurs using a validated 11-oxoetiocholanolone enzyme immunoassay and tested if fGCM levels were influenced by reproductive stages, phenological seasons, sex, and habitat degradation. The lemurs living in the degraded forest had significantly higher fGCM levels than those living in the more preserved area. In particular, the highest fGCM levels were found during the mating season in all animals and in females during gestation in the degraded forest. Since mating and gestation are both occurring during the lean season in the littoral forest, these results likely reflect a combination of ecological and reproductive pressures. Our findings provide a clear indication that habitat degradation has additive effects to the challenges found in the natural habitat. Since increased stress hormone output may have long-term negative effects on population health and reproduction, our data emphasize the need for and may add to the development of effective conservation plans for the species.

  14. Phylogeography of four frog species in forest fragments of northeastern Brazil--a preliminary study.

    Science.gov (United States)

    Carnaval, Ana Carolina O Q

    2002-11-01

    I contrast mitochondrial DNA genealogies based on 612 bp of the cytochrome b gene across four co-distributed species of frogs in Northeastern Brazil. They are Hyla albomarginata, Hyla branneri, Proceratophrys boiei, and Scinax nebulosus. Samples were collected from the core or edge of six rainforest remnants in the states of Pernambuco and Alagoas. Three fragments are located within the humid Atlantic Forest morphoclimatic domain (municipalities of Cabo de Santo Agostinho, Ibateguara, and Jaqueira), two are located in the transition zone between the Atlantic Forest domain and the semi-arid Caatinga (Caruaru and Timbaúba), and one is found within the Caatinga (Brejo da Madre de Deus). Results show that local patterns and levels of genetic diversity are influenced by taxon-specific habitat requirements. Populations of the montane, closed-canopy species P. boiei show strong geographical structure, reflecting barriers to gene flow that predate human-driven habitat destruction. Species occurring along forest edges, such as H. albomarginata and S. nebulosus, show genetic patterns similar to those of P. boiei, but lower levels of genetic divergence. The more generalist Hyla branneri shows no geographic pattern. The data are in agreement with distribution and fossil data gathered for other groups of organisms, suggesting that mesic forests occupied the currently arid Caatinga in the recent past.

  15. Geospatial characterization of deforestation, fragmentation and forest fires in Telangana state, India: conservation perspective.

    Science.gov (United States)

    Sudhakar Reddy, C; Vazeed Pasha, S; Jha, C S; Dadhwal, V K

    2015-07-01

    Conservation of biodiversity has been put to the highest priority throughout the world. The process of identifying threatened ecosystems will search for different drivers related to biodiversity loss. The present study aimed to generate spatial information on deforestation and ecological degradation indicators of fragmentation and forest fires using systematic conceptual approach in Telangana state, India. Identification of ecosystems facing increasing vulnerability can help to safeguard the extinctions of species and useful for conservation planning. The technological advancement of satellite remote sensing and Geographical Information System has increased greatly in assessment and monitoring of ecosystem-level changes. The areas of threat were identified by creating grid cells (5 × 5 km) in Geographical Information System (GIS). Deforestation was assessed using multi-source data of 1930, 1960, 1975, 1985, 1995, 2005 and 2013. The forest cover of 40,746 km(2), 29,299 km(2), 18,652 km(2), 18,368 km(2), 18,006 km(2), 17,556 km(2) and 17,520 km(2) was estimated during 1930, 1960, 1975, 1985, 1995, 2005 and 2013, respectively. Historical evaluation of deforestation revealed that major changes had occurred in forests of Telangana and identified 1095 extinct, 397 critically endangered, 523 endangered and 311 vulnerable ecosystem grid cells. The fragmentation analysis has identified 307 ecosystem grid cells under critically endangered status. Forest burnt area information was extracted using AWiFS data of 2005 to 2014. Spatial analysis indicates total fire-affected forest in Telangana as 58.9% in a decadal period. Conservation status has been recorded depending upon values of threat for each grid, which forms the basis for conservation priority hotspots. Of existing forest, 2.1% grids had severe ecosystem collapse and had been included under the category of conservation priority hotspot-I, followed by 27.2% in conservation priority hotspot-II and 51.5% in conservation

  16. Diet of Monodelphis glirina (Mammalia: Didelphidae in forest fragments in southern Amazon

    Directory of Open Access Journals (Sweden)

    Welvis Felipe Fernandes Castilheiro

    2013-06-01

    Full Text Available The current study aimed to evaluate the diet of Monodelphis glirina (Wagner, 1842 in forest fragments of Alta Floresta, located in the south of the Amazon, state of Mato Grosso. The diet was determined by the analysis of the stomach contents from 57 subjects sampled between May and September 2009. Nine food categories were present: Coleoptera, Orthoptera, Hymenoptera, Diplopoda, Nematoda, seeds, miscellaneous, hair and bait leftovers (banana and peanut butter. Coleoptera was the category eaten most frequently, rating 50% of abundance and 91.22% of occurrence. "Seeds" were the least abundant (0.11% and rated 1.75% in occurrence, probably because seeds are easy to digest. The size of the fragments negatively and significantly influenced the amount of Coleoptera in the diet. The rainy season seemed to have significant influence over the abundance of arthropods in the diet. The items in the diet suggest that M. glirina is opportunistic and has a generalist diet, tending to be insectivore when living in the forest and exploring the food resources according to their availability.

  17. Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

    International Nuclear Information System (INIS)

    Soares Quinete, Natalia; Santos de Oliveira, Elba dos; Fernandes, Daniella R.; Souza Avelar, Andre de; Erthal Santelli, Ricardo

    2011-01-01

    A superficial water quality survey in a watershed of the Paraiba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresopolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments. - Highlights: → The organochlorine pollutants occurrence in the Atlantic Rain Forest was investigated. → PARNASO was considered a control area of environmental quality. → Extractions methods were compared for typical C-rich soils samples from Brazil. → Low concentrations of organochlorine residues were found in water and soil samples. → A monitoring program is demanded due to the environmental importance of the area. - The occurrence of organochlorine pollutants in soils of the Atlantic rainforest fragments in Rio de Janeiro, Brazil demands a monitoring program of its compartments.

  18. Assessment of organochlorine pesticide residues in Atlantic Rain Forest fragments, Rio de Janeiro, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Soares Quinete, Natalia, E-mail: nataliaquinete@yahoo.com.br [Instituto Nacional de Tecnologia, Departamento de Quimica Analitica, Laboratorio de Quimica Analitica e Metrologia em Quimica, Av. Venezuela, 82 - Rio de Janeiro, RJ 20081-312 (Brazil); Santos de Oliveira, Elba dos [Instituto Nacional de Tecnologia, Departamento de Energia, Av. Venezuela, 82 - Rio de Janeiro, RJ 20081-312 (Brazil); Fernandes, Daniella R. [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Quimica Analitica, CT - Bloco A, Cidade Universitaria, 21941-909 - Rio de Janeiro (Brazil); Souza Avelar, Andre de [Universidade Federal do Rio de Janeiro, Departamento de Geografia, Instituto de Geociencias, CCMN, Bloco F, Cidade Universitaria, 21941-919 - Rio de Janeiro (Brazil); Erthal Santelli, Ricardo [Universidade Federal do Rio de Janeiro, Instituto de Quimica, Departamento de Quimica Analitica, CT - Bloco A, Cidade Universitaria, 21941-909 - Rio de Janeiro (Brazil)

    2011-12-15

    A superficial water quality survey in a watershed of the Paraiba do Sul River, the main water supply for the most populated cities of southeastern Brazil, was held in order to assess the impact of the expansion of agricultural activity in the near border of the Atlantic Rain Forest. The aim of this study was to investigate the presence of priority organochlorine pollutants in soils and superficial waters of Atlantic rainforest fragments in Teresopolis, Rio de Janeiro State. Soil sample preparations were compared by using ultrasound, microwave assisted extraction and Soxhlet extraction. Recoveries of matrix spiked samples ranged from 70 to 130%. Analysis of a certified soil material showed recoveries ranging from 71 to 234%. Although low concentrations of organochlorine residues were found in water and soil samples, this area is of environmental importance and concern, thus demanding a monitoring program of its compartments. - Highlights: > The organochlorine pollutants occurrence in the Atlantic Rain Forest was investigated. > PARNASO was considered a control area of environmental quality. > Extractions methods were compared for typical C-rich soils samples from Brazil. > Low concentrations of organochlorine residues were found in water and soil samples. > A monitoring program is demanded due to the environmental importance of the area. - The occurrence of organochlorine pollutants in soils of the Atlantic rainforest fragments in Rio de Janeiro, Brazil demands a monitoring program of its compartments.

  19. PRELIMINARY RESULTS OF BOWL TRAPPING BEES (HYMENOPTERA, APOIDEA IN A SOUTHERN BRAZIL FOREST FRAGMENT

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Gonçalves

    2013-05-01

    Full Text Available In recent years bowl traps have gained attention as a useful method for sampling bees and are now commonly used across the world for this purpose. However, specific questions about the method itself have not yet been tested on different regions of the globe. We present the preliminary results of bowl trapping in a Semidecidual Seasonal forest fragment in southern Brazil, including the test of two different color bowls, two different habitats, and the interaction of these variables in bee species number and composition. We used blue and yellow bowls in the border and in the core trails of the forest fragment. In five sampling days between October to December bowl traps captured 745 specimens of 37 morphospecies, with Halictinae bees being the richest and most abundant group. Non parametrical statistical analyses suggested that different colors of bowl traps influenced bee richness and composition and thus, they should be used together for a more complete sampling. Different trails influenced only the composition, while the interaction with different colors did not have a significant effect. These results, as well as the higher taxonomic composition of the inventoried bees, are similar to other studies reported in the literature.

  20. STRUCTURAL CHARACTERIZATION OF A SEMIDECIDUOUS FOREST FRAGMENT IN IBITURUNA COUNTY, MG

    Directory of Open Access Journals (Sweden)

    Vagner Fernandes da Silva

    2003-01-01

    Full Text Available A survey describing the physiognomic structure and the species composition and diversityof the tree community was carried out in a fragment of tropical semideciduous forest. The forestfragment, with an area of 57ha, is situated at 21 °09’S of latitude and 44 °50’W of longitude, in Ibiturunacounty, Minas Gerais state, Brazil. The surveys were carried out in two sectors of the fragment,Slope and Valley, where 26 (20 ×20m plots were located. All trees with diameter at breast height dbh ≥ 5 cm were identified and measured (diameter and height. The survey registered 1008 tree,distributed in 191 species, 128 genera and 54 families; 20 species were added to this total andregistered during incursions outside the plots. The Fabaceae (Leguminosae family stood out for itsrichness of species (30 and genera (18, representing 15,7% of the total species registered. In secondplace, the Myrtaceae family presented 20 species and 9 genera, followed by the Lauraceae family,with 17 species and 7 genera. Other families that contributed with an expressive number of specieswere: Meliaceae, with 11; Euphorbiaceae, with 8; Malvaceae and Rubiaceae, both with 7 species.This floristic profile may be considered typical of the semideciduous forests of the region.

  1. Arthropods on plants in a fragmented Neotropical dry forest: a functional analysis of area loss and edge effects.

    Science.gov (United States)

    González, Ezequiel; Salvo, Adriana; Valladares, Graciela

    2015-02-01

    Loss and fragmentation of natural ecosystems are widely recognized as the most important threats to biodiversity conservation, with Neotropical dry forests among the most endangered ecosystems. Area and edge effects are major factors in fragmented landscapes. Here, we examine area and edge effects and their interaction, on ensembles of arthropods associated to native vegetation in a fragmented Chaco Serrano forest. We analyzed family richness and community composition of herbivores, predators, and parasitoids on three native plant species in 12 fragments of varying size and at edge/interior positions. We also looked for indicator families by using Indicator Species Analysis. Loss of family richness with the reduction of forest fragment area was observed for the three functional groups, with similar magnitude. Herbivores were richer at the edges without interaction between edge and area effects, whereas predators were not affected by edge/interior position and parasitoid richness showed an interaction between area and position, with a steeper area slope at the edges. Family composition of herbivore, predator, and parasitoid assemblages was also affected by forest area and/or edge/interior situation. We found three indicator families for large remnants and five for edges. Our results support the key role of forest area for conservation of arthropods taxonomic and functional diversity in a highly threatened region, and emphasize the need to understand the interactions between area and edge effects on such diversity. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  2. Bryophytes in fragments of Terra Firme forest on the great curve of the Xingu River, Pará state, Brazil.

    Science.gov (United States)

    Pantoja, A C C; Ilkiu-Borges, A L; Tavares-Martins, A C C; Garcia, E T

    2015-08-01

    Microclimatic conditions of tropical forest favour the high richness of bryophytes, which by being sensitive to environmental changes, are important indicators of habitat conditions. The aim of this study was to determine the richness and species composition of the bryophyte flora in fragments of terra firme forest on the great curve of the Xingu River, Pará state, Brazil. The collections were made in August and September 2012 in 14 fragments, in which were installed two plots per fragment, one at the edge and one inside, measuring 10 × 10 m each. The results showed 77 species in 45 genera and 18 families. Lejeunea setiloba Spruce and Marchesinia brachiata (Sw.) Schiffn. are new records for Pará state. The richness families in this study were the ones typically found in tropical forest surveys. A high richness of rare species in comparison to common ones, a pattern usually observed for plants in tropical forests was not reported in this study, probably due to historical fragmentation and disturbance in the area. The richness and species composition were determined mainly by the physiognomic characteristics of the studied forest fragments.

  3. Deforestation and Forest Fragmentation in South Ecuador since the 1970s – Losing a Hotspot of Biodiversity

    Science.gov (United States)

    Tapia-Armijos, María Fernanda; Homeier, Jürgen; Espinosa, Carlos Iván; Leuschner, Christoph; de la Cruz, Marcelino

    2015-01-01

    Deforestation and fragmentation are major components of global change; both are contributing to the rapid loss of tropical forest area with important implications for ecosystem functioning and biodiversity conservation. The forests of South Ecuador are a biological ‘hotspot’ due to their high diversity and endemism levels. We examined the deforestation and fragmentation patterns in this area of high conservation value using aerial photographs and Aster satellite scenes. The registered annual deforestation rates of 0.75% (1976–1989) and 2.86% (1989–2008) for two consecutive survey periods, the decreasing mean patch size and the increasing isolation of the forest fragments show that the area is under severe threat. Approximately 46% of South Ecuador’s original forest cover had been converted by 2008 into pastures and other anthropogenic land cover types. We found that deforestation is more intense at lower elevations (premontane evergreen forest and shrubland) and that the deforestation front currently moves in upslope direction. Improved awareness of the spatial extent, dynamics and patterns of deforestation and forest fragmentation is urgently needed in biologically diverse areas like South Ecuador. PMID:26332681

  4. Lianas reduce carbon accumulation and storage in tropical forests.

    Science.gov (United States)

    van der Heijden, Geertje M F; Powers, Jennifer S; Schnitzer, Stefan A

    2015-10-27

    Tropical forests store vast quantities of carbon, account for one-third of the carbon fixed by photosynthesis, and are a major sink in the global carbon cycle. Recent evidence suggests that competition between lianas (woody vines) and trees may reduce forest-wide carbon uptake; however, estimates of the impact of lianas on carbon dynamics of tropical forests are crucially lacking. Here we used a large-scale liana removal experiment and found that, at 3 y after liana removal, lianas reduced net above-ground carbon uptake (growth and recruitment minus mortality) by ∼76% per year, mostly by reducing tree growth. The loss of carbon uptake due to liana-induced mortality was four times greater in the control plots in which lianas were present, but high variation among plots prevented a significant difference among the treatments. Lianas altered how aboveground carbon was stored. In forests where lianas were present, the partitioning of forest aboveground net primary production was dominated by leaves (53.2%, compared with 39.2% in liana-free forests) at the expense of woody stems (from 28.9%, compared with 43.9%), resulting in a more rapid return of fixed carbon to the atmosphere. After 3 y of experimental liana removal, our results clearly demonstrate large differences in carbon cycling between forests with and without lianas. Combined with the recently reported increases in liana abundance, these results indicate that lianas are an important and increasing agent of change in the carbon dynamics of tropical forests.

  5. Forest fuel reduces the nitrogen load

    International Nuclear Information System (INIS)

    Lundborg, A.

    1993-03-01

    A study of the literature was made on the basis of the following hypothesis: ''If nitrogen-rich felling residues are removed from the forest, the nitrogen load on the forest ecosystem is decreased and the risk of nitrogen saturation also decreases''. The study was designed to provide information on how the nitrogen situation is influenced if felling residues are removed from nitrogen-loaded forests and used as fuel. Felling residues release very little nitrogen during the first years after felling. They can immobilize nitrogen from the surroundings, make up a considerable addition to the nitrogen store in the soil, but also release nitrogen in later stages of degradation. The slash has an influence on the soil climate and thus on soil processes. Often there is an increase in the mineralization of litter and humus below the felling residues. At the same time, nitrification is favoured, particularly if the slash is left in heaps. Felling residues contain easily soluble nutrients that stimulate the metabolization of organic matter that otherwise is rather resistant to degradation. The slash also inhibits the clear-cut vegetation and its uptake of nitrogen. These effects result in increased leaching of nitrogen and minerals if the felling residues are left on the site. (99 refs.)

  6. Impact of forest fragment size on the population structure of three palm species (Arecaceae) in the Brazilian Atlantic rainforest.

    Science.gov (United States)

    Portela, Rita de Cássia Quitete; dos Santos, Flavio Antonio Maes

    2014-06-01

    The main threats to natural populations in terrestrial ecosystems have been widly recognized to be the habitat fragmentation and the exploitation of forest products. In this study, we compared the density of the populations and the structure of three tropical palm species, Astrocaryum aculeatissimum, Euterpe edulis and Geonoma schottiana. For this, we selected five forest fragments of different sizes (3 500ha, 2 400ha, 57ha, 21ha and 19ha) where palms were censused in nine 30 x 30m plots. We tracked the palms survival from 2005 to 2007, and recorded all new individuals encountered. Each individual was assigned in one of the five ontogenetic stages: seedling, infant, juvenile, immature and reproductive. The demographic structure of each palm species was analyzed and compared by a generalized linear model (GLM). The analysis was performed per palm species. The forest fragment area and the year of observation were explanatory variables, and the proportion of individuals in each ontogenetic class and palm density were response variables. The total number of individuals (from seedlings to reproductives, of all species) monitored was 6 450 in 2005, 7 268 in 2006, and 8 664 in 2007. The densities of two palm species were not influenced by the size of the fragment, but the population density of A. aculeatissimum was dependent on the size of the fragment: there were more individuals in the bigger than in the smaller forest fragments. The population structure of A. aculeatissimum, E. edulis, and G. schottiana was not altered in the smaller fragments, except the infants of G. schottiana. The main point to be drawn from the results found in this study is that the responses of density and population structure seem not to be dependent on fragment size, except for one species that resulted more abundant in bigger fragments.

  7. Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

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    Andréa O. Mesquita

    2012-09-01

    Full Text Available Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments.La fragmentación del hábitat conduce al aislamiento y la reducción de los hábitats, además provoca una serie de efectos negativos sobre las poblaciones naturales, afectando la riqueza, abundancia y distribución de las especies de animales. Dentro de este contexto, los corredores biológicos sirven

  8. Characterizing fragmentation of the collective forests in southern China from multitemporal Landsat imagery: A case study from Kecheng district of Zhejiang province

    Science.gov (United States)

    Li, M.; Zhu, Z.; Vogelmann, James E.; Xu, D.; Wen, W.; Liu, A.

    2011-01-01

    Tropical and subtropical forests provide important ecosystem goods and services including carbon sequestration and biodiversity conservation. These forests are facing increasing socioeconomic pressures and are rapidly being degraded and fragmented. This analysis focuses on the rate of change and patterns of fragmentation in a collective forest area in Zhejiang province, China, during the time period 1988–2005. The research consisted of two parts. The first was the development of general land cover maps and the identification of land cover changes by interpreting Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) time series imagery. The second part involved the computation and analysis of forest fragmentation metrics. For this portion of the study, fragmentation statistics were analyzed, and images were developed to depict forest fragmentation patterns and trends. Results revealed that there was a net loss of 7.8% in forest coverage, dropping from 66.8% in 1988 to 59.0% in 2005, primarily caused by agricultural expansion and poor forest management practices. An acceleration of forest fragmentation was also witnessed during the time intervals, which was evidenced by a decreasing trend in interior forest (57.2% in 1988, 55.0% in 1996 and 54.8% in 2005 respectively) coupled with the scales of the selected geospatial metrics. Continued forest loss and fragmentation are closely correlated with the existing political, educational, institutional and economic processes of contemporary China. To unlock the developmental potentials of the collective forests and to effectively mitigate the rate of forest loss and fragmentation, reforms of forest tenure and ecological immigration practices are recognized as a prospective alternative. The produced fragmentation maps further illustrates the importance of assessing landscape change history, especially the spatiotemporal patterns of forest fragments, when developing landscape level plans for biodiversity

  9. SEASONAL AND TOPOGRAPHYCAL VARIATION OF THE LITTER NUTRIENT CONTENTS OF A ATLANTIC FOREST FRAGMENT

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    Rosângela A. Tristão Borém

    2002-01-01

    Full Text Available ABSTRACT: The objective of this work was to study the effects of forest degradation on the supplyand contents of nutrients in the litter of two toposequences. The study area is located in a fragment ofthe Atlantic Forest, in Silva Jardim, State of Rio de Janeiro, Brazil (42°31'W and 22°31'S. The twotoposequences are under low and high degrees of human intervention. They were divided in lower,middle and upper slope, and the vegetation sampled with plots of 600m2. The litter was collected forquantitative and qualitative characterisation using a wood frame of 0,25m2 randomly distributedwithin the sample plots. Litter collection was carried out in two distinct dates in order to capture seasonalpatterns. The average litter production did not differ significantly between the toposequences.The total litter production was higher at the end of the dry season, and lower at the end of the rainyseason, indicating the seasonal pattern of the forest. The chemical analyses showed that the nutrientscontents varied widely between the toposequences. The lower and middle slope of the toposequenceunder high degree of human intervention presented the highest nutrient contents in the litter.

  10. Changes in abundance of birds in a Neotropical forest fragment over 25 years: a review

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    Robinson, W. D.

    2001-01-01

    Full Text Available Few data are available to evaluate the long term effects of habitat isolation on species richness or abundances in the tropics. Barro Colorado Island (BCI, Panama, has been studied for more than 80 years since its isolation from surrounding lowland forest when the Panama Canal was constructed. Thirty-five percent of the originally present 200 resident species have disappeared. Although the loss of species is well-studied, changes in abundance that might help predict future losses have not been evaluated. One study in 1970 and the present study conducted 25 years later estimated abundances of most bird species on BCI. Comparisons indicate at least 37 species have declined by at least 50%. Twenty-six species of edge habitats are expected to decline as forest maturation proceeds, yet 11 forest species that are now rare may be lost soon. All 26 species that were present in 1970 but not detected in the mid-1990s were rare in 1970. Thus, rarity appears to be a good predictor of extinction risk in this tropical habitat fragment.

  11. Natural canopy bridges effectively mitigate tropical forest fragmentation for arboreal mammals.

    Science.gov (United States)

    Gregory, Tremaine; Carrasco-Rueda, Farah; Alonso, Alfonso; Kolowski, Joseph; Deichmann, Jessica L

    2017-06-20

    Linear infrastructure development and resulting habitat fragmentation are expanding in Neotropical forests, and arboreal mammals may be disproportionately impacted by these linear habitat clearings. Maintaining canopy connectivity through preservation of connecting branches (i.e. natural canopy bridges) may help mitigate that impact. Using camera traps, we evaluated crossing rates of a pipeline right-of-way in a control area with no bridges and in a test area where 13 bridges were left by the pipeline construction company. Monitoring all canopy crossing points for a year (7,102 canopy camera nights), we confirmed bridge use by 25 mammal species from 12 families. With bridge use beginning immediately after exposure and increasing over time, use rates were over two orders of magnitude higher than on the ground. We also found a positive relationship between a bridge's use rate and the number of species that used it, suggesting well-used bridges benefit multiple species. Data suggest bridge use may be related to a combination of bridge branch connectivity, multiple connections, connectivity to adjacent forest, and foliage cover. Given the high use rate and minimal cost, we recommend all linear infrastructure projects in forests with arboreal mammal populations include canopy bridges.

  12. [Assessing dynamic patterns of forest fragmentation based on a landscape mosaic indicator: a case study of Oregon State, USA].

    Science.gov (United States)

    Ren, Xin-Yu; Lü, Ying-Ying; Li, Ming-Shi

    2014-08-01

    Effectively assessing landscape pattern characteristics and predicting their dynamics have been a basic prerequisite for more reasonably regulating and managing forest landscape, and maintaining landscape security patterns. In this study, based on three U. S. National Land Cover Databases (1992, 2001 and 2006), the landscape mosaic indicator in combination with the Markov model was adopted to analyze forest fragmentation patterns and changes in the characteristics of spatial interactions between forests and other land use types in Oregon State, USA. The results showed that conversion from the development-dominated type D to the single development type DD in landscape mosaic model had the highest transition probability 0.319, indicating that urbanization has been the major force responsible for the change of regional landscape patterns. In the forest security model, the highest rates of forest loss occurred in agriculture and the developed landscape mosaic type (ad), showing that in the development and agriculture dominated landscapes, encroaching upon forests was at the highest likelihood. The areal percentage of forest over the total study area was less than 50% when reaching a steady-state distribution, with an accelerating rate of forest fragmentation, and the landscape spatial distribution tended to be a mixed landscape pattern. The Kappa coefficient between the simulated values and the observed values from the 2006 landscape mosaic model was estimated at 0.82, indicating this model had a high precision. However, the accuracy of the forest security model was poor, with a Kappa coefficient of 0.21.

  13. Diet and prey availability of terrestrial insectivorous birds prone to extinction in amazonian forest fragments

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    Luiz Augusto Macedo Mestre

    2010-12-01

    Full Text Available This study compared niche breath, prey size, and diet variability in two pairs of sympatric species of terrestrial insectivorous birds, each pair containing one species that can persist in small forest fragments and one that does not. The pairs were Myrmeciza ferruginea and Sclerurus rufigularis; and Formicarius colma and F. analis, respectively. The prey availability in forest fragments was also sampled and compared to the availability in continuous forests. Niche breath indices did not differ between pair members, but diet variability differed in the opposite direction from that hypothesized. Although the two bird species most vulnerable to fragmentation fed on larger prey than less vulnerable species, prey availability, including that based on prey size did not differ among fragmented versus continuous forest sites. Thus, diet per se appeared not to be an important cause of extinction-proneness in these species. The simplest explanation proposed, that vulnerability to fragmentation was directly related to territory size, requires testing. However, it was consistent with observations that the bird species feeding on larger prey also need larger territories.Dieta e disponibilidade de presas de aves insetívoras terrestres em fragmentos florestais amazônicos. As aves insetívoras terrestres são um dos grupos mais vulneráveis à fragmentação de florestas tropicais; no entanto algumas espécies desta guilda ainda sobrevivem em fragmentos florestais e em florestas secundárias. Se a sensibilidade destas aves à fragmentação de florestas estivesse associada à dieta, então espécies com a dieta relativamente flexível teriam maior propensão em persistir nos fragmentos florestais. Este estudo comparou sobreposição trófica, amplitude de nicho, tamanho de presas e variabilidade de dieta de dois pares de espécies de aves insetívoras terrestres, onde cada par foi composto por uma espécie que persiste nos fragmentos e outra que n

  14. Climatic gradients and human development pressure determine spatial patterns of forest fragmentation in the Great Lakes basin, USA

    Science.gov (United States)

    Currie, W. S.; Hart, S.

    2015-12-01

    Over half of temperate forest area globally has been fragmented or deforested by human activities. Our objective was to gain insight into the combination of climatic, ecological, and social factors that control complex spatial patterns of forest cover and fragmentation at the regional scale. Our study area was the US portion of the land area of the Laurentian Great Lakes basin (USGL basin) of the Upper Midwest, USA, covering ca. 300,000 km2 and home to 25 million people. While this region was historically forested, today there are regional gradients in forest cover as well as complex spatial patterns of agriculture, human settlements, and tree cover. This includes large expanses of fragmented forests in the wildland-urban interface or the forest transition zone. We used structural equation modeling to test models of social and climatic-ecological factors to explain spatial patterns of forest cover and fragmentation. This is a model-driven approach to statistical analysis that is used to test proposed causal "structures" of direct and indirect relationships among variables. It is an innovative approach that makes use of large spatial datasets to test understanding. We assembled numerous spatial data layers at 1 km2 resolution across the USGL basin. We found that 64% to 75% of variance in tree cover and forest connectivity was explained through a relatively simple model combining climatic gradients and human development pressure. Human development pressure was best represented as a measurement model that explained 45% of variance in road density and 87% of housing unit density, while significantly explaining patterns of forest fragmentation. Climate could be represented by a single variable, temperature: where temperature was higher, tree cover and forest connectivity was lower due to human land use. Temperatures did not help to explain patterns of human development as roads and housing, but did affect forest fragmentation through land use as cropland. This suggests

  15. Effects of patch size and type of coffee matrix on ithomiine butterfly diversity and dispersal in cloud-forest fragments.

    Science.gov (United States)

    Muriel, Sandra B; Kattan, Gustavo H

    2009-08-01

    Determining the permeability of different types of landscape matrices to animal movement is essential for conserving populations in fragmented landscapes. We evaluated the effects of habitat patch size and matrix type on diversity, isolation, and dispersal of ithomiine butterflies in forest fragments surrounded by coffee agroecosystems in the Colombian Andes. Because ithomiines prefer a shaded understory, we expected the highest diversity and abundance in large fragments surrounded by shade coffee and the lowest in small fragments surrounded by sun coffee. We also thought shade coffee would favor butterfly dispersal and immigration into forest patches. We marked 9675 butterflies of 39 species in 12 forest patches over a year. Microclimate conditions were more similar to the forest interior in the shade-coffee matrix than in the sun-coffee matrix, but patch size and matrix type did not affect species richness and abundance in forest fragments. Furthermore, age structure and temporal recruitment patterns of the butterfly community were similar in all fragments, independent of patch size or matrix type. There were no differences in the numbers of butterflies flying in the matrices at two distances from the forest patch, but their behavior differed. Flight in the sun-coffee matrix was rapid and directional, whereas butterflies in shade-coffee matrix flew slowly. Seven out of 130 recaptured butterflies immigrated into patches in the shade-coffee matrix, and one immigrated into a patch surrounded by sun coffee. Although the shade-coffee matrix facilitated movement in the landscape, sun-coffee matrix was not impermeable to butterflies. Ithomiines exhibited behavioral plasticity in habitat use and high mobility. These traits favor their persistence in heterogeneous landscapes, opening opportunities for their conservation. Understanding the dynamics and resource requirements of different organisms in rural landscapes is critical for identifying management options that

  16. Associations between forest fragmentation patterns and geneticstructure in Pfrimer’s Parakeet (Pyrrhura pfrimeri), an endangered endemic to central Brazil’s dry forests

    Science.gov (United States)

    Haig, Susan M.; Miller, Leonard F.; Bianchi, Carlos; Mullins, Thomas D.

    2012-01-01

    When habitat becomes fragmented, populations of species may become increasingly isolated. In the absence of habitat corridors, genetic structure may develop and populations risk reductions in genetic diversity from increased genetic drift and inbreeding. Deforestation of the Cerrado biome of Brazil, particularly of the dry forests within the Parana˜ River Basin, has incrementally occurred since the 1970s and increased forest fragmentation within the region. We performed landscape genetic analyses of Pfrimer’s parakeet (Pyrrhura pfrimeri), a globally endangered endemic to the region, to determine if forest fragmentation patterns were associated with genetic structuring in this species. We used previously generated satellite imagery that identified the locations of Parana˜ River Basin forest fragments in 1977, 1993/94, and 2008. Behavioral data quantifying the affinity of Pfrimer’s parakeet for forest habitat was used to parameterize empirically derived landscape conductance surfaces. Though genetic structure was observed among Pfrimer’s parakeet populations, no association between genetic and geographic distance was detected. Likewise, least cost path lengths, circuit theorybased resistance distances, and a new measure of least cost path length complexity could not be conclusively associated with genetic structure patterns. Instead, a new quantity that encapsulated connection redundancy from the 1977 forest fragmentation data provided the clearest associations with pairwise genetic differentiation patterns (Jost’s D: r = 0.72, P = 0.006; FST: r = 0.741, P = 0.001). Our analyses suggest a 35-year or more lag between deforestation and its effect on genetic structure. Because 66 % of the Parana˜ River Basin has been deforested since 1977, we expect that genetic structure will increase substantially among Pfrimer’s Parakeet populations in the future, especially if fragmentation continues at its current pace.

  17. CHARACTERIZATION OF THE ARBOREAL FLORA OF TWO FRAGMENTS OF GALLERY FOREST OF THE “PARQUE CANJERANA”, DF.

    OpenAIRE

    Laura Dietzsch; Alba Valéria Rezende; José Roberto Rodrigues Pinto; Benedito Alísio da Silva Pereira

    2006-01-01

    This study was accomplished in two fragments of the gallery forest located in the Parque Canjerana in Brasília, DF, to characterize the structure and the floristic composition of the arboreal flora. Strips of 10 m of width, with varying lengths, depending on the limits of the forest, were systematically allocated perpendicularly to the water stream, distant 60 m from each other. Each strip was subdivided in continuous parcels of 10 x 20 m, so, in each fragment it was possible to allocate 14 ...

  18. Effect of forest fragmentation on the epiphytic lichen cover of pine trunks on the example taiga town

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    Gaigysh Irina Sergeevna

    2012-06-01

    Full Text Available The main characteristics of epiphytic lichen cover on pine trunks depending on the area of natural pine forest in Kostomuksha (north Karelia were analysed. The town of Kostomuksha was built so that to provide the conservation of forest sites. 56 fragments with the area of 0.04 - 6.13 ha were studied. The average area of fragment is 0.62 ha, with 49 fragments (88% having the area less than 1 ha. Biodiversity and lichen cover were studied in the each fragment with using framework 10x20 cm. 1792 sample plots were made on 448 trees. The total lichens cover varies from 0 to 85%,averaging 10%. 25 species of lichens were found. The number of species in the sample plots varies from 0 to 9. Dominant species found are Hypogymnia physodes, Parmeliopsis ambigua, P. hyperopta, Imshaugia aleurites, Cladonia. Species Alectoria sarmentosa, Cladonia macilenta, Pseudevernia fufruraceae, Bryoria fremontii were less common. It was shown that the main parameters of lichen cover are closely related to the size of the area left in the city forest fragments. The maximum values of species diversity and cover of lichens were found in the fragments of more 1-2 hectares.

  19. Spatial-temporal variation in the dynamics of the tree community in fragments of alluvial forest in Minas Gerais

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    Ana Carolina da Silva

    2011-12-01

    Full Text Available This study explored the dynamics pattern of the tree community in fragments of alluvial forest in the period 2005-2007 and in the period 2007-2009. The study comprises a fragment of riparian forest and five fragments of alluvial forest toward the interior of the floodplain of Sapucaí river, in São Sebastião da Bela Vista, MG, initially inventoried in 2005 and then evaluated in 2007 and again in 2009. Results revealed different patterns among fragments and among time intervals. In the fragments where in previous studies a stronger influence of floods and sodden soil had been observed, tree mortality was found to be greater in the 2007-2009 period than in the 2005-2007 period. Overall, mortality rates were found to be higher than recruitment rates, leading to loss of individuals and loss of basal area. Judging by the history of the area, it can be assumed that these losses are due to an interaction of two factors: i water excess after major flooding and ii occurrence of strong anthropization, represented by selective logging and cattle introduction in the interior of the fragments.

  20. Using Tree-Rings and Remote Sensing to Investigate Forest Productivity Response to Landscape Fragmentation in Northeastern Algeria

    Science.gov (United States)

    Rouini, N.; Lepley, K. S.; Messaoudene, M.

    2017-12-01

    Remote sensing and dendrochronology are valuable tools in the face of climate change and land use change, yet the connection between these resources remains largely unexploited. Research on forest fragmentation is mainly focused on animal groups, while our work focuses on tree communities. We link tree-rings and remotely-sensed Normalized Difference Vegetation Index (NDVI) using seasonal correlation analysis to investigate forest primary productivity response to fragmentation. Tree core samples from Quercus afares have been taken from two sites within the Guerrouche Forest in northeastern Algeria. The first site is located within a very fragmented area while the second site is intact. Fragmentation is estimated to have occurred with the construction of a road in 1930. We find raw tree-ring width chronologies from each site reveal growth release in the disturbed site after 1930. The means of each chronology for the 1930 to 2016 period are statistically different (p < 0.01). Based on these preliminary results we hypothesize that reconstructed primary productivity (NDVI) will be higher in the fragmented site after fragmentation took place.

  1. Lianas as a food resource for brown howlers (Alouatta guariba) and southern muriquis (Brachyteles arachnoides) in a forest fragment

    OpenAIRE

    M. M. Martins

    2009-01-01

    Lianas as a food resource for brown howlers (Alouatta guariba) and southern muriquis (Brachyteles arachnoides) in a forest fragment.— Lianas, woody vines, are abundant and diverse in tropical forests, but their relative contribution as a source of food for herbivores has been neglected. I compared feeding rates on lianas and trees of two sympatric primates, A. guariba and B. arachnoides, in Southeastern Brazil. Availability of liana foods was gathered in parallel with primate behavioral data ...

  2. Diversity of Social Wasps on Semideciduous Seasonal Forest Fragments with Different Surrounding Matrix in Brazil

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    Getulio Minoru Tanaka Junior

    2011-01-01

    Full Text Available We surveyed social wasps (Polistinae present in forest fragments of northwest of São Paulo state with different surroundings composed of a matrix of citrus crops and sugarcane in the expectation that the former matrix would be more diverse than the latter. We collected specimens actively using attractive liquids. We obtained 20 species in Magda, 13 in Bebedouro, 13 in Matão, and 19 in Barretos. The most common genus was Agelaia in all of the areas. The greatest Shannon-Wiener index of diversity was obtained in Magda (H′=2.12. Species such as Brachygastra moebiana, Metapolybia docilis, Mischocyttarus ignotus, M. paulistanus and M. consimilis had not been recorded on recent surveys in the state. Furthermore M. consimilis is a new record for the state. We concluded that, with our data, a relation between the occurrence of social wasps and the surrounding matrix was not detected.

  3. Performances of Different Fragment Sizes for Reduced Representation Bisulfite Sequencing in Pigs

    DEFF Research Database (Denmark)

    Yuan, Xiao Long; Zhang, Zhe; Pan, Rong Yang

    2017-01-01

    Background: Reduced representation bisulfite sequencing (RRBS) has been widely used to profile genome-scale DNA methylation in mammalian genomes. However, the applications and technical performances of RRBS with different fragment sizes have not been systematically reported in pigs, which serve a...

  4. Diversity of nitrite reductase (nirK and nirS) gene fragments in forested upland and wetland soils

    DEFF Research Database (Denmark)

    Priemé, Anders; Braker, Gesche; Tiedje, James M.

    2002-01-01

    The genetic heterogeneity of nitrite reductase gene (nirK and nirS) fragments from denitrifying prokaryotes in forested upland and marsh soil was investigated using molecular methods. nirK gene fragments could be amplified from both soils, whereas nirS gene fragments could be amplified only from...... the marsh soil. PCR products were cloned and screened by restriction fragment length polymorphism (RFLP), and representative fragments were sequenced. The diversity of nirK clones was lower than the diversity of nirS clones. Among the 54 distinct nirK RFLP patterns identified in the two soils, only one...... marsh clones and all upland clones. Only a few of the nirK clone sequences branched with those of known denitrifying bacteria. The nirS clones formed two major clusters with several subclusters, but all nirS clones showed less than 80% identity to nirS sequences from known denitrifying bacteria. Overall...

  5. Better few than hungry: flexible feeding ecology of collared lemurs Eulemur collaris in littoral forest fragments.

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    Giuseppe Donati

    Full Text Available BACKGROUND: Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce. METHODOLOGY/PRINCIPAL FINDINGS: Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when

  6. Better Few than Hungry: Flexible Feeding Ecology of Collared Lemurs Eulemur collaris in Littoral Forest Fragments

    Science.gov (United States)

    Donati, Giuseppe; Kesch, Kristina; Ndremifidy, Kelard; Schmidt, Stacey L.; Ramanamanjato, Jean-Baptiste; Borgognini-Tarli, Silvana M.; Ganzhorn, Joerg U.

    2011-01-01

    Background Frugivorous primates are known to encounter many problems to cope with habitat degradation, due to the fluctuating spatial and temporal distribution of their food resources. Since lemur communities evolved strategies to deal with periods of food scarcity, these primates are expected to be naturally adapted to fluctuating ecological conditions and to tolerate a certain degree of habitat changes. However, behavioral and ecological strategies adopted by frugivorous lemurs to survive in secondary habitats have been little investigated. Here, we compared the behavioral ecology of collared lemurs (Eulemur collaris) in a degraded fragment of littoral forest of south-east Madagascar, Mandena, with that of their conspecifics in a more intact habitat, Sainte Luce. Methodology/Principal Findings Lemur groups in Mandena and in Sainte Luce were censused in 2004/2007 and in 2000, respectively. Data were collected via instantaneous sampling on five lemur groups totaling 1,698 observation hours. The Shannon index was used to determine dietary diversity and nutritional analyses were conducted to assess food quality. All feeding trees were identified and measured, and ranging areas determined via the minimum convex polygon. In the degraded area lemurs were able to modify several aspects of their feeding strategies by decreasing group size and by increasing feeding time, ranging areas, and number of feeding trees. The above strategies were apparently able to counteract a clear reduction in both food quality and size of feeding trees. Conclusions/Significance Our findings indicate that collared lemurs in littoral forest fragments modified their behavior to cope with the pressures of fluctuating resource availability. The observed flexibility is likely to be an adaptation to Malagasy rainforests, which are known to undergo periods of fruit scarcity and low productivity. These results should be carefully considered when relocating lemurs or when selecting suitable areas for

  7. Population genetics of the wood-rotting basidiomycete Armillaria cepistipes in a fragmented forest landscape.

    Science.gov (United States)

    Heinzelmann, Renate; Rigling, Daniel; Prospero, Simone

    2012-09-01

    Armillaria cepistipes is a common wood-rotting basidiomycete fungus found in most forests in Central Europe. In Switzerland, the habitat of A. cepistipes is fragmented because of the presence of major geographical barriers, in particular the Alps, and past deforestation. We analysed the impact of habitat fragmentation on the current spatial genetic structure of the Swiss A. cepistipes population. A total of 167 isolates were sampled across an area of 41 000 km(2) and genotyped at seven microsatellite and four single nucleotide polymorphism (SNP) loci. All isolates belonged to different genotypes which, according to the Bayesian clustering algorithm implemented in Tess, originated from a single gene pool. Our analyses indicate that the overall A. cepistipes population shows little, but significant (F(ST)=0.02), genetic differentiation. Such a situation suggests gene flow is strong, possibly due to long-distance dispersal of airborne basidiospores. This hypothesis is supported by the fact that we could not detect a pattern of isolation by distance. Gene flow is partially restricted by the high mountain ranges of the Alps, as indicated by a signal of spatial autocorrelation detected among genotypes separated by less than about 80-130 km. In contrast, past deforestation seems to have no significant effect on the current spatial population structure of A. cepistipes. This might indicate the existence of a time lag between the current spatial genetic structure and the processes that have induced this specific structure. Copyright © 2012 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  8. FLORISTIC AND STRUCTURAL CHARACTERIZATION OF GALLERY FOREST FRAGMENTS OF UPPER ARAGUAIA RIVER BASIN

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    Christian Dias Cabacinha

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814575The forests of upper Araguaia river basin are daily exposed to degradation agents due to intense agriculture practices. Twenty two fragments (of 10 until 169 ha were surveyed according to point-centered quarter method to characterize vegetation structure and to create a database to forest restoration. One hundred and nine (109 species, belonging to 78 genus and 42 families, were sampled where 73.4% revealed zoochorous dispersal pattern, and 69.7% were classified to initial sucessional category. Shannon index and Pielou equability index were 3.86 nats. ind-1 and 0.82, respectively. Density and total basal area estimated were 1,351 trees.ha-1 and 19.28 m2.ha-1. The areas showed lower richness, Shannon and Pielou heterogeneity indices, lower basal area, and high number of species of intermediate stage of ecological sucession and colonization of cerrado and cerradão species in disturbed areas, altering the original landscape. Such situation, added to the importance of those areas for the biodiversity conservation and ecological services (mainly relative to the water, demands protection actions and management that use the great regenerative potential of the area, given by the existence of a great number of initial secondary species and the prevalence of zoochoric species.

  9. Landscape genetic analyses reveal fine-scale effects of forest fragmentation in an insular tropical bird.

    Science.gov (United States)

    Khimoun, Aurélie; Peterman, William; Eraud, Cyril; Faivre, Bruno; Navarro, Nicolas; Garnier, Stéphane

    2017-10-01

    Within the framework of landscape genetics, resistance surface modelling is particularly relevant to explicitly test competing hypotheses about landscape effects on gene flow. To investigate how fragmentation of tropical forest affects population connectivity in a forest specialist bird species, we optimized resistance surfaces without a priori specification, using least-cost (LCP) or resistance (IBR) distances. We implemented a two-step procedure in order (i) to objectively define the landscape thematic resolution (level of detail in classification scheme to describe landscape variables) and spatial extent (area within the landscape boundaries) and then (ii) to test the relative role of several landscape features (elevation, roads, land cover) in genetic differentiation in the Plumbeous Warbler (Setophaga plumbea). We detected a small-scale reduction of gene flow mainly driven by land cover, with a negative impact of the nonforest matrix on landscape functional connectivity. However, matrix components did not equally constrain gene flow, as their conductivity increased with increasing structural similarity with forest habitat: urban areas and meadows had the highest resistance values whereas agricultural areas had intermediate resistance values. Our results revealed a higher performance of IBR compared to LCP in explaining gene flow, reflecting suboptimal movements across this human-modified landscape, challenging the common use of LCP to design habitat corridors and advocating for a broader use of circuit theory modelling. Finally, our results emphasize the need for an objective definition of landscape scales (landscape extent and thematic resolution) and highlight potential pitfalls associated with parameterization of resistance surfaces. © 2017 John Wiley & Sons Ltd.

  10. Functional traits variation explains the distribution of Aextoxicon punctatum (Aextoxicaceae in pronounced moisture gradients within fog-dependent forest fragments

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    Beatriz eSalgado-Negret

    2015-07-01

    Full Text Available Climate change and fragmentation are major threats to world forests. Understanding how functional traits related to drought tolerance change across small-scale, pronounced moisture gradients in fragmented forests is important to predict species’ responses to these threats. In the case of Aextoxicon punctatum, a dominant canopy tree in fog-dependent rain forest patches in semiarid Chile, we explored how the magnitude, variability and correlation patterns of leaf and xylem vessel traits and hydraulic conductivity varied across soil moisture gradients established within and among forest patches of different size, which are associated with differences in tree establishment and mortality patterns. Leaf traits varied across soil-moisture gradients produced by fog interception. Trees growing at drier leeward edges showed higher LMA (leaf mass per area, trichome and stomatal density than trees from the wetter core and windward zones. In contrast, xylem vessel traits (vessels diameter and density did not vary producing loss of hydraulic conductivity at drier leeward edges. We also detected higher levels of phenotypic integration and variability at leeward edges. The ability of A. punctatum to modify leaf traits in response to differences in soil moisture availability established over short distances (<500 m facilitates its persistence in contrasting microhabitats within forest patches. However, xylem anatomy showed limited plasticity, which increases cavitation risk at leeward edges. Greater patch fragmentation, together with fluctuations in irradiance and soil moisture in small patches, could result in higher risk of drought-related tree mortality, with profound impacts on hydrological balances at the ecosystem scale.

  11. Implications of Fine-Grained Habitat Fragmentation and Road Mortality for Jaguar Conservation in the Atlantic Forest, Brazil.

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    Laury Cullen

    Full Text Available Jaguar (Panthera onca populations in the Upper Paraná River, in the Brazilian Atlantic Forest region, live in a landscape that includes highly fragmented areas as well as relatively intact ones. We developed a model of jaguar habitat suitability in this region, and based on this habitat model, we developed a spatially structured metapopulation model of the jaguar populations in this area to analyze their viability, the potential impact of road mortality on the populations' persistence, and the interaction between road mortality and habitat fragmentation. In more highly fragmented populations, density of jaguars per unit area is lower and density of roads per jaguar is higher. The populations with the most fragmented habitat were predicted to have much lower persistence in the next 100 years when the model included no dispersal, indicating that the persistence of these populations are dependent to a large extent on dispersal from other populations. This, in turn, indicates that the interaction between road mortality and habitat fragmentation may lead to source-sink dynamics, whereby populations with highly fragmented habitat are maintained only by dispersal from populations with less fragmented habitat. This study demonstrates the utility of linking habitat and demographic models in assessing impacts on species living in fragmented landscapes.

  12. Implications of Fine-Grained Habitat Fragmentation and Road Mortality for Jaguar Conservation in the Atlantic Forest, Brazil.

    Science.gov (United States)

    Cullen, Laury; Stanton, Jessica C; Lima, Fernando; Uezu, Alexandre; Perilli, Miriam L L; Akçakaya, H Reşit

    2016-01-01

    Jaguar (Panthera onca) populations in the Upper Paraná River, in the Brazilian Atlantic Forest region, live in a landscape that includes highly fragmented areas as well as relatively intact ones. We developed a model of jaguar habitat suitability in this region, and based on this habitat model, we developed a spatially structured metapopulation model of the jaguar populations in this area to analyze their viability, the potential impact of road mortality on the populations' persistence, and the interaction between road mortality and habitat fragmentation. In more highly fragmented populations, density of jaguars per unit area is lower and density of roads per jaguar is higher. The populations with the most fragmented habitat were predicted to have much lower persistence in the next 100 years when the model included no dispersal, indicating that the persistence of these populations are dependent to a large extent on dispersal from other populations. This, in turn, indicates that the interaction between road mortality and habitat fragmentation may lead to source-sink dynamics, whereby populations with highly fragmented habitat are maintained only by dispersal from populations with less fragmented habitat. This study demonstrates the utility of linking habitat and demographic models in assessing impacts on species living in fragmented landscapes.

  13. Relationships among North American songbird trends, habitat fragmentation, and landscape occupancy

    Science.gov (United States)

    Therese M. Donovan; Curtis H. Flather

    2002-01-01

    Fragmentation of breeding habitat has been hypothesized as a cause of population declines in forest-nesting migratory birds. Negative correlations between the degree of fragmentation and bird density or fecundity at local or regional scales support the fragmentation hypothesis. Yet, in spite of reduced fecundity and densities in fragmented systems, many forest-nesting...

  14. Structural aspects and floristic similarity among tropical dry forest fragments with different management histories in northern Minas Gerais, Brazil

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    Daniel Meira Arruda

    2011-02-01

    Full Text Available In order to produce useful knowledge to the initiatives of protection and management of forest fragments, more specifically for tropical dry forests which suffer with frequent anthropic activities, and due to the lack of specific studies, this article aimed describe the structure and the floristic similarity among three areas of dry forest with different management histories. The study was developed in Capitão Enéas municipality, Northern Minas Gerais, Brazil, where three fragments were evaluated, being one in regeneration for 30 years, another submitted to occasional fire and the third with selective cut in small scale. The sampling was developed through the point quarter method considering all the alive phanerophyte individuals with circumference at breast height (CBH > 15 cm. In the three fragments, 512 individuals, distributed in 60 species, 47 genera, and 23 families were sampled. The most representative families were Fabaceae (26, Anacardiaceae (4, Bignoniaceae (3 and Combretaceae (3. However, fourteen families were represented by only one species. Only eight species were common to all fragments - Myracrodruon urundeuva standed out with 26.9% of all sampled individuals - while a great number of species were exclusive of each fragment. The floristic and structural differences between the fragments are possibly related to the history and intensity of management in each area besides the topography variations and the presence or absence of limestone outcrops. These results show the importance of each fragment, indicating that the loss of anyone would cause negative impacts on the regional flora and consequently to the associated biodiversity.

  15. Bird community in an Araucaria forest fragment in relation to changes in the surrounding landscape in Southern Brazil

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    Pedro Scherer-Neto

    2012-12-01

    Full Text Available The dynamics of the bird community in a small forest fragment was evaluated along seven years in relation to changes in the surrounding landscape. The study area is an Araucaria forest fragment in Southern Brazil (state of Paraná. The sampling period covered the years 1988 through 1994 and the mark-release-recapture method was utilized. The landscape analysis was based on Landsat TM images, and changes in exotic tree plantations, native forest, open areas (agriculture, pasture, bare soil, and abandoned field, and "capoeira"(native vegetation < 2 m were quantified. The relationship between landscape changes and changes in abundance diversity of forest birds, open-area birds, forest-edge birds, and bamboo specialists was evaluated. Richness estimates were run for each year studied. The richness recorded in the study area comprised 96 species. The richness estimates were 114, 118 and 110 species for Chao 1, Jackknife 1 and Bootstrap, respectively. The bird community varied in species richness, abundance and diversity from year to year. As for species diversity, 1991, 1993 and 1994 were significantly different from the other years. Changes in the landscape contributed to the increase in abundance and richness for the groups of forest, open-area and bamboo-specialist species. An important factor discussed was the effect of the flowering of "taquara" (Poaceae, which contributed significantly to increasing richness of bamboo seed eaters, mainly in 1992 and 1993. In general, the results showed that landscape changes affected the dynamics and structure of the bird community of this forest fragment over time, and proved to have an important role in conservation of the avian community in areas of intensive forestry and agricultural activities.

  16. Policy Options to Reduce Fragmentation in the Pooling of Health Insurance Funds in Iran

    Science.gov (United States)

    Bazyar, Mohammad; Rashidian, Arash; Kane, Sumit; Vaez Mahdavi, Mohammad Reza; Akbari Sari, Ali; Doshmangir, Leila

    2016-01-01

    There are fragmentations in Iran’s health insurance system. Multiple health insurance funds exist, without adequate provisions for transfer or redistribution of cross subsidy among them. Multiple risk pools, including several private secondary insurance schemes, have resulted in a tiered health insurance system with inequitable benefit packages for different segments of the population. Also fragmentation might have contributed to inefficiency in the health insurance systems, a low financial protection against healthcare expenditures for the insured persons, high coinsurance rates, a notable rate of insurance coverage duplication, low contribution of well-funded institutes with generous benefit package to the public health insurance schemes, underfunding and severe financial shortages for the public funds, and a lack of transparency and reliable data and statistics for policy-making. We have conducted a policy analysis study, including qualitative interviews of key informants and document analysis. As a result we introduce three policy options: keeping the existing structural fragmentations of social health insurance (SHI)schemes but implementing a comprehensive "policy integration" strategy; consolidation of existing health insurance funds and creating a single national health insurance scheme; and reducing fragmentation by merging minor well-resourced funds together and creating two or three large insurance funds under the umbrella of the existing organizations. These policy options with their advantages and disadvantages are explained in the paper. PMID:27239868

  17. Policy Options to Reduce Fragmentation in the Pooling of Health Insurance Funds in Iran.

    Science.gov (United States)

    Bazyar, Mohammad; Rashidian, Arash; Kane, Sumit; Vaez Mahdavi, Mohammad Reza; Akbari Sari, Ali; Doshmangir, Leila

    2016-02-11

    There are fragmentations in Iran's health insurance system. Multiple health insurance funds exist, without adequate provisions for transfer or redistribution of cross subsidy among them. Multiple risk pools, including several private secondary insurance schemes, have resulted in a tiered health insurance system with inequitable benefit packages for different segments of the population. Also fragmentation might have contributed to inefficiency in the health insurance systems, a low financial protection against healthcare expenditures for the insured persons, high coinsurance rates, a notable rate of insurance coverage duplication, low contribution of well-funded institutes with generous benefit package to the public health insurance schemes, underfunding and severe financial shortages for the public funds, and a lack of transparency and reliable data and statistics for policy-making. We have conducted a policy analysis study, including qualitative interviews of key informants and document analysis. As a result we introduce three policy options: keeping the existing structural fragmentations of social health insurance (SHI)schemes but implementing a comprehensive "policy integration" strategy; consolidation of existing health insurance funds and creating a single national health insurance scheme; and reducing fragmentation by merging minor well-resourced funds together and creating two or three large insurance funds under the umbrella of the existing organizations. These policy options with their advantages and disadvantages are explained in the paper. © 2016 by Kerman University of Medical Sciences.

  18. Vascular epiphytic component in an urban forest fragment in Criciuma, Santa Catarina, Brazil

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    Telma Elyta Vilhalba Azeredo

    2013-06-01

    Full Text Available This study aimed to conduct a floristic and phytosociological survey, as well as analyze the spatial distribution of the vascular epiphytic component in an urban forest fragment belonging to the submontane dense ombrophilous forest in the town of Criciuma, Santa Catarina, Brazil. In addition, information on the ecological groups of epiphytic species and the strategies for pollination and dispersal were also presented. One sampled 60 trees as phorophytes with DBH ≥ 10 cm, through the point-centered quarter method, and the expeditious walking method was used for recording the epiphytic species which weren’t sampled in the phorophytes through the phytosociological method. The frequency was evaluated having the occurrence of epiphytes in the phorophytes and the segments on the bole and crown as a basis. One recorded the presence of epiphytes in the phorophytes in the segments on the bole and crown. One found 65 species distributed into 39 genera and 14 families, out of which 49 were sampled in the phytosociological survey and the remaining ones in the walking survey. Bromeliaceae showed the highest richness, followed by Orchidaceae, and Cactaceae. Tillandsia recurvata (L. L. was firstly mentioned in the southern state. The specific diversity was estimated as H’ = 3.33 and evenness (E was equal to 0.86. The ecological group of holoepiphytes was the most representative one in the area under study. Entomophily and anemochory were the prevailing strategies for pollination and dispersal, respectively. In the phytosociological survey, the number of epiphytic species in the phorophytes ranged from 0 to 21. The highest importance values were those related to Rhipsalis teres (Vell. Steud. and Microgramma vacciniifolia (Langsd. & Fisch. Copel.

  19. Comparison of Drosophilidae (Diptera) assemblages from two highland Araucaria Forest fragments, with and without environmental conservation policies.

    Science.gov (United States)

    Cavasini, R; Buschini, M L T; Machado, L P B; Mateus, R P

    2014-11-01

    Flies from the Drosophilidae family are model organisms for biological studies and are often suggested as bioindicators of environmental quality. The Araucaria Forest, one of Atlantic Forest phyto-physiognomy, displays a highly fragmented distribution due to the expansion of agriculture and urbanization. Thus, this work aimed to evaluate and compare the drosophilid assemblages from two highland Araucaria Forest fragments, one a conservation unit (PMA - Parque Municipal das Araucárias) and the other a private property without any conservational policy (FBL - Fazenda Brandalise), in space and time, using species abundances and richness, ecological indexes and Neotropical and exotic species proportions as parameters to establish the level of environmental quality of these fragments. Our results showed that the observed diversity in PMA (H' = 2.221) was approximately 40% higher than in FBL (H' = 1.592). This could be due to higher preservation quality and habitat diversity in PMA, indicating the importance of conservation units. However, richness were similar for these areas, with PMA (Dmg = 6.602) only 8% higher than FBL (Dmg = 6.128), which suggest that the larger distance from city limits and the larger size of FBL forested area could be compensating the higher disturbance caused by antrophic extractive exploitation of this fragment. This points out that, besides the quality of presevertion, the size and/or connection with other fragments should be considered for areas destined for biodiversity conservation. In general, both areas presented similar drosophilid assemblages, and the expressive abundance of both Neotropical species (mostly of the subgroup willistoni) and the exotic species D. kikkawai suggests that these areas are in intermediate stages of conservation.

  20. Forest Fragmentation in the Lower Amazon Floodplain: Implications for Biodiversity and Ecosystem Service Provision to Riverine Populations

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    Vivian Renó

    2016-10-01

    Full Text Available This article analyzes the process of forest fragmentation of a floodplain landscape of the Lower Amazon over a 30-year period and its implications for the biodiversity and the provision of ecosystem services to the riverine population. To this end, we created a multi-temporal forest cover map based on Landsat images, and then analyzed the fragmentation dynamics through landscape metrics. From the analyses of the landscape and bibliographic information, we made inferences regarding the potential impacts of fragmentation on the biodiversity of trees, birds, mammals and insects. Subsequently, we used data on the local populations’ environmental perception to assess whether the inferred impacts on biodiversity are perceived by these populations and whether the ecosystem services related to the biodiversity of the addressed groups are compromised. The results show a 70% reduction of the forest habitat as well as important changes in the landscape structure that constitute a high degree of forest fragmentation. The perceived landscape alterations indicate that there is great potential for compromise of the biodiversity of trees, birds, mammals and insects. The field interviews corroborate the inferred impacts on biodiversity and indicate that the ecosystem services of the local communities have been compromised. More than 95% of the communities report a decreased variety and/or abundance of animal and plant species, 46% report a decrease in agricultural productivity, and 19% confirm a higher incidence of pests during the last 30 years. The present study provides evidence of an accelerated process of degradation of the floodplain forests of the Lower Amazon and indicate substantial compromise of the ecosystem services provision to the riverine population in recent decades, including reductions of food resources (animals and plants, fire wood, raw material and medicine, as well as lower agricultural productivity due to probable lack of pollination

  1. FLORISTIC DIVERSITY AND EQUITABILITY IN FOREST FRAGMENTS USING ARTIFICIAL NEURAL NETWORKS

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    Christian Dias Cabacinha

    2017-01-01

    Full Text Available This study aimed to evaluate the predictive efficiency of Shannon index (H’ and Pielou Equitability index (J in forest fragments from the Brazilian Cerrado biome, from the vegetation indices and landscape metrics using artificial neural networks (ANN. Feedforward networks were used and they were trained through a back propagation error algorithm. The variables used as ANN input for simultaneous estimation of indices were: the categorical (H’ and J and the numbers related to the mean and standard deviation of vegetation indices (NDVI, SAVI, EVI, and MVI5, MVI7 and landscape metrics (AREA, GYRATE, SHAPE, CONTIG, CORE and ENN. It was generated five models of ANN from the functional relationships between numerical variables inherent to vegetation indices in two seasons, a dry season (June and a rainy season (February. The architecture of the networks was the Multilayer Perceptron (MLP, to estimate simultaneously the H’ and J: 500 using vegetation indices in the wet season (100 for each vegetation index and 500 in dry (100 for each vegetation index. The precision, accuracy and realism of biological ANN were assessed. The nets built during the rainy season and dry season that used vegetation indices MVI5 (Moisture Vegetation Index and SAVI (Soil Adjusted Vegetation Index, respectively, were more appropriate, accurate and biologically realistic to estimate both indices H’ and J. The ANN modeling demonstrated to be adequate to estimate the diversity index.

  2. Feather mites (Acari, Astigmata associated with birds in an Atlantic Forest fragment in Northeastern Brazil

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    HM Silva

    Full Text Available AbstractThe present study reports associations between feather mites (Astigmata and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

  3. Feather mites (Acari, Astigmata) associated with birds in an Atlantic Forest fragment in Northeastern Brazil.

    Science.gov (United States)

    Silva, H M; Hernandes, F A; Pichorim, M

    2015-08-01

    The present study reports associations between feather mites (Astigmata) and birds in an Atlantic Forest fragment in Rio Grande do Norte state, in Brazil. In the laboratory, mites were collected through visual examination of freshly killed birds. Overall, 172 individuals from 38 bird species were examined, between October 2011 and July 2012. The prevalence of feather mites was 80.8%, corresponding to 139 infested individuals distributed into 30 species and 15 families of hosts. Fifteen feather mite taxa could be identified to the species level, sixteen to the genus level and three to the subfamily level, distributed into the families Analgidae, Proctophyllodidae, Psoroptoididae, Pteronyssidae, Xolalgidae, Trouessartiidae, Falculiferidae and Gabuciniidae. Hitherto unknown associations between feather mites and birds were recorded for eleven taxa identified to the species level, and nine taxa were recorded for the first time in Brazil. The number of new geographic records, as well as the hitherto unknown mite-host associations, supports the high estimates of diversity for feather mites of Brazil and show the need for research to increase knowledge of plumicole mites in the Neotropical region.

  4. Efficiency of playback for assessing the occurrence of five bird species in Brazilian Atlantic Forest fragments

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    Danilo Boscolo

    2006-12-01

    Full Text Available Playback of bird songs is a useful technique for species detection; however, this method is usually not standardized. We tested playback efficiency for five Atlantic Forest birds (White-browed Warbler Basileuterus leucoblepharus, Giant Antshrike Batara cinerea, Swallow-tailed Manakin Chiroxiphia caudata, Whiteshouldered Fire-eye Pyriglena leucoptera and Surucua Trogon Trogon surrucura for different time of the day, season of the year and species abundance at the Morro Grande Forest Reserve (South-eastern Brazil and at thirteen forest fragments in a nearby landscape. Vocalizations were broadcasted monthly at sunrise, noon and sunset, during one year. For B. leucoblepharus, C. caudata and T. surrucura, sunrise and noon were more efficient than sunset. Batara cinerea presented higher efficiency from July to October. Playback expanded the favourable period for avifaunal surveys in tropical forest, usually restricted to early morning in the breeding season. The playback was efficient in detecting the presence of all species when the abundance was not too low. But only B. leucoblepharus and T. surrucura showed abundance values significantly related to this efficiency. The present study provided a precise indication of the best daily and seasonal periods and a confidence interval to maximize the efficiency of playback to detect the occurrence of these forest species.A técnica de play-back é muito útil para a detecção de aves, mas este método geralmente não é padronizado. Sua eficiência em atestar a ocorrência de cinco espécies de aves da Mata Atlântica (Pula-pula-assobiador Basileuterus leucoblepharus, Batará Batara cinerea, Tangará Chiroxiphia caudata, Olho-de-fogo Pyriglena leucoptera e Surucuá-de-barriga-vermelha Trogon surrucura foi analisada de acordo com o horário do dia, estação do ano e abundância das espécies na Reserva Florestal do Morro Grande (São Paulo, Brasil e em treze fragmentos florestais de uma paisagem adjacente

  5. Change and fragmentation trends of Zhanjiang mangrove forests in southern China using multi-temporal Landsat imagery (1977-2010)

    Science.gov (United States)

    Li, M. S.; Mao, L. J.; Shen, W. J.; Liu, S. Q.; Wei, A. S.

    2013-09-01

    Mangrove forests, which are found in saline coastal environments around the tropical and subtropical latitudes, are among the most productive terrestrial ecosystems in the world and provide valuable ecological and societal goods and services. The objective of this work was to characterize the spatio-temporal changes in mangrove distribution and fragmentation patterns in the Zhanjiang National Mangrove Forest Nature Reserve, Guangdong province of Southern China, from 1977 through 2010. In addition, a major goal was to assess the socio-economic drivers contributing to the chronic changes taking place within and around the mangrove reserve. Land use and land cover data sets were generated for the reserve for multiple years via unsupervised classification using Landsat time series images. Mangrove fragmentation patterns were then assessed with a fragmentation model. Results revealed that the mangrove spatial extent decreased sharply during the period from 1977 to 1991 due to deforestation caused by diverse development programs, particularly shrimp farming. Afterwards, there was a continuous increase in mangrove extent from 1991 to 2010 due to afforestation and conservation efforts. The mangrove fragmentation trends depicted by the fragmentation model had a high degree of correlation with the observed areal changes. Additionally, the recorded dynamics of the local biodiversity (mainly birds) were consistent with the mangrove ecosystem fragmentation trends over time, and different fragmentation components, including interior, perforated and edge, had distinct impacts on the local mangrove-dependent biodiversity. The most effective way to protect and expand the current mangroves include the following: (1) establishment of mangrove natural reserves, (2) forceful implementation of regulations, (3) establishment of educational programs related to mangrove management, (4) deepening international exchanges and cooperation and (5) increasing the transparency of the project

  6. Domestic dogs in a fragmented landscape in the Brazilian Atlantic Forest: abundance, habitat use and caring by owners

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    PC. Torres

    Full Text Available This study aimed at estimating the population size and attitudes of residents towards caring for domestic dogs, through questionnaire surveys, as well as the frequency of these animals in different habitats (anthropic and forest patch, using scent stations. The study was conducted in a severely fragmented area of the Brazilian Atlantic Forest. A large number of unrestricted dogs was recorded, averaging 6.2 ind/km². These dogs have owners and are regularly fed. Dog records decreased from the anthropogenic matrix to the forest patch edge, which suggests that dogs act as an edge effect on forest patches. Encounters between domestic dog and wild animals can still be frequent in severely fragmented landscapes, mainly at the forest edges. However the fact that most dogs have an owner and are more frequent in the anthropic habitat suggests that their putative effects are less severe than expected for a carnivore of such abundance, but the reinforcement of responsible ownership is needed to further ameliorate such effects.

  7. Biodiversity conservation values of fragmented communally reserved forests, managed by indigenous people, in a human-modified landscape in Borneo.

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    Yayoi Takeuchi

    Full Text Available This study explored the conservation values of communally reserved forests (CRFs, which local indigenous communities deliberately preserve within their area of shifting cultivation. In the current landscape of rural Borneo, CRFs are the only option for conservation because other forested areas have already been logged or transformed into plantations. By analyzing their alpha and beta diversity, we investigated how these forests can contribute to restore regional biodiversity. Although CRFs were fragmented and some had been disturbed in the past, their tree species diversity was high and equivalent to that of primary forests. The species composition of intact forests and forests disturbed in the past did not differ clearly, which indicates that past logging was not intensive. All CRFs contained unique and endangered species, which are on the IUCN Red List, Sarawak protected plants, or both. On the other hand, the forest size structure differed between disturbed and intact CRFs, with the disturbed CRFs consisting of relatively smaller trees. Although the beta diversity among CRFs was also high, we found a high contribution of species replacement (turnover, but not of richness difference, in the total beta diversity. This suggests that all CRFs have a conservation value for restoring the overall regional biodiversity. Therefore, for maintaining the regional species diversity and endangered species, it would be suitable to design a conservation target into all CRFs.

  8. Biodiversity conservation values of fragmented communally reserved forests, managed by indigenous people, in a human-modified landscape in Borneo.

    Science.gov (United States)

    Takeuchi, Yayoi; Soda, Ryoji; Diway, Bibian; Kuda, Tinjan Ak; Nakagawa, Michiko; Nagamasu, Hidetoshi; Nakashizuka, Tohru

    2017-01-01

    This study explored the conservation values of communally reserved forests (CRFs), which local indigenous communities deliberately preserve within their area of shifting cultivation. In the current landscape of rural Borneo, CRFs are the only option for conservation because other forested areas have already been logged or transformed into plantations. By analyzing their alpha and beta diversity, we investigated how these forests can contribute to restore regional biodiversity. Although CRFs were fragmented and some had been disturbed in the past, their tree species diversity was high and equivalent to that of primary forests. The species composition of intact forests and forests disturbed in the past did not differ clearly, which indicates that past logging was not intensive. All CRFs contained unique and endangered species, which are on the IUCN Red List, Sarawak protected plants, or both. On the other hand, the forest size structure differed between disturbed and intact CRFs, with the disturbed CRFs consisting of relatively smaller trees. Although the beta diversity among CRFs was also high, we found a high contribution of species replacement (turnover), but not of richness difference, in the total beta diversity. This suggests that all CRFs have a conservation value for restoring the overall regional biodiversity. Therefore, for maintaining the regional species diversity and endangered species, it would be suitable to design a conservation target into all CRFs.

  9. Assessing the effects of subtropical forest fragmentation on leaf nitrogen distribution using remote sensing data

    NARCIS (Netherlands)

    Cho, M.A.; Ramoelo, A.; Debba, P.; Mutanga, O.; Mathieu, R.; Deventer, van H.; Ndlovu, N.

    2013-01-01

    Subtropical forest loss resulting from conversion of forest to other land-cover types such as grassland, secondary forest, subsistence crop farms and small forest patches affects leaf nitrogen (N) stocks in the landscape. This study explores the utility of new remote sensing tools to model the

  10. Assessing the impact of forest fragmentation due to natural gas development on wild turkey nesting success in Van Buren County, Arkansas

    Science.gov (United States)

    Casey, James Kendall

    Natural gas exploration and production has caused large scale changes to portions of the Arkansas landscape. Well pad site construction, access roads, and pipelines utilized to extract and transport natural gas have fragmented forested areas. The forest fragmentation resulting from these rapid changes could be contributing to the documented decline in nesting success of the wild turkey (Meleagris gallopavo). This study quantified temporal changes in forest fragmentation in terms of the number of forest patches, mean forest patch area, and forest edge length. The correlation between these fragmentation variables and nesting success data was explored to test the hypotheses of this study that 1) the number of forest patches is negatively correlated to nesting success, that 2) forest patch size is positively correlated to nesting success, and that 3) forest edge habitat length is negatively correlated to nesting success. There were 838 wells added within Van Buren County during the years 2000 through 2009. These wells resulted in a total forest loss of about 1.5% area from the initial inventory of forest in 2000. Pearson product moment correlation (PPMC) values ranging from -0.19 to 0.17 suggests relationships exist between poults per hen and forest fragmentation due to natural gas development. These PPMC values and their respective directions confirm the hypothesis. However, their p-values were all greater than 0.5 which suggests the correlations may not be statistically significant. A stronger regression model, giving adjusted R squared value of 0.766, was constructed which takes into account annual precipitation, previous year's wild turkey harvest, along with the number of conifer forest patches. This study concludes that the low wild turkey nesting success may not be directly influenced by forests lost due to natural gas development within the study area Van Buren County Arkansas.

  11. EFFECTS OF HYDROGEOMORPHIC REGION, WATERSHED STORAGE, AND FOREST FRAGMENTATION ON WATERSHED EXPORTS

    Science.gov (United States)

    Turbidity was highest for South Shore streams overall, but exhibited a significant HGM x storage x fragmentation effect, with highest levels observed in South Shore low storage/high fragmentation watersheds.

  12. Strong influence of long-distance edge effect on herb-layer vegetation in forest fragments in an agricultural landscape

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, J.; Hošek, J.; Brabec, Marek; Hédl, Radim; Modrý, M.

    2013-01-01

    Roč. 15, č. 6 (2013), s. 293-303 ISSN 1433-8319 Grant - others:GA MŽP(CZ) SM/6/69/05; GA MŽP(CZ) SP/2D3/139/07 Institutional support: RVO:67985807 ; RVO:67985939 Keywords : ancient forest * edge effect * habitat fragmentation * light condition * soil nutrients * species richness Subject RIV: BB - Applied Statistics, Operational Research; EH - Ecology, Behaviour (BU-J) Impact factor: 3.324, year: 2013

  13. A Microchannel Inlet to Reduce High-Velocity Impact Fragmentation of Molecules in Orbital and Fly-by Mass Spectrometers

    Science.gov (United States)

    Turner, Brandon; Anupriya, Anupriya; Sevy, Eric; Austin, Daniel E.

    2017-10-01

    Closed source neutral mass spectrometers are often used on flyby missions to characterize the molecular components of planetary exospheres. In a typical closed source, neutrals are thermalized as they deflect off the walls within a spherical antechamber prior to ionization and mass analysis. However, the high kinetic energy of each molecule as it impacts the chamber can lead to fragmentation before the ionization region is reached. Due to this fragmentation, the original composition of the molecule can be altered, leading to ambiguous identification.Even knowing the fragmentation pathways that occur may not allow deconvolution of data to give the correct composition. Only stable, volatile fragments will be observed in the subsequent mass spectrometer and different organic compounds likely give similar fragmentation products. Simply detecting these products will not lead to unambiguous identication of the precursor molecules. Here, we present a hardware solution to this problem—an inlet that reduces the fragmentation of molecules that impact at high velocities.We present a microchannel inlet that reduces the impact fragmentation by allowing the molecules to dissipate kinetic energy faster than their respective dissociation lifetimes. Preliminary calculations indicate that impact-induced fragmentation will be reduced up to three orders of magnitude compared with conventional closed sources by using this inlet. The benefits of such an inlet apply to any orbital or flyby velocity. The microchannel inlet enables detection of semi-volatile molecules that were previously undetectable due to impact fragmentation.

  14. Bat-fruit interactions are more specialized in shaded-coffee plantations than in tropical mountain cloud forest fragments.

    Science.gov (United States)

    Hernández-Montero, Jesús R; Saldaña-Vázquez, Romeo A; Galindo-González, Jorge; Sosa, Vinicio J

    2015-01-01

    Forest disturbance causes specialization of plant-frugivore networks and jeopardizes mutualistic interactions through reduction of ecological redundancy. To evaluate how simplification of a forest into an agroecosystem affects plant-disperser mutualistic interactions, we compared bat-fruit interaction indexes of specialization in tropical montane cloud forest fragments (TMCF) and shaded-coffee plantations (SCP). Bat-fruit interactions were surveyed by collection of bat fecal samples. Bat-fruit interactions were more specialized in SCP (mean H2 ' = 0.55) compared to TMCF fragments (mean H2 ' = 0.27), and were negatively correlated to bat abundance in SCP (R = -0.35). The number of shared plant species was higher in the TMCF fragments (mean = 1) compared to the SCP (mean = 0.51) and this was positively correlated to the abundance of frugivorous bats (R= 0.79). The higher specialization in SCP could be explained by lower bat abundance and lower diet overlap among bats. Coffee farmers and conservation policy makers must increase the proportion of land assigned to TMCF within agroecosystem landscapes in order to conserve frugivorous bats and their invaluable seed dispersal service.

  15. Bat-fruit interactions are more specialized in shaded-coffee plantations than in tropical mountain cloud forest fragments.

    Directory of Open Access Journals (Sweden)

    Jesús R Hernández-Montero

    Full Text Available Forest disturbance causes specialization of plant-frugivore networks and jeopardizes mutualistic interactions through reduction of ecological redundancy. To evaluate how simplification of a forest into an agroecosystem affects plant-disperser mutualistic interactions, we compared bat-fruit interaction indexes of specialization in tropical montane cloud forest fragments (TMCF and shaded-coffee plantations (SCP. Bat-fruit interactions were surveyed by collection of bat fecal samples. Bat-fruit interactions were more specialized in SCP (mean H2 ' = 0.55 compared to TMCF fragments (mean H2 ' = 0.27, and were negatively correlated to bat abundance in SCP (R = -0.35. The number of shared plant species was higher in the TMCF fragments (mean = 1 compared to the SCP (mean = 0.51 and this was positively correlated to the abundance of frugivorous bats (R= 0.79. The higher specialization in SCP could be explained by lower bat abundance and lower diet overlap among bats. Coffee farmers and conservation policy makers must increase the proportion of land assigned to TMCF within agroecosystem landscapes in order to conserve frugivorous bats and their invaluable seed dispersal service.

  16. Survival of Adult Songbirds in Boreal Forest Landscapes Fragmented by Clearcuts and Natural Openings

    Directory of Open Access Journals (Sweden)

    Darroch M. Whitaker

    2008-06-01

    Full Text Available There exists little information on demographic responses of boreal songbirds to logging. We conducted a 4-yr (2003-2006 songbird mark-recapture study in western Newfoundland, where land cover is a naturally heterogeneous mosaic of productive spruce-fir forest, stunted taiga, and openings such as bogs, fens, and riparian zones. We compared apparent survival and rate of transience for adults of 14 species between areas having forests fragmented primarily by either natural openings or 3-7 yr-old clearcuts. Data were collected on three landscape pairs, with birds being marked on three 4-6 ha netting sites on each landscape (total = 18 netting sites. Survival rates were estimated using multi-strata mark-recapture models with landscape types specified as model strata. Landscape type was retained in the best model for only two species, Ruby-crowned Kinglet and Yellow-rumped Warbler, in both cases indicating lower apparent survival in landscapes having clearcuts. Though parameter estimates suggested lower survival in clearcut landscapes for several species, meta-analysis across all species detected no general difference between landscape types. Further, we did not detect any relation between landscape differences in survival and a species' habitat affinity, migratory strategy, or the proportion of transients in its population. Although sensitivity to logging was limited, we observed high interspecific variation in rates of breeding season apparent survival (48% [Dark-eyed Junco] to 100% [several species], overwinter apparent survival (0.3% [Ruby-crowned Kinglet] to 86.5% [Gray Jay], and transience (≈0% [several species] to 61% [Ruby-crowned Kinglet in clearcut landscapes]. For Lincoln's and White-throated Sparrows, over-winter apparent survival was >2× higher for males than females, and rate of transience was > 8× higher for White-throated Sparrow males than females. Moderately male-biased sex ratios suggested that both lower mortality and higher

  17. Domestic dogs in rural area of fragmented Atlantic Forest: potential threats to wild animals

    Directory of Open Access Journals (Sweden)

    Edilberto Martinez

    2013-11-01

    Full Text Available Domestic dogs' skills such as hunting and herding shifted as man migrated from rural areas to developing urban centers and led to a change in human-dog relationship and in the purpose of these animals in the properties. The countryside of Viçosa is characterized by small coffee farms surrounded by borders with fragments from the Brazilian Atlantic Forest. The close proximity of these environments favors the encounter between domestic and wild animals which may lead to dog attacks to wild animals and, consequently, disease transmission. The aim of this study was to understand the role of dogs in the rural environment and assess the possible risks they offer to native fauna. The data were obtained from structured questionnaires answered by dogs' owners from rural Viçosa. Results regarding the socioeconomic status of the owners revealed that the majority belonged to either the middle class or low educational level categories. In addition, it was observed that there is a preference for male dogs due to its guard activity and that most dogs live unconstrained. Even though most dogs are provided with good food management, 58% of them prey on wildlife. However, more than half of the dogs do not consume their prey which can be explained by the inherited ability of artificial selection but 36.5% of them have scavenger diet. Most of the dogs were immunized against rabies, whereas, only 28.8% were immunized against infectious diseases such as leptospirosis, distemper and parvovirus. In conclusion, the management of dogs by rural owners, mainly unrestrained living, and allied to inadequate vaccination coverage suggest that dogs are predators of Viçosa's rural wildlife and potential disseminators of disease.

  18. Feeding resource partitioning between two understorey insectivorous birds in a fragment of Neotropical cloud forest

    Directory of Open Access Journals (Sweden)

    M. A. Manhães

    Full Text Available Abstract The food habits and niche overlap based on diet composition and prey size of two species of understorey insectivorous birds were investigated in an area of montane rain forest in the state of Minas Gerais, southeastern Brazil. A total of 43 birds were captured: 33 individuals of Conopophaga lineata (Conopophagidae with 13 recaptures, and 10 individuals of Myiothlypis leucoblephara (Parulidae with 12 recaptures, from which were obtained respectively 33 and 10 fecal samples. Fragments of 16 groups of arthropods, plus insect eggs, were identified in these samples. Conopophaga lineata predominantly consumed Formicidae (32% and Isoptera (23.6%. However, the index of alimentary importance (AI of Isoptera (3.53 was lower than other groups such as Formicidae (AI = 61.88, Coleoptera (AI = 16.17, insect larvae (AI = 6.95 and Araneae (AI = 6.6. Myiothlypis leucoblephara predominantly consumed Formicidae (28.2% and Coleoptera (24.4%, although Coleoptera and Hymenoptera non-Formicidae had the highest values of AI (38.71 and 22.98 respectively. Differences in the proportions of the types of arthropods consumed by birds were not enough to reveal their separation into feeding niches (overlap = 0.618, p observed ≤ expected = 0.934, whereas differences in the use of resources was mainly due to the size of the prey (p<0.001, where C lineata, the species with the highest body mass (p<0.001 consumed larger prey. It is plausible that prey size is an axis of niche dimension that allows the coexistence of these species.

  19. Effects of reduced-impact logging and forest physiognomy on bat populations of lowland Amazonian forest.

    Science.gov (United States)

    Steven J. Presley; Michael R. Willig; Wunderle Jr. Joseph M.; Luis Nélio. Saldanha

    2008-01-01

    1.As human population size increases, demand for natural resources will increase. Logging pressure related to increasing demands continues to threaten remote areas of Amazonian forest. A harvest protocol is required to provide renewable timber resources that meet consumer needs while minimizing negative effects on biodiversity and ecosystem services. Reduced-impact...

  20. Fire regimes approaching historic norms reduce wildfire-facilitated conversion from forest to non-forest

    Science.gov (United States)

    Ryan B. Walker; Jonathan D. Coop; Sean A. Parks; Laura Trader

    2018-01-01

    Extensive high-severity wildfires have driven major losses of ponderosa pine and mixed-conifer forests in the southwestern United States, in some settings catalyzing enduring conversions to nonforested vegetation types. Management interventions to reduce the probability of stand-replacing wildfire have included mechanical fuel treatments, prescribed fire, and wildfire...

  1. Effects of soil water table regime on tree community species richness and structure of alluvial forest fragments in Southeast Brazil

    Directory of Open Access Journals (Sweden)

    AC. Silva

    Full Text Available In order to determine the influence of soil water table fluctuation on tree species richness and structure of alluvial forest fragments, 24 plots were allocated in a point bar forest and 30 plots in five forest fragments located in a floodplain, in the municipality of São Sebastião da Bela Vista, Southeast Brazil, totalizing 54, 10 X 20 m, plots. The information recorded in each plot were the soil water table level, diameter at breast height (dbh, total height and botanical identity off all trees with dbh > 5 cm. The water table fluctuation was assessed through 1 m deep observation wells in each plot. Correlations analysis indicated that sites with shallower water table in the flooding plains had a low number of tree species and high tree density. Although the water table in the point bar remained below the wells during the study period, low tree species richness was observed. There are other events taking place within the point bar forest that assume a high ecological importance, such as the intensive water velocity during flooding and sedimentation processes.

  2. Snake richness in urban forest fragments from Niterói and surroundings, state of Rio de Janeiro, southeastern Brazil

    Science.gov (United States)

    Citeli, Nathalie; Hamdan, Breno

    2016-01-01

    Abstract Background The Atlantic Forest is a hotspot for biodiversity, an area which houses high species richness and endemism, but with high level of threat. With reference to the herpetofauna, until recently there has been no detailed information regarding diversity of snakes recorded in the Atlantic Forest, the number of endemic species and their distribution ranges. While these basic data were missing, large areas of original forest have continued to be lost to increased urbanization and human population, representing a severe threat to the biodiversity. New information We recorded 28 snake species in our study area. Dipsadidae was the richest family with 14 species, followed by Colubridae (eight species), Boidae (two species), Viperidae (two species), and Anomalepididae, Elapidae and Typhlopidae (one species each). Most species were forest inhabitants (61%), of which 13 are endemic to the Atlantic Forest. There were no clearly defined species clusters regarding species composition. None of the species recorded in Niterói are listed as threatened in the Brazilian Redlist. However, most of them are strongly associated with forested areas and, perhaps, are not adapted to live in small fragments. Thus, more initiatives should be implemented to evaluate the true conservation status of these species in order to better protect them. PMID:26929711

  3. The influence of habitat fragmentation on helminth communities in rodent populations from a Brazilian Mountain Atlantic Forest.

    Science.gov (United States)

    Cardoso, T S; Simões, R O; Luque, J L F; Maldonado, A; Gentile, R

    2016-07-01

    The influence of habitat structure on helminth communities of three sigomdontinae rodent species (Akodon cursor, A. montensis and Oligoryzomys nigripes) was investigated in forest fragments within an agricultural landscape in south-eastern Brazil. This is a pionner study correlating the occurrence of helminth species of rodent hosts with microhabitat characteristics. Rodents were collected from 12 fragments and in a continuous conserved area. Up to 13 nematode, three cestode and two trematode species were identified, and habitat fragmentation was found to have more influence on the helminth composition of O. nigripes compared to the other two rodent species. Fragmentation appeared to limit the development of some helminths' life cycles, e.g. with some species such as Trichofreitasia lenti, Protospirura numidica, Cysticercus fasciolaris and Avellaria sp., occurring mostly in areas with less anthropic impact. However, fragmentation did not seem to affect the life cycles of other dominant helminths, such as the trematode Canaania obesa, the nematodes Stilestrongylus lanfrediae, S. eta and S. aculeata, and the cestode Rodentolepis akodontis. The helminth community structure followed a nested pattern of distribution in A. montensis and O. nigripes. Stilestrongylus lanfrediae seemed to be more associated with dense understorey, C. obesa with open canopy and dense understorey, and Guerrerostrongylus zetta with organic matter on the ground. Their presence in each area may be explained by aspects of their life cycles that take place in the external environment outside the host.

  4. Landscape composition influences abundance patterns and habitat use of three ungulate species in fragmented secondary deciduous tropical forests, Mexico

    Directory of Open Access Journals (Sweden)

    G. García-Marmolejo

    2015-01-01

    Full Text Available Secondary forests are extensive in the tropics. Currently, these plant communities are the available habitats for wildlife and in the future they will possibly be some of the most wide-spread ecosystems world-wide. To understand the potential role of secondary forests for wildlife conservation, three ungulate species were studied: Mazama temama, Odocoileus virginianus and Pecari tajacu. We analyzed their relative abundance and habitat use at two spatial scales: (1 Local, where three different successional stages of tropical deciduous forest were compared, and (2 Landscape, where available habitats were compared in terms of landscape composition (proportion of forests, pastures and croplands within 113 ha. To determine the most important habitat-related environmental factors influencing the Sign Encounter Rate (SER of the three ungulate species, 11 physical, anthropogenic and vegetation variables were simultaneously analyzed through model selection using Akaike’s Information Criterion. We found, that P. tajacu and O. virginianus mainly used early successional stages, while M. temama used all successional stages in similar proportions. The latter species, however, used early vegetation stages only when they were located in landscapes mainly covered by forest (97%. P. tajacu and O. virginianus also selected landscapes covered essentially by forests, although they required smaller percentages of forest (86%. All ungulate species avoided landscape fragments covered by pastures. For all three species, landscape composition and human activities were the variables that best explained SER. We concluded that landscape is the fundamental scale for ungulate management, and that secondary forests are potentially important landscape elements for ungulate conservation.

  5. Mechanisms Driving Galling Success in a Fragmented Landscape: Synergy of Habitat and Top-Down Factors along Temperate Forest Edges.

    Directory of Open Access Journals (Sweden)

    Nina-S Kelch

    Full Text Available Edge effects play key roles in the anthropogenic transformation of forested ecosystems and their biota, and are therefore a prime field of contemporary fragmentation research. We present the first empirical study to address edge effects on the population level of a widespread galling herbivore in a temperate deciduous forest. By analyzing edge effects on abundance and trophic interactions of beech gall midge (Mikiola fagi Htg., we found 30% higher gall abundance in the edge habitat as well as lower mortality rates due to decreased top-down control, especially by parasitoids. Two GLM models with similar explanatory power (58% identified habitat specific traits (such as canopy closure and altitude and parasitism as the best predictors of gall abundance. Further analyses revealed a crucial influence of light exposure (46% on top-down control by the parasitoid complex. Guided by a conceptual framework synthesizing the key factors driving gall density, we conclude that forest edge proliferation of M. fagi is due to a complex interplay of abiotic changes and trophic control mechanisms. Most prominently, it is caused by the microclimatic regime in forest edges, acting alone or in synergistic concert with top-down pressure by parasitoids. Contrary to the prevailing notion that specialists are edge-sensitive, this turns M. fagi into a winner species in fragmented temperate beech forests. In view of the increasing proportion of edge habitats and the documented benefits from edge microclimate, we call for investigations exploring the pest status of this galling insect and the modulators of its biological control.

  6. BIOFRAG - a new database for analyzing BIOdiversity responses to forest FRAGmentation

    Science.gov (United States)

    M. Pfeifer; Tamara Heartsill Scalley

    2014-01-01

    Habitat fragmentation studies have produced complex results that are challenging to synthesize. Inconsistencies among studies may result from variation in the choice of landscape metrics and response variables, which is often compounded by a lack of key statistical or methodological information. Collating primary datasets on biodiversity responses to fragmentation in a...

  7. Modelling the effect of habitat fragmentation on climate-driven migration of European forest understorey plants

    NARCIS (Netherlands)

    Dullinger, S.; Dendoncker, N.; Gattringer, Andreas; Leitner, M.; Mang, Thomas; Moser, Dietmar; Mücher, C.A.; Plutzar, Christoph; Rounsevell, Mark; Willner, Wolfgang; Zimmerman, N.E.; Hülber, Karl

    2015-01-01

    Aim
    The rate of climate change might exceed the migration capacity of plants, particularly where habitats became fragmented by human land use. Except for some tree species, the extent to which habitat fragmentation decreases migration rates has nevertheless been little evaluated. Here, we

  8. The orchid bees (Hymenoptera, Apidae, Euglossina in a forest fragment from western Paraná state, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Gonçalves

    2014-01-01

    Full Text Available An orchid bee inventory was carried out in Parque Estadual São Camilo, Palotina, Paraná (Brazil; conservation unit with about 400 hectares of Semidecidual Seasonal forest. Three bait traps were installed at the border of the fragment, each one containing the following fragrances: 1,8-cineole, eugenol, and vanilin. Sampling was carried out from 09am to 03pm, October 2011 to June 2012, summing up nine sampling days. A total of 186 specimens distributed among seven species were sampled. Eufriesea violacea with 140 specimens was the most common species, followed by Euglossa fimbriata (31, Euglossa annectans (9, Eulaema nigrita (4, Euglossa cordata (1, Euglossa pleosticta (1, and Exaerete smaragdina (1. According to qualitative and NMDS analysis, the orchid bee fauna of Parque Estadual São Camilo is representative of Semidecidual Seasonal forest, with richness comparable with other assemblages in the southern distribution of Euglossina. The sampled bee richness indicates that forest fragments, even small and isolated, are important in the conservation of this bees.

  9. Seed dissemination by frugivorous birds from forest fragments to adjacent pastures on the western slope of Volcán Barva, Costa Rica.

    Science.gov (United States)

    Barrantes, Gilbert; Pereira, Ana

    2002-06-01

    Logging, cattle raising, and agricultural activities have caused the destruction of most forested areas in Costa Rica. In some middle and highlands the abrupt topography delayed the complete destruction of montane forest. Consequently, some fragments of almost pristine forest remain along streams that run in deep canyons. Frequently, these remnants serve as corridors between larger forested areas and as routes for movement of frugivorous birds. Eighteen bird species, e.g., Turdus plebejus, Elaenia frantzii and Ptilogonys caudatus are common dwellers of forest patches throughout the Pacific slope of the Volcán Barva. These species fly frequently from forest fragments to adjacent pastures. They defected and regurgitated seeds of 28 plant species on stumps scattered on pasture areas. Isolated trees and specially the stumps are suitable microhabitats for germination of seeds and establishment of seedings.

  10. Increased autumn rainfall disrupts predator-prey interactions in fragmented boreal forests.

    Science.gov (United States)

    Terraube, Julien; Villers, Alexandre; Poudré, Léo; Varjonen, Rauno; Korpimäki, Erkki

    2017-04-01

    There is a pressing need to understand how changing climate interacts with land-use change to affect predator-prey interactions in fragmented landscapes. This is particularly true in boreal ecosystems facing fast climate change and intensification in forestry practices. Here, we investigated the relative influence of autumn climate and habitat quality on the food-storing behaviour of a generalist predator, the pygmy owl, using a unique data set of 15 850 prey items recorded in western Finland over 12 years. Our results highlighted strong effects of autumn climate (number of days with rainfall and with temperature trends in body condition, as the scaled mass index of smaller males increased while the scaled mass index of larger females decreased over the study period, probably due to sex-specific foraging strategies and energy requirements. Long-term temporal stability in local vole abundance refutes the hypothesis of climate-driven change in vole abundance and suggests that rainier autumns could reduce the vulnerability of small mammals to predation by pygmy owls. As small rodents are key prey species for many predators in northern ecosystems, our findings raise concern about the impact of global change on boreal food webs through changes in main prey vulnerability. © 2016 John Wiley & Sons Ltd.

  11. Effectiveness of community forest management at reducing deforestation in Madagascar

    DEFF Research Database (Denmark)

    Rasolofoson, Ranaivo Andriarilala; Ferraro, Paul J.; Jenkins, Clinton N.

    2015-01-01

    Community Forest Management (CFM) is a widespread conservation approach in the tropics. It is also promoted as a means by which payment for ecosystem services schemes can be implemented. However, evidence on its performance is weak. We investigated the effectiveness of CFM at reducing deforestation...... restricted the sample to only where information suggests effective CFM implementation on the ground. Likewise, we cannot detect an effect of CFM where commercial use of natural resources is allowed. However, we can detect a reduction in deforestation in CFM that does not permit commercial uses, compared...

  12. Characterization of environmental quality of forest fragments changes in Jundiaí-Mirim river basin-Brazil using the Markov Chain model

    Science.gov (United States)

    Hasimoto Fengler, Felipe; Leite de Moraes, Jener Fernando; Irio Ribeiro, Admilson; Peche Filho, Afonso; Araujo de Medeiros, Gerson; Baldin Damame, Desirée; Márcia Longo, Regina

    2015-04-01

    In Brazil is common practice the concurrency of large urban centers water catchment in distant sites. There's no policy to preserve strategic springs in the urban territory. Thus, rural areas, located in the surrounds of municipals, usually provide water and others environment services to the population that reside on cities. The Jundiaí-Mirim river basin, located in the most urbanized state in Brazil, São Paulo, composes an interesting example of this situation. It is located in a rural area near large urban centers, with large industrial parks, near the capital of state. As result of expansion of the cities on its surrounds their lands have had a historic of monetary valorization, making its territories attractive to the housing market. Consequently, the region has an intense process of urbanization that resulted in an increasing environmental disturbance in the areas of natural vegetation. In the other hand, the watershed is the principal water supplier of Jundiaí city, and houses forest remaining of an important Biome in Brazil, the Atlantic Rain Forest. Given the need to preserve its water production capacity and the forest remnants there, this study modeled the environmental quality of forest fragments through indicators of disturbance and evaluated the changes that occur between 1972 and 2013 using the Markov Chain model. The environment quality was determined by nine indicators of environmental disturbance (distance of urban areas, roads, edge land use, size, distance of others forest fragments, land capacity of use, watershed forest cover, number of forest fragments in the watersheds, shape of the forest fragment), obtained by techniques of Geoprocessing, and integrated by Multicriteria Analysis. The Markov Chain model showed a constant tendency of deteriorating in natural vegetation environmental quality, attributed to the intense process of occupation of the river basin. The results showed a historical trend of transformation in forest fragments with

  13. Dipteran fauna associated with decaying organic matter in semi-deciduous forest fragments in southern Goiás, Brazil

    Directory of Open Access Journals (Sweden)

    José Eduardo Neto de Sousa

    2014-12-01

    Full Text Available Dipteran diversity was studied in four seasonal, semi-deciduous forest fragments in southern Goiás state, Brazil. Species richness of Muscidae, Calliphoridae and Sarcophagidae families was analyzed. The insects were collected each two months over the course of one year, using traps with decaying bait. The traps were kept in the field for five days each sampling period. A total of 1,956 individuals belonging to 13 families were collected. 29 species were identified belonging to the main families. Muscidae had the highest abundance, while Sarcophagidae presented the greatest number of species. We also report the occurrence of Philornis schildi (Muscidae for the first time in Brazil. These data reinforce the importance of preserving these areas, and indicate the need for new studies to improve knowledge of the biodiversity associated with these fragments. This information may also be useful in future studies regarding the impact of human activity on insect fauna associated with this environment.

  14. Fauna and stratification of male orchid bees (Hymenoptera: Apidae) and their preference for odor baits in a forest fragment.

    Science.gov (United States)

    Ferreira, M G; de Pinho, O C; Balestieri, J B P; Faccenda, O

    2011-01-01

    This is a study of the population fluctuation of euglossine species, as well as their preferences for scent baits (cineole, eugenol, vanillin and methyl salicylate) in two forest strata (canopy and understory) at the Reserva Florestal do Azulão, a forest fragment located in the municipality of Dourados, MS, Brazil (22°12'S, 54°55'W). We collected a total of 529 males from four genera and eight species. Diversity and equitability for both strata (understory: H' = 1.195 and J' = 0.6139; canopy: H' = 1.193 and J' = 0.6131) did not show a significant difference and a high similarity index was found (P = 87.5%). On the other hand, abundance was substantially higher in the canopy (n = 358) than in the understory (n = 171). From the scents used, eugenol attracted a larger number of individuals (n = 225), but cineole and vanillin attracted a higher number of species.

  15. Birds on fragmented islands : persistence in the forests of Java and Bali

    NARCIS (Netherlands)

    Balen, van S.

    1999-01-01

    This study describes, analyses and provides suggestions for the amelioration of the impact of age-long deforestation on the distribution of forest birds on the islands of Java and Bali (Indonesia). The first section deals with colonisation and extinction processes of forest birds in a

  16. Role of edge effect on small mammal populations in a forest fragment

    International Nuclear Information System (INIS)

    Wike, L.D.

    2000-01-01

    In many cases, edge effect may determine the distribution and densities of small mammal populations. In 1995 and 1998, a mark and recapture study was conducted at the Savannah River Site (SRS), Aiken, SC, to evaluate the role of forest edge habitat. The area studied was an abandoned home site that had been recently isolated by a timber harvest. Harvest activities left a distinct edge of old field and planted pine contrasting with a relatively xeric, mixed hardwood stand. Trapping was conducted for 17 days in 1995 and 14 days in 1998. Three 30 m by 150 m grids were placed in the clear-cut, edge, and hardwood interior habitats. For both years the principal species captured were Peromyscus gossypinus, P. polionotus, and Neotoma floridana. The edge habitat accounted for approximately 55 percent of all captures and nearly four times as many recaptures as the interior and clear-cut habitats. In 1998, greater numbers of N. floridana were trapped than in 1995. The results indicate that the use of edge habitat can be pronounced even within simple communities. Stewards of managed or restored habitats need to carefully consider the role of edge in these systems. In managed areas such as waste sites, movement of material within the food chain could be reduced by minimizing edge habitat around the points of contamination

  17. STRUCTURE OF THE TREE AND REGENERATION LAYER ON A SEASONAL SEMIDECIDUOUS FOREST FRAGMENT IN ITUMBIARA, GOIÁS STATE

    Directory of Open Access Journals (Sweden)

    Michel Eduardo Valentim Milhomem

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812352Semideciduous forests occur in a few places in the Cerrado biome, but are being suppressed through byagriculture and livestock in central Brazil. The objective of this study was characterize the horizontaland vertical structures, the dispersal syndromes, successional groups and floristic similarity of the treelayer and regeneration in a semideciduous forest fragment in Itumbiara, Goiás state. All trees alive withcircumference at breast height (CAP ≥ 15 were identified and measured for height and diameter in 25 plotsof 20 x 20 m. To the regenerative stratum the criteria was the inclusion of individuals with height ≥ 1m untilCAP = 14.9 cm in 25 plots of 10 × 10 m. In both layers were sampled 100 species. The species with thehighest importance in the tree layer were Nectandra megapotamica (Spreng. Mez, and in the regenerativestratum, Siparuna guianensis Aubl. Both layers had a higher proportion of early secondary species and thezoochory dispersion syndrome was more frequent. Several important species are not represented in othersemideciduous forests, and then this forest is an important permanent conservation area.

  18. Study of multifragmentation: contribution of reduced velocity correlations between particles and fragments; Etude de la multifragmentation: apport des correlations en vitesse reduite entre particules et fragments

    Energy Technology Data Exchange (ETDEWEB)

    Le Fevre, A. [Paris-7 Univ., 75 (France)

    1997-05-14

    This work is focused on the study of fragment and light particle production mechanisms in the multifragmentation process of hot nuclei, which are formed in the central collisions of Xe+Sn at 50 MeV/u. The experiment has been performed with the INDRA multidetector. The central collision events, selected via the flow angle variable, exhibit the presence of a heavy (Z=90) and highly excited (E{sup *}=12.5 MeV/u) isotropic emission source. The comparison of the data with a statistical multifragmentation model (MMMC) and a dynamical model (BNV) makes us conclude that the multifragmentation can only be explained in the frame of a relatively cold process, around 6 MeV/u of thermal excitation energy, preceded by a primary emission stage of the expanding source, during which nearly one third of the excitation energy is dissipated. In addition, it appears that the fragment energy spectra are not explained by a purely thermal process, and that one has to put forward an expansion collective motion, of 2 MeV/u of energy, following the compression of the compound system. In order to precise the existence of a two-step particle emission (primary and secondary), we have developed and applied an original method of reduced velocity correlations between particles and fragments. It has allowed us to underline two distinct origins for the particle production: one corresponding to secondary emissions, coming from the fragments, and the other one, associated with emissions which occur prior to the fragment production. At last, it has allowed us, also to bring out a hierarchy in the emission time in the decay process, with respect to the particle type. (author) 90 refs.

  19. Human antibody fragments specific for Bothrops jararacussu venom reduce the toxicity of other Bothrops sp. venoms.

    Science.gov (United States)

    Roncolato, Eduardo Crosara; Pucca, Manuela Berto; Funayama, Jaqueline Carlos; Bertolini, Thaís Barboza; Campos, Lucas Benício; Barbosa, José Elpidio

    2013-01-01

    Approximately 20,000 snakebites are registered each year in Brazil. The classical treatment for venomous snakebite involves the administration of sera obtained from immunized horses. Moreover, the production and care of horses is costly, and the use of heterologous sera can cause hypersensitivity reactions. The production of human antibody fragments by phage display technology is seen as a means of overcoming some of these disadvantages. The studies here attempted to test human monoclonal antibodies specific to Bothrops jararacussu against other Bothrops sp. venoms, using the Griffin.1 library of human single-chain fragment-variable (scFv) phage antibodies. Using the Griffin.1 phage antibody library, this laboratory previously produced scFvs capable of inhibiting the phospholipase and myotoxic activities of Bothrops jararacussu venom. The structural and functional similarities of the various forms of phospholipase A2 (PLA₂) in Bothrops venom served as the basis for the present study wherein the effectiveness of those same scFvs were evaluated against B. jararaca, B. neuwiedi, and B. moojeni venoms. Each clone was found to recognize all three Bothrops venoms, and purified scFvs partially inhibited their in vitro phospholipase activity. In vivo assays demonstrated that the scFv clone P2B7 reduced myotoxicity and increased the survival of animals that received the test venoms. The results here indicate that the scFv P2B7 is a candidate for inclusion in a mixture of specific antibodies to produce a human anti-bothropic sera. This data demonstrates that the human scFv P2B7 represents an alternative therapeutic approach to heterologous anti-bothropic sera available today.

  20. Managing fragmentation in global environmental governance: the REDD+ Partnership as bridge organization

    NARCIS (Netherlands)

    Gupta, A.; Pistorius, T.; Vijge, M.J.

    2016-01-01

    This article analyzes the increasing institutional and organizational complexity and fragmentation surrounding the international financing mechanism REDD? (reducing emissions from deforestation and forest degradation in developing countries and related forest activities), now being negotiated within

  1. Different pollinator assemblages ensure reproductive success of Cleisostoma linearilobatum (Orchidaceae) in fragmented holy hill forest and traditional tea garden.

    Science.gov (United States)

    Zhou, Xiang; Liu, Qiang; Han, Jessie Yc; Gao, JiangYun

    2016-02-24

    Orchids are generally recognized to have specialist pollination systems and low fruit set is often thought to be characteristic of the family. In this study, we investigated the reproductive ecology of Cleisostoma linearilobatum, an epiphytic tropical orchid, in a holy hill forest fragment and a traditional tea garden in SW China using comparable methods. C. linearilobatum is self-compatible and dependent on insects for pollination. Fruit production in natural conditions was both pollinator- and resource-limited. However, the natural fruit set remained stable over multiple years at both sites. Pollination observations showed that C. linearilobatum has a generalized pollination system and seven insect species were observed as legitimate pollinators. Although the visit frequencies of different pollinators were different in the two sites, the pollinator assemblages ensured reproductive success of C. linearilobatum in both study sites over multiple years. The results partly explain why C. linearilobatum is so successful in the area, and also suggest that holy hill forest fragments and traditional tea gardens in Xishuangbanna are important in preserving orchids, especially those with generalist pollination.

  2. Relationship between Fragmentized Collective Forestland, Farmers Investment and Forest Commodity Output: An Analysis on Nine Provinces Farmers Survey Data in China

    Directory of Open Access Journals (Sweden)

    Kong Fanbin

    2016-05-01

    Full Text Available The purpose of this study is to quantify the relationship between fragmentized collective forestland, farmers investment and forest commodity output to examine the rationality of collective forest right reform after dispersed forestland operation. The data is based on the 2420 farmers’ survey data in nine provinces of China including Fujian, Jiangxi, Hunan, Sichuan, Zhejiang, Guangxi, Henan, Shandong and Liaoning. The results show that if S index is used, fragmentized forestland reaches 0.41 and can be ordered (from high to low as Zhejiang, Jiangxi, Hunan, Liaoning, Sichuan, Fujian, Guangxi and Shandong. Under certain fragmentized intervals (forestland fragmentized ratio lower than 0.22 or higher than 0.51, the higher the forestland fragmentized, the lower the farmers investment. The investment-output model indicates that forest block reflects the negative impacts to forest output while other variables such as labor, tangible inputs and forestland have positive impacts. When bamboo is produced, level of fragmentation has negative impacts on forestland acreage and significant positive impacts on labor used. The study implies that after the land is divided to households, physical investment is the key factor to affect the commodity output and should be considered by the related policies to increase the incentives of farmers. Based on this study, we provide some information and guidance on policy of farmers’ forestland operation in large scale

  3. Rhizome Fragmentation by Vertical Disks Reduces Elymus repens Growth and Benefits Italian Ryegrass-White Clover Crops

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    Björn Ringselle

    2018-01-01

    Full Text Available Tillage controls perennial weeds, such as Elymus repens, partly because it fragments their underground storage organs. However, tillage is difficult to combine with a growing crop, which limits its application. The aim of this study was to evaluate how soil vertical cutting with minimum soil disturbance and mowing affect the growth and competitive ability of E. repens in a grass–clover crop. A tractor-drawn prototype with vertical disks was used to fragment E. repens rhizomes with minimal soil and crop disturbance. In experiments performed in 2014 and 2015 at a field site close to Uppsala, Sweden, the rhizomes were fragmented before crop sowing (ERF, during crop growth (LRF, or both (ERF+LRF. Fragmentation was combined with repeated mowing (yes/no and four companion crop treatments (none, Italian ryegrass, white clover, and grass/clover mixture. The results showed that in the grass–clover crop, rhizome fragmentation reduced E. repens rhizome biomass production and increased Italian ryegrass shoot biomass. ERF and LRF both reduced E. repens rhizome biomass by about 38% compared with the control, while ERF+LRF reduced it by 63%. Italian ryegrass shoot biomass was increased by 78% by ERF, 170% by LRF and 200% by ERF+LRF. Repeated mowing throughout the experiment reduced E. repens rhizome biomass by about 75%. Combining repeated mowing with rhizome fragmentation did not significantly increase the control effect compared to mowing alone. We concluded that rhizome fragmentation using vertical disks can be used both before sowing and during crop growth to enhance the controlling effect of grass–clover crops on E. repens.

  4. Relative Importance of Nesting Habitat and Measures of Connectivity in Predicting the Occurrence of a Forest Songbird in Fragmented Landscapes

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    Stephanie Melles

    2012-12-01

    Full Text Available Theoretical and empirical studies suggest that well-connected networks of forest habitat facilitate animal movement and contribute to species' persistence and thereby the maintenance of biodiversity. Many structural and functional connectivity metrics have been proposed, e.g., distance to nearest neighboring patch or graph-based measures, but the relative importance of these measures in contrast to nesting habitat at fine spatial scales is not well established. With graph-based measures of connectivity, Euclidean distances between forest patches can be directly related to the preferred gap crossing distances of a bird (functional connectivity. We determined the relative predictive power of nesting habitat, forest cover, and structural or functional connectivity measures in describing the breeding distribution of Hooded Warblers (Setophaga citrina over two successive breeding seasons in a region highly fragmented by agriculture in southern Ontario. Logistic regression models of nesting occurrence patterns were compared using Akaike's information criterion and relative effect sizes were compared using odds ratios. Our results provide support for the expectation that nest-site characteristics are indeed related to the breeding distribution of S. citrina. However, models based on nesting habitat alone were 4.7 times less likely than a model including functional connectivity as a predictor for the breeding distribution of S. citrina. Models of nest occurrence in relation to surrounding forest cover had lower model likelihoods than models that included graph-based functional connectivity, but these measures were highly confounded. Graph-based measures of connectivity explained more variation in nest occurrence than structural measures of forest connectivity, in both 2004 and 2005. These results suggest that S. citrina selected nesting areas that were functionally connected at their preferred gap crossing distances, but nesting habitat was a critically

  5. VERTICAL STRUCTURE OF THE ARBOREAL COMPONENT UNDER REGENERATION PHASE OF A DECIDUOUS FOREST FRAGMENT, SANTA CATARINA STATE, BRAZIL

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    Welington Kiffer de Freitas

    Full Text Available ABSTRACT The objective of this study was to evaluate the structure (horizontal and vertical of a Deciduous Forest, located between the municipalities of Piratuba and Ipira (SC. 14.000 m2 of tree communities were analyzed, sub- divided into 14 plots of 10 x 100 m, where all individuals with DBH equal to or greater than 4.0 cm were sampled and identified. For natural regeneration were sampled 560 m2, divided into 14 plots of 10 x 4 m. In the tree strata were sampled 2.125 individuals belonging to 34 families, 80 genera and 113 species with a total density of 1.517 ind.ha-1. Natural regeneration were sampled 196 individuals belonging to 24 families and 49 species with a total density of 3.500 ind. ha-1. Luehea divaricata Mart., Actinostemon concolor (Spreng Müll. Arg. and Parapiptadenia rigida (Benth. Brenan had of value of increased importance (7,1%, 7,0 % and 5,3%, respectively. Actinostemon concolor got high value Relative Natural Regeneration (18,1%. The low percentage of natural regeneration of species as Luehea divaricata and Parapiptadenia rigida, respectively 3,7% and 1,5%, typical of EDF , may represent a maintenance commitment in the community. The study revealed the presence of exotic species with invasive potential, as Hovenia dulcis Thumb. These facts point to the importance of the adoption of management measures, since the forest fragment studied is advancing successional terms, however, anthropogenic interference with signals in the floristic composition. These facts point to the importance of the adoption of management measures, since the forest fragment studied is suffering anthropogenic impact, influencing the ecological succession mechanisms.

  6. Effect of the degree of anthropization in the structure, at three sites fragmented evergreen piedmont forest

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    Hugo Gabriel Sánchez Villacis

    2017-08-01

    Full Text Available The Ecuadorian Amazon is recognized worldwide for its extraordinary megadiversity and multiplicity of forest goods and services. However, the inadequate practices of extractive use of non-timber forest products, the clearing of extensive areas of forests for the development of oil activity and the unsustainable use of timber as economic sustenance of communities have led to structural and functional changes In ecosystems. The study was carried out in three sites of a degraded evergreen forest of the eastern Amazon (Mera, Shell and Puyo in order to evaluate the effect of the degree of intervention on the forest structure. A floristic inventory was carried out with 60 plots of 25 x 25 m2 and tree species ≥ 2.5 cm d1.30 and species in natural regeneration phase with h <2 m were measured. We found 35 families, 65 genera, 101 species and 2 298 individuals, with Arecaceae, Fabaceae and Moraceae being the most representative botanical families. The degree of anthropization was highly modified where Mera was the best state of conservation. It was evidenced a low floristic diversity with patterns of alteration in the vertical and horizontal structure, distinguished phytosociologically by two strata in the sites of Shell and Puyo and by three in Mera, indicator of structural changes.

  7. Lianas as a food resource for brown howlers (Alouatta guariba and southern muriquis (Brachyteles arachnoides in a forest fragment

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    M. M. Martins

    2009-01-01

    Full Text Available Lianas as a food resource for brown howlers (Alouatta guariba and southern muriquis (Brachyteles arachnoides in a forest fragment.— Lianas, woody vines, are abundant and diverse in tropical forests, but their relative contribution as a source of food for herbivores has been neglected. I compared feeding rates on lianas and trees of two sympatric primates, A. guariba and B. arachnoides, in Southeastern Brazil. Availability of liana foods was gathered in parallel with primate behavioral data collection. Liana represented 33.9% and 27.3% of food sources for A. guariba and B. arachnoides, respectively. Foods coming from trees, rather than from lianas, were significantly more consumed by B. arachnoides. However, both species took advantage of the continuously renewable and ephemeral food resources provided by liana. Availability of liana flowers correlated positively with A. guariba feeding proportions. The nutritional supply provided by lianas is apparently beneficial, or at least unharmful, but experiments comparing primate choices in forests with different liana abundances will help to shed light on their possible negative effect on communities.

  8. Bee Diversity and Solanum didymum (Solanaceae Flower–Visitor Network in an Atlantic Forest Fragment in Southern Brazil

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    Francieli Lando

    2018-01-01

    Full Text Available Brazil’s Atlantic Forest biome is currently undergoing forest loss due to repeated episodes of devastation. In this biome, bees perform the most frequent pollination system. Over the last decade, network analysis has been extensively applied to the study of plant–pollinator interactions, as it provides a consistent view of the structure of plant–pollinator interactions. The aim of this study was to use palynological studies to obtain an understanding of the relationship between floral visitor bees and the pioneer plant S. didymum in a fragment of the Atlantic Forest, and also learn about the other plants that interact to form this network. Five hundred bees were collected from 32 species distributed into five families: Andrenidae, Apidae, Colletidae, Megachilidae, and Halictidae. The interaction network consisted of 21 bee species and 35 pollen types. The Solanum-type bee species with the highest number of interactions were Anthrenoides sp. 1, Augochlora sp. 2, and Augochloropsis notophos, representing 71.78% of their interactions. Augochloropsis notophos and Augochlora sp. 2 were the only common species in the flowers of S. didymum. Given the results of our study, we conclude that Solanum is an important source of pollen grains for several native bee species, mainly for the solitary species that are more diverse in the south of Brazil. Moreover, our results indicate that bees from the families Halictidae (A. notophos, Augochlora and Andrenidae (Anthrenoides are the pollinators of S. didymum.

  9. Land fauna composition of small mammals of a fragment of Atlantic Forest in the State of Sao Paulo, Brazil

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    Darci Moraes Barros-Battesti

    2000-03-01

    Full Text Available The Atlantic Forest small mammal land fauna, except bats, and the abiotic factors that might have an influence on its composition, were studied in the Itapevi County, State of Sao Paulo, a forested region, partly altered by antropic action, from January, 1995 to June, 1996. The trapping effort consisted of 2,888 trap-nights, resulting in a 4.6% trapping success and consisted of monthly trappings, for five consecutive days. During this period, 134 specimens were captured, of which 46.3% were Didelphimorphia and 53.7% were Rodentia. Eleven species were registered: two Didelphimorphia: Didelphis marsupialis (Linnaeus, 1758 and Marmosops incanus (Lund, 1841, and nine Rodentia: Akodon cursor (Winge, 1887, Bolomys lasiurus (Lund, 1841, Oxymycterus hispidus Pictet, 1843, Oxymycterus nasutus (Waterhouse, 1837, Oligoryzomys nigripes (Olfers, 1818, Oryzomys angouya (Fischer, 1814, Raltus norvegicus (Berkenhout, 1769, Euryzygomatomys spinosus (G. Fischer, 1814 and Cavia aperea Erxleben, 1777. The relative density indices were correlated with meteorological data by Spearman and Pearson coefficients. For marsupials these correlations were not significant. For rodents, the correlations were significant and directly related to lower temperature and rainfall indices (p<0.05. During the dry season the occurrence of small mammals was 50% greater than during the wet season, probably due to foraging strategies in the studied fragment of Atlantic Forest.

  10. Potential Population Genetic Consequences of Habitat Fragmentation in Central European Forest Trees and Associated Understorey Species—An Introductory Survey

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    Christoph Dobeš

    2017-02-01

    Full Text Available Habitat fragmentation threatens the maintenance of genetic diversity of affected populations. Assessment of the risks associated with habitat fragmentation is a big challenge as the change in population genetic diversity is a dynamic process, often acting over long time periods and depending on various characteristics pertaining to both species (life history traits and their populations (extrinsic characteristics. With this survey, we provide an introductory overview for persons who have to make or are interested in making predictions about the fate of forest-dwelling plant populations which have recently become fragmented and isolated from their main occurrences. We provide a concise introduction to the field of population genetics focusing on terms, processes and phenomena relevant to the maintenance of genetic diversity and vitality of plant populations. In particular the antagonistic effects of gene flow and random genetic drift are covered. A special chapter is devoted to Central European tree species (including the Carpathians which we treat in detail with reference to an extensive literature survey on population genetic studies assembled from the whole of Europe. We further provide an overview of the population biology of associated understorey species. We conclude with recommended steps to be taken for the evaluation of potential perils of habitat fragmentation or population thinning for the genetics of tree populations. The complexity of effects exerted by life history traits and extrinsic characteristics of populations suggest population genetic development is strongly situation dependent. Therefore, we recommend following a case-by-case approach ideally supported by computer simulations to predict future population genetic development of both trees and associated understorey species.

  11. Abundance and survival rates of three leaf-litter frog species in fragments and continuous forest of the Mata Atlântica, Brazil

    Directory of Open Access Journals (Sweden)

    Henning Steinicke

    2018-04-01

    Full Text Available Habitat destruction and fragmentation alter the quality of habitats and put populations under the risk of extinction. Changes in population parameters can provide early warning signs of negative impacts. In tropical forests, where habitat loss and fragmentation are vast, such indicators are of high relevance for directing conservation efforts before effects are irreversible. Most of our knowledge from tropical ecosystems originates from community level surveys, whereas our understanding of the influence of habitat conversion on vital rates of species is limited. This study focused on the influence of anthropogenic habitat fragmentation on the survival probability and abundance of three leaf-litter frog species (Rhinella ornata, Ischnocnema guentheri and I. parva in forest patches of the Atlantic rainforest of South-east Brazil compared to a continuous forest. The species differ in their matrix tolerance: high for R. ornata and low for I. guentheri and I. parva and, thus, we examined whether their survival and abundance correspond to this classification. Ischnocnema guentheri showed highest abundances in all study sites and low mortality in the forest patches compared to the continuous forest; I. parva was encountered only in isolated fragments, with very low mortality in one isolated fragment; and the matrix tolerant species had generally low abundance and showed no clear pattern in terms of mortality in the different sites. Our counter-intuitive results show that even matrix sensitive amphibian species may show high abundance and low mortality in small forest patches. Therefore, these patches can be of high value for amphibian conservation regardless of their degree of matrix aversion. Landscape level conservation planning should not abandon small habitat patches, especially in highly fragmented tropical environments.

  12. Effect of rock fragments on macropores and water effluent in a forest ...

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-05-15

    May 15, 2012 ... flow that play an important role in water flow and solute and nutrient transport, have also been studied extensively (Kluitenberg and Horton, 1990; Cote et al.,. 2000; Larsson and Jarvis, 1999). Beasely (1976) dis- covered that interflow in the soil occurs after rainfall continues for about 20 min sloped forest ...

  13. Post-fire regeneration in seasonally dry tropical forest fragments in southeastern Brazil

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    MAYKE B. COSTA

    2017-12-01

    Full Text Available ABSTRACT Seasonally dry tropical forest is one of the highly threatened biome. However, studies on the effect of fire on these tree communities are still scarce. In this context, a floristic and structural survey in three forest areas in the southeast of Brazil that were affected by fire between 14 and 25 years ago was performed with the objective of evaluating post-fire regeneration. In each site, five systematically placed plots (25 m x 25 m each were established. The more recently burnt site had significantly lower values of richness and diversity than the other two sites. However, the sites did not differ in density and basal area. Annona dolabripetala, Astronium concinnum, Joannesia princeps and Polyandrococos caudescens were within the 10 most important species for the three sites. Comparing these data with adjacent mature forests, the results indicated differences both in structural and floristic aspects, suggesting that the time after fire was not sufficient for recuperation of these areas. The recovery process indicate at least 190 years for areas return to basal area values close to those observed in mature forests nearby.

  14. Ecologically scaled responses of forest-dwelling vertebrates to habitat fragmentation

    OpenAIRE

    Ascensão, Fernando Jorge Portela Martins, 1976-

    2013-01-01

    Tese de doutoramento, Biologia (Biologia da Conservação), Universidade de Lisboa, Faculdade de Ciências, 2013 Road habitat fragmentation has been identified as a major threat for biodiversity conservation. Roads induce a ‘barrier effect’ by representing a physical obstacle or promoting animal-vehicle collisions, disrupting daily and seasonal movements and consequently leading to the depletion and genetic subdivision of animal populations. However, road verges may also provide resources for...

  15. Helminth parasites of Hypsiboas prasinus (Anura: Hylidae) from two Atlantic forest fragments, São Paulo State, Brazil.

    Science.gov (United States)

    Madelaire, Carla Bonetti; Gomes, Fernando Ribeiro; da Silva, Reinaldo José

    2012-06-01

    Seventy-seven males of Hypsiboas prasinus from 2 Atlantic forest fragments in the municipalities of Botucatu and Jundiaí, São Paulo State, Brazil, were examined for endoparasites. The frogs were captured in summer (January until March) and winter (July/August) of 2008 and 2009. Thirty-three males (75%) from Botucatu were infected with Rhabdias cf. fuelleborni , cosmocerciid nematodes, and Cylindrotaenia americana . Twenty-five tree frogs (78.5%) from Jundiaí were infected by Rhabdias cf. fuelleborni , Physaloptera sp., and cosmocerciid nematodes. Only cosmocerciid nematodes presented a statistically significance difference in prevalence (z  =  4.345; P Hylidae. This study presents 4 new records of nematodes in H. prasinus .

  16. Quantitative ethnobotany in an atlantic forest fragment of northeastern Brazil: implications to conservation.

    Science.gov (United States)

    Da Cunha, Luiz Vital F Cruz; De Albuquerque, Ulysses P

    2006-03-01

    An ethnobotanical study was executed in the rural community of the Municipality of "Rio Formoso", starting from the forest inventory accomplished in an Atlantic Forest remnant adjacent to the studied community. Using the methodology of quantitative ethnobotany allied to the ecological parameters (richness, relative frequency, relative density, relative dominance and importance value index) the following results were obtained: 42 inventoried species gathered in 26 families, presented from 1 to 27 means of use for the community. The largest use of the plants is related to obtaining wood in order to be used in house building, firewood production and charcoal. The largest use value was attributed to the Vouacapoua virgilioides (Kunth) Kuntze. The most frequent species were Tapirira guianensis Aubl. (Anacardiaceae), Thyrsodium schomburgkianum Benth. (Anacardiaceae), Schefflera morototoni (Aubl.) Maguire, Steyem. & Frodin (Araliaceae) and Dialium guianense (Aubl.) Sandwith. (Leg-Caesalpinioideae).

  17. Bat assemblages from three Atlantic Forest fragments in Rio de Janeiro state, Southeastern Brazil

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    Roberto Leonan Novaes

    2015-01-01

    Full Text Available Bat species richness in Neotropical localities is generally higher than that of any other group of mammals, and surveys of local bat assemblages may provide useful data for conservation management plans. Although the bat fauna of the Rio de Janeiro state is currently one of the best known in Brazil, there are several localities not adequately surveyed yet, and most of them are in the mountainous regions and in the northern portion of the state. From January 2008 to November 2009, we conducted surveys of bats in three localities in the state of Rio de Janeiro (municipalities of Varre-Sai, Sumidouro, and Cantagalo, and our fieldwork constitutes the first assessment of the bat assemblages of these localities. Surveys were conducted using mist nets in four different habitat types in each locality (forest interior, forest edge, riparian forest, and open areas [pastures]. We captured a total of 148 individuals in 17 species, 14 genera and 3 families. Among them, 11 species were recorded in Sumidouro, seven in Cantagalo, and nine in Varre-Sai. Although species richness was low compared with previous surveys in other close localities, we recorded species that have been rarely sampled in Southeastern Brazil (e.g., Macrophyllum macrophyllum [Phyllostomidae]. The results reinforce the importance of sampling different habitats in short surveys to improve the number of species registered.

  18. Bat assemblages from three Atlantic Forest fragments in Rio de Janeiro state, Southeastern Brazil

    Science.gov (United States)

    Rosa, Daniel Tavares Cassilhas; Vrcibradic, Davor; Avilla, Leonardo dos Santos

    2015-01-01

    Abstract Bat species richness in Neotropical localities is generally higher than that of any other group of mammals, and surveys of local bat assemblages may provide useful data for conservation management plans. Although the bat fauna of the Rio de Janeiro state is currently one of the best known in Brazil, there are several localities not adequately surveyed yet, and most of them are in the mountainous regions and in the northern portion of the state. From January 2008 to November 2009, we conducted surveys of bats in three localities in the state of Rio de Janeiro (municipalities of Varre-Sai, Sumidouro, and Cantagalo), and our fieldwork constitutes the first assessment of the bat assemblages of these localities. Surveys were conducted using mist nets in four different habitat types in each locality (forest interior, forest edge, riparian forest, and open areas [pastures]). We captured a total of 148 individuals in 17 species, 14 genera and 3 families. Among them, 11 species were recorded in Sumidouro, seven in Cantagalo, and nine in Varre-Sai. Although species richness was low compared with previous surveys in other close localities, we recorded species that have been rarely sampled in Southeastern Brazil (e.g., Macrophyllum macrophyllum [Phyllostomidae]). The results reinforce the importance of sampling different habitats in short surveys to improve the number of species registered. PMID:25632263

  19. Old Fragments of Forest Inside an Urban Area Are Able to Keep Orchid Bee (Hymenoptera: Apidae: Euglossini) Assemblages? The Case of a Brazilian Historical City.

    Science.gov (United States)

    Ferreira, R P; Martins, C; Dutra, M C; Mentone, C B; Antonini, Y

    2013-10-01

    Retention of habitat fragments within the urban matrix can provide critical resources for the maintenance of regional biodiversity while still providing socio-economic value. Euglossini bees are important components in a community as they are important pollinators for economically valuable plants as well as hundreds of orchid species. However, some species are very sensitive to environmental impacts like urbanization. This study presents the role of antique urban fragments in a historical city in Brazil and compares it with a conservation area on the aspects of orchid bee assemblage, such as richness, composition, and abundance. Four fragments inside the city of Ouro Preto and three inside Parque Estadual do Itacolomi (PEIT) were sampled for Euglossini bees. Sorensen similarity index was used to compare community composition. The Mantel test was applied to verify the hypothesis that an urban center is a barrier for the mobility of the individuals. Fourteen Euglossini species from the region were registered. Close to 75% of the sampled bees were collected from the PEIT sampling areas. The fragments presented differences in Euglossini richness and abundance. A majority of the sampled fragments were dominated by the Eulaema cingulata Fabricius, Eulaema nigrita Lepeletier, and Euglossa securigera Dressler species. We found differences on community composition between the fragments localized in PEIT and those located in the urban center. The data suggest that there is a possible flux of individuals between the sampled fragments. The various small forest fragments in Ouro Preto, primarily in backyards, may also serve as stepping stones between sampled fragments.

  20. Fragmentation of CagA Reduces Hummingbird Phenotype Induction by Helicobactor pylori.

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    Chih-Chi Chang

    Full Text Available Infection with Helicobacter pylori (H. pylori has been linked to various gastro-intestinal diseases; nevertheless it remains to be clarified why only a minority of infected individuals develop illness. Studies from the West have indicated that the cagA gene and the associated EPIYA genotype of H. pylori is closely linked to the development of severe gastritis and gastric carcinoma; however, as yet no consistent correlation has been found among the bacteria from East Asia. In addition to genotype variation, the CagA protein undergoes fragmentation; however, the functional significance of fragmentation with respect to H. pylori infection remains unknown. In this study, we isolated 594 H. pylori colonies from 99 patients and examined the fragmentation patterns of CagA protein using immunoblotting. By analyzing the ability of the isolates to induce the host cell morphological transition to the highly invasive hummingbird phenotype, we demonstrated that H. pylori colonies with substantial CagA fragmentation are less potent in terms of causing this morphological transition. Our results uncovered a functional role for CagA fragmentation with respect to H. pylori-induced hummingbird phenotype formation and these findings suggest the possibility that the post-translational processing of CagA may be involved in H. pylori infection pathogenesis.

  1. Non PCR-amplified Transcripts and AFLP fragments as reduced representations of the quail genome for 454 Titanium sequencing

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    Leterrier Christine

    2010-07-01

    Full Text Available Abstract Background SNP (Single Nucleotide Polymorphism discovery is now routinely performed using high-throughput sequencing of reduced representation libraries. Our objective was to adapt 454 GS FLX based sequencing methodologies in order to obtain the largest possible dataset from two reduced representations libraries, produced by AFLP (Amplified Fragment Length Polymorphism for genomic DNA, and EST (Expressed Sequence Tag for the transcribed fraction of the genome. Findings The expressed fraction was obtained by preparing cDNA libraries without PCR amplification from quail embryo and brain. To optimize the information content for SNP analyses, libraries were prepared from individuals selected in three quail lines and each individual in the AFLP library was tagged. Sequencing runs produced 399,189 sequence reads from cDNA and 373,484 from genomic fragments, covering close to 250 Mb of sequence in total. Conclusions Both methods used to obtain reduced representations for high-throughput sequencing were successful after several improvements. The protocols may be used for several sequencing applications, such as de novo sequencing, tagged PCR fragments or long fragment sequencing of cDNA.

  2. Forest harvesting reduces the soil metagenomic potential for biomass decomposition.

    Science.gov (United States)

    Cardenas, Erick; Kranabetter, J M; Hope, Graeme; Maas, Kendra R; Hallam, Steven; Mohn, William W

    2015-11-01

    Soil is the key resource that must be managed to ensure sustainable forest productivity. Soil microbial communities mediate numerous essential ecosystem functions, and recent studies show that forest harvesting alters soil community composition. From a long-term soil productivity study site in a temperate coniferous forest in British Columbia, 21 forest soil shotgun metagenomes were generated, totaling 187 Gb. A method to analyze unassembled metagenome reads from the complex community was optimized and validated. The subsequent metagenome analysis revealed that, 12 years after forest harvesting, there were 16% and 8% reductions in relative abundances of biomass decomposition genes in the organic and mineral soil layers, respectively. Organic and mineral soil layers differed markedly in genetic potential for biomass degradation, with the organic layer having greater potential and being more strongly affected by harvesting. Gene families were disproportionately affected, and we identified 41 gene families consistently affected by harvesting, including families involved in lignin, cellulose, hemicellulose and pectin degradation. The results strongly suggest that harvesting profoundly altered below-ground cycling of carbon and other nutrients at this site, with potentially important consequences for forest regeneration. Thus, it is important to determine whether these changes foreshadow long-term changes in forest productivity or resilience and whether these changes are broadly characteristic of harvested forests.

  3. Dealing with reducing trends in forest ecosystem services through a ...

    African Journals Online (AJOL)

    Vulnerability of forest ecosystems in West Africa is likely to be aggravated with current and projected climate and human stresses with implications for adaptation and REDD regimes. This is because vulnerability of the forest ecosystems affects economic sectors and millions of people that depend on their services. This study ...

  4. Dealing with reducing trends in forest ecosystem services through a ...

    African Journals Online (AJOL)

    Administrator

    vulnerability of the forest ecosystems affects economic sectors and millions of people that depend on their services. This study ... Key words: Adaptation, forest ecosystem, land use land cover change, REDD, vulnerability, West Africa. INTRODUCTION ... involves degradation and deforestation, releases CO2 that contributes ...

  5. Tree diversity reduces pest damage in mature forests across Europe.

    Science.gov (United States)

    Guyot, Virginie; Castagneyrol, Bastien; Vialatte, Aude; Deconchat, Marc; Jactel, Hervé

    2016-04-01

    Forest pest damage is expected to increase with global change. Tree diversity could mitigate this impact, but unambiguous demonstration of the diversity-resistance relationship is lacking in semi-natural mature forests. We used a network of 208 forest plots sampled along two orthogonal gradients of increasing tree species richness and latitudes to assess total tree defoliation in Europe. We found a positive relationship between tree species richness and resistance to insect herbivores: overall damage to broadleaved species significantly decreased with the number of tree species in mature forests. This pattern of associational resistance was frequently observed across tree species and countries, irrespective of their climate. These findings confirm the greater potential of mixed forests to face future biotic disturbances in a changing world. © 2016 The Authors.

  6. Species richness and abundance of bats in fragments of the stational semidecidual forest, Upper Paraná River, southern Brazil

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    H. Ortêncio-Filho

    Full Text Available The Upper Paraná River floodplain is inserted in a region of the Mata Atlântica biome, which is a critical area to preserve. Due to the scarcity of researches about the chiropterofauna in this region, the present study investigated species richness and abundance of bats in remnants from the stational semidecidual forest of the Upper Paraná River, southern Brazil. Samplings were taken every month, from January to December 2006, using 32 mist nets with 8.0 x 2.5 m, resulting in 640 m²/h and totaling a capture effort of 87,040 m²/h. In order to estimate the species richness, the following estimators were employed Chao1 and Jack2. During the study, a total of 563 individuals belonging to 17 species (Artibeus planirostris, Artibeus lituratus, Carollia perspicillata, Platyrrhinus lineatus, Sturnira lilium, Artibeus fimbriatus, Myotis nigricans, Desmodus rotundus, Artibeus obscurus, Noctilio albiventris, Phylostomus discolor, Phylostomus hastatus, Chrotopterus auritus, Lasiurus ega, Chiroderma villosum, Pygoderma bilabiatum and Lasiurus blossevillii were captured. The estimated richness curves tended to stabilize, indicating that most of the species were sampled. Captured species represented 10% of the taxa recorded in Brazil and 28% in Paraná State, revealing the importance of this area for the diversity of bats. These findings indicate the need to determine actions aiming to restrict human activities in these forest fragments, in order to minimize anthropogenic impacts on the chiropterofauna.

  7. ASSESSING THE CANOPY INTEGRITY USING CANOPY DIGITAL IMAGES IN SEMIDECIDUOUS FOREST FRAGMENT IN SÃO CARLOS - SP- BRAZIL1

    Directory of Open Access Journals (Sweden)

    Thiago Yamada

    2017-11-01

    Full Text Available ABSTRACT It is well-known that conducting experimental research aiming the characterization of canopy structure of forests can be a difficult and costly task and, generally, requires an expert to extract, in loco, relevant information. Aiming at easing studies related to canopy structures, several techniques have been proposed in the literature and, among them, various are based on canopy digital image analysis. The research work described in this paper empirically compares two techniques that measure the integrity of the canopy structure of a forest fragment; one of them is based on central parts of canopy cover images and, the other, on canopy closure images. For the experiments, 22 central parts of canopy cover images and 22 canopy closure images were used. The images were captured along two transects: T1 (located in the conserved area and T2 (located in the naturally disturbance area. The canopy digital images were computationally processed and analyzed using the MATLAB platform for the canopy cover images and the Gap Light Analyzer (GLA, for the canopy closure images. The results obtained using these two techniques showed that canopy cover images and, among the employed algorithms, the Jseg, characterize the canopy integrity best. It is worth mentioning that part of the analysis can be automatically conducted, as a quick and precise process, with low material costs involved.

  8. Do insect outbreaks reduce the severity of subsequent forest fires?

    Science.gov (United States)

    Meigs, Garrett W.; Zald, Harold S. J.; Campbell, John L.; Keeton, William S.; Kennedy, Robert E.

    2016-04-01

    Understanding the causes and consequences of rapid environmental change is an essential scientific frontier, particularly given the threat of climate- and land use-induced changes in disturbance regimes. In western North America, recent widespread insect outbreaks and wildfires have sparked acute concerns about potential insect-fire interactions. Although previous research shows that insect activity typically does not increase wildfire likelihood, key uncertainties remain regarding insect effects on wildfire severity (i.e., ecological impact). Recent assessments indicate that outbreak severity and burn severity are not strongly associated, but these studies have been limited to specific insect or fire events. Here, we present a regional census of large wildfire severity following outbreaks of two prevalent bark beetle and defoliator species, mountain pine beetle (Dendroctonus ponderosae) and western spruce budworm (Choristoneura freemani), across the US Pacific Northwest. We first quantify insect effects on burn severity with spatial modeling at the fire event scale and then evaluate how these effects vary across the full population of insect-fire events (n = 81 spanning 1987-2011). In contrast to common assumptions of positive feedbacks, we find that insects generally reduce the severity of subsequent wildfires. Specific effects vary with insect type and timing, but both insects decrease the abundance of live vegetation susceptible to wildfire at multiple time lags. By dampening subsequent burn severity, native insects could buffer rather than exacerbate fire regime changes expected due to land use and climate change. In light of these findings, we recommend a precautionary approach when designing and implementing forest management policies intended to reduce wildfire hazard and increase resilience to global change.

  9. Edge effects in the primate community of the biological dynamics of Forest Fragments Project, Amazonas, Brazil.

    Science.gov (United States)

    Lenz, Bryan B; Jack, Katharine M; Spironello, Wilson R

    2014-11-01

    While much is known about abiotic and vegetative edge effects in tropical forests, considerably less is known about the impact of forest edges on large mammals. In this study, we examine edge effects in a primate community to determine: 1) the distance from the edge over which edge effects in primate density are detectable, 2) whether individual species exhibit edge effects in their density, and 3) whether biological characteristics can be used to predict primate presence in edge habitats. Given their importance to many primate species, we also examine the influence of the number of large trees. We found edge penetration distances of 150 m for the five species that experienced edge effects, suggesting that primates respond to edge-related changes in the plant community that are known to be strongest over the first 150 m. Four species had higher edge densities: Alouatta macconnelli (folivore-frugivore), Chiropotes chiropotes (frugivorous seed predator), Saguinus midas (frugivore-faunivore), and Sapajus apella apella (frugivore-faunivore); one species' density was lower: Ateles paniscus (frugivore); and the final species, Pithecia chrysocephala (frugivorous seed predator), did not show an edge-related pattern. The lone significant relationship between the biological characteristics examined (body weight, diet, group size, and home range size) and primate presence in edge habitats was a negative relationship with the amount of fruit consumed. Though we did not examine primate responses to edges that border a denuded matrix, we have shown that edges influence primate distribution even following decades of secondary forest regeneration at habitat edges. © 2014 Wiley Periodicals, Inc.

  10. Foliar growth of Eriocnema fulva Naudin (Melastomataceae in a forest fragment in southeastern Brazil

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    PM. Andrade

    Full Text Available Eriocnema fulva Naudin is an endangered herbaceous, perennial, iteroparous, evergreen species geographically restricted to southeastern-center Minas Gerais State, SE Brazil. The individuals occur as patches on rocky riverbanks shaded by seasonal semideciduous Atlantic forest; they are fixed by roots and have a pending stem. Aiming to investigate leaf development and its importance for individual survival, fifteen contiguous plots (1 x 1 m were set down in Jambreiro Forest (19° 58’-59’ S and 43° 52’-55’ W, 800-1100 m altitude, in the municipality of Nova Lima. A total of 260 individuals with the largest leaf blade length > 1 cm was tagged and measured in 1997, 1998, and 1999. Leaf expansion was recorded each month during 26 months until April 2000. Plant size was measured through leaf blade length, petiole length, stem length, and number of leaves. Significant changes were detected only after two years, thus indicating that plant growth is slow. The proportion of surviving leaves after two years was 60%. Total blade expansion took over 14 months, a slow growth rate when compared to leaves of other tropical forest canopy and understory species. Long leaf lifespans are to be found in plants exhibiting slow growth, and we observed that some leaves lived longer than three years. Petiole growth can help to better position the leaf in the search for light, thus contributing to the growth and survival of the plant. The relationships among size measures were significant, reinforcing the great contribution of leaf size for plant size. The age of the largest individual was estimated as 36 years based on the median annual leaf production rate.

  11. Foliar growth of Eriocnema fulva Naudin (Melastomataceae) in a forest fragment in southeastern Brazil.

    Science.gov (United States)

    Andrade, P M; Santos, F A M; Martins, F R

    2008-02-01

    Eriocnema fulva Naudin is an endangered herbaceous, perennial, iteroparous, evergreen species geographically restricted to southeastern-center Minas Gerais State, SE Brazil. The individuals occur as patches on rocky riverbanks shaded by seasonal semideciduous Atlantic forest; they are fixed by roots and have a pending stem. Aiming to investigate leaf development and its importance for individual survival, fifteen contiguous plots (1 x 1 m) were set down in Jambreiro Forest (19 degrees 58'-59' S and 43 degrees 52'-55' W, 800-1100 m altitude), in the municipality of Nova Lima. A total of 260 individuals with the largest leaf blade length > or = 1 cm was tagged and measured in 1997, 1998, and 1999. Leaf expansion was recorded each month during 26 months until April 2000. Plant size was measured through leaf blade length, petiole length, stem length, and number of leaves. Significant changes were detected only after two years, thus indicating that plant growth is slow. The proportion of surviving leaves after two years was 60%. Total blade expansion took over 14 months, a slow growth rate when compared to leaves of other tropical forest canopy and understory species. Long leaf lifespans are to be found in plants exhibiting slow growth, and we observed that some leaves lived longer than three years. Petiole growth can help to better position the leaf in the search for light, thus contributing to the growth and survival of the plant. The relationships among size measures were significant, reinforcing the great contribution of leaf size for plant size. The age of the largest individual was estimated as 36 years based on the median annual leaf production rate.

  12. Use of the space by the opossum Didelphis aurita Wied-Newied (Mammalia, Marsupialia in a mixed forest fragment of southern Brazil

    Directory of Open Access Journals (Sweden)

    Cáceres Nilton Carlos

    2003-01-01

    Full Text Available Use of the space by the opossum Didelphis aurita Wied-Newied, 1826 (Mammalia, Marsupialia in a mixed forest fragment of southern Brazil. The space use of the marsupial Didelphis aurita was studied in a forest fragment of southern Brazil from February 1995 to January 1996. The method used was the 'distribution utilization' in which each trap was set in 38 x 38 m quadrats. Captures of each marked individual in each point give information on its habitat use. Food availability was searched and compared to the habitat utilization and to the food consumption of opossums. Distribution patterns of captures (aggregated to random and spatial overlap between individuals were searched. Results showed aggregated distributions of individuals, particularly females, in the fragment. Females used exclusively the fragment during the drier season. Opossums tend to not choose the sites with highest food availability to establish home ranges. Spatial overlap was usually low between forest resident and neighbouring resident females, but much lower during the breeding season (only forest resident females in an apparently pattern of territoriality. Hence, core areas of females decreased in size during the breeding season. Males probably searched primarily for mates during the breeding season being less opportunistic than females in feeding habits, yet their space use did not correlate to food consumption.

  13. The utility of contemporary and historical estimates of dispersal in determining response to habitat fragmentation in a tropical forest-dependent bird community.

    Science.gov (United States)

    Bowie, Rauri C K

    2011-05-01

    It is often assumed that species which exhibit a greater propensity for dispersal are less susceptible to the impacts of habitat fragmentation; however, a growing body of literature suggests that such generalizations should be carefully evaluated as not all species appear to be equally sensitive to fragmentation. In this issue of Molecular Ecology, Callens et al. (2011) take an innovative approach to compare contemporary estimates of dispersal from an extensive mark-recapture and patch occupancy data set with historical estimates derived from multilocus population genetic models for seven sympatric forest-dependent species in the Taita Hills, Africa. As has been observed for forest-dependent species from the Amazon, populations of sedentary species were more strongly differentiated and clustered when compared to those of more dispersive taxa. The most intriguing result recovered though, was that the five species with similar historical estimates of gene flow (dispersal) differed substantially in their contemporary dispersal rates, suggesting that for some species the propensity for dispersal has decreased over time. As a consequence, the authors suggest that post-fragmentation estimates of dispersal on their own may not be the best predictors of how habitat fragmentation could affect forest-dependent animal communities.This work significantly advances our understanding of the dynamics of habitat fragmentation and makes a strong case for the need to integrate data on historical processes with contemporary data. © 2011 Blackwell Publishing Ltd.

  14. Synthesis of a tetrasaccharide fragment of hyaluronic acid having a glucuronic acid at the reducing end

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Slaghek, T.M.; Hyppönen, T.K.; Ogawa, T.; Kamerling, J.P.

    1993-01-01

    A stereocontrolled synthesis of a tetrasaccharide fragment of hyaluronic acid, beta-p-methoxyphenyl glycoside of beta-D-GlcNAc-(1¨4)-beta-D-GlcNAc-(1¨3)-beta-D-GlcNAc-(1¨4)-D-GlcA, is presented.

  15. Paying our way: thinking strategically to offset the cost of reducing fire hazard in western forests.

    Science.gov (United States)

    Rhonda Mazza

    2008-01-01

    The fire hazard in many western forests is unacceptably high, posing risks to human health and property, wildlife habitat, and air and water quality. Cost is an inhibiting factor for reducing hazardous fuel, given the amount of acreage needing treatment. Thinning overly dense forests is one way to reduce fuel loads. Much of the product removed during these treatments...

  16. Effect of selective logging on floristic and structural composition in a forest fragment from Amazon Biome

    Directory of Open Access Journals (Sweden)

    Karen Janones da Rocha

    2017-04-01

    Full Text Available This study was conducted in one region of a Seasonal Semideciduous Forest located in Tapurah (Mato Grosso State, Brazil with the aim of studying its floristic and structural composition. The fixed area method was applied to 10 × 250 m clusters, allocating and measuring five clusters with five subunits of 500 m² each. Species with a diameter at breast height greater than or equal to 10 cm were considered, and the sample sufficiency of the floristic survey was verified by a species accumulation curve. The similarities between the sample subunits were calculated by the Jaccard Similarity Index, and the species diversity with the Shannon Diversity Index and Pielou Evenness Index. The horizontal vegetation structure was characterized by density, frequency, dominance and the values of ecological importance, and diametric distribution were assessed by the Spiegel procedure. The families Vochysiaceae, Fabaceae and Sapindaceae were highly represented, and Qualea paraensis, Aspidosperma discolor and Matayba arborescens were the most important species. A high diversity and low ecological dominance were found, and the diametric structure of the trees presented a negative exponential distribution. In general, the structure, floristic composition and richness of vegetation correspond to a forest with stable and autoregenerative community after selective logging.

  17. Comparison of phytosociological parameters among three strata of a fragment of ombrophylous mixed forest

    Directory of Open Access Journals (Sweden)

    Sebastião do Amaral Machado

    2013-09-01

    Full Text Available Phytosociological studies based on sampling have been very common in the last 20 years, however, they are rarely carried out using complete enumeration of trees (census. This research compare the phytossociological parameters between three different strata from a remnant of Ombrophylous Mixed Forest (OMF, which are: OMF Montana, Border OMF Montana and OMF Alluvial. The area of 13.71 was topographically divided in blocks of 50 x 50 meters for a better control of the 100% forest inventory (census. All trees with CBH (circumference measured at 1,30 m above ground ≥ 31,5 centimeters were measured, georeferencied, numbered, painted at DBH and identified at species level. In the strata OMF Montana the species with the highest Value of Coverage (VC was Araucaria angustifolia, with 30.6%, followed by Casearia sylvestris with 25.8%. In the Border OMF Montana the species that succeeded Araucaria angustifolia (29.0% was Gochnatia polymorpha with 27.2% of VC. The third strata, OMF Alluvial, presented as predominant species Schinus terebinthifolius (55,5%, followed by Sebastiania commersoniana (27,7%, both characteristics of alluvial environments. In the three strata there was prevalence of secondary pioneer species, proving that the area is in a secondary stage of ecological succession due to past exploratory process.

  18. Quantification of litter in the forest fragment national park Serra de Itabaiana, Sergipe State

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    Audenis Fagner de Jesus Nascimento

    2013-12-01

    Full Text Available Natural forests are areas rich in biodiversity that contribute to the maintenance of environmental sustainability through the production of litter and nutrient cycling. Litter is a major route of nutrient return to the system plant – soil – plant and its determination to analyze the restructuring of anthropogenic forest environments. The knowledge of litterfall is critical to determine the potential for regeneration of an area through the intake and nutrient cycling. We quantified litter production in areas of white sand with vegetation in different stages of regeneration the National Park Sierra de Itabaiana, Sergipe State. In each of the areas of white sands open (ABA, white sands intermediary (ABI and white sands closed (ABF was installed 15 litter traps and litter fall was collected monthly from January to December 2011. The total contribution of litter on the White Sand Closed (2092 kg ha-1 was more than double the contribution in Areia Branca Open (881 kg ha-1 and White Sand Intermediate (687 kg ha-1. The leaf fraction contributed the largest mass in all areas and periods, and was the one with greater seasonal variation related to variation in precipitation. Precipitation was one of the factors that determined the seasonality of litter deposition in natural vegetation of the National Park of Sierra de Itabaiana, Sergipe State.

  19. Litter production and seed rain in semideciduous forest fragments at different successional stages in the western part of the state of Paraná, Brazil

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    Maria Angélica Gonçalves Toscan

    2014-09-01

    Full Text Available We documented litter production and seed rain in fragments of semideciduous forest (SDF in the western part of the state of Paraná, Brazil: a late successional fragment (LF; an early successional fragment (EF; and a reforested late successional fragment (RLF. In each fragment, we established three permanent plots with four litter traps each, corresponding to 12 litter traps per fragment. Botanical material was collected monthly between June 2011 and May 2012. We sorted the material by category: leaves; branches; reproductive structures; and miscellaneous. We analyzed the seed rain using the reproductive structures. Annual production was highest (11,560 kg.ha-1 in the LF, followed by the RLF, with 9330 kg.ha-1, and the EF, with 7838 kg.ha-1. The RLF yielded 7167 diaspores, from 33 species, compared with 4751 diaspores, from 38 species, for the EF; in both fragments, pioneer and anemochorous species predominated. The LF yielded 2173 diaspores, from 49 species, among which late secondary and climax species with zoochorous dispersal predominated. We observed asynchrony in the frequency of diaspore production of trees and lianas. Our data describe the dynamics of plant assemblages in SDF fragments and provide information on successional stages, dispersion syndromes, patterns of asynchrony, deciduousness, reproductive periods, and resource availability for frugivores.

  20. Climate Change Mitigation Through Reduced-Impact Logging and the Hierarchy of Production Forest Management

    Directory of Open Access Journals (Sweden)

    Ben Vickers

    2012-01-01

    Full Text Available The proposed hierarchy of production forest management provides modus operandi for forest concessions to move incrementally towards Sustainable Forest Management (SFM via Reduced-Impact Logging (RIL and forest certification. Financial benefits are sourced in the “Additionality Zone”, financing the rise in the hierarchy and offsetting prohibitive forest and carbon certification costs. RIL carbon registration components consist of developing credible baseline, additionality and leakage arguments around the business-as-usual scenario through the quantification of historical forest inventory and production records, forest infrastructure records and damage to the residual forest. If conventional harvesting is taken as a baseline, research indicates RIL can potentially reduce emissions by approximately 1–7 tCO2e ha−1yr−1. The current market price of USD $7.30 per tCO2e may result in over USD $50 ha−1yr−1 in additional revenue, well above the estimated USD $3–5 ha−1 in carbon transaction costs. Concessions in Sabah Malaysia demonstrate the financial viability of long-term RIL and certification planning. This may act as a basis for future planned forest management activities involving RIL, carbon and forest certification through the hierarchy of production forest management.

  1. Portable in-woods pyrolysis: Using forest biomass to reduce forest fuels, increase soil productivity, and sequester carbon

    Science.gov (United States)

    Deborah Page-Dumroese; Mark Coleman; Greg Jones; Tyron Venn; R. Kasten Dumroese; Nathanial Anderson; Woodam Chung; Dan Loeffler; Jim Archuleta; Mark Kimsey; Phil Badger; Terry Shaw; Kristin McElligott

    2009-01-01

    We describe the use of an in-woods portable pyrolysis unit that converts forest biomass to bio-oil and the application of the byproduct bio-char in a field trial. We also discuss how in-woods processing may reduce the need for long haul distances of lowvalue woody biomass and eliminate open, currently wasteful burning of forest biomass. If transportation costs can be...

  2. Pegylated Trastuzumab Fragments Acquire an Increased in Vivo Stability but Show a Largely Reduced Affinity for the Target Antigen

    Directory of Open Access Journals (Sweden)

    Fabio Selis

    2016-04-01

    Full Text Available PEGylation of biomolecules is a major approach to increase blood stream half-life, stability and solubility of biotherapeutics and to reduce their immunogenicity, aggregation potential and unspecific interactions with other proteins and tissues. Antibodies have generally long half-lives due to high molecular mass and stability toward proteases, however their size lowers to some extent their potential because of a reduced ability to penetrate tissues, especially those of tumor origin. Fab or otherwise engineered smaller fragments are an alternative but are less stable and are much less well retained in circulation. We have here investigated the effects of various PEGylations on the binding properties and in vivo half-life of Fab fragments derived from the enzymatic splitting of Trastuzumab. We find that PEGylation increases the half-life of the molecules but also strongly affects the ability to recognize the target antigen in a way that is dependent on the extent and position of the chemical modification. Data thus support the concept that polyethylene glycol (PEG conjugation on Trastuzumab Fabs increases half-life but reduces their affinity and this is a fine balance, which must be carefully considered for the design of strategies based on the use of antibody fragments.

  3. Pegylated Trastuzumab Fragments Acquire an Increased in Vivo Stability but Show a Largely Reduced Affinity for the Target Antigen

    Science.gov (United States)

    Selis, Fabio; Focà, Giuseppina; Sandomenico, Annamaria; Marra, Carla; Di Mauro, Concetta; Saccani Jotti, Gloria; Scaramuzza, Silvia; Politano, Annalisa; Sanna, Riccardo; Ruvo, Menotti; Tonon, Giancarlo

    2016-01-01

    PEGylation of biomolecules is a major approach to increase blood stream half-life, stability and solubility of biotherapeutics and to reduce their immunogenicity, aggregation potential and unspecific interactions with other proteins and tissues. Antibodies have generally long half-lives due to high molecular mass and stability toward proteases, however their size lowers to some extent their potential because of a reduced ability to penetrate tissues, especially those of tumor origin. Fab or otherwise engineered smaller fragments are an alternative but are less stable and are much less well retained in circulation. We have here investigated the effects of various PEGylations on the binding properties and in vivo half-life of Fab fragments derived from the enzymatic splitting of Trastuzumab. We find that PEGylation increases the half-life of the molecules but also strongly affects the ability to recognize the target antigen in a way that is dependent on the extent and position of the chemical modification. Data thus support the concept that polyethylene glycol (PEG) conjugation on Trastuzumab Fabs increases half-life but reduces their affinity and this is a fine balance, which must be carefully considered for the design of strategies based on the use of antibody fragments. PMID:27043557

  4. A degradation debt? Large-scale shifts in community composition and loss of biomass in a tropical forest fragment after 40 years of isolation.

    Directory of Open Access Journals (Sweden)

    Rakan A Zahawi

    Full Text Available Habitat loss and fragmentation are among the biggest threats to tropical biodiversity and associated ecosystem services. We examined forest dynamics in a mid-elevation 365-ha fragment in southern Costa Rica. The fragment was isolated in the mid-1970s and belongs to the Las Cruces Biological Station. A 2.25-ha permanent plot was established in the center of the old-growth forest (>400 m to nearest edge boundary and all plants >5 cm DBH were censused, mapped, and identified to species in two surveys taken ~5-6 years apart (>3,000 stems/survey. Although the reserve maintains high species richness (>200 spp., with many rare species represented by only one individual, we document a strong shift in composition with a two-fold increase in the number of soft-wooded pioneer individuals. The dominant late-successional understory tree species, Chrysochlamys glauca (Clusiaceae, and most species in the Lauraceae, declined dramatically. Turnover was high: 22.9% of stems in the first survey were lost, and 27.8% of stems in the second survey represented new recruits. Mean tree diameter decreased significantly and there was a 10% decrease in overall biomass. Such alteration has been documented previously but only in smaller fragments or within ~100 m of an edge boundary. Further penetration into this fragment was perhaps driven by a progressive invasion of disturbance-adapted species into the fragment's core over time; the loss of once-dominant late successional species could be a contributing factor. The pattern found is of particular concern given that such fragments represent a substantial portion of today's remaining tropical habitat; further studies in similar-sized fragments that have been isolated for similar prolonged periods are called for.

  5. Autoecology of Dryadosaura nordestina (Squamata: Gymnophthalmidae from Atlantic forest fragments in Northeastern Brazil

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    Adrian A. Garda

    2014-10-01

    Full Text Available Life history parameters such as diet, reproduction, and sexual dimorphism are crucial to understand ecological and evolutionary forces shaping species traits. Nevertheless, such information is scant in the literature for most Neotropical squamates. Gymnophthalmidae contains over 242 species in 46 genera and includes small-size, mostly terrestrial species, although psamophilic, semi-aquatic, and low vegetation dwellers also occur. Dryadosaura is a monospecific genus - Dryadosaura nordestina Rodrigues et al., 2005 - , occurring in Atlantic Forest areas from Rio Grande do Norte to Northern Bahia, and little is known about its ecology and natural history. We analyzed the species' diet, reproduction, and sexual dimorphism based on 170 specimens deposited in museum collections. Dryadosaura nordestina is considered generalist and active forager, based on dietary items. Arthropods, especially ants and insect larvae, dominate the diet. The reproductive period shows a peak during the rainy season (May through June, while recruitment occurs from July through November. Males are significantly larger than females, and sexes can also be distinguished based on shape variables: males have higher heads and longer bodies, while body height and width are larger in females.

  6. Ectoparasites of bats (Mammalia: Chiroptera) in Atlantic forest fragments in north-eastern Brazil.

    Science.gov (United States)

    Bezerra, Rayanna Hellem Santos; de Vasconcelos, Pedro Fonseca; Bocchiglieri, Adriana

    2016-10-01

    In Brazil, most studies involving parasites of bats (bat flies) treat the mid-west, south-east, and south of the country. This work aimed to characterize the ectoparasites community associated with bats in the Atlantic forest in the state of Sergipe, north-eastern Brazil. Sampling was conducted between January and June 2013 in the Serra de Itabaiana National Park (PNSI) and between November 2013 and June 2015 in the Wildlife Refuge Mata do Junco (RVSMJ). Parasitological indexes were determined, and the influence of host sex and the seasonality in prevalence rates and mean intensity for the most abundant parasites was evaluated. Some 129 parasites were collected in PNSI and 296 in RVSMJ, and 100 and 70.6 %, respectively, belong to the family Streblidae. The differences in parasitological rates in Sergipe in relation to other studies may be associated with the environmental characteristics and the composition of the host community. The influence of sex and the seasonal prevalence of Speiseria ambigua and Trichobius joblingi, associated with Carollia perspicillata, may be associated with a lower rate of female captures and low sampling in the dry season. This is a pioneer study in Sergipe that reveals the occurrence of 16 species of streblids and representatives of Acari and Basilia spp., highlighting the need for more studies to increase the wealth and understanding of host-parasite associations in the state.

  7. Edge effects on moisture reduce wood decomposition rate in a temperate forest.

    Science.gov (United States)

    Crockatt, Martha E; Bebber, Daniel P

    2015-02-01

    Forests around the world are increasingly fragmented, and edge effects on forest microclimates have the potential to affect ecosystem functions such as carbon and nutrient cycling. Edges tend to be drier and warmer due to the effects of insolation, wind, and evapotranspiration and these gradients can penetrate hundreds of metres into the forest. Litter decomposition is a key component of the carbon cycle, which is largely controlled by saprotrophic fungi that respond to variation in temperature and moisture. However, the impact of forest fragmentation on litter decay is poorly understood. Here, we investigate edge effects on the decay of wood in a temperate forest using an experimental approach, whereby mass loss in wood blocks placed along 100 m transects from the forest edge to core was monitored over 2 years. Decomposition rate increased with distance from the edge, and was correlated with increasing humidity and moisture content of the decaying wood, such that the decay constant at 100 m was nearly twice that at the edge. Mean air temperature decreased slightly with distance from the edge. The variation in decay constant due to edge effects was larger than that expected from any reasonable estimates of climatic variation, based on a published regional model. We modelled the influence of edge effects on the decay constant at the landscape scale using functions for forest area within different distances from edge across the UK. We found that taking edge effects into account would decrease the decay rate by nearly one quarter, compared with estimates that assumed no edge effect. © 2014 John Wiley & Sons Ltd.

  8. Edge effects and landscape matrix use by a small mammal community in fragments of semideciduous submontane forest in Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    M. Santos-Filho

    Full Text Available A community of small mammals was studied in seasonal semideciduous submontane forest in the state of Mato Grosso, Brazil. This study evaluated the use of edge and matrix pasture, by different small mammal species. Overall, 31 areas were studied, with a total sampling effort of 33,800 trap x nights. Only seven of the 25 species captured in the study sites were able to use the pasture matrix; we classified these species as generalists. Fourteen species were found to be intermediate in habits, being able to use forest edges. We found only four species habitat specialists, occurring only on transect lines in the interior of the fragment, at least 150 m from the edge. Transects located in the pasture matrix and 50 m from the edge had significantly lower species richness and abundance than transects located in the fragment edge or in the interior of the fragment. All transects located within the fragment had similar species richness and abundance, but transects located 50 m from the edge had slightly lower, but non-significant, species richness than transects located 100 m apart from edges. Rarefaction curves demonstrated that only medium-sized fragments (100 300 ha reached an asymptote of species accumulation. The other areas require further sampling, or more sampling transect, before species accumulation curves stabilize, due to a continued increase in species number.

  9. Fuels planning: Managing forest structure to reduce fire hazard

    Science.gov (United States)

    David L. Peterson; Morris C. Johnson; James K. Agee; Theresa B. Jain; Donald McKenzie; Elizabeth D. Reinhardt

    2003-01-01

    Prior to the 20th century, low intensity fires burned regularly in most arid to semiarid forest ecosystems, with ignitions caused by lightning and humans (e.g., Baisan and Swetnam 1997, Allen et al. 2002, Hessl et al. 2004). Low intensity fires controlled regeneration of fire sensitive (e.g., grand fir [Abies grandis]) species (Arno and Allison-Bunnell 2002), promoted...

  10. Towards reduced herbicide use in forest vegetation management ...

    African Journals Online (AJOL)

    Mechanical, manual, thermal, biological and chemical methods of managing forest vegetation have, to a large extent, been developed independently. The effectiveness and relatively low cost of chemical herbicides, however, have led to systems of vegetation management that rely on their continued availability and the near ...

  11. Increased chromatin fragmentation and reduced acrosome integrity in spermatozoa of red deer from lead polluted sites.

    Science.gov (United States)

    Castellanos, Pilar; del Olmo, Enrique; Fernández-Santos, M Rocío; Rodríguez-Estival, Jaime; Garde, J Julián; Mateo, Rafael

    2015-02-01

    Vertebrates are constantly exposed to a diffuse pollution of heavy metals existing in the environment, but in some cases, the proximity to emission sources like mining activity increases the risk of developing adverse effects of these pollutants. Here we have studied lead (Pb) levels in spermatozoa and testis, and chromatin damage and levels of endogenous antioxidant activity in spermatozoa of red deer (Cervus elaphus) from a Pb mining area (n=37) and a control area (n=26). Deer from the Pb-polluted area showed higher Pb levels in testis parenchyma, epididymal cauda and spermatozoa, lower values of acrosome integrity, higher activity of glutathione peroxidase (GPx) and higher values of DNA fragmentation (X-DFI) and stainability (HDS) in sperm than in the control area. These results indicate that mining pollution can produce damage on chromatin and membrane spermatozoa in wildlife. The study of chromatin fragmentation has not been studied before in spermatozoa of wildlife species, and the sperm chromatin structure assay (SCSA) has been revealed as a successful tool for this purpose in species in which the amount of sperm that can be collected is very limited. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    Science.gov (United States)

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. © 2013 John Wiley & Sons Ltd.

  13. Diversity in forest management to reduce wildfire losses: implications for resilience

    Science.gov (United States)

    Susan Charnley; Thomas A. Spies; Ana M. G. Barros; Eric M. White; Keith A. Olsen

    2017-01-01

    This study investigates how federal, state, and private corporate forest owners in a fire-prone landscape of southcentral Oregon manage their forests to reduce wildfire hazard and loss to high-severity wildfire. We evaluate the implications of our findings for concepts of social–ecological resilience. Using interview data, we found a high degree of "response...

  14. Diversity and distribution of coccidia of wild birds in an Atlantic forest fragment area in southeastern Brazil.

    Science.gov (United States)

    Oliveira, Patrícia Silva de; Ferreira, Matheus Alexandre; Silva, Lidiane Maria da; Rodrigues, Mariana Borges; Cardozo, Sergian Vianna; Berto, Bruno Pereira

    2017-01-01

    Coccidia are protozoan parasites that are frequently observed in fecal samples from wild birds, and they are extremely important for biodiversity, host specificity and conservation. The aim of the present study was to identify and quantify the coccidian species from wild birds caught in a fragmented area of Atlantic Forest in the municipality of Guapimirim in the state of Rio de Janeiro, which is located around the Serra dos Órgãos National Park. A total of 101 birds were caught and identified. The highest prevalence and density were observed in the family Columbidae (Columbiformes). Among the families of Passeriformes, the highest prevalences and densities were of birds in the families Thraupidae and Turdidae. The majority of the positive samples and those with higher densities were collected in the afternoons. Eleven coccidian species of Isospora and Eimeria were identified. Seven of these species that were morphologically identified are undescribed in the scientific literature and are believed to be new species. The present study highlights the wide distribution and dispersion of coccidia of wild birds in southeastern Brazil, and records the municipality of Guapimirim, in the state of Rio de Janeiro, as a new locality for parasitism, along with the new hosts recorded.

  15. Diversity and distribution of coccidia of wild birds in an Atlantic forest fragment area in southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Silva de Oliveira

    2017-10-01

    Full Text Available Abstract Coccidia are protozoan parasites that are frequently observed in fecal samples from wild birds, and they are extremely important for biodiversity, host specificity and conservation. The aim of the present study was to identify and quantify the coccidian species from wild birds caught in a fragmented area of Atlantic Forest in the municipality of Guapimirim in the state of Rio de Janeiro, which is located around the Serra dos Órgãos National Park. A total of 101 birds were caught and identified. The highest prevalence and density were observed in the family Columbidae (Columbiformes. Among the families of Passeriformes, the highest prevalences and densities were of birds in the families Thraupidae and Turdidae. The majority of the positive samples and those with higher densities were collected in the afternoons. Eleven coccidian species of Isospora and Eimeria were identified. Seven of these species that were morphologically identified are undescribed in the scientific literature and are believed to be new species. The present study highlights the wide distribution and dispersion of coccidia of wild birds in southeastern Brazil, and records the municipality of Guapimirim, in the state of Rio de Janeiro, as a new locality for parasitism, along with the new hosts recorded.

  16. USE OF THE DE LIOCOURT QUOTIENT IN THE EVALUATION OF THE DIAMETRIC DISTRIBUTION IN FRAGMENTS OF OMBROPHYLOUS FOREST, PERNAMBUCO STATE-BRAZIL

    Directory of Open Access Journals (Sweden)

    Francisco Tarcísio Alves Junior

    2010-08-01

    Full Text Available Great part of the biodiversity of the ecosystem of tropical forests is being lost even before we have full knowledge of its natural wealth, making it important perform studies that can provide knowledge and the maintenance of its structure, besides making possible the exploration of its products, goods and/or services in a planned and rational form, guaranteeing the continuous flow of these resources. The general objective of this study was to use the De Liocourt quotient in the evaluation of the diametric distribution in fragments of Ombrophylous Forest located in the city of Catende, Pernambuco state - Brazil, having as specific objectives: to describe the diametric structure of the fragments and the species of greater importance using the Value of Importance Index (VI; and to evaluate the degradation and the state of succession of the studied areas. The diametric distribution revealed uneven-aged forests as the diametric curve of distribution resembled a reverse J-shape. The values of basal area in the fragments were of 23.6 and 20.9 m2.ha-1, for Mata das Caldeiras and Mata das Galinhas. The fragments were, on average, in the secondary period of succession. Some species presented difficulties in the rate of recruitment, which could lead to the extinguishing of some species in the future. Species, such as Tapirira guianensis Aubl., Dialium guianense (Aubl. Sandwith and Brosimum discolor Schott, demonstrated a distinct diametric structure among the fragments. The species Plathymenia foliolosa Benth. presented accented discontinuities in the diametric structure in both areas.

  17. Dung decomposition and associated beetles in a fragmented temperate forest Descomposición de heces y sus coleópteros asociados en un bosque templado fragmentado

    Directory of Open Access Journals (Sweden)

    MARCELA A. BUSTAMANTE-SÁNCHEZ

    2004-03-01

    Full Text Available Habitat fragmentation may result in changes in species number and population abundance among habitats that differ in area, structure, or edge characteristics. These changes, in turn, may result in alterations in ecosystem process such as decomposition of organic matter. Through an experimental approach, we compared the beetles assemblages associated with dung and decomposition of cow feces in a continuous portion of Maulino forest, forest fragments and in pine plantations that surround this forest and forest remnants. Abundance and richness of dung-associated beetles were lower in forest fragments compared to the continuous forest and pine plantations. However, dung decomposition was similar in these three habitats. Beetle abundance, species richness and decomposition did not vary along edges of forest fragments and pine plantations, but beetle abundance and decomposition rate varied on the border compared to the interior of the continuous forest. Thus, although beetle assemblage changes across the fragmented landscape, these variations in species richness and abundance did not translate into alterations of an ecosystem process such as dung-decomposition, as occurs in tropical forests. The beetle assemblage at pine plantations comprises only native species and dung decomposition was similar in both fragments and continuous forest. Therefore, pine plantations maintain at least partially the structural and functional biodiversity of the native fauna, connecting the native remnants throughout the landscape, a crucial factor in biodiversity conservationLa fragmentación del hábitat puede cambiar el número de especies y la abundancia poblacional entre hábitats que difieren en área, estructura o en las características del borde. Estos cambios, a su vez, pueden alterar procesos ecosistémicos como la descomposición de la materia orgánica. A través de una aproximación experimental, comparamos un ensamble de coleópteros asociados a heces y la

  18. Reducing fragmentation in the care of frail older people: the successful development and implementation of the Health and Welfare Information Portal

    NARCIS (Netherlands)

    Robben, S.H.M.; Heinen, M.M.; Makai, P.; Olde Rikkert, M.G.M.; Perry, M.; Schers, H.J.; Melis, R.J.F.

    2013-01-01

    REDUCING FRAGMENTATION IN THE CARE OF FRAIL OLDER PEOPLE: THE SUCCESSFUL DEVELOPMENT AND IMPLEMENTATION OF THE HEALTH AND WELFARE INFORMATION PORTAL: Our fragmented health care systems are insufficiently equipped to provide frail older people with high quality of care. Therefore, we developed the

  19. [Reducing fragmentation in the care of frail older people: the successful development and implementation of the Health and Welfare Information Portal].

    NARCIS (Netherlands)

    Robben, S.H.M.; Heinen, M.M.; Makai, P.; Olde Rikkert, M.G.M.; Perry, M.; Schers, H.J.; Melis, R.J.F.

    2013-01-01

    REDUCING FRAGMENTATION IN THE CARE OF FRAIL OLDER PEOPLE: THE SUCCESSFUL DEVELOPMENT AND IMPLEMENTATION OF THE HEALTH AND WELFARE INFORMATION PORTAL: Our fragmented health care systems are insufficiently equipped to provide frail older people with high quality of care. Therefore, we developed the

  20. Colloidal centrifugation of stallion semen results in a reduced rate of sperm DNA fragmentation.

    Science.gov (United States)

    Crespo, F; Gosalvez, J; Gutiérrez-Cepeda, L; Serres, C; Johnston, S D

    2013-04-01

    Stallion spermatozoa recovered and examined immediately after colloidal centrifugation resulted in a higher straight-line velocity (VSL) than sperm processed using direct conventional centrifugation (p = 0.000), but there was no differences in the progressive motility or sperm DNA fragmentation (SDF) as determined by the sperm chromatin dispersion assay. However, when centrifuged spermatozoa were incubated at 37 °C for 24 h to determine the rate of SDF (r-SDF), a lower r-SDF (p = 0.0011) was observed in those sperm recovered after colloidal separation (0.5 ± 0.1%/h) compared to direct (1.2 ± 0.4%/h) or no centrifugation (r-SDF = 1.2 ± 0.3%/h). These results confirm that colloidal separation of stallion spermatozoa results in prolonged sperm DNA longevity, but these differences were only apparent following a period of incubation and dynamic assessment. Consequently, we strongly recommend the use of the dynamic form of the SDF assay for evaluating centrifugation and/or other ex vivo procedures, as a single basal assessment of SDF may inadvertently result in a false-positive evaluation of DNA quality. © 2012 Blackwell Verlag GmbH.

  1. Diversity in forest management to reduce wildfire losses: implications for resilience

    Directory of Open Access Journals (Sweden)

    Susan Charnley

    2017-03-01

    Full Text Available This study investigates how federal, state, and private corporate forest owners in a fire-prone landscape of southcentral Oregon manage their forests to reduce wildfire hazard and loss to high-severity wildfire. We evaluate the implications of our findings for concepts of social-ecological resilience. Using interview data, we found a high degree of "response diversity" (variation in forest management decisions and behaviors to reduce wildfire losses between and within actor groups. This response diversity contributed to heterogeneous forest conditions across the landscape and was driven mainly by forest management legacies, economics, and attitudes toward wildfire (fortress protection vs. living with fire. We then used an agent-based landscape model to evaluate trends in forest structure and fire metrics by ownership. Modeling results indicated that, in general, U.S. Forest Service management had the most favorable outcomes for forest resilience to wildfire, and private corporate management the least. However, some state and private corporate forest ownerships have the building blocks for developing fire-resilient forests. Heterogeneity in social-ecological systems is often thought to favor social-ecological resilience. We found that despite high social and ecological heterogeneity in our study area, most forest ownerships do not exhibit characteristics that make them resilient to high-severity fire currently or in the future under current management. Thus, simple theories about resilience based on heterogeneity must be informed by knowledge of the environmental and social conditions that comprise that heterogeneity. Our coupled human and natural systems (CHANS approach enabled us to understand connections among the social, economic, and ecological components of a multiownership, fire-prone ecosystem, and to identify how social-ecological resilience to wildfire might improve through interventions to address key constraints in the system. Our

  2. Building capacity for national carbon measurements for reducing emissions from deforestation and forest degradation

    Science.gov (United States)

    Goetz, S. J.; Laporte, N.; Horning, N.; Pelletier, J.; Jantz, P.; Ndunda, P.

    2014-12-01

    Many tropical countries are now working on developing their strategies for reducing emissions from deforestation and forest degradation, including activities that result in conservation or enhancement of forest carbon stocks and sustainable management of forests to effectively decrease atmospheric carbon emissions (i.e. REDD+). A new international REDD+ agreement is at the heart of recent negotiations of the parties to the UN Framework Convention on Climate Change (UNFCCC). REDD+ mechanisms could provide an opportunity to not only diminish an important source of emissions, but also to promote large-scale conservation of tropical forests and establish incentives and opportunities to alleviate poverty. Most tropical countries still lack basic information for developing and implementing their forest carbon stock assessments, including the extent of forest area and the rate at which forests are being cleared and/or degraded, and the carbon amounts associated with these losses. These same countries also need support to conduct integrated assessments of the most promising approaches for reducing emissions, and in identifying those policy options that hold the greatest potential while minimizing potential negative impacts of REDD+ policies. The WHRC SERVIR project in East Africa is helping to provide these data sets to countries via best practice tools and methods to support cost effective forest carbon monitoring solutions and more informed decision making processes under REDD+. We will present the results of our capacity building activites in the region and planned future efforts being coordinated with the NASA-SERVIR Hub in Kenya to support to REDD+ decision support.

  3. Methods to Reduce Forest Residue Volume after Timber Harvesting and Produce Black Carbon

    Directory of Open Access Journals (Sweden)

    Deborah S. Page-Dumroese

    2017-01-01

    Full Text Available Forest restoration often includes thinning to reduce tree density and improve ecosystem processes and function while also reducing the risk of wildfire or insect and disease outbreaks. However, one drawback of these restoration treatments is that slash is often burned in piles that may damage the soil and require further restoration activities. Pile burning is currently used on many forest sites as the preferred method for residue disposal because piles can be burned at various times of the year and are usually more controlled than broadcast burns. In many cases, fire can be beneficial to site conditions and soil properties, but slash piles, with a large concentration of wood, needles, forest floor, and sometimes mineral soil, can cause long-term damage. We describe several alternative methods for reducing nonmerchantable forest residues that will help remove excess woody biomass, minimize detrimental soil impacts, and create charcoal for improving soil organic matter and carbon sequestration.

  4. Partitioning of seed dispersal services between birds and bats in a fragment of the Brazilian Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Raissa Sarmento

    2014-06-01

    Full Text Available Community-level network studies suggest that seed dispersal networks may share some universal properties with other complex systems. However, most of the datasets used so far in those studies have been strongly biased towards temperate birds, including not only dispersers, but also seed predators. Recent evidence from multi-taxon networks suggests that seed dispersal networks are not all alike and may be more complex than previously thought. Here, we used network theory to evaluate seed dispersal in a strongly impacted Atlantic Forest fragment in northeastern Brazil, where bats and birds are the only extant dispersers. We hypothesized that the seed dispersal network should be more modular then nested, and that the dispersers should segregate their services according to dispersal syndromes. Furthermore, we predicted that bat and bird species that are more specialized in frugivory would be more important for maintaining the network structure. The mixed network contained 56 plant species, 12 bat species, and eight bird species, and its structure was more modular (M = 0.58 then nested (NODF = 0.21 compared with another multi-taxon network and 21 single-taxon networks (with either bats or birds. All dispersed fruits had seeds smaller than 9 mm. Bats dispersed mainly green fruits, whereas birds dispersed fruits of various colors. The network contained eight modules: five with birds only, two with bats only, and one mixed. Most dispersers were peripheral, and only specialized frugivores acted as hubs or connectors. Our results strongly support recent studies, suggesting that seed dispersal networks are complex mosaics, where different taxa form separate modules with different properties, which in turn play complementary roles in the maintenance of the associated ecosystem functions and services.

  5. Microhabitat use of the western black-crested gibbon inhabiting an isolated forest fragment in southern Yunnan, China: implications for conservation of an endangered species.

    Science.gov (United States)

    Ni, Qingyong; Liang, Zongli; Xie, Meng; Xu, Huailiang; Yao, Yongfang; Zhang, Mingwang; Li, Yan; Li, Ying; Jiang, Xuelong

    2018-01-01

    Due to the synergistic effects of hunting and habitat loss, populations of the western black-crested gibbon are currently restricted to isolated forest fragments. The home range use of this species in fragmented forests is presumptively related to spatial, food and vegetation attributes, as in other primates. We examined the distributions of different food resources, the structure of the vegetation (tree density, DBH, and height), and the microhabitat use of one gibbon group in an isolated and disturbed forest at Bajiaohe in southern Yunnan, China. The results indicated that the gibbons used the edge habitat frequently, which was subject to more anthropogenic disturbance than the interior forest, and they appeared to adapt to discontinuous canopy cover by using bamboo and tsaoko plants for travel. The group also modified its diet in response to fluctuations in food availability and the local flora. However, the gibbons intensively used areas with high tree fruit availability across the two study periods. It is suggested that the microhabitat use by the group was mostly affected by the distribution of particular food resources and canopy gaps caused by selective logging. Protecting the current distribution area and planting native important food species to boost habitat quality and connectivity should be considered as part of conservation plans of the western black crested gibbon living in limited areas.

  6. Strategic choices: Swedish climate intervention policies and the forest industry's role in reducing CO2 emissions

    International Nuclear Information System (INIS)

    Nystroem, Ingrid; Cornland, Deborah W.

    2003-01-01

    Given adequate incentive, the forest industry could play a significant role in achieving Swedish objectives for reducing CO 2 emissions. Whether or not this potential can be harnessed depends on the types of energy policy interventions that are introduced. An analysis of the potential impacts of four policy-intervention strategies on the forest industry is presented in this article. The focus of the analysis is on the four strategies' impacts on forest industry electricity demand from, and renewable energy supply to, the energy system. The strategies analyzed include a reference strategy and strategies targeting electricity production, transportation and the energy system as a whole. The method applied combines scenario analysis with systems engineering modeling. Separate scenario sets were used to reflect visions of development from the forest industry and the energy sector. Separate models were used to enable a more in-depth analysis of the forest industry's role than is commonly the case in energy systems engineering studies

  7. Sustainable forest management of tropical forests can reduce carbon emissions and stabilize timber production

    Science.gov (United States)

    N. Sasaki; G.P. Asner; Yude Pan; W. Knorr; P.B. Durst; H.O. Ma; I. Abe; A.J. Lowe; L.P. Koh

    2016-01-01

    The REDD+ scheme of the United Nations Framework Conventionon Climate Change has provided opportunities to manage tropical forests for timber production and carbon emission reductions. To determine the appropriate loggingtechniques, we analyzed potential timber production and carbon emission reductions under two logging techniques over a 40-year period of selective...

  8. Exotic Invasive Shrub Glossy Buckthorn Reduces Restoration Potential for Native Forest Herbs

    Directory of Open Access Journals (Sweden)

    Caroline Hamelin

    2017-02-01

    Full Text Available Invasive glossy buckthorn could reduce restoration potential for understory native forest herbs by compromising their growth and biodiversity. Few studies of glossy buckthorn’s effects on forest herbs exist, and none were done in early-successional, partially open hardwood forests. This study was conducted in a mature hybrid poplar plantation invaded by buckthorn, located in southeastern Québec. We tested the effect of buckthorn removal on the growth of three forest herb species, whether this effect varied among species, and if canopy type (two poplar clones influenced this effect. Forest herbs were planted in herbicide (buckthorn removed and control treatments in the plantation understory, an environment similar to that of early-successional hardwood forests. Over the first two growing seasons, species showed specific reactions to buckthorn cover. Mean relative growth rate (RGR for Asarum canadense and Polygonatum pubescens was increased in the herbicide treatment (48% and 33%, respectively and decreased in the control treatment (−35% and −33%, respectively. Sanguinaria canadensis growth was the highest among species, with no difference between treatments. No effects of canopy type were detected. Results suggest that planting forest herbs for restoration purposes may be unsuccessful if buckthorn is present. Important changes in understory flora biodiversity are likely to occur over the long term in forests invaded by buckthorn.

  9. Effects of forest management on California Spotted Owls: implications for reducing wildfire risk in fire‐prone forests.

    Science.gov (United States)

    Tempel, Douglas J; Gutiérrez, R J; Whitmore, Sheila A; Reetz, Matthew J; Stoelting, Ricka E; Berigan, William J; Seamans, Mark E; Zachariah Peery, M

    Management of many North American forests is challenged by the need to balance the potentially competing objectives of reducing risks posed by high-severity wildfires and protecting threatened species. In the Sierra Nevada, California, concern about high-severity fires has increased in recent decades but uncertainty exists over the effects of fuel-reduction treatments on species associated with older forests, such as the California Spotted Owl (Strix occidentalis occidentalis). Here, we assessed the effects of forest conditions, fuel reductions, and wildfire on a declining population of Spotted Owls in the central Sierra Nevada using 20 years of demographic data collected at 74 Spotted Owl territories. Adult survival and territory colonization probabilities were relatively high, while territory extinction probability was relatively low, especially in territories that had relatively large amounts of high canopy cover (≥70%) forest. Reproduction was negatively associated with the area of medium-intensity timber harvests characteristic of proposed fuel treatments. Our results also suggested that the amount of edge between older forests and shrub/sapling vegetation and increased habitat heterogeneity may positively influence demographic rates of Spotted Owls. Finally, high-severity fire negatively influenced the probability of territory colonization. Despite correlations between owl demographic rates and several habitat variables, life stage simulation (sensitivity) analyses indicated that the amount of forest with high canopy cover was the primary driver of population growth and equilibrium occupancy at the scale of individual territories. Greater than 90% of medium-intensity harvests converted high-canopy-cover forests into lower-canopy-cover vegetation classes, suggesting that landscape-scale fuel treatments in such stands could have short-term negative impacts on populations of California Spotted Owls. Moreover, high-canopy-cover forests declined by an average of

  10. Nigerian forest communities act to reduce carbon emissions | CRDI ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    , southeastern Nigeria, identify the conditions necessary for programs to successfully reduce carbon emissions in their communities. The study was also a means to inform local decision-makers about what communities ...

  11. Nigerian forest communities act to reduce carbon emissions | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2016-06-08

    , southeastern Nigeria, identify the conditions necessary for programs to successfully reduce carbon emissions in their communities. The study was also a means to inform local decision-makers about what communities ...

  12. The role of sex and age in the architecture of intrapopulation howler monkey-plant networks in continuous and fragmented rain forests

    Directory of Open Access Journals (Sweden)

    Julieta Benitez-Malvido

    2016-03-01

    Full Text Available We evaluated the structure of intrapopulation howler monkey-plant interactions by focusing on the plant species consumed by different sex and age classes in continuous and fragmented forests in southern Mexico. For this we used network analysis to evaluate the impact of fragmentation on howler population traits and on resource availability and food choice. A total of 37 tree and liana species and seven plant items (bark, immature fruits, flowers, mature fruits, immature leaves, mature leaves and petioles were consumed, but their relative consumption varied according to sex and age classes and habitat type. Overall, adult females consumed the greatest number of plant species and items while infants and juveniles the lowest. For both continuous and fragmented forests, we found a nested diet for howler monkey-plant networks: diets of more selective monkeys represent subsets of the diets of other individuals. Nestedness was likely due to the high selectivity of early life stages in specific food plants and items, which contrasts with the generalized foraging behaviour of adults. Information on the extent to which different plant species and primate populations depend on such interactions in different habitats will help to make accurate predictions about the potential impact of disturbances on plant-animal interaction networks.

  13. Natural vegetation cover in the landscape and edge effects: differential responses of insect orders in a fragmented forest.

    Science.gov (United States)

    González, Ezequiel; Salvo, Adriana; Valladares, Graciela

    2017-10-01

    Human activities have led to global simplification of ecosystems, among which Neotropical dry forests are some of the most threatened. Habitat loss as well as edge effects may affect insect communities. Here, we analyzed insects sampled with pan traps in 9 landscapes (at 5 scales, in 100-500 m diameter circles) comprising cultivated fields and Chaco Serrano forests, at overall community and taxonomic order level. In total 7043 specimens and 456 species of hexapods were captured, with abundance and richness being directly related to forest cover at 500 m and higher at edges in comparison with forest interior. Community composition also varied with forest cover and edge/interior location. Different responses were detected among the 8 dominant orders. Collembola, Hemiptera, and Orthoptera richness and/or abundance were positively related to forest cover at the larger scale, while Thysanoptera abundance increased with forest cover only at the edge. Hymenoptera abundance and richness were negatively related to forest cover at 100 m. Coleoptera, Diptera, and Hymenoptera were more diverse and abundant at the forest edge. The generally negative influence of forest loss on insect communities could have functional consequences for both natural and cultivated systems, and highlights the relevance of forest conservation. Higher diversity at the edges could result from the simultaneous presence of forest and matrix species, although "resource mapping" might be involved for orders that were richer and more abundant at edges. Adjacent crops could benefit from forest proximity since natural enemies and pollinators are well represented in the orders showing positive edge effects. © 2016 Institute of Zoology, Chinese Academy of Sciences.

  14. Gastrointestinal parasite infections and self-medication in wild chimpanzees surviving in degraded forest fragments within an agricultural landscape mosaic in Uganda

    Science.gov (United States)

    Hasegawa, Hideo; Bardi, Massimo; Huffman, Michael A.

    2017-01-01

    Monitoring health in wild great apes is integral to their conservation and is especially important where they share habitats with humans, given the potential for zoonotic pathogen exchange. We studied the intestinal parasites of wild chimpanzees (Pan troglodytes schweinfurthii) inhabiting degraded forest fragments amid farmland and villages in Bulindi, Uganda. We first identified protozoan and helminth parasites infecting this population. Sixteen taxa were demonstrated microscopically (9 protozoa, 5 nematodes, 1 cestode, and 1 trematode). DNA sequence analysis enabled more precise identification of larval nematodes (e.g. Oesophagostomum stephanostomum, O. bifurcum, Strongyloides fuelleborni, Necator sp. Type II) and tapeworm proglottids (genus Bertiella). To better understand the ecology of infections, we used multidimensional scaling analysis to reveal general patterns of association among parasites, climate, and whole leaf swallowing–a prevalent self-medicative behaviour at Bulindi linked to control of nodular worms (Oesophagostomum spp.). Prevalence of parasites varied with climate in diverse ways. For example, Oesophagostomum sp. was detected in faeces at higher frequencies with increasing rainfall but was most clearly associated with periods of low temperature. Certain parasites occurred together within chimpanzee hosts more or less frequently than expected by chance. For example, the commensal ciliate Troglodytella abrassarti was negatively associated with Balantidium coli and Oesophagostomum sp., possibly because the latter taxa make the large intestine less suitable for T. abrassarti. Whole leaves in faeces showed independent associations with the prevalence of Oesophagostomum sp., Strongyloides sp., and hookworm by microscopic examination, and with egestion of adult O. stephanostomum by macroscopic inspection. All parasites identified to species or genus have been reported in wild chimpanzees inhabiting less-disturbed environments than Bulindi

  15. Gastrointestinal parasite infections and self-medication in wild chimpanzees surviving in degraded forest fragments within an agricultural landscape mosaic in Uganda.

    Directory of Open Access Journals (Sweden)

    Matthew R McLennan

    Full Text Available Monitoring health in wild great apes is integral to their conservation and is especially important where they share habitats with humans, given the potential for zoonotic pathogen exchange. We studied the intestinal parasites of wild chimpanzees (Pan troglodytes schweinfurthii inhabiting degraded forest fragments amid farmland and villages in Bulindi, Uganda. We first identified protozoan and helminth parasites infecting this population. Sixteen taxa were demonstrated microscopically (9 protozoa, 5 nematodes, 1 cestode, and 1 trematode. DNA sequence analysis enabled more precise identification of larval nematodes (e.g. Oesophagostomum stephanostomum, O. bifurcum, Strongyloides fuelleborni, Necator sp. Type II and tapeworm proglottids (genus Bertiella. To better understand the ecology of infections, we used multidimensional scaling analysis to reveal general patterns of association among parasites, climate, and whole leaf swallowing-a prevalent self-medicative behaviour at Bulindi linked to control of nodular worms (Oesophagostomum spp.. Prevalence of parasites varied with climate in diverse ways. For example, Oesophagostomum sp. was detected in faeces at higher frequencies with increasing rainfall but was most clearly associated with periods of low temperature. Certain parasites occurred together within chimpanzee hosts more or less frequently than expected by chance. For example, the commensal ciliate Troglodytella abrassarti was negatively associated with Balantidium coli and Oesophagostomum sp., possibly because the latter taxa make the large intestine less suitable for T. abrassarti. Whole leaves in faeces showed independent associations with the prevalence of Oesophagostomum sp., Strongyloides sp., and hookworm by microscopic examination, and with egestion of adult O. stephanostomum by macroscopic inspection. All parasites identified to species or genus have been reported in wild chimpanzees inhabiting less-disturbed environments than

  16. Reduced NADPH oxidase type 2 activity mediates sleep fragmentation-induced effects on TC1 tumors in mice.

    Science.gov (United States)

    Zheng, Jiamao; Almendros, Isaac; Wang, Yang; Zhang, Shelley X; Carreras, Alba; Qiao, Zhuanhong; Gozal, David

    2015-02-01

    The molecular mechanisms underlying how sleep fragmentation (SF) influences cancer growth and progression remain largely elusive. Here, we present evidence that SF reduced ROS production by downregulating gp91 phox expression and activity in TC1 cell tumor associated macrophages (TAMs), while genetic ablation of phagocytic Nox2 activity increased tumor cell proliferation, motility, invasion, and extravasation in vitro . Importantly, the in vivo studies using immunocompetent syngeneic murine tumor models suggested that Nox2 deficiency mimics SF-induced TAMs infiltration and subsequent tumor growth and invasion. Taken together, these studies reveal that perturbed sleep could adversely affect innate immunity within the tumor by altering Nox2 expression and activity, and indicate that selective potentiation of Nox2 activity may present a novel therapeutic strategy in the treatment of cancer.

  17. Reduced NADPH oxidase type 2 activity mediates sleep fragmentation-induced effects on TC1 tumors in mice

    Science.gov (United States)

    Zheng, Jiamao; Almendros, Isaac; Wang, Yang; Zhang, Shelley X; Carreras, Alba; Qiao, Zhuanhong; Gozal, David

    2015-01-01

    The molecular mechanisms underlying how sleep fragmentation (SF) influences cancer growth and progression remain largely elusive. Here, we present evidence that SF reduced ROS production by downregulating gp91phox expression and activity in TC1 cell tumor associated macrophages (TAMs), while genetic ablation of phagocytic Nox2 activity increased tumor cell proliferation, motility, invasion, and extravasation in vitro. Importantly, the in vivo studies using immunocompetent syngeneic murine tumor models suggested that Nox2 deficiency mimics SF-induced TAMs infiltration and subsequent tumor growth and invasion. Taken together, these studies reveal that perturbed sleep could adversely affect innate immunity within the tumor by altering Nox2 expression and activity, and indicate that selective potentiation of Nox2 activity may present a novel therapeutic strategy in the treatment of cancer. PMID:25949873

  18. Discriminating the drivers of edge effects on nest predation: forest edges reduce capture rates of ship rats (Rattus rattus), a globally invasive nest predator, by altering vegetation structure.

    Science.gov (United States)

    Ruffell, Jay; Didham, Raphael K; Barrett, Paul; Gorman, Nic; Pike, Rhonda; Hickey-Elliott, Andrée; Sievwright, Karin; Armstrong, Doug P

    2014-01-01

    Forest edges can strongly affect avian nest success by altering nest predation rates, but this relationship is inconsistent and context dependent. There is a need for researchers to improve the predictability of edge effects on nest predation rates by examining the mechanisms driving their occurrence and variability. In this study, we examined how the capture rates of ship rats, an invasive nest predator responsible for avian declines globally, varied with distance from the forest edge within forest fragments in a pastoral landscape in New Zealand. We hypothesised that forest edges would affect capture rates by altering vegetation structure within fragments, and that the strength of edge effects would depend on whether fragments were grazed by livestock. We measured vegetation structure and rat capture rates at 488 locations ranging from 0-212 m from the forest edge in 15 forest fragments, seven of which were grazed. Contrary to the vast majority of previous studies of edge effects on nest predation, ship rat capture rates increased with increasing distance from the forest edge. For grazed fragments, capture rates were estimated to be 78% lower at the forest edge than 118 m into the forest interior (the farthest distance for grazed fragments). This relationship was similar for ungrazed fragments, with capture rates estimated to be 51% lower at the forest edge than 118 m into the forest interior. A subsequent path analysis suggested that these 'reverse' edge effects were largely or entirely mediated by changes in vegetation structure, implying that edge effects on ship rats can be predicted from the response of vegetation structure to forest edges. We suggest the occurrence, strength, and direction of edge effects on nest predation rates may depend on edge-driven changes in local habitat when the dominant predator is primarily restricted to forest patches.

  19. Potential of forest management to reduce French carbon emissions - regional modelling of the French forest carbon balance from the forest to the wood.

    Science.gov (United States)

    Valade, A.; Luyssaert, S.; Bellassen, V.; Vallet, P.

    2015-12-01

    In France the low levels of forest harvest (40 Mm3 per year over a volume increment of 89Mm3) is frequently cited to push for a more intensive management of the forest that would help reducing CO2 emissions. This reasoning overlooks the medium-to-long-term effects on the carbon uptake at the national scale that result from changes in the forest's structure and delayed emissions from products decay and bioenergy burning, both determinant for the overall C fluxes between the biosphere and the atmosphere. To address the impacts of an increase in harvest removal on biosphere-atmosphere carbon fluxes at national scale, we build a consistent regional modeling framework to integrate the forest-carbon system from photosynthesis to wood uses. We aim at bridging the gap between regional ecosystem modeling and land managers' considerations, to assess the synergistic and antagonistic effects of management strategies over C-based forest services: C-sequestration, energy and material provision, fossil fuel substitution. For this, we built on inventory data to develop a spatial forest growth simulator and design a novel method for diagnosing the current level of management based on stand characteristics (density, quadratic mean diameter or exploitability). The growth and harvest simulated are then processed with a life cycle analysis to account for wood transformation and uses. Three scenarii describe increases in biomass removals either driven by energy production target (set based on national prospective with a lock on minimum harvest diameters) or by changes in management practices (shorter or longer rotations, management of currently unmanaged forests) to be compared with business as usual simulations. Our management levels' diagnostics quantifies undermanagement at national scale and evidences the large weight of ownership-based undermanagement with an average of 26% of the national forest (between 10% and 40% per species) and thus represents a huge potential wood resource

  20. Biodiversity conservation values of fragmented communally reserved forests, managed by indigenous people, in a human-modified landscape in Borneo

    OpenAIRE

    Takeuchi, Yayoi; Soda, Ryoji; Diway, Bibian; Kuda, Tinjan ak.; Nakagawa, Michiko; Nagamasu, Hidetoshi; Nakashizuka, Tohru

    2017-01-01

    This study explored the conservation values of communally reserved forests (CRFs), which local indigenous communities deliberately preserve within their area of shifting cultivation. In the current landscape of rural Borneo, CRFs are the only option for conservation because other forested areas have already been logged or transformed into plantations. By analyzing their alpha and beta diversity, we investigated how these forests can contribute to restore regional biodiversity. Although CRFs w...

  1. Exploring the role of forest resources in reducing community vulnerability to the heat effects of climate change

    Science.gov (United States)

    Z.L. Walton; N.C. Poudyal; J. Hepinstall; C. Johnson Gaither; B.B. Boley

    2015-01-01

    While the growing literature on forest ecosystem services has examined the value and significance of a range ofservices, our understanding of the health-related benefits of ecosystem services from forests is still limited. Tocharacterize the role of forest resources in reducing community vulnerability to the heat effects of climate...

  2. Fungal Community and Ligninolytic Enzyme Activities in Quercus deserticola Trel. Litter from Forest Fragments with Increasing Levels of Disturbance

    Directory of Open Access Journals (Sweden)

    Jesús A. Rosales-Castillo

    2017-12-01

    Full Text Available Litter fungal communities and their ligninolytic enzyme activities (laccase, Mn-peroxidase, and lignin-peroxidase play a vital role in forest biogeochemical cycles by breaking down plant cell wall polymers, including recalcitrant lignin. However, litter fungal communities and ligninolytic enzyme activities have rarely been studied in Neotropical, non-coniferous forests. Here, we found no significant differences in litter ligninolytic enzyme activities from well preserved, moderately disturbed, and heavily disturbed Quercus deserticola Trel. forests in central Mexico. However, we did find seasonal effects on enzyme activities: during the dry season, we observed lower laccase, and increased Mn-peroxidase and lignin-peroxidase activities, and in the rainy season, Mn-peroxidase and lignin-peroxidase activities were lower, while laccase activity peaked. Fungal diversity (Shannon-Weaver and Simpson indices based on ITS-rDNA analyses decreased with increased disturbance, and principal component analysis showed that litter fungal communities are structured differently between forest types. White-rot Polyporales and Auriculariales only occurred in the well preserved forest, and a high number of Ascomycota were shared between forests. While the degree of forest disturbance significantly affected the litter fungal community structure, the ligninolytic enzyme activities remained unaffected, suggesting functional redundancy and a possible role of generalist Ascomycota taxa in litter delignification. Forest conservation and restoration strategies must account for leaf litter and its associated fungal community.

  3. Chronic water stress reduces tree growth and the carbon sink of deciduous hardwood forests.

    Science.gov (United States)

    Brzostek, Edward R; Dragoni, Danilo; Schmid, Hans Peter; Rahman, Abdullah F; Sims, Daniel; Wayson, Craig A; Johnson, Daniel J; Phillips, Richard P

    2014-08-01

    Predicted decreases in water availability across the temperate forest biome have the potential to offset gains in carbon (C) uptake from phenology trends, rising atmospheric CO2 , and nitrogen deposition. While it is well established that severe droughts reduce the C sink of forests by inducing tree mortality, the impacts of mild but chronic water stress on forest phenology and physiology are largely unknown. We quantified the C consequences of chronic water stress using a 13-year record of tree growth (n = 200 trees), soil moisture, and ecosystem C balance at the Morgan-Monroe State Forest (MMSF) in Indiana, and a regional 11-year record of tree growth (n > 300 000 trees) and water availability for the 20 most dominant deciduous broadleaf tree species across the eastern and midwestern USA. We show that despite ~26 more days of C assimilation by trees at the MMSF, increasing water stress decreased the number of days of wood production by ~42 days over the same period, reducing the annual accrual of C in woody biomass by 41%. Across the deciduous forest region, water stress induced similar declines in tree growth, particularly for water-demanding 'mesophytic' tree species. Given the current replacement of water-stress adapted 'xerophytic' tree species by mesophytic tree species, we estimate that chronic water stress has the potential to decrease the C sink of deciduous forests by up to 17% (0.04 Pg C yr(-1) ) in the coming decades. This reduction in the C sink due to mesophication and chronic water stress is equivalent to an additional 1-3 days of global C emissions from fossil fuel burning each year. Collectively, our results indicate that regional declines in water availability may offset the growth-enhancing effects of other global changes and reduce the extent to which forests ameliorate climate warming. © 2014 John Wiley & Sons Ltd.

  4. Fertility of agricultural soils close to native forest fragments / Fertilidade de solos agrícolas próximo a fragmentos florestais nativos

    Directory of Open Access Journals (Sweden)

    Maria Josefa Santos Yabe

    2003-05-01

    Full Text Available The government strategy to increase native forest coverage has frequently been to punish land owners that do not abide the environmental legislation. The advantages of the forest presence in agricultural areas are rarely discussed, as is the soil fertilizing potential of close forests. The influence of edge forest in the soil fertility in agricultural areas was verified in five forest fragments of Londrina – State of Paraná. The soil of the area is originated from basaltic rocks, presenting differences in agreement with the intensity of the weathering. The Latossolo Vermelho Distroférrico (oxissol presenting on the weathered palteaus, Nitossolo Vermelho Distroférrico (ultissol on the hillsides and small pockets of Neossolo Litólico (entissol on the most hilly sites. The soil fertility was evaluated, through its components, organic matter (OM, pH, potential acidity, Ca, Mg, K and P, in 5 m intervals to the distance of 50m of the edge forest towards the agricultural area. The organic matter content was higher until 10m from the forest edge, what is a demonstration of the positive effect of forests to the agriculture. Large forest fragments showed larger influence in the amount of nutrients than smaller fragments.A estratégia implementada pelo governo para aumentar a cobertura florestal tem sido a punição dos proprietários que não seguem a legislação ambiental. As vantagens da presença de floresta em áreas agrícolas são raramente discutidas, como é o potencial que a floresta possui de fertilizar o solo ao seu redor. A influência da borda florestal na fertilidade do solo em áreas agrícolas foi verificada em cinco fragmentos florestais da região de Londrina – Paraná. O solo da região é originado de rochas basálticas, apresentando diferenças de acordo com a intensidade do intemperismo. O Latossolo Vermelho Distroférrico está presente no planalto intemperizado, o Nitossolo Vermelho Distroférrico nas vertentes e pequena

  5. Reducing emissions from deforestation and forest degradation (REDD+): game changer or just another quick fix?

    Science.gov (United States)

    Venter, Oscar; Koh, Lian Pin

    2012-02-01

    Reducing emissions from deforestation and forest degradation (REDD+) provides financial compensation to land owners who avoid converting standing forests to other land uses. In this paper, we review the main opportunities and challenges for REDD+ implementation, including expectations for REDD+ to deliver on multiple environmental and societal cobenefits. We also highlight a recent case study, the Norway-Indonesia REDD+ agreement and discuss how it might be a harbinger of outcomes in other forest-rich nations seeking REDD+ funds. Looking forward, we critically examine the fundamental assumptions of REDD+ as a solution for the atmospheric buildup of greenhouse gas emissions and tropical deforestation. We conclude that REDD+ is currently the most promising mechanism driving the conservation of tropical forests. Yet, to emerge as a true game changer, REDD+ must still demonstrate that it can access low transaction cost and high-volume carbon markets or funds, while also providing or complimenting a suite of nonmonetary incentives to encourage a developing nation's transition from forest losing to forest gaining, and align with, not undermine, a globally cohesive attempt to mitigate anthropogenic climate change. © 2012 New York Academy of Sciences.

  6. Efecto de la fragmentación forestal sobre la estructura vegetacional de las poblaciones amenazadas de Legrandia concinna (Myrtaceae del centro-sur de Chile Effect of forest fragmentation on vegetation structure of Legrandia concinna (Myrtaceae threatened populations in south-central Chile

    Directory of Open Access Journals (Sweden)

    ADISON ALTAMIRANO

    2007-03-01

    tiempo a fin de evaluar la efectividad de determinadas estrategias de conservación para estas poblacionesHabitat fragmentation is one of the main threats to ecosystems integrity. In this study we assessed the influence of forest fragmentation on vegetation structure of populations of tree specie Legrandia concinna in south-central Chile. Occupancy pattern of Legrandia populations in remaining fragments of native forests was described, and relationship between landscape indices and vegetation structure variables were evaluated. Landscape indices, such as area, proximity mean index, shape and edge distance to fragment were applied to forest cover maps generated from a Landsat ETM+ satellite scene for the year 2001. Results showed high predominance of reduced size fragments, high isolation levels and regulars shapes of the fragments. Occupancy pattern suggests that Legrandia populations are found mainly in small and more isolated fragments. No significant difference was found between fragment distribution with and without presence of Legrandia related to size and isolation. However, we found that size, isolation and distance to fragment edge are significantly related to the presence of this specie. As conservation measures for this specie, we propose to include populations with high disappearance risk in protected areas, promote ex situ conservation and set up a monitoring program. This study sets a precedent related by linking landscape scale information obtained from satellite imagery and vegetation structure information measured in the field with conservation status of threatened populations. This innovative method allows monitoring changes over time to assess effectiveness of conservation strategies for these populations

  7. The economics of reducing emissions from community managed forests in Nepal Himalaya

    NARCIS (Netherlands)

    Karky, B.S.

    2008-01-01

    The climate change agenda is more important in global politics today than ever before. This research set out to examine whether community forest management (CFM) can play a signifi cant role in reducing global emissions, by taking Nepal’s community forestry sector as a case. The thesis selects three

  8. Bioenergy from trees: using cost-effective thinning to reduce forest fire hazards

    Science.gov (United States)

    Marie Oliver; Jeremy Fried; Jamie Barbour

    2009-01-01

    Increasingly large and severe wildfires threaten millions of forested acres throughout the West. Under certain conditions, mechanical thinning can address these hazardous conditions while providing opportunitiesto create renewable energy and reduce our carbon footprint but how do land managers decide whether thinning is a good idea? How do they decide where to begin,...

  9. Reducing Emissions from Deforestation and Forest Degradation (REDD+: Transaction Costs of Six Peruvian Projects

    Directory of Open Access Journals (Sweden)

    Olivia R. Rendón Thompson

    2013-03-01

    Full Text Available Reduced Emissions from Deforestation and Forest Degradation (REDD+ has received strong support as a major component of future global climate change policy. The financial mechanism of REDD+ is payment for the ecosystem service of carbon sequestration in tropical forests that is expected to create incentives for conservation of forest cover and condition. However, the costs of achieving emissions reduction by these means remain largely unknown. We assess the set-up, implementation, and monitoring costs, i.e., collectively the transaction costs, of six of the first seven REDD+ project designs from the Peruvian Amazon and compare them with established projects in Brazil and Bolivia. The estimated costs vary greatly among the assessed projects from US$0.16 to 1.44 ha-1 yr-1, with an average of US$0.73 ha-1 yr-1, though they are comparable to earlier published estimates. The results indicate that the costs of implementing REDD+ are highly uncertain for participating developing countries because of issues such as inadequate project design and how additionality is determined. Furthermore, some insight is obtained into how different activities to reduce deforestation and forest degradation, the type of implementer, and project location affect implementation costs of REDD+ projects. Even with these first estimates, the cost of preserving existing intact forests in the Peruvian Amazon may have been underestimated.

  10. Seed dissemination by frugivorous birds from forest fragments to adjacent pastures on the western slope of Volcán Barva, Costa Rica

    Directory of Open Access Journals (Sweden)

    Gilbert Barrantes

    2002-06-01

    Full Text Available Logging, cattle raising, and agricultural activities have caused the destruction of most forested areas in Costa Rica. In some middle and highlands the abrupt topography delayed the complete destruction of montane forest. Consequently, some fragments of almost pristine forest remain along streams that run in deep canyons. Frequently, these remnants serve as corridors between larger forested areas and as routes for movement of frugivorous birds. Eighteen bird species, e.g., Turdus plebejus, Elaenia frantzii and Ptilogonys caudatus are common dwellers of forest patches throughout the Pacific slope of the Volcán Barva. These species fly frequently from forest fragments to adjacent pastures. They defecated and regurgitated seeds of 28 plant species on stumps scattered on pasture areas. Isolated trees and specially the stumps are suitable microhabitats for germination of seeds and establishment of seedlingsLa deforestación, la ganadería y las actividades agrícolas han causado la destrucción de la mayoría de los bosques en Costa Rica. Sin embargo, la abrupta topografía de las zonas medias y altas del país ha retardado este proceso de deforestación en el bosque montano. Es así como aún algunos fragmentos de bosques poco alterados estan todavía en pie a lo largo de riachuelos que corren en cañones profundos. Estos fragmentos sirven como corredores entre áreas más grandes de bosque y como rutas para el movimiento altitudinal de aves frugívoras. Dieciocho aves, e.g., Turdus plebejus, Elaenia frantzii y Ptilogonys caudatus son habitantes comunes de los parches de bosque presentes en la vertiente Pacífica del Volcán Barva. Estas especies vuelan frecuentemente entre los fragmentos de bosque y potreros adyacentes. Estas aves defecaron y regurgitaron semillas de 28 especies de plantas en troncos distribuidos en los potreros. Los árboles aislados y troncos son micro-hábitats adecuados para la germinación de semillas y el establecimiento de

  11. Spatial patterns of two co-occurring savanna and forest tree species in a dense fire-protected savanna fragment

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    Rafael Carvalho da Costa

    Full Text Available ABSTRACT Savanna-forest transition under fire-exclusion could be explained by differential competitive performance of savanna and forest species under shading/fire-exclusion. Aiming to understand strategies related to either habitat affinity, we investigated spatial patterns of a savanna and a forest species in a fire-protected savanna. We predicted that: savanna species would have lower abundance than the forest species due to a restriction in the number of open microsites; segregation of size classes and a trend from clumping to regularity with size for forest species due to absence of microsite limitation and intra-specifc competition; and spatial association and increasing clustering with size for savanna species due to microsite limitation. To test these predictions, we described spatial patterns of plants in two size classes in three plots of 0.5 ha. We analyzed spatial patterns and associations of size classes using SADIE methodology. Different from what we expected, both species were more abundant among the studied plots and exhibited an increasing aggregation from small to large size classes. We also found a positive spatial association between size classes of both. These results suggest that both savanna and forest species produce similar spatial patterns independently of habitat affinity. We discuss the possible processes responsible for the observed patterns.

  12. Habitat fragmentation reduces grassland connectivity for both short-distance and long-distance wind-dispersed forbs

    NARCIS (Netherlands)

    Soons, M.B.; Messelink, J.H.; Jongejans, E.; Heil, G.W.

    2005-01-01

    1 Although habitat loss and fragmentation are assumed to threaten the regional survival of plant species, their effects on regional species dynamics via seed dispersal and colonization have rarely been quantified. 2 We assessed the impact of habitat loss and fragmentation on the connectivity, and

  13. Chameleon fragmentation

    International Nuclear Information System (INIS)

    Brax, Philippe; Upadhye, Amol

    2014-01-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ 4 and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments

  14. Chameleon fragmentation

    Energy Technology Data Exchange (ETDEWEB)

    Brax, Philippe [Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191Gif/Yvette Cedex (France); Upadhye, Amol, E-mail: philippe.brax@cea.fr, E-mail: aupadhye@anl.gov [Institute for the Early Universe, Ewha University, International Education, Building #601, 11-1, Daehyun-Dong Seodaemun-Gu, Seoul 120-750 (Korea, Republic of)

    2014-02-01

    A scalar field dark energy candidate could couple to ordinary matter and photons, enabling its detection in laboratory experiments. Here we study the quantum properties of the chameleon field, one such dark energy candidate, in an ''afterglow'' experiment designed to produce, trap, and detect chameleon particles. In particular, we investigate the possible fragmentation of a beam of chameleon particles into multiple particle states due to the highly non-linear interaction terms in the chameleon Lagrangian. Fragmentation could weaken the constraints of an afterglow experiment by reducing the energy of the regenerated photons, but this energy reduction also provides a unique signature which could be detected by a properly-designed experiment. We show that constraints from the CHASE experiment are essentially unaffected by fragmentation for φ{sup 4} and 1/φ potentials, but are weakened for steeper potentials, and we discuss possible future afterglow experiments.

  15. [Woody plant species composition and community structure in residual fragments of broad-leaved Korean pine mixed forests in Changbai Mountains area].

    Science.gov (United States)

    Song, Hou-Juan; Ye, Ji; Shi, Shuai; Zhang, Zhao-Chen; Kuang, Xu; Xing, Ding-Liang; Yuan, Zuo-Qiang; Lin, Fei; Wang, Xu-Gao; Hao, Zhan-Qing

    2014-05-01

    The broad-leaved Korean pine mixed forest represents the typical vegetation type of the eastern mountain area in Northeast China. However, due to the interference of human activities, the natural broad-leaved Korean pine forest only distributes in some residual fragments with unequal areas in Changbai Mountains and Small Hinggan Mountains. To compare and analyze the similarities and differences of broad-leaved Korean pine mixed forests in the different areas, we established six forest plots following the field protocol of the 50 hm2 forest plot in Panama (Barro Colorado Island, BCI) in 2012 in Changbai Mountain National Nature Reserve in Jilin Province and the eastern mountain area in Liaoning Province. All free-standing plant species with DBH (diameter at breast height) > or = 1 cm were mapped, tagged and identified to species. The results showed that there were 69 woody species in the six plots, comprising 42 genera and24 families. Aceraceae was the most species-rich family in all six plots. Most species belonged to the plant type of North Temperate Zone, with a minor subtropical plant species component. The statistics of species abundance, basal area, mean DBH, and importance value showed that there were obviously dominant species in each community. The DBH distribution of all individuals showed a reversed "J" type. However, the percentage of individuals in small size-class and large size-class varied in the six communities, which indicated that these communities were at different successional stages. Ranked by the importance value, the DBH distribution of the top three species in the six plots showed four distribution types: reversed "J" distribution, reversed "L" distribution, unimodal distribution, and partial peak distribution. Spatial distribution patterns of the main species in the six plots changed differently with species and size-class, and the distribution patterns of the same species varied in the different plots.

  16. Efficiency of small mammal trapping in an Atlantic Forest fragmented landscape: the effects of trap type and position, seasonality and habitat

    Directory of Open Access Journals (Sweden)

    ALM Vieira

    Full Text Available Trapping methods can strongly influence the sampling of mammal communities. This study compared the efficiency of the capture of small mammals in Sherman traps in two positions (at ground level and in trees and pitfall traps in a fragmented landscape. Trapping sessions were carried out between October 2008 and October 2009 at two fragments (8 and 17 ha, an agroforest corridor between them, and the adjacent pasture. A total effort of 4622 trap-nights resulted in 155 captures of 137 individuals from six species. Pitfalls had greater success (4.03%, followed by Shermans on the ground (2.98% and on trees (2.37%; χ2= 6.50, p = 0.04. Five species were caught in Sherman ground traps, four in pitfalls and just two on trees. There was no difference among trap types for marsupials (χ2 = 4.75; p = 0.09, while for rodents, pitfalls were more efficient than Shermans on the ground (Fisher's exact test, p = 0.02. As a result, the efficiency of each trap type differed among habitats, due to differences in their species composition. Pitfalls were more efficient in the rainy season (Fisher's exact test, p <0.0001 while Shermans on trees were more efficient in the dry season (Fisher's exact test, p = 0.009. There was no difference between seasons for Shermans on the ground (Fisher's exact test, p = 0.76. Considering the results found, we recommend that future studies of forest mammal communities, particularly those designed to test the effects of forest fragmentation, include combinations of different trap types.

  17. Degradation of the northern paraná landscape: a study on forest fragments/ Degradação da paisagem norte-paranaense: um estudo de fragmentos florestais

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    Efraim Rodrigues

    2002-05-01

    Full Text Available Due to a fast occupation process, nearly all of the native vegetal covering of northern Paraná was devastated. Considering the lack of basic studies that support the management of forest remainders, this dissertation studies the forest fragmentation of the landscape in a transect of 180 km (between Maringá and Jacarezinho, considering a time and/or age of occupation gradient. One has adopted the hypothesis that the landscape to west, colonized from 1930 (Londrina and 1947 (Maringá, suffered smaller degradation in a comparison with what happened in the landscape situated further to east (and colonized in the mid 19th century and early 20th century. Results demonstrated that the initial hypothesis should be refute. Historical and factors socioeconomic influenced the occupation way and, consequently, the distribution of the forest fragments in the landscape.Devido ao rápido processo de ocupação, quase toda cobertura vegetal nativa do Norte do Paraná foi devastada. Considerando a necessidade de estudos básicos que dêem suporte ao manejo de remanescentes florestais, este trabalho estuda a fragmentação florestal da paisagem num transecto de 180 km (entre Jacarezinho e Maringá. Adotou-se a hipótese de que a paisagem mais a oeste – colonizada a partir de 1930 (Londrina e 1947 (Maringá – sofreu menor degradação antrópica, em comparação a paisagem, situada mais à leste (colonizada em meados do século XIX e início do século XX. Os resultados demonstraram que a hipótese inicial deve ser refutada. Fatores históricos e socioeconômicos influenciaram o modo de ocupação e conseqüentemente, a distribuição dos fragmentos florestais na paisagem.

  18. Reducing greenhouse gas emissions from deforestation and forest degradation: global land-use implications.

    Science.gov (United States)

    Miles, Lera; Kapos, Valerie

    2008-06-13

    Recent climate talks in Bali have made progress toward action on deforestation and forest degradation in developing countries, within the anticipated post-Kyoto emissions reduction agreements. As a result of such action, many forests will be better protected, but some land-use change will be displaced to other locations. The demonstration phase launched at Bali offers an opportunity to examine potential outcomes for biodiversity and ecosystem services. Research will be needed into selection of priority areas for reducing emissions from deforestation and forest degradation to deliver multiple benefits, on-the-ground methods to best ensure these benefits, and minimization of displaced land-use change into nontarget countries and ecosystems, including through revised conservation investments.

  19. The role of urban forest to reduce rain acid in urban industrial areas

    Science.gov (United States)

    Slamet, B.; Agustiarni, Y.; Hidayati; Basyuni, M.

    2018-03-01

    Urban forest has many functions mainly on improving the quality of the urban environment. One of the functions is to increase pH and reduce dangerous chemical content. The aim of the research is to find out the role of vegetation density of urban forest around the industrial area in reducing the acid rain. The condition of land cover was classified into four classes which are dense, medium, sparse and open area. The water of the throughfall and stemflow was taken from each type of land cover except in the open area. Parameters measured in this study are water acidity (pH), anion content (SO4 2- and NO3 -), cation content (Ca2+, Mg2+, and NH4 +) and electrical conductivity (EC). The results indicated that urban forest vegetation was able to increase the pH of rain water from 5.42 which is in an open area without vegetation to be 7.13 and 7.32 in dense and moderate vegetation cover by throughfall mechanism, respectively. Rain water acidity also decreased through stemflow mechanism with a pH ranged from 5.92 - 6.43. Urban forest vegetation decreased sulfate content (SO42-) from 528.67 mg/l in open area to 44 - 118 mg/l by throughfall mechanism and ranged from 90 to 366.67 mg/l through stemflow mechanism. Urban forest vegetation significantly decreased the rainwater nitrate content from 27 mg/l to 0.03 - 0.70 mg/l through the mechanism of throughfall and between 1.53 - 8.82 mg/l through the stemflow mechanism. Urban forest vegetation also increased the concentration of cations (NH4+, Ca2+, Mg2+, Na+) compared with open areas. Urban forest vegetation showed increased the electrical conductivity (EC) from 208.12 μmhos/cm to 344.67 - 902.17 μmhos/cm through the through fall mechanism and 937.67 - 1058.70 μmhos/cm through the stemflow mechanism. The study suggested that urban forests play a significant role in reducing rainwater acidity and improving the quality of rainwater that reached the soil surface.

  20. High resolution remote sensing for reducing uncertainties in urban forest carbon offset life cycle assessments.

    Science.gov (United States)

    Tigges, Jan; Lakes, Tobia

    2017-10-04

    Urban forests reduce greenhouse gas emissions by storing and sequestering considerable amounts of carbon. However, few studies have considered the local scale of urban forests to effectively evaluate their potential long-term carbon offset. The lack of precise, consistent and up-to-date forest details is challenging for long-term prognoses. Therefore, this review aims to identify uncertainties in urban forest carbon offset assessment and discuss the extent to which such uncertainties can be reduced by recent progress in high resolution remote sensing. We do this by performing an extensive literature review and a case study combining remote sensing and life cycle assessment of urban forest carbon offset in Berlin, Germany. Recent progress in high resolution remote sensing and methods is adequate for delivering more precise details on the urban tree canopy, individual tree metrics, species, and age structures compared to conventional land use/cover class approaches. These area-wide consistent details can update life cycle inventories for more precise future prognoses. Additional improvements in classification accuracy can be achieved by a higher number of features derived from remote sensing data of increasing resolution, but first studies on this subject indicated that a smart selection of features already provides sufficient data that avoids redundancies and enables more efficient data processing. Our case study from Berlin could use remotely sensed individual tree species as consistent inventory of a life cycle assessment. However, a lack of growth, mortality and planting data forced us to make assumptions, therefore creating uncertainty in the long-term prognoses. Regarding temporal changes and reliable long-term estimates, more attention is required to detect changes of gradual growth, pruning and abrupt changes in tree planting and mortality. As such, precise long-term urban ecological monitoring using high resolution remote sensing should be intensified

  1. Biodiversity status of urban remnant forests in Cape coast, Ghana ...

    African Journals Online (AJOL)

    Cape Coast Metropolis, which is close to Kakum forest, has its native forests being reduced to fragments. Biodiversity in these forest reserves are exposed to the threat of being cleared over night as a result of urbanization. There are reported cases of some rare or potential medicinal plant species that have disappeared ...

  2. Distance from the edge of forest fragments influence the abundance of aphidophagous hoverflies (Diptera: Syrphidae in wheat fields

    Directory of Open Access Journals (Sweden)

    Orcial Ceolin Bortolotto

    2016-04-01

    Full Text Available This study aimed to evaluate the influence of the distance from the edge of native forests on the abundance of aphidophagous hoverflies in wheat fields. The study was conducted in four commercial fields in the North of Paraná State, Brazil, during the wheat crop season of 2009. Two transects were surveyed parallel to the edge of the forest at two distances: 25 (“near” and 525 meters (“far” from the edge. The abundance of hoverflies was compared using a χ2 test (p ≤ 0.05. In total, 1,845 hoverflies adults were collected, which represented 15 species and three genera. The most abundant species was Allograpta exotica (60.43%, followed by Toxomerus dispar (17.78% and Toxomerus watsoni (7.26% (Diptera: Syrphidae. An important inference was that all fields showed a higher abundance of aphidophagous hoverflies closer to the edge of the forest (25 m during the wheat tillering stage. The initial abundance of aphidophagous hoverflies in wheat fields is likely greater near the edge because of the availability of resources in the surrounding forest that enhance hoverfly survival during periods of low aphid infestation.

  3. Decay of aspen (Populus tremuloides Michx.) wood in moist and dry boreal, temperate, and tropical forest fragments

    Science.gov (United States)

    Grizelle Gonzalez; William Gould; Andrew T. Hudak; Teresa Nettleton Hollingsworth

    2008-01-01

    In this study, we set up a wood decomposition experiment to i) quantify the percent of mass remaining, decay constant and performance strength of aspen stakes (Populus tremuloides) in dry and moist boreal (Alaska and Minnesota, USA), temperate (Washington and Idaho, USA), and tropical (Puerto Rico) forest types, and ii) determine the effects of...

  4. Sampling scheme on genetic structure of tree species in fragmented tropical dry forest: an evaluation from landscape genetic simulations

    Science.gov (United States)

    Yessica Rico; Marie-Stephanie. Samain

    2017-01-01

    Investigating how genetic variation is distributed across the landscape is fundamental to inform forest conservation and restoration. Detecting spatial genetic discontinuities has value for defining management units, germplasm collection, and target sites for reforestation; however, inappropriate sampling schemes can misidentify patterns of genetic structure....

  5. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and

  6. Damned if you do, damned if you do not - Reduced Climate Impact vs. Sustainable Forests in Sweden

    International Nuclear Information System (INIS)

    Geijer, Erik; Bostedt, Goeran; Braennlund, Runar

    2011-01-01

    The main objective of this paper is to analyze the potential goal conflict between two of Sweden's environmental objectives: Sustainable Forests and Reduced Climate Impact - or, more precisely, the conflict between forest conservation and the supply of wood fuel. To accomplish this, we use a forest sector model that includes the suppliers and major users of roundwood. The econometric results, based on a data set that spans 40 years, show that all the own price elasticities have the expected signs. Among the three forestry products, the supply and (long-term) demand of forest fuel seems to be most sensitive to a price change. In a second step, the estimated model is used to simulate the effect of increased forest conservation - the Sustainable Forest objective - on the supply of wood fuel. If oil is used as a substitute, Swedish emissions of greenhouse gases will increase by almost 0.92 percent, which indicates a clear conflict with the Reduced Climate Impact objective. (author)

  7. Respuestas foliares de Aristotelia chilensis (Molina Stuntz (Elaeocarpaceae a la fragmentación del bosque maulino Leaf responses of Aristotelia chilensis (Molina Stuntz (Elaeocarpaceae to the fragmentation of the Maulino forest

    Directory of Open Access Journals (Sweden)

    FIORELLA REPETTO-GIAVELLI

    2007-12-01

    Full Text Available La fragmentación que ha sufrido el bosque nativo de Chile debido a la fuerte presión antrópica ha causado, además de la grave pérdida de habitat, la modificación del microclima de los parches de bosque remanente que alguna vez constituyeron un bosque continuo de especies nativas. Estos cambios generarían respuestas morfológicas, químicas y fisiológicas en plantas capaces de adaptarse a las nuevas condiciones. Este estudio tiene como objetivo identificar respuestas a nivel de las hojas ante el aumento de radiación solar y disminución de agua en el suelo que ocurre al interior de los fragmentos. Para esto utilizamos a Aristotelia chilensis, especie que crece tanto en fragmentos como en bosque continuo, y comparamos parámetros relacionados a su morfología foliar en bosque y fragmentos y medimos su repercusión en la capacidad fotosintética de A. chilensis. En términos morfológicos, se observó una disminución del área foliar y del área foliar específica en los fragmentos, siendo 1,2 veces menor que en el bosque continuo. En los fragmentos, el grosor de la epidermis y del parénquima esponjoso son más de 1,3 veces mas gruesos que en el bosque continuo. El grosor del parénquima en empalizada, en cambio, no se vio modificado. La cantidad de nitrógeno en las hojas es 1,2 veces mayor en el bosque continuo que en los fragmentos, mientras que el contenido de carbono no varía. La conductancia estomática en el bosque continuo fue 1,5 veces mayor que en los fragmentos. Aristotelia chilensis responde morfológica y fisiológicamente ante los cambios abióticos generados por la fragmentación de los bosques, lo que le permite sobrevivir tanto en ambientes de baja luminosidad como el bosque continuo y en ambientes de alta luminosidad y bajo contenido hídrico como los fragmentos de bosque, manteniendo tasas fotosintéticas semejantes en ambos ambientesFragmentation of the Maulino forest implies significant habitat loss, as well as the

  8. Fitoseídeos (Acari: Phytoseiidae associados a cafezais e fragmentos florestais vizinhos Phytoseiids (Acari: Phytoseiidae associated to coffee plantations and adjacent forest fragments

    Directory of Open Access Journals (Sweden)

    Ester Azevedo Silva

    2010-10-01

    (Phytoseiidae in Brazilian natural environments, adjacent to coffee agroecosystems (Coffea spp., or about the influence exerted by neighbor vegetation as a reservoir of predatory mites. The objective of this study was to evaluate the diversity of these organisms in coffee plantations and adjacent forest fragments. Samples of the species Calyptranthes clusiifolia (Miq. O. Berg (Myrtaceae, Esenbeckia febrifuga (A. St.-Hil. A. Juss. ex Mart., Metrodorea stipularis Mart. (Rutaceae and Allophylus semidentatus (Miq. Radlk. (Sapindaceae were collected in eight forest fragments, from 5 to 51ha, adjacent to coffee plantations, in June (end of the rainy season and October (end of the dry season in the years of 2004 and 2005, in the Southern region of State of Minas Gerais. Leaf mites were extracted using the wash method, mounted in microscopy slides with Hoyer's medium for identification. A total of 2.348 phytoseiids was collected, being 2.090 in the forest fragments and 258 in adjacent coffee plantations, belonging to 38 species. According to fauna analysis, Iphiseiodes zuluaguai Denmark & Muma, the year of 1972 presented the best indexes in the coffee agroecosystem, being very frequent and constant in those periods. In the forest fragments, Amblyseius herbicolus Chant, 1959, Iphiseiodes affs. neonobilis Denmark & Muma, 1978, Leonseius regularis DeLeon, 1965 and Euseius alatus DeLeon, 1966 were dominant, very abundant, very frequent and constant in those periods. One may conclude that the native vegetation shelters predator mite, natural enemies of mite-pests that still occur in coffee culture, making possible ecological management program development involving areas of natural vegetation and adjacent coffee agroecosystems.

  9. New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in fragments of the Atlantic Forest, Brazil.

    Science.gov (United States)

    Pereira, A I A; Fadini, M A M; Pikart, T G; Zanuncio, J C; Serrão, J E

    2012-08-01

    New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in Brazil. Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). Studies describing insects as potential hosts have received little attention. Specimens of an undescribed species of the genus Leptus were collected in association with predatory and phytophagous Heteroptera bugs in a secondary forest in Viçosa, Minas Gerais state, Brazil. New mite-host records and information on seasonality of this mite are presented.

  10. New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in fragments of the Atlantic Forest, Brazil

    OpenAIRE

    Pereira,AIA.; Fadini,MAM.; Pikart,TG.; Zanuncio,JC.; Serrão,JE.

    2012-01-01

    New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae) in Brazil. Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones). Studies describing insects as potential hosts have received little attention. Specimens of an undescribed species of the genus Leptus were collected in association with predatory and phytophagous Heteroptera bugs in a secondary forest in Viçosa, Minas Gerais state, Brazil. New mite-host records and information on seasonality of this mi...

  11. New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae in fragments of the Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    AIA. Pereira

    Full Text Available New hosts and parasitism notes for the mite Leptus (Acari: Erythraeidae in Brazil. Larval erythraeid mites are common ectoparasites of harvestmen (Opiliones. Studies describing insects as potential hosts have received little attention. Specimens of an undescribed species of the genus Leptus were collected in association with predatory and phytophagous Heteroptera bugs in a secondary forest in Viçosa, Minas Gerais state, Brazil. New mite-host records and information on seasonality of this mite are presented.

  12. Immunization with DAT fragments is associated with long-term striatal impairment, hyperactivity and reduced cognitive flexibility in mice

    Directory of Open Access Journals (Sweden)

    Adriani Walter

    2012-11-01

    Full Text Available Abstract Background Possible interactions between nervous and immune systems in neuro-psychiatric disorders remain elusive. Levels of brain dopamine transporter (DAT have been implicated in several impulse-control disorders, like attention deficit / hyperactivity disorder (ADHD and obsessive-compulsive disorder (OCD. Here, we assessed the interplay between DAT auto-immunity and behavioural / neurochemical phenotype. Methods Male CD-1 mice were immunized with DAT peptide fragments (DAT-i, or vehicle alone (VEH, to generate elevated circulating levels of DAT auto-antibodies (aAbs. Using an operant delay-of-reward task (20 min daily sessions; timeout 25 sec, mice had a choice between either an immediate small amount of food (SS, or a larger amount of food after a delay (LL, which increased progressively across sessions (from 0 to 150 sec. Results DAT-i mice exhibited spontaneous hyperactivity (2 h-longer wake-up peak; a wake-up attempt during rest. Two sub-populations differing in behavioural flexibility were identified in the VEH control group: they showed either a clear-cut decision to select LL or clear-cut shifting towards SS, as expected. Compared to VEH controls, choice-behaviour profile of DAT-i mice was markedly disturbed, together with long-lasting alterations of the striatal monoamines. Enhanced levels of DA metabolite HVA in DAT-i mice came along with slower acquisition of basal preferences and with impaired shifting; elevation also in DOPAC levels was associated with incapacity to change a rigid selection strategy. This scarce flexibility of performance is indicative of a poor adaptation to task contingencies. Conclusions Hyperactivity and reduced cognitive flexibility are patterns of behaviour consistent with enduring functional impairment of striatal regions. It is yet unclear how anti-DAT antibodies could enter or otherwise affect these brain areas, and which alterations in DAT activity exactly occurred after immunization

  13. Reproductive phenology, pollination, and fructification of Heliconia spathocircinata Aristeg. (Heliconiaceae in an Atlantic Rain Forest fragment in Rio de Janeiro City

    Directory of Open Access Journals (Sweden)

    Caio César Corrêa Missagia

    2011-09-01

    Full Text Available Aspects of phenology and reproductive biology of Heliconia spathocircinata Aristeg. in border and interior areas of an Atlantic Rain Forest fragment in Rio de Janeiro City, Brazil, are apresented. Four plots of 10x10m were delineated, two on the edge and two inside the forest, and individuals of H. spathocircinata were monitored from June 2009 to June 2010. The observations were carried out from 6 a.m. to 6 p.m. once a week on December and January, and fortnightly the rest of flowering. Heliconia spathocircinata bloomeds between November and March and the fruits were ripe two months after pollination, and there was no significant difference between edge and interior with regard to the period of flowering and fruiting. The fruit-flower ratio averaged 66.6% in the interior and 27% within the forestedge, a considerable difference. The male hummingbirds Thalurania glaucopis Gmelin, and to a lesser extent, female birds of this species, were the most frequent pollinators in the area evaluated, both edge and interior. Other species were identified as pollinators: Phaethornis ruber L., Ramphodon naevius Dumont, Eupetomena macroura Gmelin, and Amazilia fimbriata Gmelin. Of these, only P. ruber was found in both environments.

  14. Potential changes in forest composition could reduce impacts of climate change on boreal wildfires.

    Science.gov (United States)

    Terrier, Aurélie; Girardin, Martin P; Périé, Catherine; Legendre, Pierre; Bergeron, Yves

    2013-01-01

    There is general consensus that wildfires in boreal forests will increase throughout this century in response to more severe and frequent drought conditions induced by climate change. However, prediction models generally assume that the vegetation component will remain static over the next few decades. As deciduous species are less flammable than conifer species, it is reasonable to believe that a potential expansion of deciduous species in boreal forests, either occurring naturally or through landscape management, could offset some of the impacts of climate change on the occurrence of boreal wildfires. The objective of this study was to determine the potential of this offsetting effect through a simulation experiment conducted in eastern boreal North America. Predictions of future fire activity were made using multivariate adaptive regression splines (MARS) with fire behavior indices and ecological niche models as predictor variables so as to take into account the effects of changing climate and tree distribution on fire activity. A regional climate model (RCM) was used for predictions of future fire risk conditions. The experiment was conducted under two tree dispersal scenarios: the status quo scenario, in which the distribution of forest types does not differ from the present one, and the unlimited dispersal scenario, which allows forest types to expand their range to fully occupy their climatic niche. Our results show that future warming will create climate conditions that are more prone to fire occurrence. However, unlimited dispersal of southern restricted deciduous species could reduce the impact of climate change on future fire occurrence. Hence, the use of deciduous species could be a good option for an efficient strategic fire mitigation strategy aimed at reducing fire Propagation in coniferous landscapes and increasing public safety in remote populated areas of eastern boreal Canada under climate change.

  15. Short-Term Responses of Birds to Forest Gaps and Understory: An Assessment of Reduced-Impact Logging in a Lowland Amazon Forest.

    Science.gov (United States)

    Joseph M. Wunderle Jr.; Luiza Magalli Pinto Henriques; Michael R. Willig

    2006-01-01

    We studied physiognomy-specific (i.e., gaps vs. understory) responses of birds to low harvest (18.7 m3/ha), reduced-impact logging by comparing 3500 mist net captures in control and cut blocks of an Amazonian terra firme forest in Brazil at 20–42 mo postharvest. Species richness did not differ significantly between control (92 species) and cut (85) forest based on...

  16. Phytosociology and structure in a alluvial deciduous forest fragment in Santa Maria - RS = Fitossociologia e estrutura de um fragmento de Floresta Estacional Decidual Aluvial em Santa Maria - RS

    Directory of Open Access Journals (Sweden)

    Jonas Eduardo Bianchin

    2013-12-01

    Full Text Available The forest environments are profoundly altered, mainly due to human action. Specially the alluvial forests, which by its location and ecological function should be preserved and restored, for that it is essential to know the phytosociological and forest structure. The objective of this study was to evaluate the phytosociological parameters and structure of a fragment of Alluvial Deciduous Forest in Santa Maria, RS. For this, we measured 74 contiguous plots of 10 x 10 m (100 m², and considered all individuals with CBH greater than 10 cm. Thus, we identified 32 species, mostly pioneer species, from 19 families. The number of species sampled in the fragment was low, while the dead individuals showed relatively high amount, which is possibly due to human interventions in the area and the process of secondary succession. Some species, such as Casearia sylvestris, Symplocos uniflora, Mimosa bimucronata, Lithrea molleoides and Zanthoxylum rhoifollium stood out with higher rates of phytosociological parameters, with a predominance of the first two. Similarly, analysis of the Expanded Importance Value showed that C. sylvestris and S. uniflora are the most important species of the fragment, as they are more evenly distributed across all vertical strata. = As formações florestais encontram-se alteradas, sobretudo devido à ação antrópica. Principalmente as florestas aluviais, que por sua localização e função ecológica, devem ser preservadas e recuperadas, para isso é fundamental conhecer a fitossociologia e estrutura da floresta. Assim, objetivou-se com este trabalho avaliar os parâmetros fitossociológicos e estrutura de um fragmento de Floresta Estacional Decidual Aluvial em Santa Maria, RS. Para isso, foram mensuradas 74 parcelas contíguas de 10 x 10 m (100 m², e considerados todos os indivíduos com CAP maior que 10 cm. Foram identificadas 32 espécies, na sua grande maioria espécies pioneiras, pertencentes a 19 famílias botânicas. O

  17. Rickettsia rickettsii infecting Rhipicephalus sanguineus sensu lato (Latreille 1806), in high altitude atlantic forest fragments, Ceara State, Brazil.

    Science.gov (United States)

    Silva, Arannadia Barbosa; Duarte, Myrian Morato; da Costa Cavalcante, Robson; de Oliveira, Stefan Vilges; Vizzoni, Vinicius Figueiredo; de Lima Duré, Ana Íris; de Melo Iani, Felipe Campos; Machado-Ferreira, Erik; Gazêta, Gilberto Salles

    2017-09-01

    In Brazil, Spotted Fever (SF) is caused by Rickettsia rickettsii and Rickettsia parkeri strain Atlantic Forest. In recent years, several human cases of a milder SF have been reported from the Maciço de Baturité region of Ceará State. Previous studies in this region found R. parkeri strain Atlantic Forest to be present in Rhipicephalus sanguineus sensu lato and Amblyomma ovale ticks. The present study isolated and identified the Rickettsia spp. present in this new endemic area in Brazil. In March 2015, R. sanguineus s.l. and A. ovale were collected in rural areas of the Maciço de Baturité region, and subjected to the isolation technique. A bacterium was isolated from one R. sanguineus s.l., which phylogenetic analysis clustered to the R. rickettsii group. In conclusion, R. rickettsii bacteria is circulating in the studied area and may in future have an impact on the clinical diagnoses and consequently cause changes in the profile of the disease in the region. In addition, we suggest the increase of epidemiological and environmental surveillance in the area, in order to prevent Brazilian Spotted Fever cases. Copyright © 2017. Published by Elsevier B.V.

  18. Savannah Forest Beekeepers in Cameroon: Actions to Reduce Vulnerability. Chapter 7

    NARCIS (Netherlands)

    Ingram, V.J.

    2016-01-01

    The savannah forests in Adamaoua, Cameroon, are home to traditional, forest-based beekeepers, subsistence farmers and pastoralists. This sparsely populated region is economically marginal and little developed, with lower than national average incomes. Forest apiculture is important here: honey,

  19. Occurrence of anti-Leptospira spp. antibodies in Rhipidomys spp. from a forest fragment of the Brazilian Cerrado.

    Science.gov (United States)

    Gomes, D O; Ramos, G B; Alves, V B A; Ciuffa, A Z; Cuccato, L P; Dos Reis, T F M; Lima, A M C; Gonçalves, M C; Tolesano, G V; Rodrigues, V S; Szabó, M P J

    2017-03-01

    Leptospirosis is a zoonotic disease of world importance, and its transmission depends on the interaction between humans and animals. Given the necessity to investigate potential hosts of Leptospira spp., this study verified the prevalence of different serovars in the species of Rhipidomys spp., a widespread sigmodont rodent in Brazil. The studied population originates from a semi-evergreen forest located in the county of Uberlândia, in the state of Minas Gerais. The microscopic agglutination test (MAT) was performed with 14 serovars. Thirteen out of the 43 wild rodents captured showed a positive agglutination reaction, with a greater prevalence of the serovars Pyrogenes, Copenhageni, and Canicola. This study found a prevalence of 30.3% anti-Leptospira spp. antibodies; all positive animals were reactive to more than one serovar.

  20. Immunization of Mice with Lactobacillus casei Expressing a Beta-Intimin Fragment Reduces Intestinal Colonization by Citrobacter rodentium ▿ †

    OpenAIRE

    Ferreira, P. C. D.; da Silva, J. B.; Piazza, R. M. F.; Eckmann, L.; Ho, P. L.; Oliveira, M. L. S.

    2011-01-01

    Enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea in children from developing countries. Intimate adhesion of the bacteria to intestinal cells occurs via binding of the adhesin intimin to the TIR receptor exposed on cell surfaces. Here, Lactobacillus casei expressing a fragment of β-intimin (L. casei-Intcv) was tested as mucosal vaccines in mice against intestinal colonization with the murine pathogen Citrobacter rodentium. Oral or sublingual immunization of C57BL/6 mice ...

  1. Metacommunity composition of web-spiders in a fragmented neotropical forest: relative importance of environmental and spatial effects.

    Directory of Open Access Journals (Sweden)

    Ronei Baldissera

    Full Text Available The distribution of beta diversity is shaped by factors linked to environmental and spatial control. The relative importance of both processes in structuring spider metacommunities has not yet been investigated in the Atlantic Forest. The variance explained by purely environmental, spatially structured environmental, and purely spatial components was compared for a metacommunity of web spiders. The study was carried out in 16 patches of Atlantic Forest in southern Brazil. Field work was done in one landscape mosaic representing a slight gradient of urbanization. Environmental variables encompassed plot- and patch-level measurements and a climatic matrix, while principal coordinates of neighbor matrices (PCNMs acted as spatial variables. A forward selection procedure was carried out to select environmental and spatial variables influencing web-spider beta diversity. Variation partitioning was used to estimate the contribution of pure environmental and pure spatial effects and their shared influence on beta-diversity patterns, and to estimate the relative importance of selected environmental variables. Three environmental variables (bush density, land use in the surroundings of patches, and shape of patches and two spatial variables were selected by forward selection procedures. Variation partitioning revealed that 15% of the variation of beta diversity was explained by a combination of environmental and PCNM variables. Most of this variation (12% corresponded to pure environmental and spatially environmental structure. The data indicated that (1 spatial legacy was not important in explaining the web-spider beta diversity; (2 environmental predictors explained a significant portion of the variation in web-spider composition; (3 one-third of environmental variation was due to a spatial structure that jointly explains variation in species distributions. We were able to detect important factors related to matrix management influencing the web

  2. O que é melhor para manter a riqueza de espécies de morcegos (Mammalia, Chiroptera: um fragmento florestal grande ou vários fragmentos de pequeno tamanho? What is better for maintaining the richness of bat (Mammalia, Chiroptera species: a large forest fragment or many small fragments?

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    Nelio Roberto dos Reis

    2003-06-01

    Full Text Available This study was carried out with the objective of evaluating if the size of forest fragments affects the diversity of bat species. In order to do that, seven fragments were studied in Londrina, Paraná: five small fragments, whose areas varied between 1 and 10 ha; a fragment which is considered medium-sized (Parque Municipal Arthur Thomas - 85,47 ha.; and a large fragment (Parque Estadual Mata dos Godoy - 680 ha.. Thirty three species were collected. Ten species were common to all three types of fragments: Chrotopterus auritus (Peters, 1856, Carollia perspicillata (Linnaeus, 1758, Artibeus fimbriatus Gray, 1838, Artibeus lituratus (Olfers, 1818, Platyrrhinus lineatus (E. Geoffroy, 1810, Pygoderma bilabiatum (Wagner, 1843, Sturnira lilium (E. Geoffroy, 1810, Vampyressa pusilla (Wagner, 1843, Eptesicus brasiliensis (Desmarest, 1819, and Myotis nigricans (Schinz, 1821. Eight species were only found in the large fragment: Noctilio albiventris Desmarest, 1818, Glossophaga soricina (Pallas, 1766, Uroderma bilobatum Peters, 1866, Diaemus youngi (Jentink,1893, Diphylla ecaudata Spix, 1823, Eptesicus furinalis (d'Orbigny, 1847, Histiotus velatus (I. Geoffroy, 1824 and Myotis levis (I. Geoffroy, 1824. Five were only found in the small fragments: Noctilio leporinus (Linnaeus, 1758, Phyllostomus discolor Wagner, 1843, Chiroderma villosum Peters, 1860, Eptesicus sp. e Rogheessa tumida H. Allen, 1866. Chiroderma doriae, which is threatened by extinction, was captured in the large fragment and in one of the small fragments; M. ruber, also threatened by extinction, was captured in the medium-sized and large fragments. We believe that the major cause for the loss of organic diversity is not rational exploitation, but the destruction of habitats, a result of the expansion of irrational human activities.

  3. Longhorned beetle (Coleoptera: Cerambycidae diversity in a fragmented temperate forest landscape [v2; ref status: indexed, http://f1000r.es/yz

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    Daniel M Pavuk

    2013-03-01

    Full Text Available Longhorned beetles (Coleoptera: Cerambycidae are an important component of temperate forest ecosystems.  We trapped longhorned beetles in forests in northwest Ohio during 2008 to test the hypothesis that larger forests have greater species diversity than smaller forests.  Large forests had a significantly greater cerambycid species richness than small forests (t = 3.16. P = 0.02, and there was a significant relationship between forest size and cerambycid species richness.

  4. Toxoplasma gondii in domestic and wild animals from forest fragments of the municipality of Natal, northeastern Brazil.

    Science.gov (United States)

    Fournier, Gislene Fátima da Silva Rocha; Lopes, Marcos Gomes; Marcili, Arlei; Ramirez, Diego Garcia; Acosta, Igor Cunha Lima; Ferreira, Juliana Isabel Giuli da Silva; Cabral, Aline Diniz; Lima, Júlia Tereza Ribeiro de; Pena, Hilda Fátima de Jesus; Dias, Ricardo Augusto; Gennari, Solange Maria

    2014-01-01

    Toxoplasmosis stands out as a global disease that has felines as definitive hosts. In the municipality of Natal, Rio Grande do Norte State, Brazil, two parks are notable for their ecological and social importance. This study aimed to investigate the presence of Toxoplasma gondii in short hair cats, bats and small non-volant mammals in these two ecological reserves. Altogether, biological samples were obtained from 154 mammals, 92 wild animals from both areas and 62 domestic cats of the Parque da Cidade. In total, 22 (53.7%) non-volant wild mammals, 11 (21.5%) bats and 28 (52.8%) cats were positive for IgG anti-T. gondii antibodies using the Modified Agglutination Test (≥ 25). It was possible to detect the presence of T. gondii DNA, by means of a molecular amplification of a B1 gene fragment (155bp), in 92 tissue samples from wild animals, including Didelphis albiventris, Monodelphis domestica, Artibeus lituratus, Carollia perspicillata and Glossophaga soricina. Of the 62 cats examined by the same molecular method, T. gondii DNA could be detected in 4 cats. In this study, it was observed the circulation of T. gondii in wild species and domestic cats, demonstrating the involvement of wild and domestic animals in the cycle of T. gondii.

  5. Behavioral and physiological responses to subgroup size and number of people in howler monkeys inhabiting a forest fragment used for nature-based tourism.

    Science.gov (United States)

    Aguilar-Melo, Adriana R; Andresen, Ellen; Cristóbal-Azkarate, Jurgi; Arroyo-Rodríguez, Victor; Chavira, Roberto; Schondube, Jorge; Serio-Silva, Juan Carlos; Cuarón, Alfredo D

    2013-11-01

    Animals' responses to potentially threatening factors can provide important information for their conservation. Group size and human presence are potentially threatening factors to primates inhabiting small reserves used for recreation. We tested these hypotheses by evaluating behavioral and physiological responses in two groups of mantled howler monkeys (Alouatta palliata mexicana) at the "Centro Ecológico y Recreativo El Zapotal", a recreational forest reserve and zoo located in the Mexican state of Chiapas. Both groups presented fission-fusion dynamics, splitting into foraging subgroups which varied in size among, but not within days. Neither subgroup size nor number of people had an effect on fecal cortisol. Out of 16 behavioral response variables tested, the studied factors had effects on six: four were affected by subgroup size and two were affected by number of people. With increasing subgroup size, monkeys increased daily path lengths, rested less, increased foraging effort, and used more plant individuals for feeding. As the number of people increased, monkeys spent more time in lower-quality habitat, and less time engaged in social interactions. Although fecal cortisol levels were not affected by the factors studied, one of the monkey groups had almost twice the level of cortisol compared to the other group. The group with higher cortisol levels also spent significantly more time in the lower-quality habitat, compared to the other group. Our results suggest that particular behavioral adjustments might allow howler monkeys at El Zapotal to avoid physiological stress due to subgroup size and number of people. However, the fact that one of the monkey groups is showing increased cortisol levels may be interpreted as a warning sign, indicating that an adjustment threshold is being reached, at least for part of the howler monkey population in this forest fragment. © 2013 Wiley Periodicals, Inc.

  6. Soil pretreatment and fast cell lysis for direct polymerase chain reaction from forest soils for terminal restriction fragment length polymorphism analysis of fungal communities

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    Fei Cheng

    Full Text Available Abstract Humic substances in soil DNA samples can influence the assessment of microbial diversity and community composition. Using multiple steps during or after cell lysis adds expenses, is time-consuming, and causes DNA loss. A pretreatment of soil samples and a single step DNA extraction may improve experimental results. In order to optimize a protocol for obtaining high purity DNA from soil microbiota, five prewashing agents were compared in terms of their efficiency and effectiveness in removing soil contaminants. Residual contaminants were precipitated by adding 0.6 mL of 0.5 M CaCl2. Four cell lysis methods were applied to test their compatibility with the pretreatment (prewashing + Ca2+ flocculation and to ultimately identify the optimal cell lysis method for analyzing fungal communities in forest soils. The results showed that pretreatment with TNP + Triton X-100 + skim milk (100 mM Tris, 100 mM Na4P2O7, 1% polyvinylpyrrolidone, 100 mM NaCl, 0.05% Triton X-100, 4% skim milk, pH 10.0 removed most soil humic contaminants. When the pretreatment was combined with Ca2+ flocculation, the purity of all soil DNA samples was further improved. DNA samples obtained by the fast glass bead-beating method (MethodFGB had the highest purity. The resulting DNA was successfully used, without further purification steps, as a template for polymerase chain reaction targeting fungal internal transcribed spacer regions. The results obtained by terminal restriction fragment length polymorphism analysis indicated that the MethodFGB revealed greater fungal diversity and more distinctive community structure compared with the other methods tested. Our study provides a protocol for fungal cell lysis in soil, which is fast, convenient, and effective for analyzing fungal communities in forest soils.

  7. How well can step-off and gap distances be reduced when treating intra-articular distal radius fractures with fragment specific fixation when using fluoroscopy.

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    Thiart, M; Ikram, A; Lamberts, R P

    2016-12-01

    Although fragment specific fixation has proved to be an effective treatment regime, it has not been established how successfully this treatment could be performed using fluoroscopy and what the added value of arthroscopy could be. Establish gap and step-off distances after in intra-articular distal radius fractures that have been treated with fragment specific fixation while using fluoroscopy. Forty-four patients with an intra-articular distal radius fracture were treated with fragment specific fixation while using fluoroscopy. After the treatment of the intra-articular distal radius fracture with fragment specific fixation and the use of fluoroscopy, but before the completion of the surgical intervention, all gap, and step-off distances were determined by using arthroscopy. In addition, the joint was checked for any other wrist pathologies. Arthroscopy after the surgical intervention showed that in 37 patients no gap distances could be detected, while in six patients a gap distance of≤2mm was found and in one patient, a gap distance of 3mm. Similarly, arthroscopy revealed no step-off distances in 33 patients, while in 11 patients a step-off distance of≤2mm was found. Although additional wrist pathologies were found in 48% of our population, only one patient needed surgical intervention. Three months after the surgical intervention wrist flexion was 41±10°, wrist extension 51±17°, ulnar deviation 19±10°, radial deviation 32±12° while patients could pronate and supinate their wrist to 85±5° and 74±20°, respectively. Intra-articular distal radius fractures can be treated successfully with fragment specific fixation and the use of fluoroscopy. As almost all gap and step-off distances could be reduced to an acceptable level, the scope for arthroscopy to further improve this treatment regime is limited. The functional outcome scores that were found 3 months after the surgical intervention were similar to what has been reported in other studies using

  8. Estrutura de um fragmento florestal no Engenho Humaitá, Catende, Pernambuco, Brasil Structure of a forest fragment at Humaitá sugar mill, Catende, PE, Brazil

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    Francisco J. P. Guimarães

    2009-12-01

    Full Text Available Avaliou-se, neste trabalho, a estrutura de um fragmento florestal antropizado denominado Mata das Galinhas, Engenho Humaitá, Catende, Pernambuco, e se utilizaram, para avaliar a composição florística e a estrutura fitossociológica, 14 parcelas de 10 x 25 m a fim de amostrar os indivíduos arbóreos com circunferência a 1,30 m do solo (CAP ≥ 10 cm. Foram estimados, então, densidade, frequência e dominância e valor de importância (VI e o índice de Shannon, além de registrados 438 indivíduos pertencentes a 63 espécies, 45 gêneros e 29 famílias. As famílias de maior importância foram Mimosaceae, Moraceae, Anacardiaceae e Lecythidaceae e as espécies com maiores valores de VI, foram Brosimum discolor, Parkia pendula, Eschweilera ovata, Thyrsodium spruceanum, Tapirira guianensis, Protium heptaphyllum, Casearia arborea, Helicostylis tomentosa, Dialium guianense, Schefflera morototoni, Himatanthus phagedaenicus e Cupania racemosa. Quando observado isoladamente, conclui-se que o fragmento estudado possui pouca relevância; entretanto, se considerado conjuntamente com outros fragmentos da área, sua diversidade é significativa o que justificaria esforços para sua conservação e manejo.The structure of a forest fragment, known as "Mata das Galinhas" at Humaitá sugar mill, Catende, Pernambuco, Brazil was evaluated. To evaluate the floristic composition and the phytosociological structure under anthropic action 14 plots of 10 x 25 m were used to sample the arboreal individuals with circumference at breast height (CBH ≥ 10 cm. The density, frequency, and dominance, the importance value (IV and the Shannon's index were calculated. A total of 438 individuals distributed into 63 species, 45 genera and 29 families were recorded. The families of larger importance in the study were Mimosaceae, Moraceae, Anacardiaceae and Lecythidaceae. The species with larger values of IV were Brosimum discolor, Parkia pendula, Eschweilera ovata

  9. Reducing the Flexibility of Type II Dehydroquinase for Inhibition: A Fragment-Based Approach and Molecular Dynamics Study.

    Science.gov (United States)

    Peón, Antonio; Robles, Adrián; Blanco, Beatriz; Convertino, Marino; Thompson, Paul; Hawkins, Alastair R; Caflisch, Amedeo; González-Bello, Concepción

    2017-09-21

    A multidisciplinary approach was used to identify and optimize a quinazolinedione-based ligand that would decrease the flexibility of the substrate-covering loop (catalytic loop) of the type II dehydroquinase from Helicobacter pylori. This enzyme, which is essential for the survival of this bacterium, is involved in the biosynthesis of aromatic amino acids. A computer-aided fragment-based protocol (ALTA) was first used to identify the aromatic fragments able to block the interface pocket that separates two neighboring enzyme subunits and is located at the active site entrance. Chemical modification of its non-aromatic moiety through an olefin cross-metathesis and Seebach's self-reproduction of chirality synthetic principle allowed the development of a quinazolinedione derivative that disables the catalytic loop plasticity, which is essential for the enzyme's catalytic cycle. Molecular dynamics simulations revealed that the ligand would force the catalytic loop into an inappropriate arrangement for catalysis by strong interactions with the catalytic tyrosine and by expelling the essential arginine out of the active site. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Wildlife habitat fragmentation.

    Science.gov (United States)

    John. Lehmkuhl

    2005-01-01

    A primary issue in forest wildlife management is habitat fragmentation and its effects on viability, which is the "bottom line" for plant and animal species of conservation concern. Population viability is the likelihood that a population will be able to maintain itself (remain viable) over a long period of time-usually 100 years or more. Though it is true...

  11. Boreal forests

    Energy Technology Data Exchange (ETDEWEB)

    Essen, P.A.; Ericson, L. [Univ. of Umeaa, Dept. of Ecological Botany, Umeaa (Sweden); Ehnstroem, B. [Swedish Univ., of Agricultural Sciences, Swedish Threatened Species Unit, Uppsala (Sweden); Sjoeberg, K. [Swedish Univ. of Agricultural Sciences, Dept. of Animal Ecology, Umeaa (Sweden)

    1997-10-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man`s past and present impact and outline a strategy for conservation. Natural disturbances, particularly forest fire and gap formation, create much of the structural and functional diversity in forest ecosystems. Several boreal plants and animals are adapted to fire regimes. In contrast, many organisms (epiphytic lichens, fungi, invertebrates) require stable conditions with long continuity in canopy cover. The highly mechanized and efficient Fennoscandian forest industry has developed during the last century. The result is that most natural forest has been lost and that several hundreds of species, mainly cryptograms and invertebrates, are threatened. The forestry is now in a transition from exploitation to sustainable production and has recently incorporated some measures to protect the environment. Programmes for maintaining biodiversity in the boreal forest should include at least three parts. First, the system of forest reserves must be significantly improved through protection of large representative ecosystems and key biotopes that host threatened species. Second, we must restore ecosystem properties that have been lost or altered. Natural disturbance regimes must be allowed to operate or be imitated, for example by artificial fire management. Stand-level management should particularly increase the amount of coarse woody debris, the number of old deciduous trees and large, old conifers, by using partial cutting. Third, natural variation should also be mimicked at the landscape level, for example, by reducing fragmentation and increasing links between landscape elements. Long-term experiments are required to evaluate the success of different management methods in maintaining biodiversity in the boreal forest. (au) 260 refs.

  12. Boreal forests

    International Nuclear Information System (INIS)

    Essen, P.A.; Ericson, L.; Ehnstroem, B.; Sjoeberg, K.

    1997-01-01

    We review patterns and processes important for biodiversity in the Fennoscandian boreal forest, describe man's past and present impact and outline a strategy for conservation. Natural disturbances, particularly forest fire and gap formation, create much of the structural and functional diversity in forest ecosystems. Several boreal plants and animals are adapted to fire regimes. In contrast, many organisms (epiphytic lichens, fungi, invertebrates) require stable conditions with long continuity in canopy cover. The highly mechanized and efficient Fennoscandian forest industry has developed during the last century. The result is that most natural forest has been lost and that several hundreds of species, mainly cryptograms and invertebrates, are threatened. The forestry is now in a transition from exploitation to sustainable production and has recently incorporated some measures to protect the environment. Programmes for maintaining biodiversity in the boreal forest should include at least three parts. First, the system of forest reserves must be significantly improved through protection of large representative ecosystems and key biotopes that host threatened species. Second, we must restore ecosystem properties that have been lost or altered. Natural disturbance regimes must be allowed to operate or be imitated, for example by artificial fire management. Stand-level management should particularly increase the amount of coarse woody debris, the number of old deciduous trees and large, old conifers, by using partial cutting. Third, natural variation should also be mimicked at the landscape level, for example, by reducing fragmentation and increasing links between landscape elements. Long-term experiments are required to evaluate the success of different management methods in maintaining biodiversity in the boreal forest. (au) 260 refs

  13. Efeitos da fragmentação florestal sobre as comunidades de aves - DOI: 10.4025/actascibiolsci.v25i2.2030 Effects of forest fragmentation on bird communities

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    Luiz dos Anjos

    2003-04-01

    Full Text Available Este trabalho discute os efeitos da fragmentação florestal sobre as comunidades de aves verificados em diversos estudos, e apresenta considerações para a conservação da avifauna. Os principais fatores ambientais determinantes da riqueza de aves em florestas e que são alterados no processo de fragmentação são a área florestal, o grau de isolamento, a diversidade de hábitats e o efeito de borda. Os diversos estudos diferiram em seus resultados em relação aos efeitos da fragmentação sobre a avifauna, mas alguns padrões são notáveis: 1. extinção seletiva de espécies nos fragmentos (há grupos mais susceptíveis ou mais resistentes ao processo, enquanto outros são até beneficiados; 2. densidade compensatória (aumento na densidade de algumas espécies em relação a sua densidade em florestas contínuas. Os resultados levam à conclusão de que para uma plena conservação da comunidade de aves florestais de uma região é necessária a conservação das grandes florestas, ao invés de diversos fragmentos pequenosEffects of forest fragmentation on bird communities and considerations for avifauna conservation are discussed here. Forest area, isolation, habitat diversity, and edge effect are the main environmental factors that determine bird richness in forests, and they undergo alterations during forest fragmentation. Several studies have shown different results regarding to fragmentation effects on the avifauna, and some of them are noticeable, such as: (1 selective extinction within the fragments, i. e., some groups are more susceptible than others to the process and some other groups are even benefited by fragmentation; (2 compensatory density, meaning that there is a density increase of some species in relation to their density in continuous forests. It has been enforced that it is necessary to preserve large extensions of forests instead of preserving several small fragments

  14. Trap-nests used by Centris (Heterocentris) terminata Smith (Hymenoptera: Apidae, Centridini) at secondary Atlantic Forest fragments, in Salvador, Bahia State

    International Nuclear Information System (INIS)

    Drummmont, Patricia; Viana, Blandina F.; Silva, Fabiana O. da

    2008-01-01

    Ninety-five nests of Centris (Heterocentris) terminata Smith were collected in trap nests, during November/2001 and January/2003, at two fragments (PZGV e CFO-UFBA) of secondary Atlantic Forest, in Salvador, Bahia State (13 deg 01' W and 38 deg 30' S). The highest nest frequencies occurred from December to February (summer), with no nests foundations from August to October (winter - early spring). Two-hundred eight adults emerged from 347 brood cells, being 164 males and 116 females (1: 0.42). During the study period sex ratio was male biased (χ 2 = 9.342; gl = 10; P < 0.05). C. terminata nested in holes with diameters 6, 8, 10 mm, but 84,2% were constructed in 8 and 10 mm. nests had one to seven cells arranged in a linear series with the cell's partitions built with a mixture of sand and resin or oil. Male is significantly smaller than female, which emerges from the first cells constructed. Immature mortality occurred in 14.1% of brood cells (n 49), of which 13.0% were due fail in development and 1.2% due to parasitism of Coelioxys sp. (Hymenoptera: Megachilidae) e Tetraonyx sp. (Coleoptera: Meloidae). In the study site, weather, mainly pluviosity, rather than natural enemies influenced seasonal population abundance. The long period of nesting activity, local abundance and usage of trap nests, suggest the potential of C. terminata for management aiming at pollination of native and cultivated plants. (author)

  15. Host specificity and experimental assessment of the early establishment of the mistletoe Phoradendron crassifolium (Pohl ex DC. Eichler (Santalaceae in a fragment of Atlantic Forest in southeast Brazil

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    Patrícia Aparecida Messias

    2014-12-01

    Full Text Available Mistletoe establishment relies heavily on a seed reaching a proper host plant. Small frugivorous birds usually disperse large numbers of mistletoe seeds. However, in the field, mistletoes are absent from some potential available hosts. We investigated whether the mistletoe Phoradendron crassifolium has some preferences for specific host trees in a fragment of Atlantic Forest in southeast Brazil. We surveyed 397 tree individuals of 50 species within 25 families. Seven of those species (14% bore P. crassifolium infections. Although prevalence at the individual level was low (11.6%, there were marked deviations in infection levels among species and families. Most (87% of the infections (40 of 46 occurred in species belonging to the families Anacardiaceae (Lithraea molleoides and Tapirira guianensis and Siparunaceae (Siparuna guianensis, which nevertheless accounted for only 26% of the potential individual hosts (103 of 397. We also performed an experiment simulating bird behavior. We inoculated 480 mistletoe seeds to the bark of four potential hosts in field, following the fate of the seeds for five months. No differences in host preference were observed. The low specificity detected at the local level was confirmed by a survey of exsiccata collected over the geographical distribution of the mistletoe, suggesting that P. crassifolium prevalence is more dependent on dispersal limitation than on mistletoe-host compatibility.

  16. Evaluation of natural foci of Panstrongylus megistus in a forest fragment in Porto Alegre, State of Rio Grande do Sul, Brazil

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    Jose Eloy dos Santos Jr

    2013-09-01

    Full Text Available Introduction Panstrongylus megistus is commonly found in wild environments of the State of Rio Grande do Sul, Brazil. The aim of this study was to characterize the network of refuges used by triatomine in a forest fragment of Porto Alegre and to identify Trypanosoma cruzi infection, associated hosts and the epidemiological importance of both hosts and triatomines. Methods Techniques including the spool-and-line method and active searching (transects were used to identify natural foci. Results The food source for each triatomine was determined using the precipitin test, and the infection of marsupials was determined by xenodiagnosis. A total of 33 adults (domestic environment and 27 nymphs (wild environment of P. megistus were found in addition to 43 Didelphis albiventris specimens. The infection rates of triatomine adults, triatomine nymphs and opossums with T. cruzi I were 64%, 73% and 69%, respectively. Birds, rodents and opossums were the main resources used by triatomine. Conclusions This work presents the first characterization of a natural focus of P. megistus in Rio Grande do Sul. The natural characteristics of this focus and its implication in the transmission of T. cruzi are discussed.

  17. Distribuição espacial de um fragmento de Floresta Ombrófila Mista Montana Spatial distribution of a Mixed Ombrophylus Forest fragment

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    Sebastião do Amaral Machado

    2012-06-01

    Full Text Available Este trabalho teve como objetivo analisar a distribuição espacial de um fragmento de Floresta Ombrófila Mista Montana, bem como de três espécies de grupos sucessionais distintos pertencentes a ela, pela função K de Ripley. Os dados utilizados provêm de um censo realizado em um fragmento localizado no Campus Jardim Botânico da UFPR, Curitiba-PR, onde todas as árvores com DAP acima de 10cm foram georreferenciadas. Foi utilizada uma parcela de 4 ha para a análise da distribuição espacial da floresta bem como das espécies de Araucaria angustifolia (Bertol. O. Kuntze (Araucária, Casearia Sylvestris Sw. (Cafezeiro e Cedrela fissilis Vell. (Cedro. Foi analisada a relação espacial entre as espécies, bem como a relação espacial entre classes diamétricas destas. A floresta apresentou uma distribuição espacial aleatória, entretanto, as três espécies selecionadas apresentaram um padrão espacial agregado, quando analisadas separadamente. O Cafezeiro apresentou relação de atração com a Araucária e com o Cedro; estes, por sua vez, apresentaram relação de repulsão entre si. A relação espacial entre classes de DAP da Araucária foi de atração entre os indivíduos de classes menores com os indivíduos maiores. Este resultado reflete a forma de dispersão de sementes das espécies, em que a regeneração ocorre em proximidade às árvores parentais. Para o cafezeiro e o Cedro, ocorreu agregação apenas entre os indivíduos menores.The objective of this research was to analyze the spatial distribution of a Mixed Ombrophylus Forest fragment, as well as of three species pertaining to distinct successional groups belonging to the same, by the Ripley's K function. The data came from a census carried out in a fragment located in the Campus Botanical Garden, UFPR, Curitiba - PR, Brazil, where all trees with DBH above 10cm were georeferenced. One plot with 4 ha was used for the analysis of the spatial distribution of the forest and

  18. Reconciling timber extraction with biodiversity conservation in tropical forests using reduced-impact logging

    Science.gov (United States)

    Bicknell, Jake E; Struebig, Matthew J; Davies, Zoe G; Baraloto, Christopher

    2015-01-01

    Over 20% of the world's tropical forests have been selectively logged, and large expanses are allocated for future timber extraction. Reduced-impact logging (RIL) is being promoted as best practice forestry that increases sustainability and lowers CO2 emissions from logging, by reducing collateral damage associated with timber extraction. RIL is also expected to minimize the impacts of selective logging on biodiversity, although this is yet to be thoroughly tested. We undertake the most comprehensive study to date to investigate the biodiversity impacts of RIL across multiple taxonomic groups. We quantified birds, bats and large mammal assemblage structures, using a before-after control-impact (BACI) design across 20 sample sites over a 5-year period. Faunal surveys utilized point counts, mist nets and line transects and yielded >250 species. We examined assemblage responses to logging, as well as partitions of feeding guild and strata (understorey vs. canopy), and then tested for relationships with logging intensity to assess the primary determinants of community composition. Community analysis revealed little effect of RIL on overall assemblages, as structure and composition were similar before and after logging, and between logging and control sites. Variation in bird assemblages was explained by natural rates of change over time, and not logging intensity. However, when partitioned by feeding guild and strata, the frugivorous and canopy bird ensembles changed as a result of RIL, although the latter was also associated with change over time. Bats exhibited variable changes post-logging that were not related to logging, whereas large mammals showed no change at all. Indicator species analysis and correlations with logging intensities revealed that some species exhibited idiosyncratic responses to RIL, whilst abundance change of most others was associated with time. Synthesis and applications. Our study demonstrates the relatively benign effect of reduced

  19. A window of opportunity for climate-change adaptation: Easing tree mortality by reducing forest basal area

    Science.gov (United States)

    Bradford, John B.; Bell, David M.

    2017-01-01

    Increasing aridity as a result of climate change is expected to exacerbate tree mortality. Reducing forest basal area – the cross-sectional area of tree stems within a given ground area – can decrease tree competition, which may reduce drought-induced tree mortality. However, neither the magnitude of expected mortality increases, nor the potential effectiveness of basal area reduction, has been quantified in dryland forests such as those of the drought-prone Southwest US. We used thousands of repeatedly measured forest plots to show that unusually warm and dry conditions are related to high tree mortality rates and that mortality is positively related to basal area. Those relationships suggest that while increasing high temperature extremes forecasted by climate models may lead to elevated tree mortality during the 21st century, future tree mortality might be partly ameliorated by reducing stand basal area. This adaptive forest management strategy may provide a window of opportunity for forest managers and policy makers to guide forest transitions to species and/or genotypes more suited to future climates.

  20. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    Energy Technology Data Exchange (ETDEWEB)

    Norby, Richard J [ORNL; Warren, Jeffrey [ORNL; Iversen, Colleen M [ORNL; Medlyn, Belinda [Macquarie University; McMurtrie, Ross [University of New South Wales; Hoffman, Forrest M [ORNL

    2008-01-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  1. Nitrogen Limitation is Reducing the Enhancement of NPP by Elevated CO2 in a Deciduous Forest

    Science.gov (United States)

    Norby, R. J.; Warren, J. M.; Iversen, C. M.; Medlyn, B. E.; McMurtrie, R. E.; Hoffman, F. M.

    2008-12-01

    Accurate model representation of the long-term response of forested ecosystems to elevated atmospheric CO2 concentrations (eCO2) is important for predictions of future concentrations of CO2. For biogeochemical models that predict the response of net primary productivity (NPP) to eCO2, free-air CO2 enrichment (FACE) experiments provide the only source of data for comparison. A synthesis of forest FACE experiments reported a 23% increase in NPP in eCO2, and this result has been used as a model benchmark. Here, we provide new evidence from a FACE experiment in a deciduous forest in Tennessee that N limitation has significantly reduced the stimulation of NPP by eCO2, consistent with predictions from ecosystem and global models that incorporate N feedbacks. The Liquidambar styraciflua stand has been exposed to current ambient atmospheric CO2 or air enriched with CO2 to 550 ppm since 1998. Results from the first 6 years of the experiment indicated that NPP was significantly enhanced by eCO2 and that this was a consistent and sustained response. Now, with 10 years of data, our analysis must be revised. The response of NPP to eCO2 has declined from 24% in 2001-2003 to 9% in 2007. The diminishing response to eCO2 since 2004 coincides with declining NPP in ambient CO2 plots. Productivity of this forest stand is limited by N availability, and the steady decline in forest NPP is closely related to changes in the N economy, as evidenced by declining foliar N concentrations. There is a strong linear relationship between foliar [N] and NPP, and the steeper slope in eCO2 indicates that the NPP response to eCO2 should diminish as foliar N declines. Increased fine-root production and root proliferation deeper in the soil have sustained N uptake, but not to an extent sufficient to benefit aboveground production. The mechanistic basis of the N effect on NPP resides in the photosynthetic machinery. The linear relationships between Jmax and Vcmax with foliar [N] did not change from 1998

  2. Effectiveness of strict vs. multiple use protected areas in reducing tropical forest fires: a global analysis using matching methods.

    Directory of Open Access Journals (Sweden)

    Andrew Nelson

    Full Text Available Protected areas (PAs cover a quarter of the tropical forest estate. Yet there is debate over the effectiveness of PAs in reducing deforestation, especially when local people have rights to use the forest. A key analytic problem is the likely placement of PAs on marginal lands with low pressure for deforestation, biasing comparisons between protected and unprotected areas. Using matching techniques to control for this bias, this paper analyzes the global tropical forest biome using forest fires as a high resolution proxy for deforestation; disaggregates impacts by remoteness, a proxy for deforestation pressure; and compares strictly protected vs. multiple use PAs vs indigenous areas. Fire activity was overlaid on a 1 km map of tropical forest extent in 2000; land use change was inferred for any point experiencing one or more fires. Sampled points in pre-2000 PAs were matched with randomly selected never-protected points in the same country. Matching criteria included distance to road network, distance to major cities, elevation and slope, and rainfall. In Latin America and Asia, strict PAs substantially reduced fire incidence, but multi-use PAs were even more effective. In Latin America, where there is data on indigenous areas, these areas reduce forest fire incidence by 16 percentage points, over two and a half times as much as naïve (unmatched comparison with unprotected areas would suggest. In Africa, more recently established strict PAs appear to be effective, but multi-use tropical forest protected areas yield few sample points, and their impacts are not robustly estimated. These results suggest that forest protection can contribute both to biodiversity conservation and CO2 mitigation goals, with particular relevance to the REDD agenda. Encouragingly, indigenous areas and multi-use protected areas can help to accomplish these goals, suggesting some compatibility between global environmental goals and support for local livelihoods.

  3. Forest species diversity reduces disease risk in a generalist plant pathogen invasion

    Science.gov (United States)

    Haas, Sarah E.; Hooten, Mevin B.; Rizzo, David M.; Meentemeyer, Ross K.

    2011-01-01

    Empirical evidence suggests that biodiversity loss can increase disease transmission, yet our understanding of the 'diversity-disease hypothesis' for generalist pathogens in natural ecosystems is limited. We used a landscape epidemiological approach to examine two scenarios regarding diversity effects on the emerging plant pathogen Phytophthora ramorum across a broad, heterogeneous ecoregion: (1) an amplification effect exists where disease risk is greater in areas with higher plant diversity due to the pathogen's wide host range, or (2) a dilution effect where risk is reduced with increasing diversity due to lower competency of alternative hosts. We found evidence for pathogen dilution, whereby disease risk was lower in sites with higher species diversity, after accounting for potentially confounding effects of host density and landscape heterogeneity. Our results suggest that although nearly all plants in the ecosystem are hosts, alternative hosts may dilute disease transmission by competent hosts, thereby buffering forest health from infectious disease.

  4. Forest-floor disturbance reduces chipmunk (Tamias spp.) abundance two years after variable-retention harvest of Pacific Northwestern forests

    Science.gov (United States)

    Randall J. Wilk; Timothy B. Harrington; Robert A. Gitzen; Chris C. Maguire

    2015-01-01

    We evaluated the two-year effects of variable-retention harvest on chipmunk (Tamias spp.) abundance (N^) and habitat in mature coniferous forests in western Oregon and Washington because wildlife responses to density/pattern of retained trees remain largely unknown. In a randomized complete-block design, six...

  5. Immunization of mice with Lactobacillus casei expressing a beta-intimin fragment reduces intestinal colonization by Citrobacter rodentium.

    Science.gov (United States)

    Ferreira, P C D; da Silva, J B; Piazza, R M F; Eckmann, L; Ho, P L; Oliveira, M L S

    2011-11-01

    Enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea in children from developing countries. Intimate adhesion of the bacteria to intestinal cells occurs via binding of the adhesin intimin to the TIR receptor exposed on cell surfaces. Here, Lactobacillus casei expressing a fragment of β-intimin (L. casei-Int(cv)) was tested as mucosal vaccines in mice against intestinal colonization with the murine pathogen Citrobacter rodentium. Oral or sublingual immunization of C57BL/6 mice with L. casei-Int(cv) induced anti-Int(cv) IgA in feces but no IgG in sera. Conversely, anti-Int(cv) IgG was induced in the sera of mice after sublingual immunization with purified Int(cv). All vaccines were able to decrease C. rodentium recovery from feces. However, this reduction was more evident and sustained over time in mice immunized with L. casei-Int(cv) by the sublingual route. These mice also displayed an increase in interleukin 6 (IL-6) and gamma interferon (IFN-γ) secretion by spleen cells 10 days after infection. Additionally, oral or sublingual immunization of C3H/HePas mice, which are highly susceptible to C. rodentium infection, with L. casei-Int(cv) induced anti-Int(cv) antibodies and significantly increased survival after challenge. Immunohistological analysis of colon sections revealed that C. rodentium was located in deep fractions of the tissue from C3H/HePas mice immunized with L. casei whereas superficial staining was observed in colon sections from mice immunized with L. casei-Int(cv.) The results indicate that vaccines composed of L. casei expressing intimin may represent a promising approach and that the C3H/HePas infection model with C. rodentium can be used to evaluate potential vaccines against EPEC.

  6. Immunization of Mice with Lactobacillus casei Expressing a Beta-Intimin Fragment Reduces Intestinal Colonization by Citrobacter rodentium ▿ †

    Science.gov (United States)

    Ferreira, P. C. D.; da Silva, J. B.; Piazza, R. M. F.; Eckmann, L.; Ho, P. L.; Oliveira, M. L. S.

    2011-01-01

    Enteropathogenic Escherichia coli (EPEC) is a common cause of diarrhea in children from developing countries. Intimate adhesion of the bacteria to intestinal cells occurs via binding of the adhesin intimin to the TIR receptor exposed on cell surfaces. Here, Lactobacillus casei expressing a fragment of β-intimin (L. casei-Intcv) was tested as mucosal vaccines in mice against intestinal colonization with the murine pathogen Citrobacter rodentium. Oral or sublingual immunization of C57BL/6 mice with L. casei-Intcv induced anti-Intcv IgA in feces but no IgG in sera. Conversely, anti-Intcv IgG was induced in the sera of mice after sublingual immunization with purified Intcv. All vaccines were able to decrease C. rodentium recovery from feces. However, this reduction was more evident and sustained over time in mice immunized with L. casei-Intcv by the sublingual route. These mice also displayed an increase in interleukin 6 (IL-6) and gamma interferon (IFN-γ) secretion by spleen cells 10 days after infection. Additionally, oral or sublingual immunization of C3H/HePas mice, which are highly susceptible to C. rodentium infection, with L. casei-Intcv induced anti-Intcv antibodies and significantly increased survival after challenge. Immunohistological analysis of colon sections revealed that C. rodentium was located in deep fractions of the tissue from C3H/HePas mice immunized with L. casei whereas superficial staining was observed in colon sections from mice immunized with L. casei-Intcv. The results indicate that vaccines composed of L. casei expressing intimin may represent a promising approach and that the C3H/HePas infection model with C. rodentium can be used to evaluate potential vaccines against EPEC. PMID:21900533

  7. Daily activity patterns of visits by males of four species of Eulaema (Apidae: Euglossina to odor baits in a tropical forest fragment in Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Pedro N. Melo

    2009-06-01

    Full Text Available Several studies have been conducted with bees of the subtribe Euglossina using odor baits as attractants. The objective of this study was to analyze the daily activity pattern of visits by males of four species of Eulaema - Eulaema nigrita Lepeletier, 1841, Eulaema flavescens (Friese, 1899, Eulaema cingulata (Fabricius, 1804 and Eulaema bombiformis (Packard, 1869 - to vanillin and benzyl acetate baits, and their relationship with climatic and environmental factors throughout the day in different months of the year in a tropical forest fragment in Bahia. Eulaema nigrita was the most frequent species on vanillin baits and E. flavescens was the most frequent species on benzyl acetate baits. The highest frequency of visits was observed in February and December. Activities started between 5:00 and 9:00 h. In February and November, visits of E. nigrita to the bait were observed daily, following a bimodal pattern. The same activity pattern was observed for E. bombiformis in December. Males of four species of Eulaema occurred in all remaining months in a unimodal daily activity pattern, with a higher frequency before 9:30 h. The correlation between the visiting activity to odor baits and climatic factors was low. This result can be due to bee flight activity occurring within a range of adequate climatic variation, particularly temperature, which in our study ranged from 23 to 32ºC. Daily activity patterns of Euglossina males on odor baits can represent patterns of flower fragrance collection under natural conditions, with visits usually at the time of highest production.

  8. Coleoptera (Insecta as forest fragmentation indicators in the Rio Negro sub-region of the Pantanal, Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    S. Favero

    Full Text Available The purpose of this study was to evaluate the integrity of two forest fragments in Rio Negro Pantanal sub-region, using coleopterans as environmental indicators. The study was carried out at Santa Emilia Farm in the Rio Negro sub-region, municipality of Aquidauana, Mato Grosso do Sul (19º 30' 18'' S and 55° 36' 45'' W. Two sites were selected, locally denominated as "cordilheiras" (narrow and elongated strands of elevated soil, one with low degree of anthropic disturbance (CL and the other, currently undergoing restoration process (TD. The sampling sites were determined using a GPS device. Ten pit-fall traps containing water and detergent were used for the specimens sampling, which were screened and identified. Abundance, richness, diversity and similarity were determined. Abundance was higher for CL (n = 277 than for TD (n = 251. The same was observed for the diversity indices, CL showed H' = 2.83 bit.individual-1 and TD = 2.48 bit.individual-1, confirming the interferences made for abundance. Specimens of ten families were captured in CL area and seven families in TD area, indicating higher richness in CL, when compared to TD. The linear correlation coefficient (p > 0.05 indicates that both areas are significantly different, showing similarity value of 66.7%. The data show that the structure and disturbance degree in the environment integrity influence the composition of beetles fauna, causing the increase of abundance, richness and diversity in anthropogenic environments undergoing the early stage of regeneration.

  9. SRTM-DEM and Landsat ETM+ data for mapping tropical dry forest cover and biodiversity assessment in Nicaragua

    Science.gov (United States)

    S.E. Sesnie; S.E. Hagell; S.M. Otterstrom; C.L. Chambers; B.G. Dickson

    2008-01-01

    Tropical dry and deciduous forest comprises as much as 42% of the world’s tropical forests, but has received far less attention than forest in wet tropical areas. Land use change threatens to greatly reduce the extent of dry forest that is known to contain high levels of plant and animal diversity. Forest fragmentation may further endanger arboreal mammals that play...

  10. Emerging biorefinery technologies for Indian forest industry to reduce GHG emissions.

    Science.gov (United States)

    Sharma, Naman; Nainwal, Shubham; Jain, Shivani; Jain, Siddharth

    2015-11-01

    The production of biofuels as alternative energy source over fossil fuels has gained immense interest over the years as it can contribute significantly to reduce the greenhouse gas (GHG) emissions from energy production and utilization. Also with rapidly increasing fuel price and fall in oil wells, the present scenario forces us to look for an alternative source of energy that will help us in the operation of industrial as well as the transportation sector. The pulp mills in India are one of the many options. The pulp mills in India can help us to produce bio-fuels by thermo-chemical/biochemical conversion of black liquor and wood residues. These technologies include extraction of hemi-cellulose from wooden chips and black liquor, lignin from black liquor, methanol from evaporator condensates, biogas production from waste sludge, syngas production from biomass using gasification and bio-oil production from biomass using pyrolysis. The objective of this paper is to overview these emerging bio-refinery technologies that can be implemented in Indian Forest Industry to get bio-fuels, bio-chemicals and bio-energy to reduce GHG emissions. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Polyacrylamide application versus forest residue mulching for reducing post-fire runoff and soil erosion.

    Science.gov (United States)

    Prats, Sergio Alegre; Martins, Martinho António Dos Santos; Malvar, Maruxa Cortizo; Ben-Hur, Meni; Keizer, Jan Jacob

    2014-01-15

    For several years now, forest fires have been known to increase overland flow and soil erosion. However, mitigation of these effects has been little studied, especially outside the USA. This study aimed to quantify the effectiveness of two so-called emergency treatments to reduce post-fire runoff and soil losses at the microplot scale in a eucalyptus plantation in north-central Portugal. The treatments involved the application of chopped eucalyptus bark mulch at a rate of 10-12 Mg ha(-1), and surface application of a dry, granular, anionic polyacrylamide (PAM) at a rate of 50 kg ha(-1). During the first year after a wildfire in 2010, 1419 mm of rainfall produced, on average, 785 mm of overland flow in the untreated plots and 8.4 Mg ha(-1) of soil losses. Mulching reduced these two figures significantly, by an average 52 and 93%, respectively. In contrast, the PAM-treated plots did not differ from the control plots, despite slightly lower runoff but higher soil erosion figures. When compared to the control plots, mean key factors for runoff and soil erosion were different in the case of the mulched but not the PAM plots. Notably, the plots on the lower half of the slope registered bigger runoff and erosion figures than those on the upper half of the slope. This could be explained by differences in fire intensity and, ultimately, in pre-fire standing biomass. © 2013 Elsevier B.V. All rights reserved.

  12. Análise fitossociológica de um fragmento de floresta estacional decidual no município de Jaguari, RS Fitossociological analisys of a deciduous seasonal forest fragment in Jaguari county, RS

    Directory of Open Access Journals (Sweden)

    Cristiano Hack

    2005-10-01

    Full Text Available Foi realizado um estudo da vegetação de um fragmento de Floresta Estacional Decidual, na localidade de São Roque, município de Jaguari, RS, Brasil, com objetivo de caracterizar a diversidade florística, bem como as espécies mais importantes na composição do fragmento. Para a avaliação e identificação das espécies arbóreas com Circunferência à Altura do Peito (CAP = 30cm, foram demarcadas de maneira sistemática, 14 unidades amostrais de 10x100 m (1000 m². Nestas, foram avaliadas a espécie vegetal, CAP, altura total, altura comercial, posição sociológica e classe de copa. Observou-se a ocorrência de 54 espécies arbóreas e 28 famílias. O Índice de Diversidade de Shannon foi de 3,63, indicando elevada diversidade de espécies no fragmento. As famílias Sapindaceae, Myrtaceae e Meliaceae foram, em número de espécies, as mais representativas do fragmento, sendo que as espécies com maior valor de importância foram Cupania vernalis, Patagonula americana e Cabralea canjerana. No estrato superior, as espécies dominantes foram Patagonula americana, Cabralea canjerana e Luehea divaricata.A study was made in a fragment from a Deciduous Seasonal Forest, in São Roque locality, Jaguari county, RS, Brazil, with the objective of characterizing its diversity and the most important species in the forest fragment composition. For the evaluation and identification of the forest species with CBH = 30 cm there were measured, systematically, 14 sample units with 10x100 m (1000 m². In these samples there was made an evaluation of vegetation specie, CBH, total height, commercial height, sociological position and canopy class. Was found the occurrence of 54 forest species and 28 families. The Shannon’s diversity index was 3.63 and shows the great diversity of the fragment. The Sapindaceae, Myrtaceae and Meliaceae families were the most representative in the forest fragment studied. The species with the most important value were Cupania

  13. Sensitivity of the sediment trapping capacity of an estuarine mangrove forest

    NARCIS (Netherlands)

    Willemsen, Pim Wilhelmus Johannes Maria; Horstman, Erik; Borsje, Bastiaan Wijnand; Friess, D.A.; Dohmen-Janssen, Catarine M.

    2016-01-01

    Intertidal mangrove forests exist in a dynamic coastal environment that is increasingly impacted by human interference, leading to habitat fragmentation, reduced habitat quality and changing hydrodynamic and geomorphological conditions. Biophysical feedback mechanisms are essential to maintain

  14. A fragment of the Xanthomonas oryzae pv. oryzicola harpin HpaG Xooc reduces disease and increases yield of rice in extensive grower plantings.

    Science.gov (United States)

    Chen, Lei; Zhang, Shu-Jian; Zhang, Shao-Song; Qu, Shuping; Ren, Xiuyan; Long, Juying; Yin, Qian; Qian, Jun; Sun, Feng; Zhang, Chunling; Wang, Lingxian; Wu, Xiaojing; Wu, Tingquan; Zhang, Zhongkai; Cheng, Zaiquan; Hayes, Marshall; Beer, Steven V; Dong, Hansong

    2008-07-01

    Harpins of phytopathogenic bacteria stimulate defense and plant growth in many types of plants, conferring disease resistance and enhanced yield. In a previous study, we characterized nine fragments of the harpin protein HpaG(Xooc) from Xanthomonas oryzae pv. oryzicola for plant defense elicitation and plant growth stimulation activity relative to the intact protein. In plants grown under controlled conditions, the fragment HpaG10-42 was more active in both regards than HpaG(Xooc). Here, we demonstrate that the activity of HpaG10-42 in rice under field conditions significantly exceeds that of HpaG(Xooc), stimulating resistance to three important diseases and increasing grain yield. We carried out tests in 672 experimental plots with nine cultivars of rice planted at three locations. Application protocols were optimized by testing variations in application rate, frequency, and timing with respect to rice growth stage. Of the concentrations (24, 24, 12, and 6 microg/ml), and number and timing of applications (at one to four different stages of growth) tested, HpaG10-42 at 6 microg/ml applied to plants once at nursery seedling stage and three times in the field was most effective. Bacterial blight, rice blast, and sheath blight were reduced 61.6 and 56.4, 93.6 and 76.0, and 93.2 and 55.0% in indica and japonica cultivars, respectively, relative to controls. Grain yields were 22 to 27% greater. These results are similar to results obtained with typical local management practices, including use of chemicals, to decrease disease severities and increase yield in rice. Our results demonstrate that the HpaG10-42 protein fragment can be used effectively to control diseases and increase yield of this staple food crop.

  15. Historical harvests reduce neighboring old-growth basal area across a forest landscape.

    Science.gov (United States)

    Bell, David M; Spies, Thomas A; Pabst, Robert

    2017-07-01

    While advances in remote sensing have made stand, landscape, and regional assessments of the direct impacts of disturbance on forests quite common, the edge influence of timber harvesting on the structure of neighboring unharvested forests has not been examined extensively. In this study, we examine the impact of historical timber harvests on basal area patterns of neighboring old-growth forests to assess the magnitude and scale of harvest edge influence in a forest landscape of western Oregon, USA. We used lidar data and forest plot measurements to construct 30-m resolution live tree basal area maps in lower and middle elevation mature and old-growth forests. We assessed how edge influence on total, upper canopy, and lower canopy basal area varied across this forest landscape as a function of harvest characteristics (i.e., harvest size and age) and topographic conditions in the unharvested area. Upper canopy, lower canopy, and total basal area increased with distance from harvest edge and elevation. Forests within 75 m of harvest edges (20% of unharvested forests) had 4% to 6% less live tree basal area compared with forest interiors. An interaction between distance from harvest edge and elevation indicated that elevation altered edge influence in this landscape. We observed a positive edge influence at low elevations (800 m). Surprisingly, we found no or weak effects of harvest age (13-60 yr) and harvest area (0.2-110 ha) on surrounding unharvested forest basal area, implying that edge influence was relatively insensitive to the scale of disturbance and multi-decadal recovery processes. Our study indicates that the edge influence of past clearcutting on the structure of neighboring uncut old-growth forests is widespread and persistent. These indirect and diffuse legacies of historical timber harvests complicate forest management decision-making in old-growth forest landscapes by broadening the traditional view of stand boundaries. Furthermore, the consequences

  16. Using Atmosphere-Forest Measurements To Examine The Potential For Reduced Downwind Dose

    Energy Technology Data Exchange (ETDEWEB)

    Viner, B. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2015-10-13

    A 2-D dispersion model was developed to address how airborne plumes interact with the forest at Savannah River Site. Parameters describing turbulence and mixing of the atmosphere within and just above the forest were estimated using measurements of water vapor or carbon dioxide concentration made at the Aiken AmeriFlux tower for a range of stability and seasonal conditions. Stability periods when the greatest amount of mixing of an airborne plume into the forest were found for 1) very unstable environments, when atmospheric turbulence is usually at a maximum, and 2) very stable environments, when the plume concentration at the forest top is at a maximum and small amounts of turbulent mixing can move a substantial portion of the plume into the forest. Plume interactions with the forest during stable periods are of particular importance because these conditions are usually considered the worst-case scenario for downwind effects from a plume. The pattern of plume mixing into the forest was similar during the year except during summer when the amount of plume mixed into the forest was nearly negligible for all but stable periods. If the model results indicating increased deposition into the forest during stable conditions can be confirmed, it would allow for a reduction in the limitations that restrict facility operations while maintaining conservative estimates for downwind effects. Continuing work is planned to confirm these results as well as estimate specific deposition velocity values for use in toolbox models used in regulatory roles.

  17. Insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps

    Science.gov (United States)

    Burkepile, Deron E.; Parker, John D.

    2017-01-01

    Insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. Although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. We conducted a three-year experiment (2012–2014) deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in Maryland. During this study, we tracked recruitment of all tree seedlings, as well as survivorship and growth of 889 individual seedlings from five tree species: Acer rubrum, Fagus grandifolia, Fraxinus spp., Liriodendron tulipifera, and Liquidambar styraciflua. Insect herbivores had little effect on recruitment of any tree species, although there was a weak indication that recruitment of A. rubrum was higher in the presence of herbivores. Insect herbivores reduced survivorship of L. tulipifera, but had no significant effects on A. rubrum, Fraxinus spp., F. grandifolia, or L. styraciflua. Additionally, insects reduced growth rates of early pioneer species A. rubrum, L. tulipifera, and L. styraciflua, but had little effect on more shade-tolerant species F. grandifolia and Fraxinus spp. Overall, by negatively impacting growth and survivorship of early pioneer species, forest insects may play an important but relatively cryptic role in forest gap dynamics, with potentially interesting impacts on the overall maintenance of diversity. PMID:28344904

  18. Insect herbivores increase mortality and reduce tree seedling growth of some species in temperate forest canopy gaps

    Directory of Open Access Journals (Sweden)

    Nathan P. Lemoine

    2017-03-01

    Full Text Available Insect herbivores help maintain forest diversity through selective predation on seedlings of vulnerable tree species. Although the role of natural enemies has been well-studied in tropical systems, relatively few studies have experimentally manipulated insect abundance in temperate forests and tracked impacts over multiple years. We conducted a three-year experiment (2012–2014 deterring insect herbivores from seedlings in new treefall gaps in deciduous hardwood forests in Maryland. During this study, we tracked recruitment of all tree seedlings, as well as survivorship and growth of 889 individual seedlings from five tree species: Acer rubrum, Fagus grandifolia, Fraxinus spp., Liriodendron tulipifera, and Liquidambar styraciflua. Insect herbivores had little effect on recruitment of any tree species, although there was a weak indication that recruitment of A. rubrum was higher in the presence of herbivores. Insect herbivores reduced survivorship of L. tulipifera, but had no significant effects on A. rubrum, Fraxinus spp., F. grandifolia, or L. styraciflua. Additionally, insects reduced growth rates of early pioneer species A. rubrum, L. tulipifera, and L. styraciflua, but had little effect on more shade-tolerant species F. grandifolia and Fraxinus spp. Overall, by negatively impacting growth and survivorship of early pioneer species, forest insects may play an important but relatively cryptic role in forest gap dynamics, with potentially interesting impacts on the overall maintenance of diversity.

  19. Habitat fragmentation and its lasting impact on Earth’s ecosystems

    Science.gov (United States)

    Haddad, Nick M.; Brudvig, Lars A.; Clobert, Jean; Davies, Kendi F.; Gonzalez, Andrew; Holt, Robert D.; Lovejoy, Thomas E.; Sexton, Joseph O.; Austin, Mike P.; Collins, Cathy D.; Cook, William M.; Damschen, Ellen I.; Ewers, Robert M.; Foster, Bryan L.; Jenkins, Clinton N.; King, Andrew J.; Laurance, William F.; Levey, Douglas J.; Margules, Chris R.; Melbourne, Brett A.; Nicholls, A. O.; Orrock, John L.; Song, Dan-Xia; Townshend, John R.

    2015-01-01

    We conducted an analysis of global forest cover to reveal that 70% of remaining forest is within 1 km of the forest’s edge, subject to the degrading effects of fragmentation. A synthesis of fragmentation experiments spanning multiple biomes and scales, five continents, and 35 years demonstrates that habitat fragmentation reduces biodiversity by 13 to 75% and impairs key ecosystem functions by decreasing biomass and altering nutrient cycles. Effects are greatest in the smallest and most isolated fragments, and they magnify with the passage of time. These findings indicate an urgent need for conservation and restoration measures to improve landscape connectivity, which will reduce extinction rates and help maintain ecosystem services. PMID:26601154

  20. Nuclear fragmentation

    International Nuclear Information System (INIS)

    Chung, K.C.

    1989-01-01

    An introduction to nuclear fragmentation, with emphasis in percolation ideas, is presented. The main theoretical models are discussed and as an application, the uniform expansion approximation is presented and the statistical multifragmentation model is used to calculate the fragment energy spectra. (L.C.)

  1. Catalytic Properties of the Isolated Diaphorase Fragment of the NAD+-Reducing [NiFe]-Hydrogenase from Ralstonia eutropha

    Science.gov (United States)

    Lauterbach, Lars; Idris, Zulkifli; Vincent, Kylie A.; Lenz, Oliver

    2011-01-01

    The NAD+-reducing soluble hydrogenase (SH) from Ralstonia eutropha H16 catalyzes the H2-driven reduction of NAD+, as well as reverse electron transfer from NADH to H+, in the presence of O2. It comprises six subunits, HoxHYFUI2, and incorporates a [NiFe] H+/H2 cycling catalytic centre, two non-covalently bound flavin mononucleotide (FMN) groups and an iron-sulfur cluster relay for electron transfer. This study provides the first characterization of the diaphorase sub-complex made up of HoxF and HoxU. Sequence comparisons with the closely related peripheral subunits of Complex I in combination with UV/Vis spectroscopy and the quantification of the metal and FMN content revealed that HoxFU accommodates a [2Fe2S] cluster, FMN and a series of [4Fe4S] clusters. Protein film electrochemistry (PFE) experiments show clear electrocatalytic activity for both NAD+ reduction and NADH oxidation with minimal overpotential relative to the potential of the NAD+/NADH couple. Michaelis-Menten constants of 56 µM and 197 µM were determined for NADH and NAD+, respectively. Catalysis in both directions is product inhibited with K I values of around 0.2 mM. In PFE experiments, the electrocatalytic current was unaffected by O2, however in aerobic solution assays, a moderate superoxide production rate of 54 nmol per mg of protein was observed, meaning that the formation of reactive oxygen species (ROS) observed for the native SH can be attributed mainly to HoxFU. The results are discussed in terms of their implications for aerobic functioning of the SH and possible control mechanism for the direction of catalysis. PMID:22016788

  2. Splitting the Difference: A Proposal for Benefit Sharing in Reduced Emissions from Deforestation and Forest Degradation (REDD+

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    Arturo Balderas Torres

    2012-03-01

    Full Text Available The objective of REDD+ is to create incentives for the reduction of emissions from deforestation and forest degradation and for the increase of carbon stocks through the enhancement, conservation and sustainable management of forests in developing countries. As part of the international negotiations under the United Nations Framework Convention on Climate Change (UNFCCC, compensation would be estimated in relation to national performance but how these incentives will be channeled within countries has not been specified and there are concerns about how the benefits will be shared among different stakeholders. One central issue is that under the national approach good performance in one region can be offset by underperformance in other regions of the country thus preventing the generation of predictable local incentives. Other issues relate to the need to provide incentives to a wide range of stakeholders and to avoid perverse reactions. To address these and other issues we propose separating the accounting of reduced deforestation, reduced degradation and enhancement of forests. The local attribution of credits would be easier for carbon enhancement, and possibly reduced degradation, than for reduced deforestation, since carbon gains can, in principle, be measured locally in the first two cases, while estimating achievements in reduced deforestation requires a regional approach. This separation in attribution of rewards can help to create adequate incentives for the different stakeholders and overcome some of the problems associated with the design and implementation of national REDD+ programs.

  3. Airborne dust absorption by semi-arid forests reduces PM pollution in nearby urban environments.

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    Uni, Daphna; Katra, Itzhak

    2017-11-15

    Dust storms are a major source of global atmospheric particulate matter (PM), having significant impacts on air pollution and human health. During dust storms, daily averages of atmospheric PM concentrations can reach high levels above the World Health Organization (WHO) guideline for air quality. The objective of this study was to explore the impact of forests on PM distribution following dust events in a region that is subjected to frequent dust storms (Northern Negev, Israel). Dust was measured in a forest transect including urban environments that are nearby the forest and at a distal location. During a background period, without dust events, the forest with its surrounding areas were characterized by lower monthly average of PM concentrations (38μg/m 3 ) compared with areas that are not affected by the forest (54μg/m 3 ). Such difference can be meaningful for long-term human health exposure. A reduction in PM levels in the forest transect was evident at most measured dust events, depending on the storm intensity and the locations of the protected areas. A significant reduction in PM 2.5 /PM 10 during dust events, indicates the high efficiency of the forest trees to absorb airborne PM 2.5 . Analysis of dust particles absorbed on the foliage revealed a total dust deposits of 8.1-9.2g/m 2 , which is equal to a minimum of 418.2tons removed from the atmosphere per a forest foliage area (30km 2 ). The findings can support environmental strategies to enhance life quality in regions that are subjected to dust storms, or under potential risk of dust-related PM due to land use and/or climate changes. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Forest Cover Estimation in Ireland Using Radar Remote Sensing: A Comparative Analysis of Forest Cover Assessment Methodologies

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    Devaney, John; Barrett, Brian; Barrett, Frank; Redmond, John; O`Halloran, John

    2015-01-01

    Quantification of spatial and temporal changes in forest cover is an essential component of forest monitoring programs. Due to its cloud free capability, Synthetic Aperture Radar (SAR) is an ideal source of information on forest dynamics in countries with near-constant cloud-cover. However, few studies have investigated the use of SAR for forest cover estimation in landscapes with highly sparse and fragmented forest cover. In this study, the potential use of L-band SAR for forest cover estimation in two regions (Longford and Sligo) in Ireland is investigated and compared to forest cover estimates derived from three national (Forestry2010, Prime2, National Forest Inventory), one pan-European (Forest Map 2006) and one global forest cover (Global Forest Change) product. Two machine-learning approaches (Random Forests and Extremely Randomised Trees) are evaluated. Both Random Forests and Extremely Randomised Trees classification accuracies were high (98.1–98.5%), with differences between the two classifiers being minimal (<0.5%). Increasing levels of post classification filtering led to a decrease in estimated forest area and an increase in overall accuracy of SAR-derived forest cover maps. All forest cover products were evaluated using an independent validation dataset. For the Longford region, the highest overall accuracy was recorded with the Forestry2010 dataset (97.42%) whereas in Sligo, highest overall accuracy was obtained for the Prime2 dataset (97.43%), although accuracies of SAR-derived forest maps were comparable. Our findings indicate that spaceborne radar could aid inventories in regions with low levels of forest cover in fragmented landscapes. The reduced accuracies observed for the global and pan-continental forest cover maps in comparison to national and SAR-derived forest maps indicate that caution should be exercised when applying these datasets for national reporting. PMID:26262681

  5. Forest Cover Estimation in Ireland Using Radar Remote Sensing: A Comparative Analysis of Forest Cover Assessment Methodologies.

    Directory of Open Access Journals (Sweden)

    John Devaney

    Full Text Available Quantification of spatial and temporal changes in forest cover is an essential component of forest monitoring programs. Due to its cloud free capability, Synthetic Aperture Radar (SAR is an ideal source of information on forest dynamics in countries with near-constant cloud-cover. However, few studies have investigated the use of SAR for forest cover estimation in landscapes with highly sparse and fragmented forest cover. In this study, the potential use of L-band SAR for forest cover estimation in two regions (Longford and Sligo in Ireland is investigated and compared to forest cover estimates derived from three national (Forestry2010, Prime2, National Forest Inventory, one pan-European (Forest Map 2006 and one global forest cover (Global Forest Change product. Two machine-learning approaches (Random Forests and Extremely Randomised Trees are evaluated. Both Random Forests and Extremely Randomised Trees classification accuracies were high (98.1-98.5%, with differences between the two classifiers being minimal (<0.5%. Increasing levels of post classification filtering led to a decrease in estimated forest area and an increase in overall accuracy of SAR-derived forest cover maps. All forest cover products were evaluated using an independent validation dataset. For the Longford region, the highest overall accuracy was recorded with the Forestry2010 dataset (97.42% whereas in Sligo, highest overall accuracy was obtained for the Prime2 dataset (97.43%, although accuracies of SAR-derived forest maps were comparable. Our findings indicate that spaceborne radar could aid inventories in regions with low levels of forest cover in fragmented landscapes. The reduced accuracies observed for the global and pan-continental forest cover maps in comparison to national and SAR-derived forest maps indicate that caution should be exercised when applying these datasets for national reporting.

  6. A Conformational Change of C Fragment of Tetanus Neurotoxin Reduces Its Ganglioside-Binding Activity but Does Not Destroy Its Immunogenicity ▿

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    Yu, Rui; Yi, Shaoqiong; Yu, Changming; Fang, Ting; Liu, Shuling; Yu, Ting; Song, Xiaohong; Fu, Ling; Hou, Lihua; Chen, Wei

    2011-01-01

    The C fragment of tetanus neurotoxin (TeNT-Hc) with different conformations was observed due to the four cysteine residues within it which could form different intramolecular disulfide bonds. In this study, we prepared and compared three types of monomeric TeNT-Hc with different conformational components: free sulfhydryls (50 kDa), bound sulfhydryls (44 kDa), and a mixture of the two conformational proteins (half 50 kDa and half 44 kDa). TeNT-Hc with bound sulfhydryls reduced its binding activity to ganglioside GT1b and neuronal PC-12 cells compared to what was seen for TeNT-Hc with free sulfhydryls. However, there was no significant difference among their immunogenicities in mice, including induction of antitetanus toxoid IgG titers, antibody types, and protective capacities against tetanus neurotoxin challenge. Our results showed that the conformational changes of TeNT-Hc resulting from disulfide bond formation reduced its ganglioside-binding activity but did not destroy its immunogenicity, and the protein still retained continuous B cell and T cell epitopes; that is, the presence of the ganglioside-binding site within TeNT-Hc may be not essential for the induction of a fully protective antitetanus response. TeNT-Hc with bound sulfhydryls may be developed into an ideal human vaccine with a lower potential for side effects. PMID:21813664

  7. Tree Size Inequality Reduces Forest Productivity: An Analysis Combining Inventory Data for Ten European Species and a Light Competition Model.

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    Bourdier, Thomas; Cordonnier, Thomas; Kunstler, Georges; Piedallu, Christian; Lagarrigues, Guillaume; Courbaud, Benoit

    2016-01-01

    Plant structural diversity is usually considered as beneficial for ecosystem functioning. For instance, numerous studies have reported positive species diversity-productivity relationships in plant communities. However, other aspects of structural diversity such as individual size inequality have been far less investigated. In forests, tree size inequality impacts directly tree growth and asymmetric competition, but consequences on forest productivity are still indeterminate. In addition, the effect of tree size inequality on productivity is likely to vary with species shade-tolerance, a key ecological characteristic controlling asymmetric competition and light resource acquisition. Using plot data from the French National Geographic Agency, we studied the response of stand productivity to size inequality for ten forest species differing in shade tolerance. We fitted a basal area stand production model that included abiotic factors, stand density, stand development stage and a tree size inequality index. Then, using a forest dynamics model we explored whether mechanisms of light interception and light use efficiency could explain the tree size inequality effect observed for three of the ten species studied. Size inequality negatively affected basal area increment for seven out of the ten species investigated. However, this effect was not related to the shade tolerance of these species. According to the model simulations, the negative tree size inequality effect could result both from reduced total stand light interception and reduced light use efficiency. Our results demonstrate that negative relationships between size inequality and productivity may be the rule in tree populations. The lack of effect of shade tolerance indicates compensatory mechanisms between effect on light availability and response to light availability. Such a pattern deserves further investigations for mixed forests where complementarity effects between species are involved. When studying the

  8. Comunidades de abelhas Euglossina (Hymenoptera, Apidae em fragmentos de Mata Atlântica no Sudeste do Brasil Euglossine bee (Hymenoptera, Apidae community in Atlantic Forest fragments in southeastern Brazil

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    André Villaça Ramalho

    2009-01-01

    (21 ha e Afetiva (19 ha. 4094 individuals belonging to 17 species of three genera (Euglossa, Eulaema and Exaerete were captured. The species with highest values of relative abundance were Euglossa cordata (Linnaeus, 1758, Eulaema cingulata (Fabricius, 1804, Eulaema nigrita Lepeletier, 1841 and Euglossa sapphirina Moure, 1968, the last one being more important in the smaller remnants. Among the collected species Euglossa analis Westwood, 1840 is suggested as possible indicator of preserved forests. Comparing the five areas, positive and significant correlations were observed, bee species richness with area size and bee diversity (H' with floristic diversity (H'. These results suggest that losses in forest size and habitat quality influence euglossine bee communities negatively by reducing the abundance and richness of species. The highest similarity values were observed in the Imbaú region remnants, distant from each other by up to 2 km, suggesting that these areas are not isolated for euglossine populations, or they have been suffering similar fragmentation effects.

  9. Prolongation of soil frost resulting from reduced snow cover increases nitrous oxide emissions from boreal forest soil

    Energy Technology Data Exchange (ETDEWEB)

    Maljanen, M.; Martikainen, P.J. (Univ. of Kuopio, Dept. of Environmental Science (Finland)); Alm, J.; Repo, T. (Finnish Forest Research Inst., Joensuu Research Centre (Finland))

    2010-07-01

    Emission rates of the greenhouse gas, nitrous oxide (N{sub 2}O), from northern upland forest soils are generally low. According to recent climate scenarios, the snow cover in the boreal region is predicted to decrease and which will result in lower soil temperatures. In this study, we investigated whether lower soil temperatures during winter can also trigger N{sub 2}O emissions from boreal forest soils with originally low N{sub 2}O emissions, as has earlier been shown for northern agricultural soils with higher N{sub 2}O emissions. We measured the N{sub 2}O emissions from a spruce forest in eastern Finland where the soil temperature was changed by manipulating snow-pack thickness and using insulating covers. The effects of the treatments on methane (CH{sub 4}) and carbon dioxide (CO{sub 2}) fluxes were also studied for comparative purposes. The results show that there can be an increase in N{sub 2}O emissions and CO{sub 2} production rate from boreal upland forest soils resulting from a thinner snow cover that causes a prolongation of soil frost. Reducing the snow pack thickness had only minor effects on the CH{sub 4} fluxes. (orig.)

  10. Efficacy of hand-broadcast application of baits containing 0.005% diphacinone in reducing rat populations in Hawaiian forests

    Science.gov (United States)

    Foote, David; Lindsey, Gerald D.; Perry, Charlotte F.; Spurr, Eric

    2013-01-01

    Introduced black rats (Rattus rattus), Polynesian rats (R. exulans/i>), and Norway rats (R. norvegicus) impact insular bird, plant, and invertebrate populations worldwide. We investigated the efficacy of hand-broadcast application of Ramik® Green containing 0.005% diphacinone for rodent control in paired 4-ha treatment and non-treatment plots in both wet and mesic forest in Hawaiʽi. Radio telemetry of black rats, the predominant species, indicated 100% mortality in both treatment plots within about one week of bait application. Live trapping and non-toxic census bait block monitoring two to four weeks after each of 12 repeat bait applications in the wet forest, and three repeat bait applications in the mesic forest, indicated rat abundance was reduced on average by 84–88%. However, reinvasion could have occurred within this time. Rat populations in the treatment plots usually recovered to pre-poison levels within two to five months. House mice (Mus musculus), Indian mongooses (Herpestes auropunctatus), and feral cats (Felis catus) also ate bait or other animals that had eaten bait. This study demonstrates the efficacy of ground-based broadcast toxicant baits for the control of rats in Hawaiian montane wet forests.

  11. Effects of reduced impact logging on bat biodiversity in terra firme forest of lowland Amazonia.

    Science.gov (United States)