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Sample records for forest fragmentation behavioral

  1. Behavioral modifications in northern bearded saki monkeys (Chiropotes satanas chiropotes) in forest fragments of central Amazonia.

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    Boyle, Sarah Ann; Smith, Andrew T

    2010-01-01

    We investigated behavioral differences among seven groups of northern bearded saki monkeys (Chiropotes satanas chiropotes) living in five forest fragments and two areas of continuous forest at the Biological Dynamics of Forest Fragments Project study area, located approximately 80 km north of Manaus, Brazil. We collected data in six research cycles from July-August 2003 to January 2005-April 2006. When bearded saki monkeys were present in a study area, we followed the group from dawn until dusk for three consecutive days. Every 5 min, we conducted behavioral scans of all visible individuals. There was a positive relationship between forest size and group size, but animals in the small forest fragments lived at greater densities. Bearded saki monkeys in the smaller fragments spent more time resting, less time traveling, and less time vocalizing, but there was no relationship between forest size and the amount of time spent feeding. Our results indicate that the main behavioral differences among the groups are related to the amount of forest resources (e.g., fruit trees, space) available to the monkeys in the smaller fragments, as well as the resulting smaller group sizes. We stress the need to preserve large tracts of forest and provide connectivity between forest patches.

  2. The Effects of Selective Logging Behaviors on Forest Fragmentation and Recovery

    OpenAIRE

    Rondon, Xanic J.; Cumming, Graeme S; Cossío, Rosa E.; Jane Southworth

    2012-01-01

    To study the impacts of selective logging behaviors on a forest landscape, we developed an intermediate-scale spatial model to link cross-scale interactions of timber harvesting, a fine-scale human activity, with coarse-scale landscape impacts. We used the Lotka-Volterra predator-prey model with Holling’s functional response II to simulate selective logging, coupled with a cellular automaton model to simulate logger mobility and forest fragmentation. Three logging scenarios were simulated, ea...

  3. The Effects of Selective Logging Behaviors on Forest Fragmentation and Recovery

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    Xanic J. Rondon

    2012-01-01

    Full Text Available To study the impacts of selective logging behaviors on a forest landscape, we developed an intermediate-scale spatial model to link cross-scale interactions of timber harvesting, a fine-scale human activity, with coarse-scale landscape impacts. We used the Lotka-Volterra predator-prey model with Holling’s functional response II to simulate selective logging, coupled with a cellular automaton model to simulate logger mobility and forest fragmentation. Three logging scenarios were simulated, each varying in timber harvesting preference and logger mobility. We quantified forest resilience by evaluating (1 the spatial patterns of forest fragmentation, (2 the time until the system crossed a threshold into a deforested state, and (3 recovery time. Our simulations showed that logging behaviors involving decisions made about harvesting timber and mobility can lead to different spatial patterns of forest fragmentation. They can, together with forest management practices, significantly delay or accelerate the transition of a forest landscape to a deforested state and its return to a recovered state. Intermediate-scale models emerge as useful tools for understanding cross-scale interactions between human activities and the spatial patterns that are created by anthropogenic land use.

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

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    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.

  5. Fragmentation of eastern United States forest types

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    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...

  6. Behavior and foraging technique of the Ingram's squirrel Guerlinguetus ingrami (Sciuridae: Rodentia in an Araucaria moist forest fragment

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    Calebe Pereira Mendes

    2014-06-01

    Full Text Available This work describes the foraging techniques, body positions and behavior of free-ranging Ingram's squirrel Guerlinguetus ingrami Thomas, 1901 in a region of the Araucaria moist forest, in the Atlantic Forest of southern Brazil. The animals were observed using the "all occurrence sampling" method with the aid of binoculars and a digital camcorder. All behaviors were described in diagrams and an ethogram. We recorded five basic body positions, 24 behaviors, two food choices, and three feeding strategies utilized to open fruits of Syagrus romanzoffiana (Cham., the main food source of Ingram's squirrels. We also observed a variance in the animals' stance, which is possibly influenced by predation risk, and discuss the causes of some behaviors.

  7. 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.

  8. Global Forest Area Trends Underestimate Threats from Forest Fragmentation

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    Forest loss and fragmentation of the remainder threaten the ecological attributes and functions which depend upon forests1. Forest interior area is particularly valued because it is relatively remote from human influence2, 3, 4, 5. Recent global assessments report declines in t...

  9. Global Forest Area Trends Underestimate Threats from Forest Fragmentation

    Science.gov (United States)

    Forest loss and fragmentation of the remainder threaten the ecological attributes and functions which depend upon forests1. Forest interior area is particularly valued because it is relatively remote from human influence2, 3, 4, 5. Recent global assessments report declines in t...

  10. Use of space, activity patterns, and foraging behavior of red howler monkeys (Alouatta seniculus) in an Andean forest fragment in Colombia.

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    Palma, Ana Cristina; Vélez, Adriana; Gómez-Posada, Carolina; López, Harrison; Zárate, Diego A; Stevenson, Pablo R

    2011-10-01

    Howler monkeys are among the most studied primates in the Neotropics, however, behavioral studies including estimation of food availability in Andean forests are scarce. During 12 months we studied habitat use, behavior, and feeding ecology of two groups of red howler monkeys (Alouatta seniculus) in an isolated fragment in the Colombian Andes. We used a combination of focal animal and instantaneous sampling. We estimated fruit production (FP) using phenology transects, and calculated young leaf abundance by observing marked trees. The home range area used by each group was 10.5 and 16.7 ha and daily distances traveled were 431 ± 228 and 458 ± 259 m, respectively. We found that both groups spent most of their time resting (62-64%). Resting time did not increase with leaf consumption as expected using a strategy of energy minimization. We did not find a relationship between daily distances traveled and leaf consumption. However, howlers consumed fruits according to their availability, and the production of young leaves did not predict feeding time on this resource. Overall, our results are similar to those found on other forest types. We found that despite limited FP in Andean forests, this did not lead to a higher intake of leaves, longer resting periods, or shorter traveling distances for red howlers.

  11. Long-term effects of fragmentation and fragment properties on bird species richness in Hawaiian forests

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    David J. Flaspohler; Christian P. Giardina; Gregory P. Asner; Patrick Hart; Jonathan Price; Cassie Ka’apu Lyons; Xeronimo. Castaneda

    2010-01-01

    Forest fragmentation is a common disturbance affecting biological diversity, yet the impacts of fragmentation on many forest processes remain poorly understood. Forest restoration is likely to be more successful when it proceeds with an understanding of how native and exotic vertebrates utilize forest patches of different size. We used a system of forest fragments...

  12. Distribution and Causes of Global Forest Fragmentation

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    K. Bruce Jones

    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.

  13. Forest fragmentation and Lyme disease

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    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...

  14. Temporal change in fragmentation of continental US forests

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    James D. Wickham; Kurt H. Riitters; Timothy G. Wade; Collin Homer

    2008-01-01

    Changes in forest ecosystem function and condition arise from changes in forest fragmentation. Previous studies estimated forest fragmentation for the continental United States (US). In this study, new temporal land-cover data from the National Land Cover Database (NLCD) were used to estimate changes in forest fragmentation at multiple scales for the continental US....

  15. 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...

  16. Behavioral and physiological responses to subgroup size and number of people in howler monkeys inhabiting a forest fragment used for nature-based tourism.

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    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.

  17. Tropical Forest Landscape Fragmentation in Batang Toru Watershed, North Sumatra

    OpenAIRE

    Samsuri Samsuri; I Nengah Surati Jaya; Cecep Kusmana; Kukuh Murtilaksono

    2014-01-01

    Timber-based forest management is now shifting to as broader scope including ecosystem-based management. Timber-oriented forest management frequently affects the fragmentation of forest landscape. This paper defines the degree of forest landscape fragmentation in Batang Toru watershed, North Sumatra through indentification of correlation between forest landscape fragmentation and driving factors including biophysical and anthropogenic factors. Identification structure, pattern, and fragmentat...

  18. National assessment of the evolution of forest fragmentation in Mexico

    Institute of Scientific and Technical Information of China (English)

    Rafael Moreno-Sanchez; Francisco Moreno-Sanchez; Juan Manuel Torres-Rojo

    2011-01-01

    This paper presents assessments of the fragmentation of the temperate and tropical forests in Mexico at the national level for two dates 1993 and 2002. The study was based on land use and vegetation cover data sets scale 1:250,000. Two broad forest types (Temperate Forests and Tropical Forests) and five more specific forest types (Broadleaf Forests, and Coniferous Forests; Tropical Dry Deciduous Forests, Tropic al Sub-evergreen Forests, and Tropical Evergreen Forests) were defined to conduct the analyses. FragStats 3.3 was used to estimate nine metrics of the spatial pattern of the forests for each forest type and date considered. The results indicate that the land cover transitions that have occurred between 1993 and 2002 have resulted in more isolated forest patches with simpler shapes in both the Temperate and Tropical Forests.The remaining Tropical Forest patches have become smaller and more numerous. In contrast, the remaining Temperate Forest patches are fewer and on average larger. Of the more specific forest types defined in this study, the Broadleaf Forests have the highest indicators of fragmentation.However these forests are usually embedded or adjacent to Coniferous Forests. Of more concern for conservation purposes are the high values of fragmentation metrics found for the Tropical Evergreen Forests and Tropical Dry Deciduous Forests, because these forest types are usually surrounded by non-forest land covers or anthropogenic land uses.

  19. Fragmentation of Forest Communities in the Eastern United States

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    Forest fragmentation threatens the sustainability of forest communities and therefore the beta diversity of forestland in the eastern United States. We combined forest inventory data with land cover data to compare 70 forest communities in terms of the amount and ownership of int...

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

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    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...

  1. 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.

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

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    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

  3. Tropical forest fragmentation limits pollination of a keystone understory herb.

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    Hadley, Adam S; Frey, Sarah J K; Robinson, W Douglas; Kress, W John; Betts, Matthew G

    2014-08-01

    Loss of native vegetation cover is thought to be a major driver of declines in pollination success worldwide. However, it is not well known whether reducing the fragmentation of remaining vegetation can ameliorate these negative effects. We tested the independent effects of composition vs. configuration on the reproductive success of a keystone tropical forest herb (Heliconia tortuosa). To do this we designed a large-scale mensurative experiment that independently varied connected forest-patch size (configuration) and surrounding amount of forest (composition). In each patch, we tested whether pollen tubes, fruit, and seed set were associated with these landscape variables. We also captured hummingbirds as an indication of pollinator availability in a subset of patches according to the same design. We found evidence for an effect of configuration on seed set of H. tortuosa, but not on other aspects of plant reproduction; proportion of seeds produced increased 40% across the gradient in patch size we observed (0.64 to > 1300 ha), independent of the amount of forest in the surrounding landscape at both local and landscape scales. We also found that the availability of pollinators was dependent upon forest configuration; hummingbird capture rates increased three and one-half times across the patch size gradient, independent of forest amount. Finally, pollinator availability was strongly positively correlated with seed set. We hypothesize that the effects of configuration on plant fitness that we observed are due to reduced pollen quality resulting from altered hummingbird availability and/or movement behavior. Our results suggest that prioritizing larger patches of tropical forest may be particularly important for conservation of this species.

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

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    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

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

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    Barrantes, Gilbert; Ocampo, Diego; Ramírez-Fernández, José D.

    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. PMID:27672498

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

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    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

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

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    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.

  8. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project

    OpenAIRE

    Ewers, Robert M.; Didham, Raphael K.; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L.; Turner, Edgar C.

    2011-01-01

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project repres...

  9. 'Islands' in an island: multiscale effects of forest fragmentation on lowland forest birds in Taiwan

    OpenAIRE

    Lin, Fang-yee

    2013-01-01

    Intensive agricultural developments and increasing human population has caused severe lowland-forest loss and fragmentation in the western coastal plain in Taiwan over the past centuries. The goal of this study is to explore the multiscale impacts of forest fragmentation on species richness and community composition of lowland-forest birds in Taiwan. At a regional scale, Island Biogeography Theory was applied to examine area and isolation effects on species richness of lowland-forest birds us...

  10. Effects of forest fragmentation on amazonian understory bird communities

    OpenAIRE

    Bierregaard Jr,Richard O.; Lovejoy, Thomas

    1989-01-01

    SUMMARYData form an intensive mist-netting mark-recapture program in the central Amazon demostrate significant changes in the undesrtory avian community in isolate patches of 1 and 10 ha of terra firme forest. Following isolation, capture rates increase significantly as birds fleeing the felled forest entered the. newly formed forest fragments. Movement to and from the reserve is restricted, as witnessed by an increase in recapture percentages following isolation. Species of birds that axe. o...

  11. Fragmented forest in tropical landscape--the case of the State of Selangor, Malaysia

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    This paper presents the pattern and changes of fragmented forest in relation with changes of total forest cover in the state of Selangor in three decades.In this study, inventoried forest cover maps of Selangor in 1971/1972, 1981/1982 and 1991/1992 produced by the Forestry Department of Peninsular Malaysia were digitized to examine the changes in area and number of fragmented forest.Results showed that in 1971/ 1972, 16 fragmented forests were identified in Selangor.All fragmented forests were identified as dipterocarp forest.A decade later the number of fragmented forests increased by approximately 44% (23).Of the 23 fragmented forests, two were peat swamp forests whereas the remaining were dipterocarp forests.In 1991/1992 the number of fragmented forests (12) was reduced by 47.8%.Two of the fragmented forests were identified as peat swamp forest, seven dipterocarp forest and the other three was mixed of dipterocarp forests and plantation forests.Fragmentation of both dipterocarp and peat swamp forests occurred profoundly during the period between 1971/1972 and 1981/1982, which consequently increased the number of fragmented forests compared with before the period of 1971/1972 where fragmentation happened only at dipterocarp forests.However, many fragmented forests vanished between the 1981/1982 and 1991/1992 periods.

  12. 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 th

  13. FOREST FRAGMENTATION AS AN ECONOMIC INDICATOR

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    Despite concern over the ecological consequences of conversion of land from natural cover to anthropogenic uses, there are few studies that show a quantitative relationship between fragmentation and economic factors. For the southside economic region of Virginia, we generated a ...

  14. The paradox of forest fragmentation genetics

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    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...

  15. Changes in fragmentation of western Washington forest land (Project WC-EM-08-01)

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    Andrew Gray

    2013-01-01

    Land conversion and forest fragmentation is an important issue across the country. Forest fragmentation is one of the international Montréal criteria and indicators that the Forest Service, U.S. Department of Agriculture, must assess periodically (Riitters and others 2004). Characteristics of increased fragmentation include increases in the amount of forest-nonforest...

  16. 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....

  17. Forests on thawing permafrost: fragmentation, edge effects, and net forest loss.

    Science.gov (United States)

    Baltzer, Jennifer L; Veness, Tyler; Chasmer, Laura E; Sniderhan, Anastasia E; Quinton, William L

    2014-03-01

    Much of the world's boreal forest occurs on permafrost (perennially cryotic ground). As such, changes in permafrost conditions have implications for forest function and, within the zone of discontinuous permafrost (30-80% permafrost in areal extent), distribution. Here, forested peat plateaus underlain by permafrost are elevated above the surrounding permafrost-free wetlands; as permafrost thaws, ground surface subsidence leads to waterlogging at forest margins. Within the North American subarctic, recent warming has produced rapid, widespread permafrost thaw and corresponding forest loss. Although permafrost thaw-induced forest loss provides a natural analogue to deforestation occurring in more southerly locations, we know little about how fragmentation relates to subsequent permafrost thaw and forest loss or the role of changing conditions at the edges of forested plateaus. We address these knowledge gaps by (i) examining the relationship of forest loss to the degree of fragmentation in a boreal peatland in the Northwest Territories, Canada; and (ii) quantifying associated biotic and abiotic changes occurring across forest-wetland transitions and extending into the forested plateaus (i.e., edge effects). We demonstrate that the rate of forest loss correlates positively with the degree of fragmentation as quantified by perimeter to area ratio of peat plateaus (edge : area). Changes in depth of seasonal thaw, soil moisture, and effective leaf area index (LAIe ) penetrated the plateau forests by 3-15 m. Water uptake by trees was sevenfold greater in the plateau interior than at the edges with direct implications for tree radial growth. A negative relationship existed between LAIe and soil moisture, suggesting that changes in vegetation physiological function may contribute to changing edge conditions while simultaneously being affected by these changes. Enhancing our understanding of mechanisms contributing to differential rates of permafrost thaw and associated

  18. Chimpanzee seed dispersal in a montane forest fragment in Rwanda.

    Science.gov (United States)

    Chancellor, Rebecca L; Rundus, Aaron S; Nyandwi, Sylvain

    2017-03-01

    Primate seed dispersal plays an important role in forest regeneration. It may be particularly important to anthropogenically disturbed habitats such as forest fragments. However, few studies have examined primate seed dispersal in these types of environments. Chimpanzees (Pan troglodytes) are frugivorous and large-bodied, and are therefore able to disperse both large and small seeds, making them an important seed dispersal species. We examined chimpanzee seed dispersal in Gishwati forest, a 14 km(2) montane rainforest fragment in Rwanda. We systematically collected ≤24-hr-old fecal samples and counted the number of seeds of each fruit species. We also recorded observations of seeds found in wadges. We found that chimpanzees dispersed at least 18 fruit species in 14 families in their feces. Ninety-five percent of feces had seeds, the most common of which were Ficus spp., Myrianthus holstii, and Maesa lanceolata. We estimated that the Gishwati chimpanzee community with a density of 1.7 individuals per km(2) dispersed an average of 592 (>2 mm) seeds km(-2)  day(-1) . We also found that chimpanzees dispersed the seeds of at least two fruit species, Ficus spp. and Chrysophyllum gorungosanum, in their wadges. In addition, 17% of the tree species recorded in our vegetation plots were chimpanzee-dispersed. This study emphasizes the importance of chimpanzees as large seed dispersers in regenerating forest fragments.

  19. 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

  20. Transitions in forest fragmentation: implications for restoration opportunities at regional scales

    Science.gov (United States)

    James D. Wickham; K. Bruce Jones; Kurt H. Riitters; Timothy G. Wade; Robert V. O' Neill

    1999-01-01

    Where the potential natural vegetation is continuous forest (e.g., eastern US), a region can be divided into smaller units (e.g., counties, watersheds), and a graph of the proportion of forest in the largest patch versus the proportion in anthropogenic cover can be used as an index of forest fragmentation. If forests are not fragmented beyond that converted to...

  1. A large-scale forest fragmentation experiment: the Stability of Altered Forest Ecosystems Project.

    Science.gov (United States)

    Ewers, Robert M; Didham, Raphael K; Fahrig, Lenore; Ferraz, Gonçalo; Hector, Andy; Holt, Robert D; Kapos, Valerie; Reynolds, Glen; Sinun, Waidi; Snaddon, Jake L; Turner, Edgar C

    2011-11-27

    Opportunities to conduct large-scale field experiments are rare, but provide a unique opportunity to reveal the complex processes that operate within natural ecosystems. Here, we review the design of existing, large-scale forest fragmentation experiments. Based on this review, we develop a design for the Stability of Altered Forest Ecosystems (SAFE) Project, a new forest fragmentation experiment to be located in the lowland tropical forests of Borneo (Sabah, Malaysia). The SAFE Project represents an advance on existing experiments in that it: (i) allows discrimination of the effects of landscape-level forest cover from patch-level processes; (ii) is designed to facilitate the unification of a wide range of data types on ecological patterns and processes that operate over a wide range of spatial scales; (iii) has greater replication than existing experiments; (iv) incorporates an experimental manipulation of riparian corridors; and (v) embeds the experimentally fragmented landscape within a wider gradient of land-use intensity than do existing projects. The SAFE Project represents an opportunity for ecologists across disciplines to participate in a large initiative designed to generate a broad understanding of the ecological impacts of tropical forest modification.

  2. 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.

  3. Thermokarst Rates Intensify Due to Climate Change and Forest Fragmentation in an Alaskan Boreal Forest Lowland

    Science.gov (United States)

    Lara, M. J.; Genet, H.; McGuire, A. D.; Euskirchen, E. S.; Zhang, Y.; Brown, D. N.; Jorgenson, T.; Romanovsky, V. E.; Breen, A. L.; Bolton, W. R.

    2015-12-01

    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 ~0.5o C of thawing. Increases in the collapse of 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 30x30 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, respectively. Gradient boosting and regression tree models identify precipitation and forest fragmentation as the primary factors controlling birch and spruce forest change, respectively. Between 1950-2009 landscape-level analysis estimates a transition of ~15 km² of birch forest area to wetlands on the Tanana Flats, where the greatest change followed warm periods. This work highlights the vulnerability of lowland

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

    Directory of Open Access Journals (Sweden)

    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

  5. 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

  6. 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

  7. 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 spe

  8. 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

  9. Orchidaceae in an Atlantic Forest area: floristics and similarity to other Dense Ombrophilous Forest fragments

    Directory of Open Access Journals (Sweden)

    Marília Suzy Wängler

    2015-03-01

    Full Text Available The Brazilian Atlantic Forest is considered a global hotspot for biodiversity although it is currently threatened and highly fragmented. Orchidaceae in this phytogeographical domain is represented by 148 genera, of which 142 are endemic; Rio de Janeiro State contains approximately one third of all Brazilian orchid species. The Wildlife Protection Zone of the Palmares Environmental Protection Area (ZVS da APA Palmares is located in the municipality of Paty do Alferes in Rio de Janeiro State and forms a mosaic of Dense Ombrophilous Forest fragments together with other conservation areas in the state. We surveyed Orchidaceae at 12 collection sites between July 2010 and February 2012 and analyzed floristic similarities between the collection sites and between 12 fragments of dense ombrophilous forest in Brazil utilizing PAST software and the Sørensen coefficient. The survey identified 27 genera and 43 species. Low indices of similarity among the areas were observed as well as weak support for grouping the ZVS da APA Palmares with the Serra da Tiririca Mountains. Greater conservation efforts are recommended for remnant fragments of Dense Ombrophilous Forest.

  10. Mosquito (Diptera: Culicidae) diversity of a forest-fragment mosaic in the Amazon rain forest.

    Science.gov (United States)

    Hutchings, Rosa Sá Gomes; Sallum, Maria Anice Mureb; Hutchings, Roger William

    2011-03-01

    To study the impact of Amazonian forest fragmentation on the mosquito fauna, an inventory of Culicidae was conducted in the upland forest research areas of the Biological Dynamics of Forest Fragments Project located 60 km north of Manaus, Amazonas, Brazil. The culicid community was sampled monthly between February 2002 and May 2003. CDC light traps, flight interception traps, manual aspiration, and net sweeping were used to capture adult specimens along the edges and within forest fragments of different sizes (1, 10, and 100 ha), in second-growth areas surrounding the fragments and around camps. We collected 5,204 specimens, distributed in 18 genera and 160 species level taxa. A list of mosquito taxa is presented with 145 species found in the survey, including seven new records for Brazil, 16 new records for the state of Amazonas, along with the 15 morphotypes that probably represent undescribed species. No exotic species [Aedes aegypti (L.) and Aedes albopictus (Skuse)] were found within the sampled areas. Several species collected are potential vectors of Plasmodium causing human malaria and of various arboviruses. The epidemiological and ecological implications of mosquito species found are discussed, and the results are compared with other mosquito inventories from the Amazon region.

  11. Microclimate of Atlantic forest fragments: regional and local scale heterogeneity

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    Flavio Nunes Ramos

    2006-11-01

    Full Text Available The aim of this work was to investigate whether (i the organisms within different fragments, on regional scale (separated by up to 100 km, could be submitted to similar climatic conditions (rainfall and temperature, and whether (ii the edge formation in forest fragments could stimulate microclimatic changes (canopy cover, air temperature and soil humidity, on local scale. The organisms within different fragments, on regional scale, were submitted to different climatic conditions, and the edge formation in the forest fragment stimulated microclimatic changes, on local scale, although in a heterogenic way. Not just the distance from the edge influenced the microclimatic differences. Probably, the edge age, location, the matrix structure, as well as, gap proximity could change the microclimatic even within edges.O objetivo deste trabalho foi investigar se (i os organismos dentro de diferentes fragmentos, em escala regional (separados por até 100 km, podem ser submetidos a condições climáticas similares (pluviosidade e temperatura e se (ii a formação de borda em fragmentos florestais pode estimular mudanças microclimáticas (abertura de dossel, temperatura do ar e umidade do solo, em escala regional. O estudo foi conduzido em cinco fragmentos (escala regional no Rio de Janeiro, sudeste do Brasil, e em escala local, dentro de um deles. Os organismos dentro dos diferentes fragmentos, em escala regional, foram submetidos a diferentes condições climáticas, e a formação de borda nos fragmentos florestais estimulou mudanças climáticas, de maneira heterogênea. Não apenas a distância das bordas tem influencia nas diferenças microclimáticas. Provávelmente, a idade e localização da borda, a estrutura da matriz, assim como a proximidade de clareiras pode modificar o microclima mesmo entre bordas.

  12. Frugivorous bats maintain functional habitat connectivity in agricultural landscapes but rely strongly on natural forest fragments.

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    Simon P Ripperger

    Full Text Available Anthropogenic changes in land use threaten biodiversity and ecosystem functioning by the conversion of natural habitat into agricultural mosaic landscapes, often with drastic consequences for the associated fauna. The first step in the development of efficient conservation plans is to understand movement of animals through complex habitat mosaics. Therefore, we studied ranging behavior and habitat use in Dermanura watsoni (Phyllostomidae, a frugivorous bat species that is a valuable seed disperser in degraded ecosystems. Radio-tracking of sixteen bats showed that the animals strongly rely on natural forest. Day roosts were exclusively located within mature forest fragments. Selection ratios showed that the bats foraged selectively within the available habitat and positively selected natural forest. However, larger daily ranges were associated with higher use of degraded habitats. Home range geometry and composition of focal foraging areas indicated that wider ranging bats performed directional foraging bouts from natural to degraded forest sites traversing the matrix over distances of up to three hundred meters. This behavior demonstrates the potential of frugivorous bats to functionally connect fragmented areas by providing ecosystem services between natural and degraded sites, and highlights the need for conservation of natural habitat patches within agricultural landscapes that meet the roosting requirements of bats.

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

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    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.

  14. Effects of pioneer tree species hyperabundance on forest fragments in northeastern Brazil.

    Science.gov (United States)

    Tabarelli, Marcelo; Aguiar, Antonio V; Girão, Luciana C; Peres, Carlos A; Lopes, Ariadna V

    2010-12-01

    Despite many studies on fragmentation of tropical forests, the extent to which plant and animal communities are altered in small, isolated forest fragments remains obscure if not controversial. We examined the hypothesis that fragmentation alters the relative abundance of tree species with different vegetative and reproductive traits. In a fragmented landscape (670 km(2) ) of the Atlantic Forest of northeastern Brazil, we categorized 4056 trees of 182 species by leafing pattern, reproductive phenology, and morphology of seeds and fruit. We calculated relative abundance of traits in 50 1-ha plots in three types of forest configurations: forest edges, small forest fragments (3.4-83.6 ha), and interior of the largest forest fragment (3500 ha, old growth). Although evergreen species were the most abundant across all configurations, forest edges and small fragments had more deciduous and semideciduous species than interior forest. Edges lacked supra-annual flowering and fruiting species and had more species and stems with drupes and small seeds than small forest fragments and forest interior areas. In an ordination of species similarity and life-history traits, the three types of configurations formed clearly segregated clusters. Furthermore, the differences in the taxonomic and functional (i.e., trait-based) composition of tree assemblages we documented were driven primarily by the higher abundance of pioneer species in the forest edge and small forest fragments. Our work provides strong evidence that long-term transitions in phenology and seed and fruit morphology of tree functional groups are occurring in fragmented tropical forests. Our results also suggest that edge-induced shifts in tree assemblages of tropical forests can be larger than previously documented.

  15. Massive structural and compositional changes over two decades in forest fragments near Kampala, Uganda.

    Science.gov (United States)

    Bulafu, C; Baranga, D; Mucunguzi, P; Telford, R J; Vandvik, V

    2013-10-01

    Private forests harbor considerable biodiversity, however, they are under greater threat than reserved areas, particularly from urbanization, agriculture, and intense exploitation for timber and fuel wood. The extent to which they may act as habitats for biodiversity and how level of protection impacts trends in biodiversity and forest structure over time remain underresearched. We contribute to filling this research gap by resampling a unique data set, a detailed survey from 1990 of 22 forests fragments of different ownership status and level of protection near Kampala, Uganda. Eleven of the 22 fragments were lost over 20 years, and six of the remnants reduced in size. Forest structure and composition also showed dramatic changes, with six of the remnant fragments showing high temporal species turnover. Species richness increased in four of the remaining forests over the resample period. Forest ownership affected the fate of the forests, with higher loss in privately owned forests. Our study demonstrates that ownership affects the fate of forest fragments, with private forests having both higher rates of area loss, and of structural and compositional change within the remaining fragments. Still, the private forests contribute to the total forest area, and they harbor biodiversity including IUCN "vulnerable" and "endangered" species. This indicates the conservation value of the fragments and suggests that they should be taken into account in forest conservation and restoration.

  16. 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

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

    Science.gov (United States)

    Rueda, Marta; Moreno Saiz, Juan Carlos; Morales-Castilla, Ignacio; Albuquerque, Fabio S; Ferrero, Mila; Rodríguez, Miguel Á

    2015-01-01

    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 forest amount is of

  18. Understanding the impacts of forest fragmentation in the Southern Appalachian Mountains

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, S.M.

    1993-06-01

    Southern Appalachian forests are rich in biological diversity. These forests contain many species adapted to conditions ranging from mesic coves to xeric ridges. The major plant communities include wetlands and balds as well as hardwood and coniferous forests. To understand the impacts of habitat fragmentation, the sensitivity of ecosystems, communities, and species to fragmentation must be determined. Recognizing the natural patterns of heterogeneity in these forest and the importance of this heterogeneity to ecological processes will promote our understanding of fragmentation. The impact of a specific forest use (economic development, forest harvesting, recreation) depends on the type of habitat modification.and the spatial extent and pattern of this use. Information on ecological processes, maps of natural communities, and projections about activities that modify forests are needed in order to implement management strategies that will minimize forest fragmentation.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Effects of microhabitat on palm seed predation in two forest fragments in southeast Brazil

    Science.gov (United States)

    Fleury, Marina; Galetti, Mauro

    2004-12-01

    The establishment of plants depends crucially on where seeds are deposited in the environment. Some authors suggest that in forest understory seed predation is lower than in gaps, and higher than at the forest edge. However, most studies have been carried out in large forest patches and very little is known about the effects of microhabitat conditions on seed predation in forest fragments. We evaluated the effects of three microhabitats (gaps, forest edge, and understory) on seed predation of two palm species ( Euterpe edulis and Syagrus romanzoffiana) in two semi-deciduous forest fragments (230 and 2100 ha) in southeast Brazil. Our objective was to test two hypotheses: (1) Low rodent abundance in small fragments as a result of meso-predator action levels leads to lower seed predation in small fragments. (2) Most mammal species in small fragments are generalists with respect to diet and habitat, so that seed predation is similar in different microhabitats (gaps, forest edge and understory) in the small fragment, but not in the larger one. The study community of small fragments is usually composed of generalist species (in diet and habitat aspects), so we expected the same rate of seed predation among microhabitats (gaps, forest edge and understory) in the tested smaller fragment. The experiment was carried out in the dry season (for E. edulis) and in the wet season (for S. romanzoffiana) in 1999. We conclude that post-dispersal seed predation in forest fragments can be directly connected with mammal communities, reflecting their historical and ecological aspects.

  1. 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

  2. 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, Anthony; 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

  3. National assessment of the fragmentation, accessibility and anthropogenic pressure on the forests in Mexico

    Institute of Scientific and Technical Information of China (English)

    Rafael Moreno-Sanchez; Juan Manuel Torres-Rojo; Francisco Moreno-Sanchez; Sue Hawkins; Justin Little; Susan McPartland

    2012-01-01

    Forest managers and policy makers increasingly demand to have access to estimates of forest fragmentation,human accessibility to forest areas and levels of anthropogenic pressure on the remaining forests to integrate them into monitoring systems,management and conservation plans.Forest fragmentation is defined as the breaking up of a forest unit,where the number of patches and the amount of expose edge increase while the amount of core area decreases.Forest fragmentation studies in Mexico have been limited to local or regional levels and have concentrated only on specific forest types.This paper presents an assessment of the fragmentation of all forest types at the national level,their effective proximity to anthropogenic influences,and the development of an indicator of anthropogenic pressure on the forests areas.Broadleaf forests,tropical evergreen forests and tropical dry deciduous forests show the greatest fragmentation.Almost half (47%) of the tropical forests are in close effective proximity to anthropogenic influences and only 12% of their area can be considered isolated from anthropogenic influences.The values for the temperate forests are 23% and 29% respectively.Anthropogenic pressure in the immediate vicinity of anthropogenic activities is much higher in the tropical forests (75 in a scale 0-100) than in the temperate forests (30).When considering these results jointly,the tropical forests,and more specifically,the tropical evergreen forests and tropical dry deciduous forests are under the greatest pressure and risks of degradation.

  4. 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

  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. Forest fragmentation and selective logging have inconsistent effects on multiple animal-mediated ecosystem processes in a tropical forest.

    Directory of Open Access Journals (Sweden)

    Matthias Schleuning

    Full Text Available Forest fragmentation and selective logging are two main drivers of global environmental change and modify biodiversity and environmental conditions in many tropical forests. The consequences of these changes for the functioning of tropical forest ecosystems have rarely been explored in a comprehensive approach. In a Kenyan rainforest, we studied six animal-mediated ecosystem processes and recorded species richness and community composition of all animal taxa involved in these processes. We used linear models and a formal meta-analysis to test whether forest fragmentation and selective logging affected ecosystem processes and biodiversity and used structural equation models to disentangle direct from biodiversity-related indirect effects of human disturbance on multiple ecosystem processes. Fragmentation increased decomposition and reduced antbird predation, while selective logging consistently increased pollination, seed dispersal and army-ant raiding. Fragmentation modified species richness or community composition of five taxa, whereas selective logging did not affect any component of biodiversity. Changes in the abundance of functionally important species were related to lower predation by antbirds and higher decomposition rates in small forest fragments. The positive effects of selective logging on bee pollination, bird seed dispersal and army-ant raiding were direct, i.e. not related to changes in biodiversity, and were probably due to behavioural changes of these highly mobile animal taxa. We conclude that animal-mediated ecosystem processes respond in distinct ways to different types of human disturbance in Kakamega Forest. Our findings suggest that forest fragmentation affects ecosystem processes indirectly by changes in biodiversity, whereas selective logging influences processes directly by modifying local environmental conditions and resource distributions. The positive to neutral effects of selective logging on ecosystem processes

  7. Centennial impacts of fragmentation on the canopy structure of tropical montane forest

    Science.gov (United States)

    Nicholas Vaughn; Greg Asner; Christian Giardina

    2014-01-01

    Fragmentation poses one of the greatest threats to tropical forests with short-term changes to the structure of forest canopies affecting microclimate, tree mortality, and growth. Yet the long-term effects of fragmentation are poorly understood because (1) most effects require many decades to materialize, but long-term studies are very rare, (2) the effects of edges on...

  8. Ticks infesting birds in Atlantic Forest fragments in Rio Claro, State of Sao Paulo, Brazil.

    Science.gov (United States)

    Sanches, Gustavo Seron; Martins, Thiago Fernandes; Lopes, Ileyne Tenório; Costa, Luís Flávio da Silva; Nunes, Pablo Henrique; Camargo-Mathias, Maria Izabel; Labruna, Marcelo Bahia

    2013-01-01

    In the present study, we report tick infestations on wild birds in plots of the Atlantic Forest reforested fragments with native species and plots reforested with Eucalyptus tereticornis in the municipality of Rio Claro, State of Sao Paulo, Brazil. A total of 256 birds were captured: 137 individuals of 33 species, in planted native forest; and 128 individuals of 37 species, in planted Eucalyptus tereticornis forest. Nymphs of two tick species were found on the birds: Amblyomma calcaratum and Amblyomma longirostre, the former was more abundant in the fragments reforested with Atlantic forest native species, and the latter in the fragment reforested with E. tereticornis. New host records were presented for A. calcaratum.

  9. Using fragmentation to assess degradation of forest edges in Democratic Republic of Congo.

    Science.gov (United States)

    Shapiro, Aurélie C; Aguilar-Amuchastegui, Naikoa; Hostert, Patrick; Bastin, Jean-François

    2016-12-01

    Recent studies have shown that fragmentation is an increasing threat to global forests, which has major impacts on biodiversity and the important ecosystem services provided by forested landscapes. Several tools have been developed to evaluate global patterns of fragmentation, which have potential applications for REDD+. We study how canopy height and above ground biomass (AGB) change across several categories of forest edges determined by fragmentation analysis. We use Democratic Republic of Congo (DRC) as an example. An analysis of variance of different edge widths and airborne estimated canopy height found that canopy heights were significantly different in forest edges at a distance of 100 m from the nonforest edge. Biomass was significantly different between fragmentation classes at an edge distance of 300 m. Core forest types were found to have significantly higher canopy height and greater AGB than forest edges and patches, where height and biomass decrease significantly as the level of fragmentation increases. A change analysis shows that deforestation and degradation are increasing over time and biomass loss associated with degradation account for at least one quarter of total loss. We estimate that about 80 % of primary forests are intact, which decreases 3.5 % over the 15 year study period, as primary forest is either deforested or transitioned to forest edge. While the carbon loss per hectare is lower than that of deforestation, degradation potentially affects up to three times more area than deforestation alone. When defining forest degradation by decreased biomass without any loss in forest area, assessing transitions of core forest to edges over time can contribute an important element to REDD+MRV systems. The estimation of changes between different forest fragmentation types and their associated biomass loss can provide an estimate of degradation carbon emission factors. Forest degradation and emissions due to fragmentation are often

  10. National Assessment of the Fragmentation Levels and Fragmentation-Class Transitions of the Forests in Mexico for 2002, 2008 and 2013

    Directory of Open Access Journals (Sweden)

    Elizabeth Clay

    2016-02-01

    Full Text Available Landscape modification and habitat fragmentation are key drivers of global species and biodiversity loss, as well as a major threat to the conservation of forest ecosystems. Mexico is one of the five biologically richest countries in the world. This study first generated a national level assessment of the fragmentation of temperate and tropical forests in Mexico for 2002, 2008, and 2013. Then, using these results, it explores how transitions to non-forest or to other fragmentation classes have evolved within the previous date fragmentation classes for the 2002–2008 and 2008–2013 periods. The Morphological Spatial Pattern Analysis (MSPA method was used to assess the forest fragmentation. The results show that high fragmentation classes are more likely to transition to no-forest land covers in tropical than in temperate forests and that these conversions were larger during 2002–2008 than during the 2008–2013 period in both forest types. When analyzing the transitions between fragmentation classes, a higher percent of the forest area remained the same fragmentation class between 2008 and 2013 than from 2002 to 2008. Transitions between forest fragmentation classes were relatively small compared to transitions to no-forest land covers, and transitions to higher fragmentation classes were slightly larger in tropical than in temperate forests.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Fine-scale movement decisions of tropical forest birds in a fragmented landscape.

    Science.gov (United States)

    Gillies, Cameron S; Beyer, Hawthorne L; St Clair, Colleen Cassady

    2011-04-01

    The persistence of forest-dependent species in fragmented landscapes is fundamentally linked to the movement of individuals among subpopulations. The paths taken by dispersing individuals can be considered a series of steps built from individual route choices. Despite the importance of these fine-scale movement decisions, it has proved difficult to collect such data that reveal how forest birds move in novel landscapes. We collected unprecedented route information about the movement of translocated forest birds from two species in the highly fragmented tropical dry forest of Costa Rica. In this pasture-dominated landscape, forest remains in patches or riparian corridors, with lesser amounts of living fencerows and individual trees or "stepping stones." We used step selection functions to quantify how route choice was influenced by these habitat elements. We found that the amount of risk these birds were willing to take by crossing open habitat was context dependent. The forest-specialist Barred Antshrike (Thamnophilus doliatus) exhibited stronger selection for forested routes when moving in novel landscapes distant from its territory relative to locations closer to its territory. It also selected forested routes when its step originated in forest habitat. It preferred steps ending in stepping stones when the available routes had little forest cover, but avoided them when routes had greater forest cover. The forest-generalist Rufous-naped Wren (Campylorhynchus rufinucha) preferred steps that contained more pasture, but only when starting from non-forest habitats. Our results showed that forested corridors (i.e., riparian corridors) best facilitated the movement of a sensitive forest specialist through this fragmented landscape. They also suggested that stepping stones can be important in highly fragmented forests with little remaining forest cover. We expect that naturally dispersing birds and species with greater forest dependence would exhibit even stronger

  13. 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.

  14. Responses of Bats to Forest Fragmentation in the Mississippi River Alluvial Valley, Arkansas, USA

    OpenAIRE

    Risch, Thomas S.; Karen F. Gaines; Connior, Matthew B.; Rex E. Medlin

    2010-01-01

    Intense conversion of bottomland hardwood forests to rice and soybeans in the Mississippi River Valley of Arkansas has restricted the remaining forest to isolated fragments. Habitat fragmentation has proven to be detrimental to population sustainability of several species, and is the subject of intense study with often species and latitude specific responses. We compared both coarse land area classes and landscape fragmentation metrics from six 30 km × 30 km subsets centered on publicly owned...

  15. 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

  16. Living in forest fragments reduces group cohesion in diademed sifakas (Propithecus diadema) in eastern Madagascar by reducing food patch size.

    Science.gov (United States)

    Irwin, Mitchell T

    2007-04-01

    Forest fragmentation is thought to threaten primate populations, yet the mechanisms by which this occurs remain largely unknown. However, fragmentation is known to cause dietary shifts in several primate species, and links between food resource distribution and within-group spatial dynamics are well documented. Thus, fragmentation has the potential to indirectly affect spatial dynamics, and these changes may present additional stresses to fragmented populations. I present the results from a 12-month study of Propithecus diadema at Tsinjoarivo, eastern Madagascar, including two groups in fragments and two in continuous forest. Instantaneous data on activity and spatial position were collected during all-day focal animal follows. Fragment groups had much lower cohesion, being more likely to have no neighbor within 5 and 10 m. For continuous forest groups, cohesion was highest in the rainy season (when food patches are large) and lowest in winter (when the animals rely on small-crowned mistletoes), and the chance of having no neighbor within 5 m was positively correlated with mistletoe consumption. Thus their decreased cohesion in fragment groups is inferred to result from their increased reliance on mistletoes and other small resources, which causes them to spread out among multiple patches. This scenario is consistent with the reduced body mass of subordinate individuals (males and immatures) in fragments, and suggests the occurrence of steeper within-group fitness gradients. Further research is necessary to determine whether these patterns apply to other primates; however, since fragmentation tends to cause the loss of the largest trees, many primates in fragments may lose their largest food resources and undergo similar behavioral shifts.

  17. 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

  18. 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 Natio

  19. 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 Natio

  20. The conservation value of small, isolated fragments of lowland tropical rain forest.

    Science.gov (United States)

    Turner, I M; T Corlett, R

    1996-08-01

    Deforestation is occurring at an alarming rate in the lowland tropics. In many tropical regions, rain forest is restricted to small (rainforest species that are on the brink of extinction. In areas with little rain forest remaining, fragments can be the 'seeds' from which to re-establish extensive forest.

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

    DEFF Research Database (Denmark)

    Baez, S.; Balslev, Henrik

    2007-01-01

    to be idiosyncratic and to depend on the level of disturbance at edges. This paper explores how variation in forest structure at the edges of two old-growth forest fragments in a tropical rain forest in western Ecuador affects palms of different species, life-forms, and size classes. We investigate (1) how edge...

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

    Directory of Open Access Journals (Sweden)

    Rodrigo L L Orihuela

    Full Text Available 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Near-complete extinction of native small mammal fauna 25 years after forest fragmentation.

    Science.gov (United States)

    Gibson, Luke; Lynam, Antony J; Bradshaw, Corey J A; He, Fangliang; Bickford, David P; Woodruff, David S; Bumrungsri, Sara; Laurance, William F

    2013-09-27

    Tropical forests continue to be felled and fragmented around the world. A key question is how rapidly species disappear from forest fragments and how quickly humans must restore forest connectivity to minimize extinctions. We surveyed small mammals on forest islands in Chiew Larn Reservoir in Thailand 5 to 7 and 25 to 26 years after isolation and observed the near-total loss of native small mammals within 5 years from disappearing) to be 13.9 years. These catastrophic extinctions were probably partly driven by an invasive rat species; such biotic invasions are becoming increasingly common in human-modified landscapes. Our results are thus particularly relevant to other fragmented forest landscapes and suggest that small fragments are potentially even more vulnerable to biodiversity loss than previously thought.

  9. 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...

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

    Science.gov (United States)

    Chinchilla, Federico A

    2009-09-01

    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.

  11. Effects of forest fragmentation on male and female reproductive success in Cestrum parqui (Solanaceae).

    Science.gov (United States)

    Aguilar, Ramiro; Galetto, Leonardo

    2004-03-01

    In this paper we evaluate the effects of forest fragmentation on male (pollen removal, pollen load, and pollen tubes) and female reproductive success (fruit- and seed-set) of Cestrum parqui, a self-incompatible, pollination-specialist plant species. We also measure focal individual conspecific density to account for possible density-related effects that could influence the response variables. We calculate an index which incorporates male and female fitness and gives an integrated assessment of overall reproductive success. Forest fragmentation strongly affected the amount of pollen grains on stigmas and number of pollen tubes as well as seed-set, decreasing from continuous forest to small forest fragments, whereas focal individual conspecific density failed to explain any of the variability for the studied variables. Declines in overall reproductive success (i.e. male and female) in small forest fragments are ascribed to decreases in both the quality and quantity of pollination. Self-incompatibility coupled with a specialist pollination system may be particularly important traits determining the negative fragmentation effects observed in C. parqui. Logarithmic regression models described the behaviour of the variables along the fragmentation size gradient, allowing us to detect a threshold below which the effects of fragmentation begin to negatively affect reproductive success in C. parqui. Our results emphasize the importance of evaluating both components of the total plant fitness, as well as including simultaneously several aspects of pollination and reproduction processes when assessing the effects of forest fragmentation on plant reproductive success.

  12. 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

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

    Science.gov (United States)

    Dong, Jinwei; Xiao, Xiangming; Sheldon, Sage; Biradar, Chandrashekhar; Zhang, Geli; Duong, Nguyen Dinh; Hazarika, Manzul; Wikantika, Ketut; Takeuhci, Wataru; Moore, Berrien

    2014-01-01

    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 biodiversity.

  14. 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...

  15. ANALYSIS OF SPACE-TIME DYNAMICS OF FOREST FRAGMENTS IN THE ALEGRE RIVER SUBWATERSHED, BRAZIL

    Directory of Open Access Journals (Sweden)

    Kmila Gomes da Silva

    2015-06-01

    Full Text Available Knowing the history of forest fragmentation in watersheds helps plan and implement practices based on restoration of degraded forest areas. Structural analysis of forest fragments in the Alegre River subwatershed, State of Espírito Santo, was based on landscape metrics using ArcGIS 10 software with Patch Analyst extension, regarding changes during 1975, 2002, and 2007. Analysis showed an increase of about 7% in the total area of forest cover and emergence of 645 new forest fragments. Numerous patches and a small drainage area resulted in a high perimeter-to-area ratio. Simple geometric shapes predominated in smaller patches ( 20 ha were close to each other, with a tendency to decrease proximity metric values. The results show that despite increase in vegetated area, the environmental quality of forest remnants is highly jeopardized.

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

    Science.gov (United States)

    Santos, Bráulio A; Arroyo-Rodríguez, Víctor; Moreno, Claudia E; Tabarelli, Marcelo

    2010-09-08

    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 (tree phylogenetic diversity in the severely fragmented Brazilian Atlantic forest.

  17. Forest cover change and fragmentation using Landsat data in Maçka State Forest Enterprise in Turkey.

    Science.gov (United States)

    Cakir, Günay; Sivrikaya, Fatih; Keleş, Sedat

    2008-02-01

    Monitoring forest cover change and understanding the dynamic of forest cover is increasingly important in sustainable development and management of forest ecosystems. This paper uses remote sensing (RS) techniques to monitor forest cover change in Maçka State Forest Enterprise (MSFE) located in NE of Turkey through 1975 to 2000 and then analyses spatial and temporal changes in forest cover by Geographical Information Systems (GIS) and FRAGSTATStrade mark. Forest cover changes were detected from a time series of satellite images of Landsat MSS in 1975, Landsat TM in 1987, and Landsat ETM+ in 2000 using RS and GIS. The results showed that total forest area, productive forest area and degraded forest area increased while broadleaf forest area and non forest area decreased. Mixed forest and degraded forest increased during the first (1975-1987) period, but decreased during the second (1987-2000) period. During the whole study period, the annual forestation rate was 152 ha year(-1), equivalent to 0.27% year(-1) using the compound-interest-rate formula. The total number of patches increased from 36,204 to 48,092 (33%), and mean size of forest patch (MPS) decreased from 2.8 ha to 2.1 ha during a 25 year period. Number of smaller patches (patches in 0-100 ha size class) increased, indicating more fragmented landscape over time that might create a risk for the maintenance of biodiversity of the area. While total population increased from 1975 to 2000 (3.7%), rural population constantly decreased. The increase of forest areas may well be explained by the fact that demographic movement of rural areas concentrated into Maçka City Center. These figures also indicated that decrease in the rural population might likely lead to the release of human pressure to forest areas, probably resulting in a positive development of forest areas.

  18. Population genetics provides an efficient tool to quantify fragmentation impact in forest ecosystems

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available A method in population genetics (Dutech et al., Am. J. Bot. 92 (2, 252-261, February 2005 is described and discussed as an interesting tool for investigating the effects of fragmentation in forest ecosystems.

  19. 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

    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...... as far as 2 km away. We conclude that populations of this army ant species are less vulnerable to fragmentation than those of the neotropical E. burchellii, and that D. molestus can survive better in matrix habitat between forests because of several key differences in the foraging and nesting behaviour...... 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Numata, Izaya; Cochrane, Mark A [GIScCE, South Dakota State University (United States); Souza, Carlos M Jr; Sales, Marcio H [Instituto do Homen e Meio Ambiente da Amazonia-IMAZON (Brazil)

    2011-10-15

    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.

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

    Science.gov (United States)

    Li, M.; Mao, L.; Zhou, C.; Vogelmann, J.E.; Zhu, Z.

    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 the

  2. 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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Modeling landowner behavior regarding forest certification

    Science.gov (United States)

    David C. Mercker; Donald G. Hodges

    2008-01-01

    Nonindustrial private forest owners in western Tennessee were surveyed to assess their awareness, acceptance, and perceived benefits of forest certification. More than 80 percent of the landowners indicated a willingness to consider certification for their lands. A model was created to explain landowner behavior regarding their willingness to consider certification....

  6. Island vs. countryside biogeography: an examination of how Amazonian birds respond to forest clearing and fragmentation

    Science.gov (United States)

    Jared D. Wolfe; Philip C. Stouffer; Karl Mokross; Luke L. Powell; Marina M. Anciães

    2015-01-01

    Avian diversity in fragmented Amazonian landscapes depends on a balance between extinction and colonization in cleared and disturbed areas. Regenerating forest facilitates bird dispersal within degraded Amazonian landscapes and may tip the balance in favor of persistence in habitat patches. Determining the response of Amazonian birds to fragmentation may be...

  7. 7.0 Monitoring the status and impacts of forest fragmentation and urbanization

    Science.gov (United States)

    Rachel Riemann; Karen Riva-Murray; Peter S. Murdoch

    2008-01-01

    The geographic expansion of urban and suburban development and the influx of residential and recreational development into previously forested areas are growing concerns for natural resource managers. This project sought to: identify and characterize urbanization and forest fragmentation over large areas with the detail and accuracy required for studies of wildlife...

  8. 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...

  9. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico

    Science.gov (United States)

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua and A. suspensa at four sites in Guánica, Puerto Rico; one forest fragment in Ponce, Puerto Rico; in a commercial mango orchard in Guayanilla, PR; and an experimental carambola orcha...

  10. 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

  11. Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species

    OpenAIRE

    Honnay, Olivier; Jacquemyn, Hans; Bossuyt, B; Hermy, Martin

    2005-01-01

    Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not...

  12. 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.

  13. Quantitative analysis of forest fragmentation in the atlantic forest reveals more threatened bird species than the current red list.

    Directory of Open Access Journals (Sweden)

    Jessica K Schnell

    Full Text Available Habitat loss and attendant fragmentation threaten the existence of many species. Conserving these species requires a straightforward and objective method that quantifies how these factors affect their survival. Therefore, we compared a variety of metrics that assess habitat fragmentation in bird ranges, using the geographical ranges of 127 forest endemic passerine birds inhabiting the Atlantic Forest of Brazil. A common, non-biological metric - cumulative area of size-ranked fragments within a species range - was misleading, as the least threatened species had the most habitat fragmentation. Instead, we recommend a modified version of metapopulation capacity. The metric links detailed spatial information on fragment sizes and spatial configuration to the birds' abilities to occupy and disperse across large areas (100,000+ km(2. In the Atlantic Forest, metapopulation capacities were largely bimodal, in that most species' ranges had either low capacity (high risk of extinction or high capacity (very small risk of extinction. This pattern persisted within taxonomically and ecologically homogenous groups, indicating that it is driven by fragmentation patterns and not differences in species ecology. Worryingly, we found IUCN considers some 28 of 58 species in the low metapopulation capacity cluster to not be threatened. We propose that assessing the effect of fragmentation will separate species more clearly into distinct risk categories than does a simple assessment of remaining habitat.

  14. 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...

  15. Forest fragmentation effects on patch occupancy and population viability of herbaceous plant species.

    Science.gov (United States)

    Honnay, Olivier; Jacquemyn, Hans; Bossuyt, Beatrijs; Hermy, Martin

    2005-06-01

    Habitat fragmentation is one of the major threats to species diversity. In this review, we discuss how the genetic and demographic structure of fragmented populations of herbaceous forest plant species is affected by increased genetic drift and inbreeding, reduced mate availability, altered interactions with pollinators, and changed environmental conditions through edge effects. Reported changes in population genetic and demographic structure of fragmented plant populations have, however, not resulted in large-scale extinction of forest plants. The main reason for this is very likely the long-term persistence of small and isolated forest plant populations due to prolonged clonal growth and long generation times. Consequently, the persistence of small forest plant populations in a changing landscape may have resulted in an extinction debt, that is, in a distribution of forest plant species reflecting the historical landscape configuration rather than the present one. In some cases, fragmentation appears to affect ecosystem integrity rather than short-term population viability due to the opposition of different fragmentation-induced ecological effects. We finally discuss extinction and colonization dynamics of forest plant species at the regional scale and suggest that the use of the metapopulation concept, both because of its heuristic power and conservation applications, may be fruitful.

  16. 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...

  17. 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...

  18. 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.

  19. Landscape fragmentation, severe drought, and the new Amazon forest fire regime.

    Science.gov (United States)

    Alencar, Ane A; Brando, Paulo M; Asner, Gregory P; Putz, Francis E

    2015-09-01

    Changes in weather and land use are transforming the spatial and temporal characteristics of fire regimes in Amazonia, with important effects on the functioning of dense (i.e., closed-canopy), open-canopy, and transitional forests across the Basin. To quantify, document, and describe the characteristics and recent changes in forest fire regimes, we sampled 6 million ha of these three representative forests of the eastern and southern edges of the Amazon using 24 years (1983-2007) of satellite-derived annual forest fire scar maps and 16 years of monthly hot pixel information (1992-2007). Our results reveal that changes in forest fire regime properties differentially affected these three forest types in terms of area burned and fire scar size, frequency, and seasonality. During the study period, forest fires burned 15% (0.3 million ha), 44% (1 million ha), and 46% (0.6 million ha) of dense, open, and transitional forests, respectively. Total forest area burned and fire scar size tended to increase over time (even in years of average rainfall in open canopy and transitional forests). In dense forests, most of the temporal variability in fire regime properties was linked to El Nino Southern Oscillation (ENSO)-related droughts. Compared with dense forests, transitional and open forests experienced fires twice as frequently, with at least 20% of these forests' areas burning two or more times during the 24-year study period. Open and transitional forests also experienced higher deforestation rates than dense forests. During drier years, the end of the dry season was delayed by about a month, which resulted in larger burn scars and increases in overall area burned later in the season. These observations suggest that climate-mediated forest flammability is enhanced by landscape fragmentation caused by deforestation, as observed for open and transitional forests in the Eastern portion of the Amazon Basin.

  20. Tree structure and diversity of lowland Atlantic forest fragments:comparison of disturbed and undisturbed remnants

    Institute of Scientific and Technical Information of China (English)

    Fabrcio Alvim Carvalho; Joao Marcelo Alvarenga Braga; Marcelo Trindade Nascimento

    2016-01-01

    This study describes the tree community structure of three moist lowland Atlantic Forest fragments in Rio de Janeiro State, southeastern Brazil. Two fragments were disturbed and an undisturbed one was used as refer-ence. Our hypothesis was that disturbed fragments show distinct structural patterns in comparison with undisturbed stands due to past disturbance practices and forest frag-mentation. Four 100 9 5 m sampling plots were demar-cated in each fragment and all live and dead trees with DBH C 5 cm were located, measured and identified. The results supported our hypothesis, due to the high values found for standing dead trees, an increase of dominance of a few pioneer species, lower values of large trees and species richness in disturbed fragments in comparison with the undisturbed one. The advanced fragmentation process in the Southern Brazilian lowland areas and the high spe-cies richness in undisturbed areas highlight these forest fragments as priority areas for conservation and management.

  1. 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

  2. Mammal assemblages in forest fragments and landscapes occupied by black howler monkeys.

    Science.gov (United States)

    Rangel-Negrín, Ariadna; Coyohua-Fuentes, Alejandro; Canales-Espinosa, Domingo; Dias, Pedro Américo D

    2014-07-01

    Species assemblages in disturbed habitats vary as a function of the interaction between species requirements and the spatial configuration of the habitat. There are many reports accounting for the presence of howler monkeys in fragments where other mammals are absent, suggesting that they are more resilient. In the present study we explored this idea and predicted that if howler monkeys were more resilient to habitat loss and fragmentation than other mammals, mammal assemblages in fragments occupied by howler monkeys should include fewer species with decreasing amount of habitat (smaller fragment size and less habitat in the landscape) and increasing number of forest fragments. We explored these relationships by additionally considering the feeding and life habits of mammal species, as well as the isolation and proximity of each fragment to human settlements and roads. We sampled the presence of mammals in five fragments occupied by black howler monkeys (Alouatta pigra) in the Mexican state of Campeche. Through direct sights performed during 240 h in each fragment, we observed 23 species. At the landscape scale, higher fragmentation was associated with a decrease in herbivores, omnivores and total number of species. At the fragment scale semiarboreal, omnivore, and total number of species increased with increasing fragment size. This study supports the idea that howler monkeys are more resilient to forest loss and fragmentation than other native mammals, and our exploratory analyses suggest that the specific mammal assemblages that are found in fragments are related to both landscape and fragment scale spatial attributes, as well as with species-specific characteristics.

  3. Classification of Forest Fragmentation in North America - Direct Download

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This map layer is a grid map of North America including the Caribbean and most of Mexico. The map layer is an excerpt from a global assessment of forest...

  4. 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.

  5. 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.

  6. 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

  7. Diurnal raptors in the fragmented rain forest of the Sierra Imataca, Venezuela

    Science.gov (United States)

    Alvarez, E.; Ellis, D.H.; Smith, D.G.; LaRue, C.T.; Bird, David M.; Varland, Daniel E.; Negro, Juan Jose

    1996-01-01

    The rain forest of the Sierra Imataca in eastern Venezuela has been subjected to extensive deforestation for pastures and agricultural settlements. In the last decade the opening of access roads combined with intensified logging and mining activities have fragmented a significant portion of the remaining forest. We noted local distribution and habitat use for 42 species of diurnal raptors observed in affected areas in this region. We observed some raptors considered as forest interior species and other open country species foraging and roosting in man-made openings inside the forest.

  8. Enhanced seed dispersal of Prunus africana in fragmented and disturbed forests?

    Science.gov (United States)

    Farwig, Nina; Böhning-Gaese, Katrin; Bleher, Bärbel

    2006-03-01

    Forest destruction and disturbance can have long-term consequences for species diversity and ecosystem processes such as seed dispersal. Understanding these consequences is a crucial component of conserving vulnerable ecosystems. In the heavily fragmented and disturbed Kakamega Forest, western Kenya, we studied seed dispersal of Prunus africana (Rosaceae). In the main forest, five forest fragments, and differently disturbed sites, we quantified the overall frugivore community as an indicator for species diversity. Furthermore, we determined the frugivores on 28 fruiting P. africana trees, estimated seed dispersal, crop size and the general fruit availability of surrounding trees. During the overall frugivore census we recorded 49 frugivorous species; 36 of them were observed visiting P. africana trees and feeding on their fruits. Although overall frugivore species richness was 1.1 times lower in fragments than in main forest sites and 1.02 times higher in highly disturbed than in less disturbed sites, P. africana experienced 1.1 times higher numbers of frugivores in fragments than in main forest sites and 1.5 times higher numbers of frugivores in highly disturbed than in less disturbed sites. Correspondingly, seed dispersal was 1.5 times higher in fragments than in main forest sites and 1.5 times higher in more disturbed than less disturbed sites. Fruit availability of surrounding trees and crop size influenced the number of visitors to some degree. Thus, the number of dispersed seeds seemed to be slightly higher in fragmented and highly disturbed sites. This indicates that loss of single species does not necessarily lead to a decrease of ecosystem services. However, loss of diversity could be a problem in the long term, as a multitude of species might act as buffer against future environmental change.

  9. 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

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    María Fernanda Tapia-Armijos

    Full Text Available 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.

  12. 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.

  13. 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.

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

    National Research Council Canada - National Science Library

    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...

  15. 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

    very low environmental quality to others uses and a static behavior of forest fragments with high environmental quality. It was explained by the tendency of occupation in forest fragments near urban areas, roads, with small size and high perturbation, and difficulties in occupation of forest fragments with high size, isolated from urban areas end roads. It was concluded that: (a) urbanization and deforestation of natural vegetation were primarily responsible for changes in environmental quality; (b) there is a need to create public policies to preserve the natural vegetation in the Jundiaí-Mirim river basin.

  16. 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.

  17. Effects of forest fragmentation on nocturnal Asian birds: A case study from Xishuangbanna, China.

    Science.gov (United States)

    K Dayananda, Salindra; Goodale, Eben; Lee, Myung-Bok; Liu, Jia-Jia; Mammides, Christos; O Pasion, Bonifacio; Quan, Rui-Chang; W Ferry Slik, J; Sreekar, Rachakonda; W Tomlinson, Kyle; Yasuda, Mika

    2016-05-18

    Owls have the potential to be keystone species for conservation in fragmented landscapes, as the absence of these predators could profoundly change community structure. Yet few studies have examined how whole communities of owls respond to fragmentation, especially in the tropics. When evaluating the effect of factors related to fragmentation, such as fragment area and distance to the edge, on these birds, it is also important in heterogeneous landscapes to ask how 'location factors' such as the topography, vegetation and soil of the fragment predict their persistence. In Xishuangbanna, southwest China, we established 43 transects (200 m×60 m) within 20 forest fragments to sample nocturnal birds, both visually and aurally. We used a multimodel inference approach to identify the factors that influence owl species richness, and generalized linear mixed models to predict the occurrence probabilities of each species. We found that fragmentation factors dominated location factors, with larger fragments having more species, and four of eight species were significantly more likely to occur in large fragments. Given the potential importance of these birds on regulating small mammal and other animal populations, and thus indirectly affecting seed dispersal, we suggest further protection of large fragments and programs to increase their connectivity to the remaining smaller fragments.

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

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    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.

  19. Habitat fragmentation impacts on biodiversity of evergreen broadleaved forests in Jinyun Mountains,China

    Institute of Scientific and Technical Information of China (English)

    YAN Ming; ZHONG Zhangcheng; LIU Jinchun

    2007-01-01

    The plant communities and their microclimates were surveyed and observed,and the soil fertilities were determined in six plots of evergreen broadleaved forests of different sizes and similar slope aspects on Jinyun Mountains of Chongqing in China from April to October,2003.The relationships of biotic and abiotic factors were analyzed using the Simpson,Shannon-Wiener,and Hill diversity indices,and stepwise multilinear regression analyses techniques.The results showed that compared with continuous evergreen broadleaved forests,five fragmentations had a lower species diversity index,and different life forms showed differences in diversity index.With the decrease in patch areas,the daily differences in air temperature (△Ta),ground surface temperature (△Ts),daily differences in relative humidity (△RH),maximum wind velocity (Vmax),differences in photosynthetic available radiation (△PAR)(at noon)of both edges and interiors,all tended to increase.Maximum wind velocity (Vmax)and photo effective radiation in forest edges were higher than those in interior forest,which presented a stronger temperature-gained edge effect.In all the fragmentations of evergreen broadleaved forests,the depth of the edge effect was the nearest from interior forest in the biggest patch (about 15 meters away from interior forest),while the depth of the edge effect was the farthest from interior forest in the smallest patch (about 25 meters away from interior forest).With regard to the water conservation function,soil water content improved along with increasing species diversity.Some of the nutritional function substances of soil increased with increasing species diversity.The elements of microclimate,such as Ta,△Ta,△Ts,ARH,Vmax,and PAR,changed along with the extent of fragmented forest.

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

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    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.

  1. 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).

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

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    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.

  3. Diversity and similarity of native forest fragments located in the northeast region of Minas Gerais

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    Christianne Riquetti Corsini

    2014-03-01

    Full Text Available In this study 26 distributed fragments of native forest in four located hydrographical Basins in the northeast region of Minas Gerais had been showed, with the purpose of analyzing the floristic similarity exists between 26 forest fragments native inserted in four basins in the northeast of the state of Minas Gerais and the diversity and evenness of physiognomies studied and groups of fragments formed. Systematic sampling with units was used shows of 1000 m² each, where the sample area varied of 1 the 6 has, as the area I break up of it. We measured the circumference at 1.30m (CAP and the total height and collected botanical material of all individuals with CAP greater or equal to 15.7 cm. Six groups were formed according to the floristic similarity coefficient Sorensen, with four groups there was an association of more than a physiognomy, showing regions of transition within the area. The Shannon diversity index, ranged from 2.236 in deciduous forest to 4.523 in Semideciduous Forest. The maximum and minimum values of evenness index Pielou were 0.850 and 0.616 , respectively. The floristic group 2 (Semideciduous Forest and Cerrado sensu stricto had the highest average value of diversity (3.585 and evenness (0.750 , and group 1 (Deciduous Forest had the lowest values (H': 2.426 and J': 0.687 .

  4. Does population increase equate to conservation success? Forest fragmentation and conservation of the black howler monkey

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    Miriam S Wyman

    2011-01-01

    Full Text Available The Community Baboon Sanctuary (CBS in Belize is a community reserve for the endangered black howler monkey (Alouatta pigra. This study assessed the performance of the CBS as an International Union for Conservation of Nature (IUCN Category IV protected area through deforestation and forest fragmentation of the CBS and 500 m river buffer, and impacts on black howler monkey habitat over 15 years (1989-2004. Using satellite imagery remote sensing and landscape metrics, this study helps fill the gap in our understanding of forest fragmentation processes and habitat provision, using the black howler monkey as a specific example. Increased fragmentation resulted in decreased forest cover by 33% within both the CBS and river buffer. However, connectivity between habitat patches has remained high, indicating that dispersal and colonising potential between most forest patches has not been jeopardised. We conclude that conservation within the CBS may be more complex than simply equating forest conservation with black howler monkey conservation. One could say the CBS has been successful at black howler monkey conservation, as documented by population increases over the past 20 years. However, if the conservation objective is forest preservation, one could conclude conservation failure and may signal that the CBS should not be managed for a single outcome as assigned by an IUCN Category IV designation.

  5. 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

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

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    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.

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

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    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. Dynamics and Edge Effect of an Atlantic Forest Fragment in Brazil

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    Poliana Gabriella Araújo Mendes

    Full Text Available ABSTRACT The woody plants in an edge area formed approximately 35 years ago in an Atlantic Forest fragment in northeastern Brazil were examined, and three environments defined: edge, intermediate, and interior. Canopy tree densities and basal areas were found to be similar in all three environments, and also similar to previous published studies in the same region; species richness was greatest at the forest edge. The understory showed greater species richness in the forest interior, but greater diversity and equitability in the intermediate environment. Understory environments close to the forest edge demonstrated larger stem diameters than in the forest interior, although at lesser densities and with smaller total basal areas. Our results indicated the existence of distinct patterns in canopy and understory that most likely reflect differences in the response times of these two vegetation layers, with the understory being more sensitive to alterations in environmental structure.

  9. 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.

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

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    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.

  11. Forest Fragmentation and Landscape Transformation in a Reindeer Husbandry Area in Sweden

    Science.gov (United States)

    Kivinen, Sonja; Berg, Anna; Moen, Jon; Östlund, Lars; Olofsson, Johan

    2012-02-01

    Reindeer husbandry and forestry are two main land users in boreal forests in northern Sweden. Modern forestry has numerous negative effects on the ground-growing and arboreal lichens that are crucial winter resources for reindeer husbandry. Using digitized historical maps, we examined changes in the forest landscape structure during the past 100 years, and estimated corresponding changes in suitability of forest landscape mosaics for the reindeer winter grazing. Cover of old coniferous forests, a key habitat type of reindeer herding system, showed a strong decrease during the study period, whereas clear-cutting and young forests increased rapidly in the latter half of the 20th century. The dominance of young forests and fragmentation of old-growth forests (decreased patch sizes and increased isolation) reflect decreased amount of arboreal lichens as well as a lowered ability of the landscape to sustain long-term persistence of lichens. The results further showed that variation in ground lichen cover among sites was mainly related to soil moisture conditions, recent disturbances, such as soil scarification and prescribed burning, and possibly also to forest history. In general, the results suggest that the composition and configuration of the forest landscape mosaic has become less suitable for sustainable reindeer husbandry.

  12. Ecological Restoration and Reforestation of Fragmented Forests in Kianjavato, Madagascar

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    Christophe Manjaribe

    2013-01-01

    Full Text Available A reforestation effort in Kianjavato Commune in southeast Madagascar is presented that combines native diversity with rapidly growing introduced and native pioneer trees. This work utilizes a three-tiered corridor design that capitalizes on the region’s mountainous terrain. The process of seed selection, transplantation, and survival rate of seedlings over a 16 month period is reported. The uppermost 50% of each mountain is planted with 38 woody species and most closely approximates native forest. This tier was divided into two categories, pioneer and secondary species. Most of the pioneer species were not native; however, results showed that four fast-growing, environmentally-tolerant native species could be suitable alternatives: Streblus mauritianus, Syzygium bernieri, Treculia madagascariensis and Uapaca thouarsii. More than 70,000 seeds of secondary species were extracted from fecal samples from wild, free-ranging black and white ruffed lemurs; the majority of which germinated significantly better after gut passage. The most effective pretreatment that enhanced germination was to scarify unwashed seeds. Commercially valuable trees, belonging to the community members, were grown on the lower half of each mountain. Lastly, the various contributions of the community are described along with agroforestry development plans designed to reduce pressure on forest resources and generate supplemental income.

  13. 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

  14. 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.

  15. Internal habitat quality determines the effects of fragmentation on austral forest climbing and epiphytic angiosperms.

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    Ainhoa Magrach

    Full Text Available Habitat fragmentation has become one of the major threats to biodiversity worldwide, particularly in the case of forests, which have suffered enormous losses during the past decades. We analyzed how changes in patch configuration and habitat quality derived from the fragmentation of austral temperate rainforests affect the distribution of six species of forest-dwelling climbing and epiphytic angiosperms. Epiphyte and vine abundance is primarily affected by the internal characteristics of patches (such as tree size, the presence of logging gaps or the proximity to patch edges rather than patch and landscape features (such as patch size, shape or connectivity. These responses were intimately related to species-specific characteristics such as drought- or shade-tolerance. Our study therefore suggests that plant responses to fragmentation are contingent on both the species' ecology and the specific pathways through which the study area is being fragmented, (i.e. extensive logging that shaped the boundaries of current forest patches plus recent, unregulated logging that creates gaps within patches. Management practices in fragmented landscapes should therefore consider habitat quality within patches together with other spatial attributes at landscape or patch scales.

  16. Internal habitat quality determines the effects of fragmentation on austral forest climbing and epiphytic angiosperms.

    Science.gov (United States)

    Magrach, Ainhoa; Larrinaga, Asier R; Santamaría, Luis

    2012-01-01

    Habitat fragmentation has become one of the major threats to biodiversity worldwide, particularly in the case of forests, which have suffered enormous losses during the past decades. We analyzed how changes in patch configuration and habitat quality derived from the fragmentation of austral temperate rainforests affect the distribution of six species of forest-dwelling climbing and epiphytic angiosperms. Epiphyte and vine abundance is primarily affected by the internal characteristics of patches (such as tree size, the presence of logging gaps or the proximity to patch edges) rather than patch and landscape features (such as patch size, shape or connectivity). These responses were intimately related to species-specific characteristics such as drought- or shade-tolerance. Our study therefore suggests that plant responses to fragmentation are contingent on both the species' ecology and the specific pathways through which the study area is being fragmented, (i.e. extensive logging that shaped the boundaries of current forest patches plus recent, unregulated logging that creates gaps within patches). Management practices in fragmented landscapes should therefore consider habitat quality within patches together with other spatial attributes at landscape or patch scales.

  17. 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

    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 or facul......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...... 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...... 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...

  18. Edge effect on vascular epiphytic composition in a fragment of Atlantic Forest in northeastern Brazil

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    Randolpho Gonçalves Dias-Terceiro

    2015-06-01

    Full Text Available Epiphytes are common in the canopy of temperate and tropical forests, where they substantially contribute to species diversity and to key ecosystem processes. However, little is known about the effects caused by deforestation on this group of species, especially in northeastern Brazil, an area experiencing intense anthropogenic pressure. This study aimed to evaluate the effect of environmental variables on the structure of assemblies of vascular epiphytes in a fragment of open ombrophilous forest, Areia, northeastern Brazil. Sixty 10 × 10 m sampling plots were installed to cover different environments within the fragment. The relationship between environmental variables and species composition was evaluated by means of a generalized linear mixed model. The composition of assemblies of epiphytes differed with respect to distance from the edge and luminosity. In the study area, deforestation led to a change in the composition of epiphytic species both at the edge and the interior of the fragment.

  19. 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

    2017-01-01

    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. PMID:28195145

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

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    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.

  1. 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.

  2. Dung beetle assemblages (Coleoptera, Scarabaeinae in Atlantic forest fragments in southern Brazil

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    Renata C. Campos

    2013-03-01

    Full Text Available Dung beetle assemblages (Coleoptera, Scarabaeinae in Atlantic forest fragments in southern Brazil. The beetles of the subfamily Scarabaeinae are important organisms that participate in the cycle of decomposition, especially in tropical ecosystems. Most species feed on feces (dung or carcasses (carrion and are associated with animals that produce their food resources. Dung beetles are divided into three functional groups: rollers, tunnelers and dwellers. This present work aims to study the diversity of dung beetle communities inhabiting fragments of the Atlantic Forest, with the purpose of describing the ecology of the species in southern Brazil. This study was conducted in the region of Campos Novos, in Santa Catarina, where twenty sites of Atlantic forest fragments were sampled. Samplings of dung beetles were conducted using 200 pitfall traps, of which 100 were baited with human feces and another 100 with carrion. Size and environmental complexity were also measured for each forest fragment. A total of 1,502 dung beetles, belonging to six tribes, 12 genera and 33 species, were collected. Results of the Levin's index of niche breadth indicated that 11 species were categorized as being coprophagous, ten as generalists, and two as necrophagous. Most species are tunnelers (19, nine of rollers and four of dwellers. The great diversity of Scarabaeinae in the region of Campos Novos, including several rare species, adds important data to the Scarabaeinae fauna in the central-western region of Santa Catarina. It may also help choosing priority areas for conservation in the region, where human impact, with large areas of monoculture, increasingly threatens the fragments of Mixed Ombrophilous Forest.

  3. Observed Differences in the Human Footprint and Forest Fragmentation in the Primary Forest Area of the Democratic Republic of Congo: A Remote Sensing Study for 2000-2010

    Science.gov (United States)

    Molinario, G.

    2015-12-01

    Conflict in the Democratic Republic of Congo (DRC) and neighboring countries has caused the displacement of people internally and internationally sometimes leading to drastic changes in the impact that traditional slash and burn shifting cultivation has on the forest ecosystem. In other areas, the lack of infrastructure and governance has isolated and protected areas of core forest from large scale exploitation. Observing specific patterns of forest fragmentation caused either by the expansion of existing rural complex areas or of isolated forest perforations has allowed us to track the differential growth of the human footprint throughout forested area of the country during the period 2000-2010. Our methodological approach involved the development of a model of shifting cultivation and forest fragmentation in which spatial rules applied morphological image processing to the Forets d'Afrique Central Evaluee par Teledetection (FACET) product. The result is a disaggregated classification of the primary forest into patch, edge, perforated, fragmented and core forest subtypes which we subsequently re-aggregated into homogenous anthropogenic macro-areas of rural complex and isolated forest perforations. We tracked how subsequent forest loss observed in 2005 and 2010 grew or shrunk these areas, presumably with differential impacts on the forest ecosystem. Using this approach we were able to map forest degradation by contextualizing the contribution of forest loss to change in different types of areas, highlighting how it can be greatly underestimated by a non contextualized per-pixel assessment of forest cover loss.

  4. Within and Among Patch Variability in Patterns of Insect Herbivory Across a Fragmented Forest Landscape.

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    Dorothy Y Maguire

    Full Text Available Fragmentation changes the spatial patterns of landscapes in ways that can alter the flow of materials and species; however, our understanding of the consequences of this fragmentation and flow alteration for ecosystem processes and ecosystem services remains limited. As an ecological process that affects many ecosystem services and is sensitive to fragmentation, insect herbivory is a good model system for exploring the role of fragmentation, and the resulting spatial patterns of landscapes, in the provision of ecosystem services. To refine our knowledge of how changes in landscape pattern affect insect herbivory, we quantified the combined influence of among patch (patch area and patch connectivity and within patch (location within patch; canopy, edge, interior factors on amounts of insect herbivory in a fragmented forest landscape. We measured herbivory in 20 forest patches of differing size and connectivity in southern Quebec (Canada. Within each patch, herbivory was quantified at the interior, edge, and canopy of sugar maple trees during the spring and summer of 2011 and 2012. Results show that connectivity affects herbivory differently depending on the location within the patch (edge, interior, canopy, an effect that would have gone unnoticed if samples were pooled across locations. These results suggest considering structure at both the patch and within patch scales may help to elucidate patterns when studying the effects of fragmentation on ecosystem processes, with implications for the services they support.

  5. Impact of human pressure and forest fragmentation on the Endangered Barbary macaque Macaca sylvanus in the Middle Atlas of Morocco

    OpenAIRE

    Ménard, Nelly; Rantier, Yann; Foulquier, Adrien; Qarro, Mohamed; Chillasse, Lahcen; Vallet, Dominique; Pierre, Jean-Sébastien; Butet, Alain

    2014-01-01

    International audience; Overexploitation of forests by humans can lead to highly fragmented populations of forest-dependent species that have poor dispersal abilities. We tested the influence of habitat quality, landscape structure and human pressure on densities of the Barbary macaque Macaca sylvanus in the largest wild population, in the Middle Atlas of Morocco. We surveyed 14 forest fragments of 5-142 km2 that are separated from each other by an inhospitable matrix. We estimated the habita...

  6. Tropical Forest Fragmentation Affects Floral Visitors but Not the Structure of Individual-Based Palm-Pollinator Networks

    Science.gov (United States)

    Dáttilo, Wesley; Aguirre, Armando; Quesada, Mauricio; Dirzo, Rodolfo

    2015-01-01

    Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae) and its floral visitors (including both effective and non-effective pollinators) at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i) Does fragment size affect the structure of individual-based plant-pollinator networks? (ii) Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii) Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in remnant forests

  7. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Science.gov (United States)

    Dáttilo, Wesley; Aguirre, Armando; Quesada, Mauricio; Dirzo, Rodolfo

    2015-01-01

    Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae) and its floral visitors (including both effective and non-effective pollinators) at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i) Does fragment size affect the structure of individual-based plant-pollinator networks? (ii) Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii) Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in remnant forests.

  8. Tropical forest fragmentation affects floral visitors but not the structure of individual-based palm-pollinator networks.

    Directory of Open Access Journals (Sweden)

    Wesley Dáttilo

    Full Text Available Despite increasing knowledge about the effects of habitat loss on pollinators in natural landscapes, information is very limited regarding the underlying mechanisms of forest fragmentation affecting plant-pollinator interactions in such landscapes. Here, we used a network approach to describe the effects of forest fragmentation on the patterns of interactions involving the understory dominant palm Astrocaryum mexicanum (Arecaceae and its floral visitors (including both effective and non-effective pollinators at the individual level in a Mexican tropical rainforest landscape. Specifically, we asked: (i Does fragment size affect the structure of individual-based plant-pollinator networks? (ii Does the core of highly interacting visitor species change along the fragmentation size gradient? (iii Does forest fragment size influence the abundance of effective pollinators of A. mexicanum? We found that fragment size did not affect the topological structure of the individual-based palm-pollinator network. Furthermore, while the composition of peripheral non-effective pollinators changed depending on fragment size, effective core generalist species of pollinators remained stable. We also observed that both abundance and variance of effective pollinators of male and female flowers of A. mexicanum increased with forest fragment size. These findings indicate that the presence of effective pollinators in the core of all forest fragments could keep the network structure stable along the gradient of forest fragmentation. In addition, pollination of A. mexicanum could be more effective in larger fragments, since the greater abundance of pollinators in these fragments may increase the amount of pollen and diversity of pollen donors between flowers of individual plants. Given the prevalence of fragmentation in tropical ecosystems, our results indicate that the current patterns of land use will have consequences on the underlying mechanisms of pollination in

  9. Mites associated to Xylopia aromatica (Lam. Mart. (Annonaceae in urban and rural fragments of semidecidual forest

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    Felipe M. Nuvoloni

    2011-12-01

    Full Text Available Mites associated to Xylopia aromatica (Lam. Mart. (Annonaceae in urban and rural fragments of semidecidual forest. Native plants can shelter a great diversity of mites. Notwithstanding, the conservation of the forest fragments where the plants are located can influence the structure of the mites community. Generally, in homogenous environments the diversity is lower due to the dominance of one or a few species. In this work, we studied the mite community on Xylopia aromatica (Lam. Mart. (Annonaceae in two fragments of semidecidual forest: one on rural and other on urban area. Seven individuals of X. aromatica were monthly sampled from April 2007 to March 2008, in each of these fragments. Descriptive indexes of diversity, dominance and evenness were applied to verify the ecological patterns of the mite community, besides the Student's t-test to compare the abundance between the fragments. We collected 27,365 mites of 37 species belonging to 11 families. Calacarus sp. (Eriophyidae was the most abundant species, representing 73% of the total sampled. The abundance was greater in the urban fragment (67.7%, with the diversity index reaching only 25% of the theoretical maximum expected. Probably, these values might have been influenced by the location of this fragment in the urban area, being more homogeneous and submitted directly to the presence of atmospheric pollution. In this manner, X. aromatica is able to shelter a higher diversity of mites when inserted in preserved ecosystems, since the highest diversity of available resources allows the establishment of richer and most diverse mite community.

  10. Fragmentation

    Science.gov (United States)

    K.H. Riitters

    2009-01-01

    Effective resource management takes into account the administrative and biophysical settings within which natural resources occur. A setting may be described in many ways; for example, by forest land ownership, by reserved and roadless designation, or by the distribution of human populations in relation to forest (chapter 3). The physical arrangement of forest in a...

  11. Effects of forest fragmentation on phenological patterns and reproductive success of the tropical dry forest tree Ceiba aesculifolia.

    Science.gov (United States)

    Herrerías-Diego, Yvonne; Quesada, Mauricio; Stoner, Kathryn E; Lobo, Jorge A

    2006-08-01

    Spatial isolation caused by forest fragmentation and temporal isolation caused by asynchronous flowering of plants have been proposed as important factors that affect the reproduction ofplant populations. In a 4-year study, we determined the effects of forest fragmentation and spatial isolation on flowering phenology and reproductive success of the tropical tree Ceiba aesculifolia ([Kunth] Britton & Rose). We conducted our study in the dry forest of Mexico and compared populations in two habitat conditions based on density and environmental conditions: (1) disturbed habitat (four populations of reproductive individuals/ha surrounded by agriculturalfields or pastures) and (2) undisturbed habitat (three populations of groups of >6 reproductive individuals/ha surrounded by undisturbed mature forest). We compared the following variables within these populations over 4 years: flowering overlap, proportion of individuals with flowers and fruit, total flower production, total fruit production, fruit set, seed production, and seed abortion. Little overlap in flowering occurred among the populations in the two habitat conditions. The flowering period of trees in the disturbed habitat initiated between 15 to 20 days before the flowering period of trees in the undisturbed habitat during 3 years. Flowering of trees in the undisturbed habitat peaked at the end of the flowering period of the trees in the disturbed habitat. The proportion of trees that flowered was greater in the undisturbed habitat. Nevertheless, total flower production was greater in the disturbed habitat and these differences were maintained across 3 years. The proportion of individuals that produced fruit did not differ across habitat conditions but did differ across years. Total fruit production was greater in the disturbed habitat, but fruit set and seed production were the same across years and between habitat conditions. Seed abortion varied over years between habitats. We concluded that forest

  12. Effect of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora, a tree native to the Atlantic Forest.

    Science.gov (United States)

    de Almeida, D J; Faria, M V; da Silva, P R

    2012-12-06

    Habitat fragmentation, caused by the expansion of agriculture in natural areas, may be one of the strongest impacts humans have on the ecosystem. These changes can decrease the number of individuals in a population, leading to endogamy. In allogamous species, endogamy can have a negative effect on reproductive capacity. In this study, we analyzed the effects of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora L., a tree species native to the Atlantic Forest. We analyzed 4 populations, 3 of which were connected by forest corridors and 1 of which was isolated by agricultural fields on all sides. For microsporogenesis analysis, 9000 meiocytes representing all stages of meiosis were evaluated. To perform the pollen viability test, we evaluated 152,000 pollen grains. Microsporogenesis was stable in plants from populations that were connected by forest corridors (abnormalities, less than 6%), while microsporogenesis in plants from the isolated population showed a higher level of abnormalities (13-29%). Average pollen viability was found to be more than 93% in the non-isolated populations and 82.62% in the isolated population. The χ(2) test showed that, in the isolated population, the meiotic index was significantly lower than that in the non-isolated populations (P = 0.03). The analysis of variance for the percentage of viable pollen grains confirmed the significant difference between the isolated and non-isolated populations. Our data show that forest fragmentation has a direct effect on microsporogenesis and pollen viability in E. uniflora and can directly influence the reproductive capacity of isolated populations of this species.

  13. Long-term fragmentation effects on the distribution and dynamics of canopy gaps in a tropical montane forest

    Science.gov (United States)

    Nicholas R. Vaughn; Gregory P. Asner; Christian P. Giardina

    2015-01-01

    Fragmentation alters forest canopy structure through various mechanisms, which in turn drive subsequent changes to biogeochemical processes and biological diversity. Using repeated airborne LiDAR (Light Detection and Ranging) mappings, we investigated the size distribution and dynamics of forest canopy gaps across a topical montane forest landscape in Hawaii naturally...

  14. 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

    2017-02-10

    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.

  15. Kinetic Behavior of Aggregation-Fragmentation Process with Annihilation

    Institute of Scientific and Technical Information of China (English)

    KE JianHong; LIN ZhenQuan

    2002-01-01

    The kinetic behavior of an aggregation-fragmentation-annihilation system with two distinct species is stead-ied. We propose that the aggregation reaction occurs only between two clusters of the same species, and the irreversibleannihilation reaction occurs only between two clusters of different species, meanwhile there exists the fragmentationreaction of a cluster into two smaller clusters for either species. Based on the mncan-field theory, we investigate therate equations of the process with constant reaction rates and obtain the asymptotic descriptions of the cluster-massdistribution. In the case of the same initial concentrations of two species, the scaling descriptions for the cluster-massdistributions of the two species are found to break down completely. It is also observed that the kinetic behaviors ofdistinct species are quite complicated for the case of different initial concentrations of the two species. Tile clusters oflarger initial concentration species (heavy species) possess peculiar scaling properties, while the cluster-mass distributionoflight species has not scaling behavior. The exponents describing the scaling behavior for heavy species strongly dependon its fragmentation rate and initial monomer concentrations of two kinds of reactants.

  16. Effects of local tree diversity on herbivore communities diminish with increasing forest fragmentation on the landscape scale.

    Directory of Open Access Journals (Sweden)

    Franziska Peter

    Full Text Available Forest fragmentation and plant diversity have been shown to play a crucial role for herbivorous insects (herbivores, hereafter. In turn, herbivory-induced leaf area loss is known to have direct implications for plant growth and reproduction as well as long-term consequences for ecosystem functioning and forest regeneration. So far, previous studies determined diverging responses of herbivores to forest fragmentation and plant diversity. Those inconsistent results may be owed to complex interactive effects of both co-occurring environmental factors albeit they act on different spatial scales. In this study, we investigated whether forest fragmentation on the landscape scale and tree diversity on the local habitat scale show interactive effects on the herbivore community and leaf area loss in subtropical forests in South Africa. We applied standardized beating samples and a community-based approach to estimate changes in herbivore community composition, herbivore abundance, and the effective number of herbivore species on the tree species-level. We further monitored leaf area loss to link changes in the herbivore community to the associated process of herbivory. Forest fragmentation and tree diversity interactively affected the herbivore community composition, mainly by a species turnover within the family of Curculionidae. Furthermore, herbivore abundance increased and the number of herbivore species decreased with increasing tree diversity in slightly fragmented forests whereas the effects diminished with increasing forest fragmentation. Surprisingly, leaf area loss was neither affected by forest fragmentation or tree diversity, nor by changes in the herbivore community. Our study highlights the need to consider interactive effects of environmental changes across spatial scales in order to draw reliable conclusions for community and interaction patterns. Moreover, forest fragmentation seems to alter the effect of tree diversity on the herbivore

  17. Effects of local tree diversity on herbivore communities diminish with increasing forest fragmentation on the landscape scale.

    Science.gov (United States)

    Peter, Franziska; Berens, Dana G; Farwig, Nina

    2014-01-01

    Forest fragmentation and plant diversity have been shown to play a crucial role for herbivorous insects (herbivores, hereafter). In turn, herbivory-induced leaf area loss is known to have direct implications for plant growth and reproduction as well as long-term consequences for ecosystem functioning and forest regeneration. So far, previous studies determined diverging responses of herbivores to forest fragmentation and plant diversity. Those inconsistent results may be owed to complex interactive effects of both co-occurring environmental factors albeit they act on different spatial scales. In this study, we investigated whether forest fragmentation on the landscape scale and tree diversity on the local habitat scale show interactive effects on the herbivore community and leaf area loss in subtropical forests in South Africa. We applied standardized beating samples and a community-based approach to estimate changes in herbivore community composition, herbivore abundance, and the effective number of herbivore species on the tree species-level. We further monitored leaf area loss to link changes in the herbivore community to the associated process of herbivory. Forest fragmentation and tree diversity interactively affected the herbivore community composition, mainly by a species turnover within the family of Curculionidae. Furthermore, herbivore abundance increased and the number of herbivore species decreased with increasing tree diversity in slightly fragmented forests whereas the effects diminished with increasing forest fragmentation. Surprisingly, leaf area loss was neither affected by forest fragmentation or tree diversity, nor by changes in the herbivore community. Our study highlights the need to consider interactive effects of environmental changes across spatial scales in order to draw reliable conclusions for community and interaction patterns. Moreover, forest fragmentation seems to alter the effect of tree diversity on the herbivore community, and thus

  18. Effects of Local Tree Diversity on Herbivore Communities Diminish with Increasing Forest Fragmentation on the Landscape Scale

    Science.gov (United States)

    Peter, Franziska; Berens, Dana G.; Farwig, Nina

    2014-01-01

    Forest fragmentation and plant diversity have been shown to play a crucial role for herbivorous insects (herbivores, hereafter). In turn, herbivory-induced leaf area loss is known to have direct implications for plant growth and reproduction as well as long-term consequences for ecosystem functioning and forest regeneration. So far, previous studies determined diverging responses of herbivores to forest fragmentation and plant diversity. Those inconsistent results may be owed to complex interactive effects of both co-occurring environmental factors albeit they act on different spatial scales. In this study, we investigated whether forest fragmentation on the landscape scale and tree diversity on the local habitat scale show interactive effects on the herbivore community and leaf area loss in subtropical forests in South Africa. We applied standardized beating samples and a community-based approach to estimate changes in herbivore community composition, herbivore abundance, and the effective number of herbivore species on the tree species-level. We further monitored leaf area loss to link changes in the herbivore community to the associated process of herbivory. Forest fragmentation and tree diversity interactively affected the herbivore community composition, mainly by a species turnover within the family of Curculionidae. Furthermore, herbivore abundance increased and the number of herbivore species decreased with increasing tree diversity in slightly fragmented forests whereas the effects diminished with increasing forest fragmentation. Surprisingly, leaf area loss was neither affected by forest fragmentation or tree diversity, nor by changes in the herbivore community. Our study highlights the need to consider interactive effects of environmental changes across spatial scales in order to draw reliable conclusions for community and interaction patterns. Moreover, forest fragmentation seems to alter the effect of tree diversity on the herbivore community, and thus

  19. Who wants to conserve remaining forest fragments in the Manompana Corridor?

    Directory of Open Access Journals (Sweden)

    Hans R. Felber

    2012-12-01

    Full Text Available Contiguous forests in Madagascar are continuously converted into forest fragments due to deforestation, and dispersed into landscape mosaics dominated by agriculture. These fragments are of increasing importance for biodiversity conservation as well as for the well being of rural inhabitants, providing a high diversity of timber and non- timber forest products. An increasing number of international projects are therefore trying to preserve remaining forests and to transfer the management of these forests to local communities. However, it is not known how important the preservation of forest fragments is to local people. We therefore explore the importance of forest fragments as a source of cash income to different groups separated by wealth level and access to forest resources. A multi-method research approach was taken, based on score application exercises as well as interviews with individual households and focus groups. Our study site was located at the east coast of Madagascar in the Manompana corridor. Results show that some groups are significantly more interested in the preservation of forest fragments than others. Interest is significantly related to the wealth of local inhabitants as well as to the walking distance between villages and forest resources. Nevertheless, interest in resource preservation does not depend on how important fragments are to local people, but rather on the awareness about resource scarcity. RésuméEn raison d’une forte déforestation sur la côte est de Madagascar, de nombreux massifs forestiers d’un seul tenant et de vastes écosystèmes interconnectés ont été détruits, laissant des fragments de forêts qui s’intègrent dans une mosaïque paysagère dominée par l’agriculture. Ces fragments gagnent en importance. Ils jouent un rôle de premier plan dans les réseaux de biodiversité en assurant un certain niveau de connectivité. Mais les fragments sont essentiels au bien - être de la population

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Patch size and isolation predict plant species density in a naturally fragmented forest.

    Science.gov (United States)

    Munguía-Rosas, Miguel A; Montiel, Salvador

    2014-01-01

    Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest). We surveyed the vascular flora (except lianas and epiphytes) of 19 forest patches using five belt transects (50×4 m each) per patch (area sampled per patch = 0.1 ha). As predicted, plant species density was positively associated (logarithmically) with patch size and negatively associated (linearly) with patch isolation (distance to the nearest patch). Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation), however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented.

  2. Patch size and isolation predict plant species density in a naturally fragmented forest.

    Directory of Open Access Journals (Sweden)

    Miguel A Munguía-Rosas

    Full Text Available Studies of the effects of patch size and isolation on plant species density have yielded contrasting results. However, much of the available evidence comes from relatively recent anthropogenic forest fragments which have not reached equilibrium between extinction and immigration. This is a critical issue because the theory clearly states that only when equilibrium has been reached can the number of species be accurately predicted by habitat size and isolation. Therefore, species density could be better predicted by patch size and isolation in an ecosystem that has been fragmented for a very long time. We tested whether patch area, isolation and other spatial variables explain variation among forest patches in plant species density in an ecosystem where the forest has been naturally fragmented for long periods of time on a geological scale. Our main predictions were that plant species density will be positively correlated with patch size, and negatively correlated with isolation (distance to the nearest patch, connectivity, and distance to the continuous forest. We surveyed the vascular flora (except lianas and epiphytes of 19 forest patches using five belt transects (50×4 m each per patch (area sampled per patch = 0.1 ha. As predicted, plant species density was positively associated (logarithmically with patch size and negatively associated (linearly with patch isolation (distance to the nearest patch. Other spatial variables such as patch elevation and perimeter, did not explain among-patch variability in plant species density. The power of patch area and isolation as predictors of plant species density was moderate (together they explain 43% of the variation, however, a larger sample size may improve the explanatory power of these variables. Patch size and isolation may be suitable predictors of long-term plant species density in terrestrial ecosystems that are naturally and anthropogenically fragmented.

  3. 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...

  4. Characterization of Amazonian forest fragments in the catchment of the Taxidermista I River in Alta Floresta, MT

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    Carlos José da Silva

    2013-11-01

    Full Text Available Maintaining the connectivity of the remaining forest in the state of Mato Grosso is critically important, and the preservation of riparian vegetation of streams contributes greatly to retaining the integrity of the mosaic of habitats found in this region. The aim of this study was to characterize the Amazonian forest fragments remaining in the catchment of the Taxidermista I River, in Alta Floresta, MT, in order to provide input for the implementation of recovery projects in degraded areas and the conservation of forest fragments. The forest fragments were vectorized and the size, perimeter, and distance of each fragment to the nearest watercourse were evaluated. The circularity index, or the edge/interior ratio, was also determined. In the watershed of the Taxidermista I River, 63 forest fragments ranging in size from 0.44 to 67.51 ha, with perimeters between 262.67 and 4756.26 m, were recorded. The distance from each forest fragment to the nearest watercourse ranges from 0 to 450 m; however, 71.4% of the fragments are connected to a watercourse. The majority of the fragments in this watershed are elongated and occupy a small area, but their perimeter/edge is large relative to their size, which makes them susceptible to edge effects, especially from nearby cattle farms.

  5. Floristic diversity analysis along a fragmentation gradients: a case study of beech forests in the Molisean Appenines (southern Italy

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    Frate L

    2011-11-01

    Full Text Available The process of fragmentation of natural habitats is increasing exponentially worldwide and represents one of the foremost threats to biological diversity. Forest fragmentation is considered to heavily affect the demographic and genetic structure of forest plant populations. Habitat fragmentation is a landscape process occurring when areas of continuous habitat are broken into smaller and discontinuous patches. In this paper we analyzed the effects of fragmentation on vascular plant diversity of Fagus sylvatica forest in central Italy (habitat of Community interest -92/43/ECC- “Appenine beech forests with Taxus and Ilex” - cod. 9210*. First, by integrating five parameters that describe beech forest patches structure (patch area, perimeter, shape index, corea area, euclidean nearest neighbor we identified three levels of fragmentation: high, medium and absent. Then the vascular plants of each level of fragmentation were sampled following a random stratified design. The diversity of vascular plant species was analyzed considering two species groups: all sampled species and “diagnostic” species of the habitat 9210* (sensu Directive 92/43/ECC. We compared the biodiversity patterns of the different fragmentation levels by using rarefaction curves and Rényi’s profiles. We also tested the significance of the founded differences by a bootstrapping procedure. The diversity pattern of the two species groups (diagnostics and all species showed two opposite trends. As the diversity of the entire pool of species increased on fragmented beech forests the diversity of the diagnostic group decreased. The differences between diversity values of high and low fragmentation levels resulted significant. Our results emphasize the existence of two diagnostic species: Cardamine kitaibelii and Paris quadrifolia that are indicators of not fragmented beech forests. Additionally the diversity pattern of the diagnostics species allow us to propose them as

  6. Distribution of Atta (Hymenoptera - Formicidae) in "terra-firme" rain forest of Central Amazonia: density, species composition and preliminary results on effects of forest fragmentation

    OpenAIRE

    Vasconcelos,Heraldo Luís de

    1988-01-01

    One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the mo...

  7. Species richness of anthophilous butterflies of an Atlantic Forest fragment in Southeastern Brazil

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    Kelen Coelho Cruz

    2012-10-01

    Full Text Available The objectives of this study were to identify anthophilous butterflies on psychophilous flowers of four Asteraceae species in an Atlantic Forest fragment in Viçosa, Minas Gerais State, Southeastern Brazil, and to determine whether there are species in common with other lepidopteran inventories of the Southeastern and Midwestern regions of Brazil. It is the first inventory of anthophilous butterflies of a semideciduous forest fragment in Zona da Mata, State of Minas Gerais. A total of 108 species were recorded, representing the fourth largest lepidopteran survey in this State. The results demonstrated that Asteraceae species may be important tools for monitoring anthophilous butterflies. The similarity with other inventories ranged from 1 to 92.55%. Fifteen species were reported for the first time in the State of Minas Gerais, and among them, Melanis alena and Thisbe irenea were observed in this study only.

  8. Spatially explicit measurements of forest structure and fire behavior following restoration treatments in dry forests

    Science.gov (United States)

    Justin Paul Ziegler; Chad Hoffman; Michael Battaglia; William Mell

    2017-01-01

    Restoration treatments in dry forests of the western US often attempt silvicultural practices to restore the historical characteristics of forest structure and fire behavior. However, it is suggested that a reliance on non-spatial metrics of forest stand structure, along with the use of wildland fire behavior models that lack the ability to handle complex structures,...

  9. 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

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

    Science.gov (United States)

    2015-01-01

    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 variation. PMID

  11. 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.

  12. 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

  13. 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

  14. Species interactions regulate the collapse of biodiversity and ecosystem function in tropical forest fragments.

    Science.gov (United States)

    Bregman, Tom P; Lees, Alexander C; Seddon, Nathalie; Macgregor, Hannah E A; Darski, Bianca; Aleixo, Alexandre; Bonsall, Michael B; Tobias, Joseph A

    2015-10-01

    Competitive interactions among species with similar ecological niches are known to regulate the assembly of biological communities. However, it is not clear whether such forms of competition can predict the collapse of communities and associated shifts in ecosystem function in the face of environmental change. Here, we use phylogenetic and functional trait data to test whether communities of two ecologically important guilds of tropical birds (frugivores and insectivores) are structured by species interactions in a fragmented Amazonian forest landscape. In both guilds, we found that forest patch size, quality, and degree of isolation influence the phylogenetic and functional trait structure of communities, with small, degraded, or isolated forest patches having an increased signature of competition (i.e., phylogenetic and functional trait overdispersion in relation to null models). These results suggest that local extinctions in the context of fragmentation are nonrandom, with a consistent bias toward more densely occupied regions of niche space. We conclude that the loss of biodiversity in fragmented landscapes is mediated by niche-based competitive interactions among species, with potentially far-reaching implications for key ecosystem processes, including seed dispersal and plant damage by phytophagous insects.

  15. 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.

  16. Got Dung? Resource Selection by Dung Beetles in Neotropical Forest Fragments and Cattle Pastures.

    Science.gov (United States)

    Bourg, A; Escobar, F; MacGregor-Fors, I; Moreno, C E

    2016-10-01

    Both the impact of habitat modification on the food preferences of species and its impact on ecosystem functioning are poorly understood. In this study, we analyzed food selection by dung beetles in 80 tropical forest fragments and their adjacent cattle pastures in the Los Tuxtlas Biosphere Reserve, Mexico. Ten pitfall traps were placed at each site, half baited with human dung and the other half with fish carrion. We assessed dung beetle food selection and classified any specialization in resource use quantitatively using a multinomial classification model. We collected 15,445 beetles belonging to 42 species, 8747 beetles (38 species) in forest fragments and 6698 beetles (29 species) in cattle pastures. Twenty-five species were present in both habitats. Of all the beetles captured, 76% were caught in dung traps (11,727 individuals) and 24% in carrion traps (3718 individuals). We found 21 species of dung specialists, 7 carrion specialists, 8 generalists, and 6 species too rare to classify. The bait most frequently selected by beetles in this study was dung in both forests and pastures. Specialists tended to remain specialists in both habitats, while generalists tended to change their selection of bait type depending on the habitat. In summary, our results show that replacing forests with cattle pastures modifies the patterns of resource selection by dung beetles and this could affect ecosystem functioning.

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

    Science.gov (United States)

    Uezu, Alexandre; Metzger, Jean Paul

    2016-01-01

    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.

  18. 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.

  19. Determining coniferous forest cover and forest fragmentation with NOAA-9 advanced very high resolution radiometer data

    Science.gov (United States)

    Ripple, William J.

    1995-01-01

    NOAA-9 satellite data from the Advanced Very High Resolution Radiometer (AVHRR) were used in conjunction with Landsat Multispectral Scanner (MSS) data to determine the proportion of closed canopy conifer forest cover in the Cascade Range of Oregon. A closed canopy conifer map, as determined from the MSS, was registered with AVHRR pixels. Regression was used to relate closed canopy conifer forest cover to AVHRR spectral data. A two-variable (band) regression model accounted for more variance in conifer cover than the Normalized Difference Vegetation Index (NDVI). The spectral signatures of various conifer successional stages were also examined. A map of Oregon was produced showing the proportion of closed canopy conifer cover for each AVHRR pixel. The AVHRR was responsive to both the percentage of closed canopy conifer cover and the successional stage in these temperate coniferous forests in this experiment.

  20. Biodiversity of leaf-litter ants in fragmented tropical rainforests of Borneo: the value of publically and privately managed forest fragments

    OpenAIRE

    Tawatao, N; Lucey, JM; M Senior (Referee); Benedick, S; Vun Khen, C; Hill, JK; Hamer, KC

    2014-01-01

    In view of the rapid rate of expansion of agriculture in tropical regions, attention has focused on the potential for privately-managed rainforest patches within agricultural land to contribute to biodiversity conservation. However, these sites generally differ in their history of forest disturbance and management compared with other forest fragments, and more information is required on the biodiversity value of these privately-managed sites, particularly in oil-palm dominated landscapes of S...

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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.

  3. Habitat fragmentation leads to reduced pollinator visitation, fruit production and recruitment in urban mangrove forests.

    Science.gov (United States)

    Hermansen, Tyge D; Minchinton, Todd E; Ayre, David J

    2017-09-08

    Mangrove forests worldwide undergo anthropogenic fragmentation that may threaten their existence, and yet there have been few tests of the effects of fragmentation on demographic processes critical for mangrove regeneration. Predicting the effects of habitat fragmentation on mangroves is problematic as pollinators may move more freely across water than terrestrial habitat, and propagules can be widely dispersed by water. Here, within each of two estuaries, we compared pollinator diversity and activity, reproductive effort and output, and rates of recruitment for sets of three large (>1500 trees), medium (300-500) and small (fragmentation on the abundance of pollinators (honeybees), the production and quality of fruit and the survival rate of seedlings to be similar, showing significant reduction of recruitment in small stands. This study provides the first rigorous evidence that recruitment of mangroves, like for many terrestrial plants, is negatively impacted by habitat fragmentation. From a management perspective, we argue that in the short term our data imply the importance of conserving the largest possible stands. However, additional work is needed to determine (1) the proportion of recruits within small stands that originate within large stands, (2) how seedling performance varies with fruit size and genotype, and (3) how seedling size and performance vary with the abundance and diversity of pollen.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. Habitat Fragmentation can Modulate Drought Effects on the Plant-soil-microbial System in Mediterranean Holm Oak (Quercus ilex) Forests.

    Science.gov (United States)

    Flores-Rentería, Dulce; Curiel Yuste, Jorge; Rincón, Ana; Brearley, Francis Q; García-Gil, Juan Carlos; Valladares, Fernando

    2015-05-01

    Ecological transformations derived from habitat fragmentation have led to increased threats to above-ground biodiversity. However, the impacts of forest fragmentation on soils and their microbial communities are not well understood. We examined the effects of contrasting fragment sizes on the structure and functioning of soil microbial communities from holm oak forest patches in two bioclimatically different regions of Spain. We used a microcosm approach to simulate the annual summer drought cycle and first autumn rainfall (rewetting), evaluating the functional response of a plant-soil-microbial system. Forest fragment size had a significant effect on physicochemical characteristics and microbial functioning of soils, although the diversity and structure of microbial communities were not affected. The response of our plant-soil-microbial systems to drought was strongly modulated by the bioclimatic conditions and the fragment size from where the soils were obtained. Decreasing fragment size modulated the effects of drought by improving local environmental conditions with higher water and nutrient availability. However, this modulation was stronger for plant-soil-microbial systems built with soils from the northern region (colder and wetter) than for those built with soils from the southern region (warmer and drier) suggesting that the responsiveness of the soil-plant-microbial system to habitat fragmentation was strongly dependent on both the physicochemical characteristics of soils and the historical adaptation of soil microbial communities to specific bioclimatic conditions. This interaction challenges our understanding of future global change scenarios in Mediterranean ecosystems involving drier conditions and increased frequency of forest fragmentation.

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

    Directory of Open Access Journals (Sweden)

    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

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

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    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.

  10. Impacts of forest fragmentation on species richness: a hierarchical approach to community modelling

    Science.gov (United States)

    Zipkin, Elise F.; DeWan, Amielle; Royle, J. Andrew

    2009-01-01

    1. Species richness is often used as a tool for prioritizing conservation action. One method for predicting richness and other summaries of community structure is to develop species-specific models of occurrence probability based on habitat or landscape characteristics. However, this approach can be challenging for rare or elusive species for which survey data are often sparse. 2. Recent developments have allowed for improved inference about community structure based on species-specific models of occurrence probability, integrated within a hierarchical modelling framework. This framework offers advantages to inference about species richness over typical approaches by accounting for both species-level effects and the aggregated effects of landscape composition on a community as a whole, thus leading to increased precision in estimates of species richness by improving occupancy estimates for all species, including those that were observed infrequently. 3. We developed a hierarchical model to assess the community response of breeding birds in the Hudson River Valley, New York, to habitat fragmentation and analysed the model using a Bayesian approach. 4. The model was designed to estimate species-specific occurrence and the effects of fragment area and edge (as measured through the perimeter and the perimeter/area ratio, P/A), while accounting for imperfect detection of species. 5. We used the fitted model to make predictions of species richness within forest fragments of variable morphology. The model revealed that species richness of the observed bird community was maximized in small forest fragments with a high P/A. However, the number of forest interior species, a subset of the community with high conservation value, was maximized in large fragments with low P/A. 6. Synthesis and applications. Our results demonstrate the importance of understanding the responses of both individual, and groups of species, to environmental heterogeneity while illustrating the utility

  11. Long-term effects of habitat fragmentation on mating patterns and gene flow of a tropical dry forest tree, Ceiba aesculifolia (Malvaceae: Bombacoideae).

    Science.gov (United States)

    Quesada, Mauricio; Herrerías-Diego, Yvonne; Lobo, Jorge A; Sánchez-Montoya, Gumersindo; Rosas, Fernando; Aguilar, Ramiro

    2013-06-01

    Tropical forest loss and fragmentation isolate and reduce the size of remnant populations with negative consequences for mating patterns and genetic structure of plant species. In a 4-yr study, we determined the effect of fragmentation on mating patterns and pollen pool genetic structure of the tropical tree Ceiba aesculifolia in two habitat conditions: isolated trees in disturbed areas (≤3 trees/ha), and trees (≥6 trees/ha) in undisturbed mature forest. • Using six allozyme loci, we estimated the outcrossing rate (tm), the mean relatedness of progeny (rp) within and between fruits, the degree of genetic structure of pollen pools (Φft), and the effective number of pollen donors (Nep). • The outcrossing rates reflected a strict self-incompatible species. Relatedness of progeny within fruits was similar for all populations, revealing single sires within fruits. However, relatedness of progeny between fruits within trees was consistently greater for trees in fragmented conditions across 4 yr. We found high levels of genetic structure of pollen pools in all populations with more structure in isolated trees. The effective number of pollen donors was greater for trees in undisturbed forest than in disturbed conditions. • Our study showed that the progeny produced by isolated trees in disturbed habitats are sired by a fraction of the diversity of pollen donors found in conserved forests. The foraging behavior of bats limits the exchange of pollen between trees, causing higher levels of progeny relatedness in isolated trees.

  12. Interspecific infanticide and infant-directed aggression by spider monkeys (Ateles hybridus) in a fragmented forest in Colombia.

    Science.gov (United States)

    Rimbach, Rebecca; Pardo-Martinez, Alejandra; Montes-Rojas, Andres; Di Fiore, Anthony; Link, Andres

    2012-11-01

    Interspecific aggression amongst nonhuman primates is rarely observed and has been mostly related to scenarios of resource competition. Interspecific infanticide is even rarer, and both the ultimate and proximate socio-ecological factors explaining this behavior are still unclear. We report two cases of interspecific infanticide and five cases of interspecific infant-directed aggression occurring in a well-habituated primate community living in a fragmented landscape in Colombia. All cases were initiated by male brown spider monkeys (Ateles hybridus) and were directed toward infants of either red howler monkeys (Alouatta seniculus: n = 6 cases) or white-fronted capuchins (Cebus albifrons: n = 1 case). One individual, a subadult spider monkey male, was involved in all but one case of interspecific infanticide or aggression. Other adult spider monkeys participated in interspecific aggression that did not escalate into potentially lethal encounters. We suggest that competition for food resources and space in a primate community living in high population densities and restricted to a forest fragment of ca. 65 ha might partly be driving the observed patterns of interspecific aggression. On the other hand, the fact that all but one case of interspecific infanticide and aggression involved the only subadult male spider monkey suggests this behavior might either be pathological or constitute a particular case of redirected aggression. Even if the underlying principles behind interspecific aggression and infanticide are poorly understood, they represent an important factor influencing the demographic trends of the primate community at this study site. © 2012 Wiley Periodicals, Inc.

  13. 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.

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

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    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.

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

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    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.

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

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    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.

  17. 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.

  18. 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

    -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....... The aim of the simulations was to identify suitable locations for wildlife passes. We found that jaguars move preferentially to undisturbed forests and that females avoid moving close to roads and to areas with even low levels of human occupation. Males also avoid roads, but to a lesser degree, and appear...

  19. 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

  20. Boreal Forest Fires - Behavior and Atmospheric Impacts

    Science.gov (United States)

    Stocks, B. J.

    2003-12-01

    Fire is a natural and essential stand-renewing agent in circumboreal forests, and eliminating fire in this region is neither economically possible nor ecologically desirable. In general, boreal fire is managed on the basis of values-at-risk, with high levels of protection afforded to economically and recreationally important areas, while fire is permitted to burn naturally in many remote areas. Current estimates are that an average of 5-15 million hectares burn annually across the boreal zone, with at least 50% of the area burning in largely unmanaged forest. High-intensity crown fires account for the vast majority of the area burned in the boreal zone, particularly in North America. These fires typically consume 20-30 tonnes/ha of fuel, spread at rates up to 100 m/min, and generate intensity levels (or energy release rates) approaching 100,000 kW/m of fire front. Deep forest floor (organic) layers common to boreal forests contribute significantly to high levels of fuel consumption and assist in the propagation of crown fires. When crown fires are sustained through a peak afternoon burning period, they usually produce towering convection columns that can reach the upper troposphere directly. Numerous boreal fires columns reaching 11-14 kilometres in height have been documented in the fire literature. Given the lower altitude of the tropopause at boreal zone latitudes it is not surprising that some boreal fire columns have been recently reported reaching the lower stratosphere. Current global and regional climate models suggest a significant increase in both the severity and frequency of boreal fires under a changing climate, with potentially major impacts on terrestrial carbon storage and the global carbon budget, as well as hemispheric smoke transport. Modelling convection column dynamics is essential to predicting the future transport and atmospheric impacts of boreal fire smoke, and this science requires a solid understanding of fuel consumption and fire

  1. Quick assessment of wealth ants (Hymenoptera, Formicidae in rain forest fragments in the Alta Floresta region, MT

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    Jéssica Borges da Veiga

    2015-12-01

    Full Text Available Forest fragmentation can change the community and wealth of ants, through changes to the vegetation structure, solar radiation and food availability. This study aims to evaluate the generic richness of ants in two forest fragments in the municipality of Alta Floresta - MT. Samples were collected at three points of both fragments (interior, transition and surrounding matrix, being delimited one quadrant of 5x5 m for each point, using attractive bait. The ants were identified according to Baccaro (2006 identification key. For statistical diagnosis used the Multivariate analysis of conglomerates through BioEstat 5.0 software, and analyzed the similarities between subfamilies, genera and environments. The study found a total of 71 ants distributed in seven subfamilies and 12 genera, especially the genus Camponotus to occur mainly in disturbed habitats and Paraponera kind to occur in forest area. The transition environment was the least similar to the other due to a higher number of individuals and general wealth. In this study, the forest fragment 2 had a higher number of ants in their transition area and is considered the richest in ant fauna when compared to the forest fragment 1.

  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. 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.

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

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    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.

  5. 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.

  6. 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.

  7. 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.

  8. Effects of Habitat Structure and Fragmentation on Diversity and Abundance of Primates in Tropical Deciduous Forests in Bolivia.

    Science.gov (United States)

    Pyritz, Lennart W; Büntge, Anna B S; Herzog, Sebastian K; Kessler, Michael

    2010-10-01

    Habitat structure and anthropogenic disturbance are known to affect primate diversity and abundance. However, researchers have focused on lowland rain forests, whereas endangered deciduous forests have been neglected. We aimed to investigate the relationships between primate diversity and abundance and habitat parameters in 10 deciduous forest fragments southeast of Santa Cruz, Bolivia. We obtained primate data via line-transect surveys and visual and acoustic observations. In addition, we assessed the vegetation structure (canopy height, understory density), size, isolation time, and surrounding forest area of the fragments. We interpreted our results in the context of the historical distribution data for primates in the area before fragmentation and interviews with local people. We detected 5 of the 8 historically observed primate species: Alouatta caraya, Aotus azarae boliviensis, Callithrix melanura, Callicebus donacophilus, and Cebus libidinosus juruanus. Total species number and detection rates decreased with understory density. Detection rates also negatively correlated with forest areas in the surroundings of a fragment, which may be due to variables not assessed, i.e., fragment shape, distance to nearest town. Observations for Alouatta and Aotus were too few to conduct further statistics. Cebus and Callicebus were present in 90% and 70% of the sites, respectively, and their density did not correlate with any of the habitat variables assessed, signaling high ecological plasticity and adaptability to anthropogenic impact in these species. Detections of Callithrix were higher in areas with low forest strata. Our study provides baseline data for future fragmentation studies in Neotropical dry deciduous forests and sets a base for specific conservation measures.

  9. 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

  10. Forest fragments as barriers to fruit fly dispersal: Anastrepha (Diptera: Tephritidae) populations in orchards and adjacent forest fragments in Puerto Rico.

    Science.gov (United States)

    Jenkins, David A; Kendra, Paul E; Van Bloem, Skip; Whitmire, Stefanie; Mizell, Russ; Goenaga, Ricardo

    2013-04-01

    McPhail-type traps baited with ammonium acetate and putrescine were used to monitor populations of Anastrepha obliqua (Macquart) and Anastrepha suspensa (Loew) in two orchards with hosts of these flies (mango, Mangifera indica L., and carambola, Averrhoa carambola L.), as well as in forest fragments bordering these orchards. Contour maps were constructed to measure population distributions in and around orchards. Our results indicate that Anastrepha populations are focused around host fruit in both space and time, that traps do not draw fruit flies away from hosts, even when placed within 15 m of the host, and that lures continue to function for 6 mo in the field. The contour mapping analyses reveal that populations of fruit flies are focused around ovipositional hosts. Although the trapping system does not have a very long effective sampling range, it is ideal, when used in combination with contour analyses, for assessing fine-scale (on the order of meters) population distributions, including identifying resources around which fly populations are focused or, conversely, assessing the effectiveness of management tools. The results are discussed as they pertain to monitoring and detecting Anastrepha spp. with the McPhail-type trap and ammonium acetate and putrescine baiting system and the dispersal of these flies within Puerto Rico.

  11. 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.

  12. 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, J.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

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  16. Blow Flies from Forest Fragments Embedded in Different Land Uses: Implications for Selecting Indicators in Forensic Entomology.

    Science.gov (United States)

    de Souza, Mirian S; Pepinelli, Mateus; de Almeida, Eduardo C; Ochoa-Quintero, Jose M; Roque, Fabio O

    2016-01-01

    Given the general expectation that forest loss can alter biodiversity patterns, we hypothesize that blow fly species abundances differ in a gradient of native vegetation cover. This study was conducted in 17 fragments across different landscapes in central Brazil. Different land cover type proportions were used to represent landscape structure. In total, 2334 specimens of nine species of Calliphoridae were collected. We used principal component analysis (PCA) to reduce dimensionality and multicollinearity of the landscape data. The first component explained 70%, and it represented a gradient of forest-pasture land uses. Alien species showed a wide distribution in different fragments with no clear relationship between the abundance values and the scores of PCA axes, whereas native species occurred only in areas with a predominance of forest cover. Our study revealed that certain native species may be sensitive to forest loss at the landscape scale, and they represent a bioindicator in forensic entomology.

  17. 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.

  18. Movement and resource use by a group of Alouatta pigra in a forest fragment in Balancán, México.

    Science.gov (United States)

    Pozo-Montuy, Gilberto; Serio-Silva, Juan Carlos

    2007-04-01

    Uncommonly observed behaviors were systematically recorded in a troop (n = 9 individuals) of black howler monkeys (Alouatta pigra) inhabiting a small forest fragment (1.7 ha) in Leona Vicario, Balancán, Tabasco, Mexico. Between February 2002 and January 2003 (n = 499 h), we observed behaviors such as ground travel (85 occasions, total = 269 min/10.8% of total locomotion time), ground foraging (eight occasions, total = 50 min/0.84% of total feeding time) and drinking water pooled in tree holes (20 times, total = 93 min/0.31% of total activity time). Total time (412 min) for these non-resting behaviors (feeding and locomotion on the ground) is almost equivalent to time devoted to social activities (420 min). These behaviors indicate that howler monkeys may be responding to pressures imposed by the small size of the fragment by adopting diverse strategies to cover their basic nutritional needs in this environment. They accomplish this while exposing themselves to potential predation by coyotes (Canis latrans), as was observed once during the study. It is likely that these behaviors are occurring at an increasing rate among monkeys in fragmented landscapes.

  19. Integration of ALOS/PALSAR backscatter with a LiDAR-derived canopy height map to quantify forest fragmentation

    Science.gov (United States)

    Pinto, N.; Dubayah, R.; Simard, M.; Fatoyinbo, T. E.

    2011-12-01

    Habitat loss is the main predictor of species extinctions and must be characterized in high-biodiversity ecosystems where land cover change is pervasive. Forests' ability to support viable animal populations is typically modeled as a function of the presence of linkages or corridors, and quantified with fragmentation metrics. In this scenario, small forest patches and linear (e.g. riparian) zones can act as keystone structures. Fine-resolution, all-weather Synthetic Aperture Radar (SAR) data from ALOS/PALSAR is well-suited to resolve forest fragments in tropical sites. This study summarizes a technique for integrating fragmentation metrics from ALOS/PALSAR with vertical structure data from ICESat/GLAS to produce fine-resolution (30 m) forest habitat metrics that capture both local quality (canopy height) as well as spatial context and multi-scale connectivity. We illustrate our approach with backscatter images acquired over the Brazilian Atlantic Forest, a biodiversity hotspot. ALOS/PALSAR 1.1 images acquired over the dry season were calibrated to calculate gamma naught and map forest cover via tresholding. We employ network algorithms to locate dispersal bottlenecks between conservation units. The location of keystone structures is compared against a model that uses coarse (500m) percent tree cover as an input.

  20. Phenology of tree species in a forest fragment in western Santa Catarina

    Directory of Open Access Journals (Sweden)

    Edilvane Inês Zonta

    2015-12-01

    Full Text Available This study analyzed the phenological patterns of tree synusia, and their relationships with climate variables, in a forest fragment in the municipality of São Miguel do Oeste, SC. From October 2012 to October 2013, phenological events were evaluated using the number of species in the phenophase and the Fournier intensity index. Individuals of twenty species of trees (in 13 families were monitored for budding, presence of mature leaves, leaf fall, flowers at anthesis, and presence of immature and mature fruits. The standardized Morisita index was used to test seasonality of the phenophases and the Spearman correlation was used to evaluate the possible relationships of phenophases with temperature and precipitation. Leaf fall was seasonal and had a high negative correlation with temperature. Budding and flowering showed seasonality and high intensity in September. Mature and immature fruits occurred at different times throughout the year. The triggering of the phenophases was correlated with temperature, mainly for the vegetative phenophases.

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

    Science.gov (United States)

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

    2011-12-01

    A superficial water quality survey in a watershed of the Paraíba 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 Teresópolis, 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.

  2. Yeast communities in two Atlantic rain Forest fragments in Southeast Brazil

    Science.gov (United States)

    Pimenta, Raphael S.; Alves, Priscila D. D.; Almeida, Gabriel M. F.; Silva, Juliana F.M; Morais, Paula B.; Corrêa Jr., Ary; Rosa, Carlos A.

    2009-01-01

    We studied the yeast communities associated with fruits, mushrooms, tree exudates, and flies of the genus Drosophila, in two Atlantic Rain Forest fragments in state of Minas Gerais, Brazil. A total of 456 samples were collected from Rio Doce State Park and 142 from Ecological Station of Universidade Federal de Minas Gerais. From these samples, 608 yeast isolates were obtained, belonging to 71 different species. Among the yeasts isolated from Rio Doce State Park, 17 isolates were recovered from fruits, 12 from mushrooms, 13 from tree exudates, and 299 from Drosophila spp. In the Ecological Station of Universidade Federal de Minas Gerais, 24 isolates were recovered from fruits and 243 from Drosophila spp. Distinct communities of yeast were observed in Drosophila flies, fruits, mushrooms and tree exudates. The highest number of yeast species was recovered from Drosophila flies suggesting that flies are the natural vectors of these microorganisms. PMID:24031324

  3. 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...

  4. Population structure of Symphonia globulifera L. f. (Clusiaceae in fragments of seasonally flooded lowland Atlantic Forest

    Directory of Open Access Journals (Sweden)

    Marcelo Trindade Nascimento

    2012-06-01

    Full Text Available This paper assesses the population structure of Symphonia globulifera in forest fragments of lowland Atlantic Forest in the Poço das Antas Biological Reserve (RBPA and the União Biological Reserve (RBU, Rio de Janeiro, Brazil. A comparative analysis of the role of seed and vegetative reproduction in the plant population structure was also carried out. Three sampling areas were selected in the RBPA (PORT, CM and ARI and one area in the RBU. Two types of population structure were found: 1 populations with low recruitment and with several individuals originated from seeds that appeared to be senescent (PORT and ARI, and 2 populations with high number of recruits from vegetative reproduction (CM and RBU. Seedlings and saplings showed, in general, a higher number of individuals from vegetative reproduction. On the other hand, adults had a predominance of individuals from seed reproduction. These structured patterns appear to be related to the water regimes in each area. Therefore, these data suggest the occurrence of a strong differentiated mortality of seedlings and saplings from vegetative reproduction.

  5. STRUCTURAL DYNAMICS IN A FRAGMENT OF SEASONAL SEMIDECIDUOUS FOREST IN LAVRAS, MG, BRAZIL

    Directory of Open Access Journals (Sweden)

    Pablo Burkowski Meyer

    2015-06-01

    Full Text Available The present contribution aimed at describing the structural dynamics of the tree community of a forest fragment of seasonal semi-deciduous forest (Mata do Capivari situated in Lavras, Minas Gerais State, South-eastern Brazil. The study was based on three surveys carried out during an 11-year period (1997, 2003 and 2008 in 28 20×20 m permanent plots where records were made of the species and diameter at breast height (dbh of trees with dbh ≥ 5 cm, including survival, mortality and recruits. The hypothesis was that the patterns of dynamics found in the first interval (1997-2003 persisted in the second (2003-2008. The descriptors of dynamics were the rates of mortality and recruitment of individual trees (dynamics of demography, rates of gain and loss of tree basal area (dynamics of biomass, and respective net change rates. Between 2003 and 2008, the mortality rate, of 3.30%.yr-1, surpassed the recruitment rate, of 2.78%.yr-1. The gain rate in basal area was 2.72%.yr-1, only a little inferior to the loss rate, of 2.98%.yr-1. In general, these patterns repeated those of the first interval (1998-2003, with a persisting slow demographic decline, particularly concentrated near the river, and a nearly stable basal area. Comparatively speaking, the Mata do Capivari is one of the most stable among those studied in the region despite persistent human interference.

  6. NUTRIENTS IN THE LITTER OF A SEASONAL DECIDUOUS FOREST FRAGMENT OF ITAARA, RS

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    Márcio Viera

    2010-12-01

    Full Text Available The aim of the present study was to quantity aboveground mass and nutrients in a deciduous seasonal forest fragment in the district of Itaara, RS, Brazil. For quantification and fractionation of the litter, sampling was carried out using two methodologies: the first one for leaves and branches with diameter smaller than 1 cm (S0 and the second one for woody material with diameter varying from 1 cm to 3 cm (S1, 3.1 cm to 6 cm (S2, and greater than 6 cm (S3.  To evaluate the S0 fraction, 50 randomly sample were collected with a metallic frame of 25 cm x 25 cm, and for S1, S2 and S3 10 plots of 3 m x 2 m were distributed randomly in the area of study.  Samples was packed and taken to the Laboratory of Forest Ecology of the Universidade Federal de Santa Maria, where they were dried, weighed, ground and analyzed for nutrient contents. The woody senescent litter represented about 45% of the litter layer.  Litter classes differed statistically in relation to nutrient content (p < 0.05, except for Mg and Cu; usually the S0 fraction presented higher contents. The fractions S1, S2 and S3 showed an accumulation of nutrients ranging from 53.3% to 8.7% K for Fe in the total litter, demonstrating the importance of quantification of these components during the evaluation of nutrient stocks contained in the litter of the forest ecosystem.

  7. 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

    2017-07-20

    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.

  8. 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.

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

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    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

  10. Low functional richness and redundancy of a predator assemblage in native forest fragments of Chiloe island, Chile.

    Science.gov (United States)

    Farias, Ariel A; Jaksic, Fabian M

    2011-07-01

    1. Changes in land use and habitat fragmentation are major drivers of global change, and studying their effects on biodiversity constitutes a major research programme. However, biodiversity is a multifaceted concept, with a functional component linking species richness to ecosystem function. Currently, the interaction between functional and taxonomic components of biodiversity under realistic scenarios of habitat degradation is poorly understood. 2. The expected functional richness (FR)-species richness relationship (FRSR) is positive, and attenuated for functional redundancy in species-rich assemblages. Further, environmental filters are expected to flatten that association by sorting species with similar traits. Thus, analysing FRSR can inform about the response of biodiversity to environmental gradients and habitat fragmentation, and its expected functional consequences. 3. Top predators affect ecosystem functioning through prey consumption and are particularly vulnerable to changes in land use and habitat fragmentation, being good indicators of ecosystem health and suitable models for assessing the effects of habitat fragmentation on their FR. 4. Thus, this study analyses the functional redundancy of a vertebrate predator assemblage at temperate forest fragments in a rural landscape of Chiloe island (Chile), testing the existence of environmental filters by contrasting an empirically derived FRSR against those predicted from null models, and testing the association between biodiversity components and the structure of forest fragments. 5. Overall, contrasts against null models indicate that regional factors determine low levels of FR and redundancy for the vertebrate predator assemblage studied, while recorded linear FRSR indicates proportional responses of the two biodiversity components to the structure of forest fragments. Further, most species were positively associated with either fragment size or shape complexity, which are highly correlated. This, and the

  11. 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. PMID:27973584

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Effects of corticoliberin fragment CRF(4-6) on sexual behavior in male rats [corrected].

    Science.gov (United States)

    Andreev-Andrievskii, A A; Tsvirkun, D V; Makarenko, E Yu; Andreeva, L A; Mart'yanov, A A

    2006-09-01

    Centrally administered doses of the tripeptide corticoliberin fragment CRF(4-6) (Pro-Pro-Ile) suppressed mating behavior in male rats. Doses of 1 and 2 microg of the tripeptide produced dose-dependent increases in the latent periods of mounting, intromission, and ejaculation. Changes in measures of sexual behavior demonstrated that the corticoliberin fragment CRF(4-6) suppressed both sexual motivation and sexual performance.

  16. Pollination of euglossinophylic epiphytic orchids in agroecosystems and forest fragments in southeast Mexico

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    Anne Damon

    2012-09-01

    Full Text Available To determine the reproductive status of the native orchids of the biodiversity “hotspot”, Biological Corridor Tacaná-Boquerón, in the region of Soconusco, southeast Mexico, which are suffering the effects of habitat degradation, unsustainable exploitation and potentially, climate change, we analysed the species richness, abundance, habitat and abiotic preferences, pollinaria transport and relation to orchid populations, of male Euglossine bees (Hymenoptera: Apidea: Euglossini in agroecosystems and forest fragments within the region. Using volatile baits we trapped 2,480 bees, consisting of 14 species, during a total of 256 hours, of which 284 individuals (11.5% had pollinaria of 18 orchid species adhered to their bodies. Three species of Eufriesia (E. caerulescens, E. mexicana, E. rugosa and one species of Euglossa (E. villosa were recorded for the first time. We report Eulaema meriana as the pollinator of the recently rediscovered Plectrophora alata. We did not detect habitat preferences for the species of Euglossini captured, and they were frequent, or even more frequent, in intensive coffee plantations, as are many of the orchid species, which can be classified as a disturbed habitat. Bees tended to be more abundant with increasing light intensity and decreasing humidity at each site. There was little indication of pollinator specificity and the position of the pollinaria of each orchid species on the bodies of the bees was also variable. We did not recover any pollinaria from various euglossinophylic, epiphytic orchid species present in the region and three bee species showed signs of population decline. However, our results indicate that many species of orchids with this pollination syndrome are receiving pollination service within an increasingly fragmented and disturbed environment, suggesting that both the orchids and the bees are adapting to the changes.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Quantifying habitat requirements of tree-living species in fragmented boreal forests with Bayesian methods.

    Science.gov (United States)

    Berglund, Håkan; O'Hara, Robert B; Jonsson, Bengt Gunnar

    2009-10-01

    Quantitative conservation objectives require detailed consideration of the habitat requirements of target species. Tree-living bryophytes, lichens, and fungi are a critical and declining biodiversity component of boreal forests. To understand their requirements, Bayesian methods were used to analyze the relationships between the occurrence of individual species and habitat factors at the tree and the stand scale in a naturally fragmented boreal forest landscape. The importance of unexplained between-stand variation in occurrence of species was estimated, and the ability of derived models to predict species' occurrence was tested. The occurrence of species was affected by quality of individual trees. Furthermore, the relationships between occurrence of species at the tree level and size and shape of stands indicated edge effects, implying that some species were restricted to interior habitats of large, regular stands. Yet for the habitat factors studied, requirements of many species appeared similar. Species occurrence also varied between stands; most of the seemingly suitable trees in some stands were unoccupied. The models captured most variation in species occurrence at tree level. They also successfully accounted for between-stand variation in species occurrence, thus providing realistic simulations of stand-level occupancy of species. Important unexplained between-stand variation in species occurrence warns against a simplified view that only local habitat factors influence species' occurrence. Apparently, similar stands will host populations of different sizes due to historical, spatial, and stochastic factors. Thus, habitat suitability cannot be assessed simply by population sizes, and stands lacking a species may still provide suitable habitat and merit protection.

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

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    R Cavasini

    Full Text Available 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. 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.

  1. 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

  2. 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

  3. Effects of forest fragmentation on the seedling recruitment of a tropical herb: assessing seed vs. safe-site limitation.

    Science.gov (United States)

    Uriarte, María; Bruna, Emilio M; Rubim, Paulo; Anciães, Marina; Jonckheere, Inge

    2010-05-01

    Studies simultaneously evaluating the importance of safe-site and seed limitation for plant establishment are rare, particularly in human-modified landscapes. We used spatially explicit neighborhood models together with data from 10 0.5-ha mapped census plots in a fragmented landscape spanning 1000 km2 to (1) evaluate the relative importance of seed production, dispersal, and safe-site limitation for the recruitment of the understory herb Heliconia acuminata; and (2) determine how these processes differ between fragments and continuous forests. Our analyses demonstrated a large degree of variation in seed production, dispersal, and establishment among and within the 10 study plots. Seed production limitation was strong but only at small spatial scales. Average dispersal distance was less than 4 m, leading to severe dispersal limitation at most sites. Overall, safe-site limitation was the most important constraint on seedling establishment. Fragmentation led to a more heterogeneous light environment with negative consequences for seedling establishment but had little effect on seed production or dispersal. These results suggest that the effects of fragmentation on abiotic processes may be more important than the disruption of biotic interactions in driving biodiversity loss in tropical forests, at least for some functional groups. These effects may be common when the matrix surrounding fragments contains enough tree cover to enable movement of dispersers and pollinators.

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

    Science.gov (United States)

    Kelch, Nina-S; Neves, Frederico S; Fernandes, G Wilson; Wirth, Rainer

    2016-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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.

  7. 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 spati

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Seed shadow, seedling recruitment, and spatial distribution of Buchenavia capitata (Combretaceae) in a fragment of the Brazilian Atlantic Forest

    OpenAIRE

    SANTOS,B. A.; F. P. L. Melo; Tabarelli,M.

    2006-01-01

    Here we describe the seed shadow, seedling recruitment, ontogenetic structure and spatial distribution of Buchenavia capitata (an emergent canopy tree) in a 380-ha fragment of the Atlantic forest in northeast Brazil. In particular, we examine seed distribution around 10 parental trees and both seedling recruitment and mortality, during an 18 month period beneath and around parental trees. Moreover, we describe: (1) B. capitata occurrence within treefall gaps; (2) population structure in terms...

  13. 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. PMID:25992550

  14. 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

  15. Richness and abundance of bats captured at the edge and within a forest fragment in Acre, Brazil

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    Armando Muniz Calouro

    2010-12-01

    Full Text Available As a consequence of deforestation, forest fragmentation is a reality that is increasingly present in the western part of the state of Acre, Brazil. The objective of this study was to evaluate variations in the richness and abundance of bats in an urban forest fragment of approximately 150ha, which is located in Rio Branco (AC. Collections were performed in two places: two points that were 200m from the edge and two that were 20m from the edge. Mist-nets were opened four hours after sundown during three nights/month. The Shannon-Wiener diversity index (H’ and the Jaccard Similarity index (J were used for comparative analysis. On 48 nights (November/2005 to July/2007, 85 individual bats of 15 species were captured, with greater richness and abundance of chiropters within the fragment. The similarity index of species was low (J=0.44, indicating habitat preference. The diversity index (H’=2.091 was similar to that of previous studies in the Amazon, especially in Brazil, with lower diversity at the edge (H’=1.864 than inside the fragment (H’=2.047. Carollia perspicillata (n=32 and Artibeus lituratus (n=13 were responsible for 57.6% of the total captured. The characteristics of the matrix and the adaptation of the bats to the mist-nets explained the observed values.

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

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    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.

  17. 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.

  18. 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 forests strengthened the functional response of owls to variations in vole abundance and were more prone to switch from main prey to alternative prey (passerine birds) depending on local climate conditions. High-quality habitat may allow pygmy owls to buffer negative effects of inclement weather and cyclic variation in vole abundance. Additionally, our results evidenced sex-specific 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.

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

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    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.

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

    Science.gov (United States)

    Manhães, M A; Dias, M M; Lima, A L C

    2015-11-01

    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.

  1. Effects of logging, hunting, and forest fragment size on physiological stress levels of two sympatric ateline primates in Colombia

    Science.gov (United States)

    Rimbach, Rebecca; Link, Andrés; Heistermann, Michael; Gómez-Posada, Carolina; Galvis, Nelson; Heymann, Eckhard W.

    2013-01-01

    Habitat fragmentation and anthropogenic disturbances are of major concern to the conservation of endangered species because of their potentially negative impact on animal populations. Both processes can impose physiological stress (i.e. increased glucocorticoid output) on animals, and chronically elevated stress levels can have detrimental effects on the long-term viability of animal populations. Here, we investigated the effect of fragment size and human impact (logging and hunting pressure) on glucocorticoid levels of two sympatric Neotropical primates, the red howler monkey (Alouatta seniculus) and the critically endangered brown spider monkey (Ateles hybridus). These two species have been reported to contrast strongly in their ability to cope with anthropogenic disturbances. We collected faecal samples from eight spider monkey groups and 31 howler monkey groups, living in seven and 10 different forest fragments in Colombia, respectively. We measured faecal glucocorticoid metabolite (FGCM) levels in both species using previously validated methods. Surprisingly, fragment size did not influence FGCM levels in either species. Spider monkeys showed elevated FGCMs in fragments with the highest level of human impact, whereas we did not find this effect in howler monkeys. This suggests that the two species differ in their physiological responsiveness to anthropogenic changes, further emphasizing why brown spider monkeys are at higher extinction risk than red howler monkeys. If these anthropogenic disturbances persist in the long term, elevated FGCM levels can potentially lead to a state of chronic stress, which might limit the future viability of populations. We propose that FGCM measurements should be used as a tool to monitor populations living in disturbed areas and to assess the success of conservation strategies, such as corridors connecting forest fragments. PMID:27293615

  2. Tropical forests and fragmentation: A case of South Garo Hills, Meghalaya, North East India

    Science.gov (United States)

    Ashish Kumar; Bruce Marcot; Rohitkumar Patel

    2017-01-01

    This study presents an ecological assessment of tropical forests at stand and landscape levels to provide knowledge, tools and, indicators to evaluate specific diversity patterns and related ecological processes happening in these tropical forest conditions; and for monitoring landscape changes for managing forest and wildlife resources of Jhum (shifting cultivation)...

  3. 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.

  4. Temporal scaling behavior of forest and urban fires

    Science.gov (United States)

    Wang, J.; Song, W.; Zheng, H.; Telesca, L.

    2009-04-01

    It has been found that many natural systems are characterized by scaling behavior. In such systems natural factors dominate the event dynamics. Forest fires in different countries have been found to exhibit frequency-size power law over many orders of magnitude and with similar value of parameters. But in countries with high population density such as China and Japan, more than 95% of the forest fire disasters are caused by human activities. Furthermore, with the development of society, the wildland-urban interface (WUI) area is becoming more and more populated, and the forest fire is much connected with urban fire. Therefore exploring the scaling behavior of fires dominated by human-related factors is very challenging. The present paper explores the temporal scaling behavior of forest fires and urban fires in Japan with mathematical methods. Two factors, Allan factor (AF) and Fano factor (FF) are used to investigate time-scaling of fire systems. It is found that the FF for both forest fires and urban fires increases linearly in log-log scales, and this indicates that it behaves as a power-law for all the investigated timescales. From the AF plot a 7 days cycle is found, which indicates a weekly cycle. This may be caused by human activities which has a weekly periodicity because on weekends people usually have more outdoor activities, which may cause more hidden trouble of fire disasters. Our findings point out that although the human factors are the main cause, both the forest fires and urban fires exhibit time-scaling behavior. At the same time, the scaling exponents for urban fires are larger than forest fires, signifying a more intense clustering. The reason may be that fires are affected not only by weather condition, but also by human activities, which play a more important role for urban fires than forest fires and have a power law distribution and scaling behavior. Then some work is done to the relative humidity. Similar distribution law characterizes the

  5. 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

  6. 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.

  7. Characteristic Fragmentation Behavior of Steroidal Phosphoramidate Conjugates in Electrospray Ionization Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    JI, San-Hao; JU, Yong; XIAO, Qiang; ZHAO, Yu-Fen

    2006-01-01

    Novel steroidal phosphoramidate conjugates of 3'-azido-2',3'-dideoxythymidine (AZT) and amino acid esters were synthesized and determined by positive and negative ion electrospray ionization mass spectrometry. The MS fragmentation behaviors of the steroidal phosphoramidate conjugates have been investigated in conjunction with tandem mass spectrometry of ESI-MS/MS. There were three characteristic fragment ions in the positive ion ESI mass spectra, which were the Na adduct ions with loss of steroidal moiety, amino acid ester moiety from pseudo molecular ion (M+Na)+, and the phosphoamino acid methyl ester Na adduct ion by a-cleavage of the phosphoramidate respectively. The main fragment ions in negative ion ESI mass spectra were the ion (M-HN3)-, the ion (M - AZT - H)- , and the ion (M-steroidal moiety-H)- besides the pseudo molecular ion (M-H)-. The fragmentation patterns did not depend on the attached amino acid ester moiety.

  8. 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.

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

    Science.gov (United States)

    Kelch, Nina-S.; Neves, Frederico S.; Fernandes, G. Wilson

    2016-01-01

    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. PMID:27310599

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

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    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.

  11. Seed storage behavior of forest tree species seeds

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    Marcela Carlota Nery

    2014-09-01

    Full Text Available Seeds of five forest species were classified according to their physiological storage behavior. Seeds of Casearia sylvestris Swart (Salicaceae, Qualea grandiflora Mart. (Vochysiaceae, Guarea kunthiana A. Juss. (Meliaceae, Eremanthus incanus Less. (Asteraceae, Protium heptaphyllum March. (Burseraceae were collected and taken to the laboratory, where they were processed and submitted to both rapid and slow drying, storage and assayed for viability. After physiological classification regarding storage behavior, it was observed that seeds of C. sylvestris and E. incanus presented orthodox behavior. Seeds of G. kunthiana and P. heptaphyllum were classified as recalcitrant and Q. grandiflora as an intermediate, which did not tolerate low moisture content.

  12. Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species

    Science.gov (United States)

    Prospere, Kurt; McLaren, Kurt P.; Wilson, Byron

    2016-10-01

    The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

  13. Characterizing the Status (Disturbed, Hybrid or Novel) of Swamp Forest Fragments in a Caribbean Ramsar Wetland: The Impact of Anthropogenic Degradation and Invasive Plant Species.

    Science.gov (United States)

    Prospere, Kurt; McLaren, Kurt P; Wilson, Byron

    2016-10-01

    The last remaining Amazonian-type swamp forest fragments in Black River Lower Morass, Jamaica, have been subjected to a myriad of anthropogenic disturbances, compounded by the establishment and spread of several invasive plant species. We established 44 permanent sample plots (covering 3.92 ha) across 10 of these swamp forest fragments and sampled all non-woody plants and all trees ≥2 cm DBH found in the plots. These data were used to (1) identify thresholds of hybridity and novelty, (2) derive several diversity and structural descriptors used to characterize the swamp forest fragments and (3) identify possible indicators of anthropogenic degradation. These were incorporated into a framework and used to determine the status of the swamp forest fragments so that appropriate management and conservation measures can be implemented. We recorded 43 woody plant species (9 endemic, 28 native and 4 non-native) and 21 non-tree species. The composition and structure of all the patches differed significantly due to the impact of the herbaceous invasive plant Alpinia allughas, the presence and diversity of other non-native plants, and differing intensities of anthropogenic disturbance (e.g., burning, cutting and harvesting of non-timber forest products). We ranked forest patches along a continuum representing deviations from a historical proxy (least disturbed) swamp forest to those with dramatically altered structural and floristic attributes (=novel swamp forests). Only one fragment overrun with A. allughas was classified as novel. If effective conservation and management does not come to the BRLM, the remaining swamp forest fragments appear doomed to further degradation and will soon disappear altogether.

  14. Unusual secondary electron emission behavior in carbon nanotube forests.

    Science.gov (United States)

    Alam, Md K; Yaghoobi, P; Nojeh, A

    2009-01-01

    Electron yield was measured from patterned carbon nanotube forests for a wide range of primary beam energies (400-20,000 eV). It was observed that secondary and backscattered electron emission behaviors in these forests are quite different than in bulk materials. This seems to be primarily because of the increased range of electrons due to the porous nature of the forests and dependent on their structural parameters, namely nanotube length, diameter and inter-nanotube spacing. In addition to providing insight into the electron microscopy of nanotubes, these results have interesting implications on designing novel secondary electron emitters based on the structural degrees of freedom of nanomaterials. (c) 2010 Wiley Periodicals, Inc.

  15. 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...

  16. 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...

  17. The composition of arbuscular mycorrhizal fungal communities in the roots of a ruderal forb is not related to the forest fragmentation process.

    Science.gov (United States)

    Grilli, Gabriel; Urcelay, Carlos; Galetto, Leonardo; Davison, John; Vasar, Martti; Saks, Ülle; Jairus, Teele; Öpik, Maarja

    2015-08-01

    Land-use changes and forest fragmentation have strong impact on biodiversity. However, little is known about the influence of new landscape configurations on arbuscular mycorrhizal fungal (AMF) community composition. We used 454 pyrosequencing to assess AMF diversity in plant roots from a fragmented forest. We detected 59 virtual taxa (VT; phylogenetically defined operational taxonomic units) of AMF - including 10 new VT - in the roots of Euphorbia acerensis. AMF communities were mainly composed of members of family Glomeraceae and were similar throughout the fragmented landscape, despite variation in forest fragment size (i.e. small, medium and large) and isolation (i.e. varying pairwise distances). AMF communities in forest fragments were phylogenetically clustered compared with the global, but not regional and local AMF taxon pools. This indicates that non-random community assembly processes possibly related to dispersal limitation at a large scale, rather than habitat filtering or biotic interactions, may be important in structuring the AMF communities. In this system, forest fragmentation did not appear to influence AMF community composition in the roots of the ruderal plant. Whether this is true for AMF communities in soil and the roots of other ecological groups of host plants or in other habitats deserves further study.

  18. 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 number of rema

  19. Fission fragment angular distribution in heavy-ion-induced fission with anomalous behavior

    Science.gov (United States)

    Soheyli, S.; Feizi, B.

    2014-08-01

    Fission fragment angular distribution in heavy-ion-induced fission reactions is of particular importance. Transition state theory is provided to determine the angular distribution of fission fragments which includes standard saddle-point statistical and standard scission-point statistical models. The standard saddle-point statistical model was not able to reproduce the experimental fission fragment angular anisotropies for several heavy-ion-induced fission systems. In contrast to the standard saddle-point model, the standard scission-point statistical model was fairly successful in the prediction of angular anisotropy in heavy-ion-induced fission reaction systems with an anomalous behavior in angular anisotropy of fission fragments, but this model is not widely used as the standard saddle-point statistical model. In this research, a generalized model is introduced for the prediction of fission fragments angular anisotropy in the heavy-ion-induced fission reaction systems having an anomalous behavior. For this purpose, we study the N14,O16,F19+Th232;O16,F19+U238;Mg24,Si28,S32+Pb208;S32+Au197; and O16+Cm248 reaction systems. Finally, it is shown that the presented model is much more successful than previous models.

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

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    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.

  1. Seed predation by rodents and safe sites for large-seeded trees in a fragment of the Brazilian Atlantic forest

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    SRR. Pinto

    Full Text Available Seed predation by small rodents is an emerging theme in the ecology of modified landscapes. Here we investigate the role played by the small rodent Oryzomys oniscus as a seed predator of large-seeded trees in a large remnant of the Atlantic forest - the Coimbra forest (3,500 ha, Alagoas state, northeastern Brazil. O. oniscus was captured and identified by setting twenty 500 m long transects, each one composed of 25 traps 20 m apart. This procedure resulted in 483 trap-nights set during a 20-mo period. We used 692 seeds (>15 mm length from ten local large-seeded tree species for the seed predation trials that basically consisted of three treatments: one seed on the ground freely accessed by vertebrates (unprotected seed, one seed totally protected by an exclosure, and one partially-protected seed (exclosure just for medium-sized and large vertebrates. O. oniscus was captured throughout the Coimbra forest including forest edges (76 captures and interior areas (67, and this small rodent was responsible for all seed predation visually documented inside exclosures. A 24 hours period of seed exposition permitted elevated rates of seed removal and predation. Seeds were much more removed/predated beneath fruiting trees, but rates varied according to the level of seed protection - 26.3% of predation among partially-protected versus 19.2% among unprotected seeds. Seeds suffered higher levels of seed predation/removal at the forest edge as well (up to 90%. In both habitats, most seeds (>84% remained intact beneath trees without fruits, regardless of the level of seed protection. Our results suggest that O. oniscus may operate as an effective large-seed predator in forest fragments, in which adult trees without fruits constitute low resource spots and thereby provide, at least temporarily, safe sites for large seeds.

  2. Heterozygote excess through life history stages in Cestrum miradorense Francey (Solanaceae), an endemic shrub in a fragmented cloud forest habitat.

    Science.gov (United States)

    Reyes-Zepeda, F; González-Astorga, J; Montaña, C

    2013-01-01

    Comparisons of genetic diversity and population genetic structure among different life history stages provide important information on the effect of the different forces and micro-evolutionary processes that mould diversity and genetic structure after fragmentation. Here we assessed genetic diversity and population genetic structure using 32 allozymic loci in adults, seeds, seedlings and juveniles of eight populations of the micro-endemic shrub Cestrum miradorense in a highly fragmented cloud forest in central-eastern Mexico. We expected that due to its long history or rarity, this species may have endured the negative effects of fragmentation and would show moderate to high levels of genetic diversity. High genetic diversity (H(e) = 0.445 ± 0.03), heterozygote excess (F(IT) = -0.478 ± 0.034, F(IS) = -0.578 ± 0.023) and low population differentiation (F(ST) = 0.064 ± 0.011) were found. Seeds had higher genetic diversity (H(e) = 0.467 ± 0.05) than the later stages (overall mean for adults, seedlings and juveniles H(e) = 0.438 ± 0.08). High gene flow was observed despite the fact that the fragmentation process began more than 100 years ago. We conclude that the high genetic diversity was the result of natural selection, which favours heterozygote excess in all stages, coupled with a combination of a reproductive system and seed/pollen dispersal mechanisms that favour gene flow.

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

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    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.

  4. Functional decay in tree community within tropical fragmented landscapes: Effects of landscape-scale forest cover.

    Science.gov (United States)

    Rocha-Santos, Larissa; Benchimol, Maíra; Mayfield, Margaret M; Faria, Deborah; Pessoa, Michaele S; Talora, Daniela C; Mariano-Neto, Eduardo; Cazetta, Eliana

    2017-01-01

    As tropical rainforests are cleared, forest remnants are increasingly isolated within agricultural landscapes. Understanding how forest loss impacts on species diversity can, therefore, contribute to identifying the minimum amount of habitat required for biodiversity maintenance in human-modified landscapes. Here, we evaluate how the amount of forest cover, at the landscape scale, affects patterns of species richness, abundance, key functional traits and common taxonomic families of adult trees in twenty Brazilian Atlantic rainforest landscapes. We found that as forest cover decreases, both tree community richness and abundance decline, without exhibiting a threshold. At the family-level, species richness and abundance of the Myrtaceae and Sapotaceae were also negatively impacted by the percent forest remaining at the landscape scale. For functional traits, we found a reduction in shade-tolerant, animal-dispersed and small-seeded species following a decrease in the amount of forest retained in landscapes. These results suggest that the amount of forest in a landscape is driving non-random losses in phylogenetic and functional tree diversity in Brazil's remaining Atlantic rainforests. Our study highlights potential restraints on the conservation value of Atlantic rainforest remnants in deforested landscapes in the future.

  5. Massive structural and compositional changes over two decades in forest fragments near Kampala, Uganda

    OpenAIRE

    Bulafu, Collins Edward; Baranga, Deborah; Mucunguzi, Patrick; Telford,Richard; Vandvik, Vigdis

    2013-01-01

    Private forests harbor considerable biodiversity, however, they are under greater threat than reserved areas, particularly from urbanization, agriculture, and intense exploitation for timber and fuel wood. The extent to which they may act as habitats for biodiversity and how level of protection impacts trends in biodiversity and forest structure over time remain underresearched. We contribute to filling this research gap by resampling a unique data set, a detailed survey from 1990 of 22 fores...

  6. 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

  7. Vertical structure of an assemblage of bats (Mammalia: Chiroptera in a fragment of Atlantic Forest in Southern Brazil

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    Fernando Carvalho

    2013-10-01

    Full Text Available Few studies have focused the vertical structure of bat assemblages, and how it influences community composition. The goal of this study was to analyze the vertical structure of an assemblage of bats in a forest fragment in southern Brazil. Bats were sampled using mist-nets placed at three heights (understory, below-canopy, and canopy. Forest strata were compared with respect to their species richness and diversity. The latter was estimated using the Shannon-Wiener index (H', and the statistical significance of differences among strata was assessed using t tests. We used an index of Constancy (C to determine the frequency of a given species in each vegetation stratum, such that a species was considered as "frequent" (C > 50, "less frequent" (25 < C < 50 and "occasional" (C < 25. We captured 485 bats belonging to two families and 24 species. In the understory layer, we captured 173 individuals in 13 species, which resulted in a diversity index of H' = 1.981. In the under-canopy, 153 individuals were caught in 18 species and the resulting diversity index was H' = 2.509. Finally, in the canopy, 159 bats were caught, in 22 species, with the resulting diversity index of H' = 2.442. In the understory and in the canopy, only one species Artibeus lituratus (Olfers, 1818 was classified as "frequent." Four species A. lituratus, Sturnira lilium (É. Geoffroy, 1810, Anoura geoffroyi Gray, 1838, and Eptesicus diminutus Osgood, 1915 were classified as "less frequent" in the under-canopy stratum. All other species recorded in each stratum were classified as "occasional." The studied bat assemblage showed vertical stratification, with the higher strata harboring increased diversity. Our study shows how important it is to sample the upper levels of a forest fragment to obtain a more representative understanding of the use of space by a bat assemblage.

  8. Litter fall production and decomposition in a fragment of secondary Atlantic Forest of São Paulo, sp, southeastern Brazil

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    Maurício Lamano Ferreira

    2014-08-01

    Full Text Available Litter fall consists of all organic material deposited on the forest floor, being of extremely important for the structure and maintenance of the ecosystem through nutrient cycling. This study aimed to evaluate the production and decomposition of litter fall in a secondary Atlantic forest fragment of secondary Atlantic Forest, at the Guarapiranga Ecological Park, in São Paulo, SP. The litter samples were taken monthly from May 2012 to May 2013. To assess the contribution of litter fall forty collectors were installed randomly within an area of 0.5 ha. The collected material was sent to the laboratory to be dried at 65 °C for 72 hours, being subsequently separated into fractions of leaves, twigs, reproductive parts and miscellaneous, and weighed to obtain the dry biomass. Litterbags were placed and tied close to the collectors to estimate the decomposition rate in order to evaluate the loss of dry biomass at 30, 60, 90, 120 and 150 days. After collection, the material was sent to the laboratory to be dried and weighed again. Total litter fall throughout the year reached 5.7 Mg.ha-1.yr-1 and the major amount of the material was collected from September till March. Leaves had the major contribution for total litter fall (72%, followed by twigs (14%, reproductive parts (11% and miscellaneous (3%. Reproductive parts had a peak during the wet season. Positive correlation was observed between total litter and precipitation, temperature and radiation (r = 0.66, p<0.05; r = 0.76, p<0.05; r = 0.58, p<0.05, respectively. The multiple regression showed that precipitation and radiation contributed significantly to litter fall production. Decomposition rate was in the interval expected for secondary tropical forest and was correlated to rainfall. It was concluded that this fragment of secondary forest showed a seasonality effect driven mainly by precipitation and radiation, both important components of foliage renewal for the plant community and that

  9. Secondary seed dispersal by dung beetles in an Amazonian forest fragment of Colombia: influence of dung type and edge effect.

    Science.gov (United States)

    Santos-Heredia, Carolina; Andresen, Ellen; Stevenson, Pablo

    2011-12-01

    Seeds of many plant species are secondarily dispersed by dung beetles, but the outcome of this interaction is highly context-specific. Little is known about how certain anthropogenic disturbances affect this plant-animal interaction. The aims of this study were to assess the effect of dung type on secondary dispersal by dung beetles in a forest fragment, and to determine whether this interaction is affected by edge effects. Using pitfall traps, we captured dung beetles attracted to dung of 2 frugivorous mammals: woolly monkeys and howler monkeys. We found differences between both dung beetle assemblages, but these differences were not consistent in time. Using seeds surrounded by both dung types, we carried out a field experiment using seeds of 2 plant species. We found that the probability of secondary dispersal by dung beetles was higher for seeds placed in woolly monkey dung. Finally, we carried out a field experiment using plastic beads as seed mimics to assess edge effects. We found that secondary seed dispersal by dung beetles was negatively affected by edges. The disruption of plant-animal interactions along anthropogenic forest edges could have long-term negative effects on forest dynamics by affecting processes of regeneration.

  10. Log-periodic behavior in a forest-fire model

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    B. D. Malamud

    2005-01-01

    Full Text Available This paper explores log-periodicity in a forest-fire cellular-automata model. At each time step of this model a tree is dropped on a randomly chosen site; if the site is unoccupied, the tree is planted. Then, for a given sparking frequency, matches are dropped on a randomly chosen site; if the site is occupied by a tree, the tree ignites and an 'instantaneous' model fire consumes that tree and all adjacent trees. The resultant frequency-area distribution for the small and medium model fires is a power-law. However, if we consider very small sparking frequencies, the large model fires that span the square grid are dominant, and we find that the peaks in the frequency-area distribution of these large fires satisfy log-periodic scaling to a good approximation. This behavior can be examined using a simple mean-field model, where in time, the density of trees on the grid exponentially approaches unity. This exponential behavior coupled with a periodic or near-periodic sparking frequency also generates a sequence of peaks in the frequency-area distribution of large fires that satisfy log-periodic scaling. We conclude that the forest-fire model might provide a relatively simple explanation for the log-periodic behavior often seen in nature.

  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. Floristic and phytosociological investigation of trees in a seasonal deciduous forest fragment at São Miguel do Oeste, Santa Catarina

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    Geniane Schneider

    2014-06-01

    Full Text Available The forests in Santa Catarina have been reduced and fragmented, and seasonal deciduous forests are among the most afflicted. The aim of the investigation was to describe arboreal composition and structure in a seasonal deciduous forest fragment. We established ten sample units of 20x20 m, covering a total area of 0.4 ha. Trees with circumference at breast height (CBH ≥ 25 cm were identified, and species richness and diversity were evaluated. A total of 205 individuals was sampled from 54 species, representing 44 genera and 23 families. Tree diversity was estimated to be 3.472 (nats using the Shannon-Weiner index (H’, and Pielou’s evenness (J’ was estimated at 0.87. The families with the largest number of species were Fabaceae, Myrtaceae, Meliaceae, Lauraceae and Sapindaceae. The species with the highest importance and coverage values were Nectandra megapotamica (Spreng. Mez, Sorocea bonplandii (Baill. W.C. Burger, Lanjouw & Boer, and Ocotea diospyrifolia (Meisn. Mez. Species richness and diversity are within the range of values cited for seasonal deciduous forests in the Floristic Forest Inventory of Santa Catarina, which shows the impact of exploration and fragmentation on this habitat. Nevertheless, the studied area has apparently conserved a significant portion of the tree species cited for this forest type.

  13. Experimental study on fragmentation behaviors of molten LBE and water contact interface

    Institute of Scientific and Technical Information of China (English)

    黄望哩; 洒荣园; 周丹娜; 姜华磊; 黄群英

    2015-01-01

    Based on the design of CLEAR (China LEAd-based Reactor), it is important to study the molten LBE (Lead-Bismuth Eutectic)/water interaction following an incidental steam generator tube rupture (SGTR) accident. Experiments were carried out to investigate the fragmentation behavior of the molten LBE/water contacting interface, with a high-speed video camera to record the fragmentation behavior of 300–600◦C LBE at 20◦C and 80◦C of water temperature. Violent explosion phenomenon occurred at water temperature of 20◦C, while no explosion occurred at 80◦C. Shapes of the LBE debris became round at 80◦C of water temperature, whereas the debris was of the needle-like shape at 20◦C. For all the molten LBE and water temperatures in the present study, the debris sized at 2.8–5.0 mm had the largest mass fraction. The results indicate that the dominant physical mechanism of the molten LBE fragmentation was the Kelvin-Helmholtz instability between LBE/water direct contact interface.

  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. 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.

  16. Testing Dragonflies as Species Richness Indicators in a Fragmented Subtropical Atlantic Forest Environment.

    Science.gov (United States)

    Renner, S; Sahlén, G; Périco, E

    2016-06-01

    We surveyed 15 bodies of water among remnants of the Atlantic Forest biome in southern Brazil for adult dragonflies and damselflies to test whether an empirical selection method for diversity indicators could be applied in a subtropical ecosystem, where limited ecological knowledge on species level is available. We found a regional species pool of 34 species distributed in a nested subset pattern with a mean of 11.2 species per locality. There was a pronounced difference in species composition between spring, summer, and autumn, but no differences in species numbers between seasons. Two species, Homeoura chelifera (Selys) and Ischnura capreolus (Hagen), were the strongest candidates for regional diversity indicators, being found only at species-rich localities in our surveyed area and likewise in an undisturbed national forest reserve, serving as a reference site for the Atlantic Forest. Using our selection method, we found it possible to obtain a tentative list of diversity indicators without having detailed ecological information of each species, providing a reference site is available for comparison. The method thus allows for indicator species to be selected in blanco from taxonomic groups that are little known. We hence argue that Odonata can already be incorporated in ongoing assessment programs in the Neotropics, which would also increase the ecological knowledge of the group and allow extrapolation to other taxa.

  17. Trait-mediated seed predation, dispersal and survival among frugivore-dispersed plants in a fragmented subtropical forest, Southwest China.

    Science.gov (United States)

    Lai, Xin; Guo, Cong; Xiao, Zhishu

    2014-06-01

    By tracking the fate of individual seeds from 6 frugivore-dispersed plants with contrasting seed traits in a fragmented subtropical forest in Southwest China, we explored how rodent seed predation and hoarding were influenced by seed traits such as seed size, seed coat hardness and seed profitability. Post-dispersal seed fates varied significantly among the 6 seed species and 3 patterns were witnessed: large-seeded species with a hard seed coat (i.e. Choerospoadias axillaries and Diospyros kaki var. silvestris) had more seeds removed, cached and then surviving at caches, and they also had fewer seeds predated but a higher proportion of seeds surviving at the source; medium-sized species with higher profitability and thinner seed coat (i.e. Phoebe zhennan and Padus braohypoda) were first harvested and had the lowest probability of seeds surviving either at the source or at caches due to higher predation before or after removal; and small-seeded species with lower profitability (i.e. Elaeocarpus japonicas and Cornus controversa) had the highest probability of seeds surviving at the source but the lowest probability of seeds surviving at caches due to lower predation at the source and lower hoarding at caches. Our study indicates that patterns of seed predation, dispersal and survival among frugivore-dispersed plants are highly determined by seed traits such as seed size, seed defense and seed profitability due to selective predation and hoarding by seed-eating rodents. Therefore, trait-mediated seed predation, dispersal and survival via seed-eating rodents can largely affect population and community dynamics of frugivore-dispersed plants in fragmented forests.

  18. 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.

  19. Reproductive phenology, seed removal and early regeneration in relation to distance from parental plants of a native palm in small Atlantic forest fragments

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    Vanessa Mariano

    2016-01-01

    Full Text Available ABSTRACT The Brazilian Atlantic Forest is a global biodiversity hotspot, but most of what remains are small fragments. Small fragments are often harsh environments for forest plant recruitment due to edge effects and the loss of frugivorous animals that provide seed dispersal. We recorded the one-year reproductive phenology of the keystone palm Syagrus romanzoffiana in small (<2.5ha Atlantic Forest fragments in southeastern Brazil. We tested the Janzen-Connell hypothesis with seed-removal experiments and followed the five-year survival of recruits in relation to the distance from parental plants. Palms produced many fruits throughout the year (mean 2,600/plant. More seedlings were found away from parental plants than near them, thereby supporting the Janzen-Connell hypothesis. Almost 45% of seedlings alive in 2010 were dead five years later, but recruitment of new seedlings compensated for this mortality. Distance-dependent factors influenced the density of early ontogenetic stages, but had limited effects on juveniles or on seed removal. High seed production, seed dispersal provided by disturbance-tolerant frugivores and the relatively long-term survival of adults, seedlings and juveniles seem to allow the persistence of S. romanzoffiana in the forest fragments, but possibly at the cost of an increased clumped distribution and reduced gene flow at the landscape scale.

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

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    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.

  1. Behavioral response of the coachwhip (Masticophis flagellum) to habitat fragment size and isolation in an urban landscape

    Science.gov (United States)

    Mitrovich, Milan J.; Diffendorfer, Jay E.; Fisher, Robert N.

    2009-01-01

    Habitat fragmentation is a significant threat to biodiversity worldwide. Habitat loss and the isolation of habitat fragments disrupt biological communities, accelerate the extinction of populations, and often lead to the alteration of behavioral patterns typical of individuals in large, contiguous natural areas. We used radio-telemetry to study the space-use behavior of the Coachwhip, a larger-bodied, wide-ranging snake species threatened by habitat fragmentation, in fragmented and contiguous areas of coastal southern California. We tracked 24 individuals at three sites over two years. Movement patterns of Coachwhips changed in habitat fragments. As area available to the snakes was reduced, individuals faced increased crowding, had smaller home-range sizes, tolerated greater home-range overlap, and showed more concentrated movement activity and convoluted movement pathways. The behavioral response shown by Coachwhips suggests, on a regional level, area-effects alone cannot explain observed extinctions on habitat fragments but, instead, suggests changes in habitat configuration are more likely to explain the decline of this species. Ultimately, if "edge-exposure" is a common cause of decline, then isolated fragments, appropriately buffered to reduce emigration and edge effects, may support viable populations of fragmentation-sensitive species.

  2. 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.

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

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    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.

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

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    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.

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

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    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.

  6. Foraging behavior of three passerines in mature bottomland hardwood forests during summer.

    Energy Technology Data Exchange (ETDEWEB)

    Buffington, J., Matthew; Kilgo, John, C.; Sargent, Robert, A.; Miller, Karl, V.; Chapman, Brian, R.

    2001-08-01

    Attention has focused on forest management practices and the interactions between birds and their habitat, as a result of apparent declines in populations of many forest birds. Although avian diversity and abundance have been studied in various forest habitats, avian foraging behavior is less well known. Although there are published descriptions of avian foraging behaviors in the western United States descriptions from the southeastern United States are less common. This article reports on the foraging behavior of the White-eyed Vireo, Northern Parula, and Hooded Warbler in mature bottomland hardwood forests in South Carolina.

  7. Forest fire spread with non-universal critical behavior

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    Khelloufi, K.; Baara, Y.; Clerc, J. P.; Porterie, B.; Zekri, N.

    2013-10-01

    The critical behavior of spread dynamics is examined using a forest fire model. This model is characterized by long-range interactions due to flame radiation and a weighting process induced by the combustibles’ ignition energy and the flame residence time. Unlike magnetic systems, this model exhibits a non-universal phase transition. The critical exponents of the rate of spread depend both on the local interaction and on weighting. Near the transition, the exponent x of rate of spread is found to be equivalent to that of correlation time. The weighting process exhibits a new phase transition related to the heating process. This transition is analogous to the gelation transition in spin glasses.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wike, L.D.

    2000-06-27

    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.

  9. 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.

  10. 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.

  11. Seed shadow, seedling recruitment, and spatial distribution of Buchenavia capitata (Combretaceae) in a fragment of the Brazilian Atlantic forest.

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    Santos, B A; Melo, F P L; Tabarelli, M

    2006-08-01

    Here we describe the seed shadow, seedling recruitment, ontogenetic structure and spatial distribution of Buchenavia capitata (an emergent canopy tree) in a 380-ha fragment of the Atlantic forest in northeast Brazil. In particular, we examine seed distribution around 10 parental trees and both seedling recruitment and mortality, during an 18 month period beneath and around parental trees. Moreover, we describe: (1) B. capitata occurrence within treefall gaps; (2) population structure in terms of ontogenetic stages for the whole site; and (3) spatial distribution of adults within an area of 51 hectares. 99% of seeds were found beneath parent crowns (n = 4,236) and seed density reached 14.6 +/- 29.9 seeds/m2 (0-140 seeds/m2). 49% of all seeds germinated but seedling mortality reached 100% after an 18 month period. In addition, saplings of B. capitata were not found in forest understory and within 30 treefall gaps (94-2,350 m2). The adults showed an average DBH of 69.3 +/- 22.1 cm, were 19.2 +/- 2.9 m tall and presented a clumped spatial distribution. B. capitata matched some of the features presented by shade intolerant trees or large-gap specialists, and we hypothesize that low rates or even lack of long distance seed dispersal events may be reducing the probability of B. capitata seeds reaching suitable habitats for successful seedling recruitment and growth. Because of that (1) seedlings face high levels of early mortality; (2) there is no sapling recruitment at the study site; and (3) local population faces senility and it is threatened by local extinction.

  12. Seed shadow, seedling recruitment, and spatial distribution of Buchenavia capitata (Combretaceae in a fragment of the Brazilian Atlantic Forest

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    B. A. Santos

    Full Text Available Here we describe the seed shadow, seedling recruitment, ontogenetic structure and spatial distribution of Buchenavia capitata (an emergent canopy tree in a 380-ha fragment of the Atlantic forest in northeast Brazil. In particular, we examine seed distribution around 10 parental trees and both seedling recruitment and mortality, during an 18 month period beneath and around parental trees. Moreover, we describe: (1 B. capitata occurrence within treefall gaps; (2 population structure in terms of ontogenetic stages for the whole site; and (3 spatial distribution of adults within an area of 51 hectares. 99% of seeds were found beneath parent crowns (n = 4,236 and seed density reached 14.6 ± 29.9 seeds/m² (0-140 seeds/m². 49% of all seeds germinated but seedling mortality reached 100% after an 18 month period. In addition, saplings of B. capitata were not found in forest understory and within 30 treefall gaps (94-2,350 m². The adults showed an average DBH of 69.3 ± 22.1 cm, were 19.2 ± 2.9 m tall and presented a clumped spatial distribution. B. capitata matched some of the features presented by shade intolerant trees or large-gap specialists, and we hypothesize that low rates or even lack of long distance seed dispersal events may be reducing the probability of B. capitata seeds reaching suitable habitats for successful seedling recruitment and growth. Because of that (1 seedlings face high levels of early mortality; (2 there is no sapling recruitment at the study site; and (3 local population faces senility and it is threatened by local extinction.

  13. Post-fragmentation population structure in a cooperative breeding Afrotropical cloud forest bird: emergence of a source-sink population network.

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    Husemann, M; Cousseau, L; Callens, T; Matthysen, E; Vangestel, C; Hallmann, C; Lens, L

    2015-03-01

    The impact of demographic parameters on the genetic population structure and viability of organisms is a long-standing issue in the study of fragmented populations. Demographic and genetic tools are now readily available to estimate census and effective population sizes and migration and gene flow rates with increasing precision. Here we analysed the demography and genetic population structure over a recent 15-year time span in five remnant populations of Cabanis's greenbul (Phyllastrephus cabanisi), a cooperative breeding bird in a severely fragmented cloud forest habitat. Contrary to our expectation, genetic admixture and effective population sizes slightly increased, rather than decreased between our two sampling periods. In spite of small effective population sizes in tiny forest remnants, none of the populations showed evidence of a recent population bottleneck. Approximate Bayesian modelling, however, suggested that differentiation of the populations coincided at least partially with an episode of habitat fragmentation. The ratio of meta-Ne to meta-Nc was relatively low for birds, which is expected for cooperative breeding species, while Ne /Nc ratios strongly varied among local populations. While the overall trend of increasing population sizes and genetic admixture may suggest that Cabanis's greenbuls increasingly cope with fragmentation, the time period over which these trends were documented is rather short relative to the average longevity of tropical species. Furthermore, the critically low Nc in the small forest remnants keep the species prone to demographic and environmental stochasticity, and it remains open if, and to what extent, its cooperative breeding behaviour helps to buffer such effects.

  14. Diversity and seasonality of Scarabaeinae (Coleoptera: Scarabaeidae in forest fragments in Santa Maria, Rio Grande do Sul, Brazil

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    PEDRO G. DA SILVA

    2013-05-01

    Full Text Available Scarabaeinae specimens were collected with the use of pitfall traps baited with human excrement, rotten meat and rotting banana, between May 2009 and April 2010, in three forest fragments in Santa Maria, Rio Grande do Sul, Brazil: ‘Morro do Elefante' (MOEL, ‘Morro do Cerrito' (MOCE and ‘Campus da Universidade Federal de Santa Maria' (UFSM. A total of 19,699 individuals belonging to 33 species were collected. Canthidium aff. trinodosum Boheman, 1858, Canthon latipes Blanchard, 1845, Dichotomius assifer (Eschscholtz 1822, Eurysternus caribaeus (Herbst 1789, Canthidium sp. and Canthon lividus Blanchard, 1845, were the most abundant species. MOEL showed the greatest richness, MOCE the greatest abundance, while UFSM showed the lowest values of richness and abundance. The greatest similarity (qualitative and quantitative was found between MOEL and MOCE, while the lowest occurred between MOCE and UFSM. Only 51% of the species were common to all three fragments. The richness and abundance of Scarabaeinae were positively correlated with the air temperature. The richness of the fragment decreased according to the smaller size and the greater degree of disturbance of vegetation structure.Espécimes de Scarabaeinae foram coletados com o uso de armadilhas de queda iscadas com excremento humano, carne apodrecida e banana em decomposição, entre maio de 2009 e abril de 2010, em três fragmentos florestais em Santa Maria, Rio Grande do Sul, Brasil: Morro do Elefante (MOEL, Morro do Cerrito (MOCE e Campus da Universidade Federal de Santa Maria (UFSM. Um total de 19.699 indivíduos de 33 espécies foi coletado; Canthidium aff. trinodosum Boheman, 1858, Canthon latipes Blanchard, 1845, Dichotomius assifer (Eschscholtz 1822, Eurysternus caribaeus (Herbst 1789, Canthidium sp. e Canthon lividus Blanchard, 1845 foram as espécies mais abundantes. MOEL apresentou a maior riqueza, MOCE a maior abundância, enquanto UFSM teve os menores valores de riqueza e abund

  15. Diversity and seasonality of Scarabaeinae (Coleoptera: Scarabaeidae in forest fragments in Santa Maria, Rio Grande do Sul, Brazil

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    PEDRO G. DA SILVA

    2013-06-01

    Full Text Available Scarabaeinae specimens were collected with the use of pitfall traps baited with human excrement, rotten meat and rotting banana, between May 2009 and April 2010, in three forest fragments in Santa Maria, Rio Grande do Sul, Brazil: ‘Morro do Elefante’ (MOEL, ‘Morro do Cerrito’ (MOCE and ‘Campus da Universidade Federal de Santa Maria’ (UFSM. A total of 19,699 individuals belonging to 33 species were collected. Canthidium aff. trinodosum Boheman, 1858, Canthon latipes Blanchard, 1845, Dichotomius assifer (Eschscholtz 1822, Eurysternus caribaeus (Herbst 1789, Canthidium sp. and Canthon lividus Blanchard, 1845, were the most abundant species. MOEL showed the greatest richness, MOCE the greatest abundance, while UFSM showed the lowest values of richness and abundance. The greatest similarity (qualitative and quantitative was found between MOEL and MOCE, while the lowest occurred between MOCE and UFSM. Only 51% of the species were common to all three fragments. The richness and abundance of Scarabaeinae were positively correlated with the air temperature. The richness of the fragment decreased according to the smaller size and the greater degree of disturbance of vegetation structure.Espécimes de Scarabaeinae foram coletados com o uso de armadilhas de queda iscadas com excremento humano, carne apodrecida e banana em decomposição, entre maio de 2009 e abril de 2010, em três fragmentos florestais em Santa Maria, Rio Grande do Sul, Brasil: Morro do Elefante (MOEL, Morro do Cerrito (MOCE e Campus da Universidade Federal de Santa Maria (UFSM. Um total de 19.699 indivíduos de 33 espécies foi coletado; Canthidium aff. trinodosum Boheman, 1858, Canthon latipes Blanchard, 1845, Dichotomius assifer (Eschscholtz 1822, Eurysternus caribaeus (Herbst 1789, Canthidium sp. e Canthon lividus Blanchard, 1845 foram as espécies mais abundantes. MOEL apresentou a maior riqueza, MOCE a maior abundância, enquanto UFSM teve os menores valores de riqueza e

  16. Usual populations, unusual individuals: insights into the behavior and management of Asian elephants in fragmented landscapes.

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    Nishant M Srinivasaiah

    Full Text Available BACKGROUND: A dearth in understanding the behavior of Asian elephants (Elephas maximus at the scale of populations and individuals has left important management issues, particularly related to human-elephant conflict (HEC, unresolved. Evaluation of differences in behavior and decision-making among individual elephants across groups in response to changing local ecological settings is essential to fill this gap in knowledge and to improve our approaches towards the management and conservation of elephants. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized certain behavioral decisions that would be made by Asian elephants as reflected in their residence time and movement rates, time-activity budgets, social interactions and group dynamics in response to resource availability and human disturbance in their habitat. This study is based on 200 h of behavioral observations on 60 individually identified elephants and a 184-km(2 grid-based survey of their natural and anthropogenic habitats within and outside the Bannerghatta National Park, southern India during the dry season. At a general population level, the behavioral decisions appeared to be guided by the gender, age and group-type of the elephants. At the individual level, the observed variation could be explained only by the idiosyncratic behaviors of individuals and that of their associating conspecific individuals. Recursive partitioning classification trees for residence time of individual elephants indicated that the primary decisions were taken by individuals, independently of their above-mentioned biological and ecological attributes. CONCLUSIONS/SIGNIFICANCE: Decision-making by Asian elephants thus appears to be determined at two levels, that of the population and, more importantly, the individual. Models based on decision-making by individual elephants have the potential to predict conflict in fragmented landscapes that, in turn, could aid in mitigating HEC. Thus, we must target individuals

  17. Effects of invasion by Tradescantia zebrina Heynh. on tree species regeneration in a secondary Atlantic Forest fragment, in Londrina (PR

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    Maurício Cruz Mantoani

    2013-09-01

    Full Text Available Currently considered as one of the major causes of the loss of biodiversity on the planet, invasive alien species cause serious problems to natural ecosystems, leading many native species to become locally extinct. Surprisingly, invasions can come from ordinary sources, such as home gardens. This study aimed to verify the invasive impact of Tradescantia zebrina Heynh., a exotic ornamental herb, on tree regeneration of a secondary Atlantic Forest fragment where the understory is partly dominated by T. zebrina. To test the hypothesis that T. zebrina is limiting the recruitment of native tree species, plots were placed in non-invaded and invaded sites. All tree seedlings between 10 cm and 1 m tall were recorded, and the composition and structure of regeneration were compared between treatments. Tradescantia zebrina proved to be a strong competitor because it influenced abundance and species richness. Although there are reports in the literature of using non-selective herbicides, it is urgent to carry out further studies on how to control T. zebrina with the goal of restoring native vegetation.

  18. Effect of Corrupt Behavior of the Forestry Bureaucrats on the Forest Sustainability

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    Sudarsono Soedomo

    2012-11-01

    Full Text Available 800x600 This article show that corrupt bureaucrats do not always result in a negative effect on the forest sustainability. Even under a certain condition, a corrupt behavior may result in a positive effect on the forest sustainability. An inappropriate policy is more important a cause of the forest sustainability than a corrupt behavior. Therefore, fixing this structural mistake needs to be prioritized in combating the forest destruction, for this structural mistake is the real primary cause of the forest destruction in Indonesia. Fixing this structural mistake is much more effective in combating the forest destruction than finding honest bureaucrats. Keywords:     Birokrat, Distortionary, Nondistortionary, Kelestarian, Korup. Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4

  19. Early trends in landcover change and forest fragmentation due to shale-gas development in Pennsylvania: a potential outcome for the Northcentral Appalachians.

    Science.gov (United States)

    Drohan, P J; Brittingham, M; Bishop, J; Yoder, K

    2012-05-01

    Worldwide shale-gas development has the potential to cause substantial landscape disturbance. The northeastern U.S., specifically the Allegheny Plateau in Pennsylvania, West Virginia, Ohio, and Kentucky, is experiencing rapid exploration. Using Pennsylvania as a proxy for regional development across the Plateau, we examine land cover change due to shale-gas exploration, with emphasis on forest fragmentation. Pennsylvania's shale-gas development is greatest on private land, and is dominated by pads with 1-2 wells; less than 10 % of pads have five wells or more. Approximately 45-62 % of pads occur on agricultural land and 38-54 % in forest land (many in core forest on private land). Development of permits granted as of June 3, 2011, would convert at least 644-1072 ha of agricultural land and 536-894 ha of forest land. Agricultural land conversion suggests that drilling is somewhat competing with food production. Accounting for existing pads and development of all permits would result in at least 649 km of new road, which, along with pipelines, would fragment forest cover. The Susquehanna River basin (feeding the Chesapeake Bay), is most developed, with 885 pads (26 % in core forest); permit data suggests the basin will experience continued heavy development. The intensity of core forest disturbance, where many headwater streams occur, suggests that such streams should become a focus of aquatic monitoring. Given the intense development on private lands, we believe a regional strategy is needed to help guide infrastructure development, so that habitat loss, farmland conversion, and the risk to waterways are better managed.

  20. Avaliação dos fragmentos florestais do município de Jaboticabal-SP Evaluation of forest fragment in JaboticabaL- S.P

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    Thiago Claudino Greggio

    2009-02-01

    Full Text Available Este estudo foi conduzido no Município de Jaboticabal, SP, com o objetivo de avaliar a evolução temporal e o número de fragmentos florestais no período de 29 anos, utilizando-se técnicas de sensoriamento remoto e fotointerpretação. Para a elaboração dos mapas foram utilizadas Cartas do IBGE de 1971 e fotografias áreas de 2000. Os resultados apontaram diminuição das áreas de floresta. Em 1971, o município apresentava 3,63% da área total com fragmentos florestais, e em 2000 observou-se, apenas, 1,55% dessa área. Tal fato ocorreu tendo em vista o avanço de práticas agrícolas com predominância da cultura de cana-de-açúcar. A porcentagem de fragmentos florestais em 1971, com áreas menores que 10 ha, era de 46,72%, já em 2000 esse número passou para 78,51%, concluindo-se um processo de fragmentação acentuado (31,79% no período analisado. Os fragmentos florestais com maior extensão em 1971 se apresentaram extremamente fragmentados em 2000. Aproximadamente 60% dos fragmentos, nas duas épocas, apresentavam forma alongada, indicando alta relação perímetro/área.This study was conducted in Jaboticabal-SP, to evaluate the evolution and number of forest fragments in the period of 29 years, using remote sensing and photointerpretation techniques. The IBGE Maps (1971 and 2000 aerial photos were used to map the area. The reduction of the natural forest areas occurred during the time evaluated. In 1971, the municipality presented 3.63% of the total area in forest fragments, but only 1.55% of this area in 2000. This was due to the advance of agricultural practices, mainly sugarcane, in the area. The percentage of forest fragments lower than 10ha, in 1971, was 46.72% of the total area, but in 2000, this number increased to 78.51%,reaching a marked fragmentation process (31.79%in the analyzed period. The forest fragments with higher extension in 1971 were extremely fragmented in 2000. Approximately 60% of these areas, at both times

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

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    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

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

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    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.

  3. The effects of fragmentation on Araucaria forest: analysis of the fern and lycophyte communities at sites subject to different edge conditions

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    Vinícius Leão da Silva

    2015-06-01

    Full Text Available Edge effects impact species richness and composition as a result of environmental changes caused by fragmentation. This study analyzed edge effects on a community of terrestrial ferns and lycophytes in an Araucaria forest in Brazil at sites subjected to differing edge conditions: (1 a site bordering a road running through the interior of a conservation unit, and (2 a site bordering an agricultural property. Twelve 10 × 10 m plots were selected at the edge and in the interior of each site, and accounted for a total of 48 plots. The edges had lost their characteristic floristic identity, suggesting that many species are sensitive to variations in environmental conditions. The edge effect had a negative impact on species richness as shown by the greater average numbers of fern and lycophyte species in forest interiors at both sites. The results showed that the forest fragments in contact with agricultural areas were subjected to more intense edge effects than the fragments bordering a road within a conservation unit.

  4. Effects of forest fragmentation on dipterofauna (Calliphoridae at the Reserva Biológica do Tinguá, Nova Iguaçu, RJ

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    ACP. Ferraz

    Full Text Available Samples were collected every month in three different sites of the Reserva Biológica do Tinguá, Brazil: site A was located on the border of the forest and sites B and C were located 1,000 and 500 m, respectively, towards the forest interior. The objective was to determine edge effects on a fragment of the Atlantic Forest. The greatest species richness was observed in sites A and B (23 species, compared with site C (16 species. Site A showed the greatest abundance and constancy, independent of the degree of synanthropy. Asynanthropic species were more abundant and constant in sites B and C. Site B showed the greatest diversity; and sites A and B showed the greatest similarity of populations. There was no significant correlation between Calliphoridae richness and canopy openness except in site C. Richness and abundance were positively correlated with subwood density, except for richness in site B.

  5. Partitioning of seed dispersal services between birds and bats in a fragment of the Brazilian Atlantic Forest

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    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.

  6. Sleep Fragmentation Exacerbates Mechanical Hypersensitivity and Alters Subsequent Sleep-Wake Behavior in a Mouse Model of Musculoskeletal Sensitization

    Science.gov (United States)

    Sutton, Blair C.; Opp, Mark R.

    2014-01-01

    Study Objectives: Sleep deprivation, or sleep disruption, enhances pain in human subjects. Chronic musculoskeletal pain is prevalent in our society, and constitutes a tremendous public health burden. Although preclinical models of neuropathic and inflammatory pain demonstrate effects on sleep, few studies focus on musculoskeletal pain. We reported elsewhere in this issue of SLEEP that musculoskeletal sensitization alters sleep of mice. In this study we hypothesize that sleep fragmentation during the development of musculoskeletal sensitization will exacerbate subsequent pain responses and alter sleep-wake behavior of mice. Design: This is a preclinical study using C57BL/6J mice to determine the effect on behavioral outcomes of sleep fragmentation combined with musculoskeletal sensitization. Methods: Musculoskeletal sensitization, a model of chronic muscle pain, was induced using two unilateral injections of acidified saline (pH 4.0) into the gastrocnemius muscle, spaced 5 days apart. Musculoskeletal sensitization manifests as mechanical hypersensitivity determined by von Frey filament testing at the hindpaws. Sleep fragmentation took place during the consecutive 12-h light periods of the 5 days between intramuscular injections. Electroencephalogram (EEG) and body temperature were recorded from some mice at baseline and for 3 weeks after musculoskeletal sensitization. Mechanical hypersensitivity was determined at preinjection baseline and on days 1, 3, 7, 14, and 21 after sensitization. Two additional experiments were conducted to determine the independent effects of sleep fragmentation or musculoskeletal sensitization on mechanical hypersensitivity. Results: Five days of sleep fragmentation alone did not induce mechanical hypersensitivity, whereas sleep fragmentation combined with musculoskeletal sensitization resulted in prolonged and exacerbated mechanical hypersensitivity. Sleep fragmentation combined with musculoskeletal sensitization had an effect on

  7. Relationships Between Bird Communities and Forest Age, Structure, Species Composition and Fragmentation in the West Gulf Coastal Plain

    Science.gov (United States)

    Richard N. Conner; James G. Dickson

    1997-01-01

    Bird communities of the West Gulf Coastal Plain are strongly influenced by the stage of forest succession, species composition of understory and overstory vegetation, and forest structure. Alteration of plant communities through forest management and natural disturbances typically does not eliminate birds as a fauna1 group from the area affected, but will replace some...

  8. Understory avifauna exhibits altered mobbing behavior in tropical forest degraded by selective logging.

    Science.gov (United States)

    Hua, Fangyuan; Sieving, Kathryn E

    2016-11-01

    In understanding the impacts of selective logging on biodiversity, relatively little is known about the critical behavioral link between altered forest conditions and population persistence. Predator-mobbing is a widespread anti-predator behavior in birds that expresses a well-known trade-off influencing prey survival under predation risk. Here, we ask whether the predator-mobbing behavior of understory forest birds is altered by selective logging and associated forest structural changes in the highly endangered lowland rainforest of Sumatra. At four study sites spanning a gradient of logging-induced forest degradation, we used standardized mobbing and owl call playbacks with predator model presentation to elicit the predator-mobbing behavior of understory prey birds, compared birds' mobbing intensity across sites, and related variation in this intensity to forest vegetation structure. We found that selective logging altered birds' predator-mobbing intensity (measured by behavioral conspicuousness and propensity to approach the predator) as well as forest structure, and that vegetative changes to canopy and understory were correlated with contrasting responses by the two major bird foraging guilds, gleaning versus flycatching birds. We additionally discuss the implications of our findings for further hypothesis testing pertaining to the impacts of selective logging on the ecological processes underlying prey mobbing behavior, particularly with regards to predator-prey interactions and prey accruement of energy reserves.

  9. Forest insurance market participants’ game behavior in China: An analysis based on tripartite dynamic game model

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    Ning Ma

    2015-11-01

    Full Text Available Purpose: In forest insurance market, there are three main participants including the insurance company, the forest farmer and the government. As different participant has different benefit object, there will be a complex and dynamic game relationship among all participants. The purpose of this paper is to make the game relationship among all participants in forest insurance market clear, and then to put forward some policy suggestions on the implementation of forest insurance from the view of game theory. Design/methodology/approach: Firstly, the static game model between the insurance company and the forest farmer is set up. According to the result of static game model, it’s difficult to implement forest insurance without government. Secondly, the tripartite dynamic game model among the government, the insurance company and the forest farmer is proposed, and the equilibrium solution of tripartite dynamic game model is acquired. Finally, the behavioral characteristics of all participants are analyzed according to the equilibrium solution of tripartite dynamic game model. Findings: the government’s allowance will be an important positive factor to implement forest insurance. The loss of the insurance company, which the lower insurance premium brings, can be compensated by the allowance from the government. The more the government provides allowance, the more actively the insurance company will implement forest insurance at a low insurance premium. In this situation, the forest farmer will be more likely to purchase the forest insurance, then the scope of forest insurance implementation will expend. Originality/value: There is a complex and dynamic game relationship among all participants in forest insurance market. Based on the tripartite dynamic game model, to make the game relationship between each participant clear is conducive to the implementation of forest insurance market in China.

  10. 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.

  11. Developing an Experimental Simulation Method for Rock Avalanches: Fragmentation Behavior of Brittle Analogue Material

    Science.gov (United States)

    Thordén Haug, Øystein; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2013-04-01

    Gravitational mass movement on earth and other planets show a scale dependent behavior, of which the physics is not fully understood. In particular, the runout distance for small to medium sized landslides (volume granular material down a chute. Though such granular avalanche models provide important insights into avalanche dynamics, they imply that the material fully disintegrate instantaneously. Observations from nature, however, suggests that a transition from solid to "liquid" occurs over some finite distance downhill, critically controlling the mobility and energy budget of the avalanche. Few experimental studies simulated more realistically the material failing during sliding and those were realized in a labscale centrifuge, where the range of volumes/scales is limited. To develop a new modeling technique to study the scale dependent runout behavior of rock avalanches, we designed, tested and verified several brittle materials allowing fragmentation to occur under normal gravity conditions. According to the model similarity theory, the analogue material must behave dynamically similar to the rocks in natural rock avalanches. Ideally, the material should therefore deform in a brittle manner with limited elastic and ductile strains up to a certain critical stress, beyond which the material breaks and deforms irreversibly. According to scaling relations derived from dimensional analysis and for a model-to-prototype length ratio of 1/1000, the appropriate yield strength for an analogue material is in the order of 10 kPa, friction coefficient around 0.8 and stiffness in the order of MPa. We used different sand (garnet, quartz) in combination with different matrix materials (sugar, salt, starch, plaster) to cement it. The deformation behavior and strength of the samples was tested using triaxial compression tests at atmospheric confining pressures. Proper material properties were obtained using well-sorted, well-rounded, medium grained quartz sand with gypsum

  12. Groupings of life-history traits are associated with distribution of forest plant species in a fragmented landscape

    NARCIS (Netherlands)

    Endels, Patrick; Adriaens, Dries; Bekker, Renee M.; Knevel, Irma C.; Decocq, Guillaume; Hermy, Martin

    2007-01-01

    Questions: 1. Do relationships among forest plant traits correspond to dispersability-persistence trade-offs or other intertrait correlations found in the literature? 2. Do species groups delineated by trait similarity, differ in occurrence in ancient vs. new forests or isolated vs more continuous f

  13. The effect of habitat fragmentation on the genetic structure of a top predator: loss of diversity and high differentiation among remnant populations of Atlantic Forest jaguars (Panthera onca).

    Science.gov (United States)

    Haag, T; Santos, A S; Sana, D A; Morato, R G; Cullen, L; Crawshaw, P G; De Angelo, C; Di Bitetti, M S; Salzano, F M; Eizirik, E

    2010-11-01

    Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with evidence of recent allelic loss in local areas. Although some migrant and admixed individuals were identified, our results indicate that recent large-scale habitat removal and fragmentation among these areas has been sufficiently strong to promote differentiation induced by drift and loss of alleles at each site. Low estimated effective sizes supported the inference that genetic drift could have caused this effect within a short time frame. These results indicate that jaguars' ability to effectively disperse across the human-dominated landscapes that separate the fragments is currently very limited, and that each fragment contains a small, isolated population that is already suffering from the effects of genetic drift. © 2010 Blackwell Publishing Ltd.

  14. Weedy and secundary palm species in central amazonian forest Fragments Palmeiras invasoras e sucessoras secundárias em fragmentos amazônicos

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    Aldicir Scariot

    2001-08-01

    Full Text Available Forest fragmentation may affect the abundance and distribution of organisms. Some species populations decrease being eventually driven to local extinction while other species may experience population increase. In a survey of the composition and abundance of secondary and weedy palms in eight forest fragments (three of 1-, three of 10- and two of 100-ha, in three sites (Dimona, Porto Alegre and Esteio in central Amazonia, five native palm species which do not occur in the continuous forest were identified. Three were secondary species (Astrocaryum acaule Mart., Bactris maraja Mart. var. maraja and Bactris sp, one weedy (Lepidocaryum tenue Mart., and one of unknown status (B. oligocarpa Barb. Rodr. & Trail. The highest abundance was found in the 1-ha fragments which had 172 of the 206 palms found compared with 33 in the 10-ha and one in the 100-ha fragments. However, most of these palms occur in the Dimona site, which accounted for 195 of the 206 of the individuals, compared with seven in Esteio and four in Porto Alegre. The weedy L. tenue, which forms clonal populations, although occurring only in Dimona, accounted for 91% of the individuals recorded. It is possible that with increased habitat degradation of small fragments, some populations of secondary and weedy species will also increase, what may be detrimental to the closed forest plant species populations occurring in forest fragments.A fragmentação das florestas pode afetar a abundância e distribuição dos organismos. Populações de algumas espécies diminuem e eventualmente são extintas localmente enquanto populações de outras espécies podem aumentar. Em um estudo da composição e abundância de palmeiras secundárias e invasoras em oito fragmentos de florestas (três de 1-, três de 10- e dois de 100-ha, em três sítios (Dimona, Porto Alegre e Esteio na Amazônia Central, cinco espécies nativas de palmeiras que não ocorreram nas áreas planas de floresta contínua de terra

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

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    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

  16. The effect of forest fragmentation on risk of predation of passerine bird nests at Fort McClellan, Alabama

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many species of Neotropical migrant songbirds areexperiencing population declines. Degradation of habitat on thebreeding grounds, particularly the fragmentation and...

  17. Patterns and predictors of β-diversity in the fragmented Brazilian Atlantic forest: a multiscale analysis of forest specialist and generalist birds.

    Science.gov (United States)

    Morante-Filho, José Carlos; Arroyo-Rodríguez, Víctor; Faria, Deborah

    2016-01-01

    Biodiversity maintenance in human-altered landscapes (HALs) depends on the species turnover among localities, but the patterns and determinants of β-diversity in HALs are poorly known. In fact, declines, increases and neutral shifts in β-diversity have all been documented, depending on the landscape, ecological group and spatial scale of analysis. We shed some light on this controversy by assessing the patterns and predictors of bird β-diversity across multiple spatial scales considering forest specialist and habitat generalist bird assemblages. We surveyed birds from 144 point counts in 36 different forest sites across two landscapes with different amount of forest cover in the Brazilian Atlantic forest. We analysed β-diversity among points, among sites and between landscapes with multiplicative diversity partitioning of Hill numbers. We tested whether β-diversity among points was related to within-site variations in vegetation structure, and whether β-diversity among sites was related to site location and/or to differences among sites in vegetation structure and landscape composition (i.e. per cent forest and pasture cover surrounding each site). β-diversity between landscapes was lower than among sites and among points in both bird assemblages. In forest specialist birds, the landscape with less forest cover showed the highest β-diversity among sites (bird differentiation among sites), but generalist birds showed the opposite pattern. At the local scale, however, the less forested landscape showed the lowest β-diversity among points (bird homogenization within sites), independently of the bird assemblage. β-diversity among points was weakly related to vegetation structure, but higher β-diversity values were recorded among sites that were more isolated from each other, and among sites with higher differences in landscape composition, particularly in the less forested landscape. Our findings indicate that patterns of bird β-diversity vary across scales

  18. Bryophytes in fragments of Terra Firme forest on the great curve of the Xingu River, Pará state, Brazil 1 Part of Master's Dissertation of the first author.

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    ACC. Pantoja

    Full Text Available Abstract 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.

  19. Development of customized fire behavior fuel models for boreal forests of northeastern China.

    Science.gov (United States)

    Wu, Zhi Wei; He, Hong Shi; Chang, Yu; Liu, Zhi Hua; Chen, Hong Wei

    2011-12-01

    Knowledge of forest fuels and their potential fire behavior across a landscape is essential in fire management. Four customized fire behavior fuel models that differed significantly in fuels characteristics and environmental conditions were identified using hierarchical cluster analysis based on fuels data collected across a boreal forest landscape in northeastern China. Fuel model I represented the dense and heavily branched Pinus pumila shrubland which has significant fine live woody fuels. These forests occur mainly at higher mountain elevations. Fuel model II is applicable to forests dominated by Betula platyphylla and Populus davidiana occurring in native forests on hill slopes or at low mountain elevations. This fuel model was differentiated from other fuel models by higher herbaceous cover and lower fine live woody loading. The primary coniferous forests dominated by Larix gmelini and Pinus sylvestris L. var. mongolica were classified as fuel model III and fuel model IV. Those fuel models differed from one another in average cover and height of understory shrub and herbaceous layers as well as in aspect. The potential fire behavior for each fuel model was simulated with the BehavePlus5.0 fire behavior prediction system. The simulation results indicated that the Pinus pumila shrubland fuels had the most severe fire behavior for the 97th percentile weather condition, and had the least severe fire behavior under 90th percentile weather condition. Fuel model II presented the least severe fire potential across weather conditions. Fuel model IV resulted in greater fire severity than Fuel model III across the two weather scenarios that were examined.

  20. ENVIROMENTAL VARIABLE INFLUENCE ON THE TREE COMMUNITY STRUCTURE AND FLORISTIC PATTERNS IN A MONTANE ARAUCARIA FOREST FRAGMENT IN LAGES, SANTA CATARINA STATE

    Directory of Open Access Journals (Sweden)

    Pedro Higuchi

    2012-03-01

    Full Text Available http://dx.doi.org/10.5902/198050985081This study aimed to characterize the floristic composition and structure of the tree component of a montane Araucaria Forest fragment and to assess the influence of environmental variables on the patterns observed. The study area was located in the municipality of Lages, Santa Catarina state, close to the margin of the Caveiras River. The vegetation and the environmental variables (physical and chemical soils characteristics, relief and canopy cover were surveyed within 50, 20 x 10m, permanent plots allocated systematically stratified in the forest fragment. All trees with circumference at breast height (CBH ³ 15,7 cm were measured (CBH and height and identified. It was calculated the importance value (VI of the species found, performed the ordination of plots according to the abundance of species through the analysis of NMDS (Nonmetric Multidimensional Scaling and plotted the "a posterior" the significant environmental variables in the ordination diagram. One thousand, eight hundred and forty-three (1,843 individuals were sampled, which added up to a total basal area of 36.45 m2, distributed in 37 botanical families, 63 genera and 92 species. The three species with the highest values of VI were Araucaria angustifolia (Bertol. Kuntze, Lithraea brasiliensis Marchand and Jacaranda puberula Cham. The variables that showed the higher correlation with the tree component structure and floristic composition were the pH, the plot highest declivity and the Mg content.

  1. Research on Households’Behaviors of Forest Land Transfer in Zhejiang Collective Forest Area%浙江省集体林区农户林地流转行为研究

    Institute of Scientific and Technical Information of China (English)

    潘丽莎; 吴伟光; 赵夫明

    2016-01-01

    基于浙江省集体林区4县(市)192个农户的实地调查数据,在对集体林区农户林地经营与流转状况进行简要分析的基础上,采用计量经济学方法对影响农户林地转出行为的主要因素进行分析。结果表明:集体林区林地资源丰富,农户林业经营积极性较强,但林业收入贡献总体较低,林地流转市场有一定的发育但欠发达,交易行为欠规范;林地细碎化程度、家庭劳动力数量、户主年龄对林地转出行为有显著负面影响,家庭可支配收入和非农收入占比对林地转出行为有显著正面影响。%Based on the survey data of 192 households living in 4 counties in Zhejiang collective forest ar-ea,this research analyzes the management situation of forest land and the households’behavior intransfer-briefly.Then this paper puts emphasis on the influence factors in transfering out forest land by applying e-conometrics method.Results show that:the forest resource is abundant in the collective forest area,farmers hold positive attitude towards forestry production and management.But the income of forestry plays no sig-nificant role in the whole income structure;the transaction market is immature while the process of trans-action is lack of norm.Fragment of forest land,labor number and householders’ages have significant neg-ative impact on farmers’behaviors of transferring out forest land.Income and the proportion of nonagricul-tural income have positive effect on households’behaviors of transferring out forest land.

  2. Degradation of the northern paraná landscape: a study on forest fragments/ Degradação da paisagem norte-paranaense: um estudo de fragmentos florestais

    Directory of Open Access Journals (Sweden)

    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.

  3. Behavior near the extinction time in self-similar fragmentations I: The stable case

    OpenAIRE

    Goldschmidt, Christina; Haas, Bénédicte

    2010-01-01

    The stable fragmentation with index of self-similarity α∈[−1/2, 0) is derived by looking at the masses of the subtrees formed by discarding the parts of a (1+α)−1–stable continuum random tree below height t, for t≥0. We give a detailed limiting description of the distribution of such a fragmentation, (F(t), t≥0), as it approaches its time of extinction, ζ. In particular, we show that t1/αF((ζ−t)+) converges in distribution as t→0 to a non-trivial limit. In order to prove this, we go further a...

  4. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird.

    Science.gov (United States)

    Habel, J C; Mulwa, R K; Gassert, F; Rödder, D; Ulrich, W; Borghesio, L; Husemann, M; Lens, L

    2014-09-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distributions and predict potential future range shifts under a scenario of climate warming. We found well-supported genetic and morphologic clusters corresponding to the mountain ranges where populations were sampled, with 43% of all alleles being restricted to single mountains. Our data suggest that large-scale and long-term geographic isolation on mountain islands caused genetically and morphologically distinct population clusters in Z. poliogaster. However, major genetic and biometric splits were not correlated to the geographic distances among populations. This heterogeneous pattern can be explained by past climatic shifts, as highlighted by our SDM projections. Anthropogenically fragmented populations showed lower genetic diversity and a lower mean body mass, possibly in response to suboptimal habitat conditions. On the basis of these findings and the results from our SDM analysis we predict further loss of genotypic and phenotypic uniqueness in the wake of climate change, due to the contraction of the species' climatic niche and subsequent decline in population size.

  5. Can't See the Wood for the Litter: Evaluation of Litter Behavior Modification in a Forest

    Science.gov (United States)

    Lindemann-Matthies, Petra; Bonigk, Isabel; Benkowitz, Dorothee

    2012-01-01

    This study investigated elementary school children's (n = 171) litter behavior during guided forest tours following two different treatments. Four classes received a verbal appeal not to litter in the forest, while another four classes received both a verbal appeal and a demonstration of the desired litter behavior (picking up litter, putting it…

  6. Can't See the Wood for the Litter: Evaluation of Litter Behavior Modification in a Forest

    Science.gov (United States)

    Lindemann-Matthies, Petra; Bonigk, Isabel; Benkowitz, Dorothee

    2012-01-01

    This study investigated elementary school children's (n = 171) litter behavior during guided forest tours following two different treatments. Four classes received a verbal appeal not to litter in the forest, while another four classes received both a verbal appeal and a demonstration of the desired litter behavior (picking up litter, putting it…

  7. Fragmentation patterns and systematic transitions of the forested land-scape in the upper Amazon region, Ecuador 1990-2008

    Institute of Scientific and Technical Information of China (English)

    Santiago Bonilla-Bedoya; Juan R. Molina; José E. Macedo-Pezzopane; Miguel A. Herrera-Machuca

    2014-01-01

    The analysis of the systeTatic transitions in the forested landscape and the study of the forest fragTentation patterns allow us to deepen our understanding of the changes in the vegetation ground cover. The iTportance of knowing the intricate patterns of the land usage of the upper basin of the ATazon region is widely recognized. This zone is one of the Tost diverse biological areas in the world, is hoTe to large areas of Tature tropical cloud forest and deTonstrates high probabilities of stable cliTatic conditions in light of global warTing. The research quan-tified systeTatic transitions through the"loss"and"gain"of the different categories of landscape during the eighteen-year study period of the Ecuadorian ATazon Region (EAR), the forest fragTentation patterns were also analyzed based on a set of indicators. Therefore, with respect to the entirety of the landscape, the results registered for the ground coverage in forested areas during the first period (1990-2000), show a decrease of 6.99% and an increase of 0.68%; and during the second period (2000-2008), show a decrease of 3.99%and an increase of 2.14%. It deTonstrated that forest and agricultural areas tended to replace or be replaced by herbaceous vegetation faster than expected fortuitously. Finally, the indices of fragTentation signaled intense changes during the 1990-2000 period with a reduction during the period 2000-2008. Per-centages registered in the Largest Patch Index (LPI) were between 79.58%;52.39%and 49.99%respectively;while the Patch Density (PD) varied between 0.04;0.06 and 0.07. This suggests the propensity of for-est cover to reTain intact. The results of this investigation suggest a tendency towards stability in Ecuador’s ATazon landscape. Within the fraTework for developTent and TanageTent of this area, the tendency is natural regeneration. This perTits a consolidation of the conservation, reforestation, forestation and agricultural forestry plans, prograTs and systeTs for the protected

  8. Marking behavior of Andean bears in an Ecuadorian cloud forest

    NARCIS (Netherlands)

    Filipczyková, Eva; Heitkonig, Ignas; Castellanos, Armando; Hantson, Wouter; Steyaert, Sam M.J.G.

    2017-01-01

    Very little is known about marking behavior of the endangered Andean bear (Tremarctos ornatus). Here, we present a first detailed description of Andean bear marking behavior obtained using camera traps. From November 2012 to April 2013, we inspected 16 bear trails in the Napo province of eastern

  9. Depreciative Behavior in Forest Campgrounds: An Exploratory Study.

    Science.gov (United States)

    Clark, Roger N.; And Others

    "Vandalism, theft, littering, rule violation, and nuisance behaviors were studied in 3 campgrounds during 1968 using participant observation techniques. Information was gathered on the extent and character of such behaviors and factors associated with their occurrence." Nuisance acts were most common (50%) followed by legal violations…

  10. The Effect of Degassing Efficiency on the Fragmentation Behavior of Volcanic Rocks

    Science.gov (United States)

    Mueller, S.; Scheu, B.; Spieler, O.; Dingwell, D. B.

    2005-12-01

    The degassing efficiency of volcanic rocks is a decisive measure for the eruptive style and thus the explosivity of a volcano, since it directly affects magma fragmentation behaviour. Vesicles in ascending magma may bear overpressure if the relevant magma viscosity entails a relaxation time scale which is significantly larger than the time scale of ambient pressure reduction due to magma ascent. As long as this overpressure does not overcome the tensile strength of the magma, the system is in a structurally stable state, eventually degassing quiescently via an interconnected pore network. However, if a decompressive event (e.g. sector collapse) disturbs this stable pressure situation, two possible scenarios are conceivable: (1) An interconnected pore network has been established whose permeability is sufficiently high, so vesicle overpressure can be reduced efficiently by gas filtration. (2) The permeability of the network (or cluster of isolated pores, respectively) is low and gas overpressure can not be reduced within the required time scale. In this case the expansion of the pressurized gas may cause bubble wall failure and magma fragmentation into pyroclasts. This study compares experimentally derived fragmentation threshold values of volcanic rock samples, determined with a shock-tube based setup, to unsteady-state permeability values of the same sample sets. In order to cover a wide range in rock properties, we analysed samples from a broad variety of volcanic deposits. Among the treated volcanoes were Colima (Mexico), Bezymianny (Russia), Krakatoa and Merapi, (both Indonesia), Unzen (Japan), Lipari and Campi Flegrei (both Italy), Pinatubo (Philippines), and Santorini (Greece). The correlation of extensive databases of both investigated parameters revealed that permeabilities above a transition zone between 10-13 and 10-12 m2 shift the fragmentation threshold towards higher values. By means of this dataset the influence of the permeability on fragmentation

  11. Spatial fluctuation of forest fires and their regional behaviors

    Institute of Scientific and Technical Information of China (English)

    Mingyu WANG; Long SUN; Lifu SHU; Xiaorui TIAN

    2008-01-01

    Historical forest fire records from Alaska State (1950-2000),California State (1895-2001), USA and Heilongjiang Province (1980-1999), China were used to calculate the longitude and latitude of the annual burned area's centroids for these regions. Fluctuation phenomena by year were analyzed using spectrum analysis. The results show that centroids of burned areas in these three regions are in a fluctuating condition that encircles the distribution center. The distribution centers are 151.11°W, 64.96°N in Alaska State, 120.02°W, 37.11°N in California State and 127.07°E, 49.59°N in Heilongjiang Province, respectively. The fluctuation of the burned area's centroids in Alaska State and California State in longitude has obvious periodicity,and the periodicities are 4.2 years,6.25 years in Alaska State and 6.24 years, 106 years in California State. The fluctuation of the burned area's centroids in Heilongjiang Province has a periodicity both in longitude and latitude, and the periodicities are both 3.3 years, 6.67 years. Fluctuation of the burned area's centroids in Alaska State and California State in latitude does not have periodicity, and big forest fires with low frequencies predominate.

  12. The Effects of Litter on Littering Behavior in a Forest Environment

    Science.gov (United States)

    Crump, S. Larry; And Others

    1977-01-01

    The effects of littered and nonlittered areas on littering behavior were determined in picnic areas in the Uinta National Forest, Utah. Littered and nonlittered conditions were controlled by spreading or removing litter from specified areas. Observations revealed that in the nonlittered areas there was more litter than in the littered areas. (CS)

  13. 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

  14. Behavior of expelled glass fragments during projectile penetration and perforation of glass.

    Science.gov (United States)

    Haag, Lucien C

    2012-03-01

    Bullets striking common forms of flat glass with an orthogonal intercept angle result in a cloud of ejected glass fragments that are in concert with the exiting bullet's flight path. This is not the case with strikes at angles other than orthogonal. In these situations, the expelled glass fragments follow a very different course from that of the exiting projectile. This is both counterintuitive and a potential source of serious error in the evaluation and reconstruction of a shooting victim's position and orientation at the moment the victim was struck by a bullet that has passed through a nearby source of glass such as a vehicle side window or a window in a building. The flight path of the ejected glass fragments is, however, predictable and is dictated by the orientation of the plane of the glass opposite the projectile's impact site.In all cases, these expelled glass particles have considerable velocity and can produce pseudostippling of the skin in individuals located downrange of bullet-struck glass and near the projectile's exit site. The distribution and location of such pseudostippling and its relationship to the associated bullet hole in glass have important reconstructive value. A proper and reliable reconstruction of the victim's position in such cases will require the integration of scene information with the autopsy findings.

  15. 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.

  16. 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.

  17. The relevance of forest fragmentation on the incidence of human babesiosis: investigating the landscape epidemiology of an emerging tick-borne disease.

    Science.gov (United States)

    Walsh, Michael G

    2013-04-01

    Babesiosis is an emerging arthropod-borne infection that has been increasing in incidence for the last decade in the northeastern United States. Babesiosis may share features of its landscape epidemiology with other arthropod-borne infections transmitted by the same tick vectors in similar geographic spaces. This study examined 11 years of surveillance data in New York State to measure the relationship between forest fragmentation and the incidence of human babesiosis. Adjusted Poisson models showed that increasing edges of contact between forested land and developed land, as measured by their shared perimeters, was associated with a higher incidence of babesiosis cases (incident rate ratio [IRR]=1.015, 95% confidence interval [CI] 1.01-1.02; pbabesiosis risk. Higher temperature was also strongly associated with increasing babesiosis risk (IRR=1.18, 95% CI 1.10-1.27; pbabesiosis risk. While direct causal conclusions cannot be drawn from these data, these findings do identify a potentially important signal in the epidemiology of babesiosis and suggest that the underlying physical landscape may play a role in shaping points of contact between humans and tick vectors and the subsequent transmission of Babesia microti.

  18. Study on fragmentation and dissolution behavior of carbide in a hot-rolled hypereutectic high chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fei; Jiang, Yehua, E-mail: jiangyehua@kmust.edu.cn; Xiao, Han; Tan, Jun

    2015-01-05

    Highlights: • The method to prepare Carbon steel/High chromium iron is totally new. • High chromium iron can achieve small plastic deformation during hot rolling process. • Carbides in high chromium irons are crushed, refined obviously and becoming isolated, which is benefit to improve the impact toughness. • The carbide fragmentation and dissolution behavior of the hot-rolled HCCI were analyzed. - Abstract: A sandwich-structured composite containing a hypereutectic high chromium cast iron (HCCI) and low carbon steel (LCS) claddings was newly fabricated by centrifugal casting, then the blank was hot-rolled into composite plate. The carbide fragmentation and dissolution behavior of the hot-rolled HCCI were analyzed. During hot rolling, significant refinement of carbides was discovered in hot-rolled HCCI specimens. The carbides were broken and partly dissolved into the austenite matrix. The results show that carbides are firstly dissolved under the action of stress. There are grooves appeared at the boundaries of the carbides. The grooves reduce the cross section of the carbide. When the cross section of the carbide reaches to the required minimum critical cross section, the carbide breaks through the tensile force. After break, carbides continue to dissolve since more interfaces between the matrix and carbides are generated. The secondary carbides precipitated due to the dissolution are index as fcc and stacking faults parallel to the {1 1 1} are observed.

  19. Impacts of forest fragmentation on the mating system and genetic diversity of white spruce (Picea glauca) at the landscape level.

    Science.gov (United States)

    O'Connell, L M; Mosseler, A; Rajora, O P

    2006-12-01

    We studied the mating system of white spruce (Picea glauca) in a landscape fragmented by agriculture in northern Ontario, Canada. We sampled 23 stands that ranged in size from 1 to >500 trees isolated by 250-3000 m from the nearest other stand. Six polymorphic allozyme loci from four enzyme systems were used to genotype approximately 10 000 embryos from 104 families. We detected no allele frequency heterogeneity in the pollen pool among stands or families (Phi(FT)=-0.025). Overall, estimates of outcrossing were high (t(m)=94% and mean t(s)=91%) but significantly different from unity. Bi-parental inbreeding (t(m)-t(s)=3.2%) was low but significantly different from zero. Allozyme-based outcrossing estimates did not differ significantly among three stand-size classes (SSCs): small (large (> or =100 trees). The number of effective pollen donors was high in all SSCs, but was significantly lower in small stands (N(ep)=62.5) than in medium-sized and large stands (both N(ep)=143). The primary selfing rate was significantly higher in medium stands than in large stands. We found no significant difference in genetic diversity measures in the filial (seed) population among SSCs. Overall, these results indicate that white spruce stands in this fragmented landscape are resistant to genetic diversity losses, primarily through high pollen-mediated gene-flow and early selection against inbred embryos. We discuss the importance of using seed data, in conjunction with genetic data, to evaluate the impacts of fragmentation on natural populations.

  20. 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

  1. Longhorned beetle (Coleoptera: Cerambycidae diversity in a fragmented temperate forest landscape [v2; ref status: indexed, http://f1000r.es/yz

    Directory of Open Access Journals (Sweden)

    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.

  2. 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

  3. Metacommunity composition of web-spiders in a fragmented neotropical forest: relative importance of environmental and spatial effects.

    Science.gov (United States)

    Baldissera, Ronei; Rodrigues, Everton N L; Hartz, Sandra M

    2012-01-01

    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-spider beta

  4. Potential of the seedling community of a forest fragment for tropical forest restoration Potencial da comunidade de plântulas de um fragmento florestal para a restauração de florestas tropicais

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto Gorne Viani

    2009-12-01

    Full Text Available Forest restoration projects are usually planted with a reduced number of species as compared to standing forests, largely due to the low availability of native species in seedling nurseries. In the present study, the potential of the native seedling community as a source of seedlings for forest restoration is analyzed. To do so, the seedling community from a forest fragment located in the southeast of Brazil was evaluated. Individuals (tree and shrub species up to 30 cm height were measured and identified in 20 4 × 4 m plots. Altogether, 6,136 individuals (17 individuals m-2 belonging to 119 species were sampled. The seedling community showed a spatial heterogeneity with respect to the density of individuals and composition of species, and also a spatial aggregation for the 10 most abundant species. Several species that occurred in high densities in the seedling community are not presently available in regional forest nurseries and are therefore not used in restoration projects. This result and the high number of individuals and species found in the fragment suggest a great potential of this type of forest remnants as a source of highly diverse seedling banks for use in restoration projects.Devido à baixa disponibilidade de mudas nos viveiros florestais, os projetos de restauração florestal são freqüentemente implantados com um número reduzido de espécies. Avaliou-se o potencial da comunidade de plântulas como fonte de mudas para a restauração florestal. Para tanto, a comunidade de plântulas de um remanescente florestal localizado no Sudeste do Brasil foi avaliada. Indivíduos arbustivos ou arbóreos com até 30 cm foram medidos e identificados em 20 parcelas de 4 × 4 m cada. Ao todo foram amostrados 6.136 indivíduos (17 indivíduos m-2, pertencentes a 119 espécies. A comunidade estudada apresentou heterogeneidade espacial em relação à densidade de indivíduos e a composição de espécies e agregação espacial para as 10 esp

  5. Evaluation of the behavior of water in soil under eucalipto and native forest covers

    Directory of Open Access Journals (Sweden)

    Geberson Ricardo de Paula

    2013-12-01

    Full Text Available Areas occupied by grasslands have been replaced by eucalyptus plantations, which modifies the landscape, the regional economy, and water dynamics in soils. Thus, this study aimed to evaluate the behavior of water in Oxisol in two vegetation land covers, a six years old eucalyptus plantation, and a native forest in regeneration process for twenty years. The study was developed in the Una River Basin from June 2009 to April 2011. Ninety six moisture sensors were installed (Watermark™ at depths of 20, 60, and 120 cm. It was observed that, upon the occurrence of rainfall, the superficial and intermediate layers had increased humidity, which did not occur in the deepest layer. It was found that there were differences in soil moisture measured in the areas of eucalyptus and native forest and throughout the study period humidity was maintained between field capacity and permanent wilting point, with no water restriction. Canopy temperature of the eucalyptus plantation remained lower, indicating that its evapotranspiration was higher than in the forest area. The differences in moisture can be explained by the difference between the physical properties of soils in the study areas, because although they have the same slope, receive the same insolation and are close to each other, soil covered by eucalyptus presented a water storage capacity 63% above the area with native forest. It was also observed that all rainfall reaching the soil surface infiltrated and there was no runoff in the two areas studied. It was concluded that the results of this research provide important insights about differences in the behavior of water in the soil when covered by eucalyptus or native forest. For this reason, we suggest further studies with greater geographic reach in paired areas with different slopes, aspects and soil types.

  6. Behavioral ecology of Heteragrion consors Hagen (Odonata, Megapodagrionidae: a shade-seek Atlantic forest damselfly

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    Geovanni Ribeiro Loiola

    2011-09-01

    Full Text Available Behavioral ecology of Heteragrion consors Hagen (Odonata: Megapodagrionidae: a shade-seek Atlantic forest damselfly. The intensity of the inter and intra-sexual selection can affect male behavioral traits as territorial fidelity and aggressiveness allowing the existence of different strategies. However, its differential success could be affected by environmental - as the diel variation in temperature - and physiological constrains - as the variation in thermoregulatory abilities. In this context, we present a behavioral analysis of Heteragrion consors (Zygoptera, Megapodagrionidae trying to characterize its mating system, diel activity pattern, temporal budget, territoriality and reproductive biology. These data were obtained based on field observations using the focal individual method and mark-recapture techniques in 120 m of a shaded Atlantic Forest stream in Brazil. The males of this species were territorial, varying in its local fidelity, while the females appear sporadically. Males were perched in the majority of the time, but were also observed in cleaning movements, longitudinal abdominal flexion, wing flexion and sperm transfer during perch. The males presented a perched thermoregulatory behavior related to an exothermic regulation. Foraging and agonistic interactions were rare, but dominate the other behavioral activities. Abdominal movements associated to long lasting copula pointed to the existence of sperm competition in this species. Males performed contact post-copulatory guarding of the females. These observations pointed to a non-resource mating system for this species.

  7. Toxoplasma gondii in domestic and wild animals from forest fragments of the municipality of Natal, northeastern Brazil

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    Gislene Fátima da Silva Rocha Fournier

    2014-12-01

    Full Text Available 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.

  8. Pollen-mediated gene dispersal within continuous and fragmented populations of a forest understorey species, Trillium cuneatum.

    Science.gov (United States)

    Gonzales, Eva; Hamrick, J L; Smouse, P E; Dyer, R J

    2006-07-01

    Pollen movement plays a critical role in the distribution of genetic variation within and among plant populations. Direct measures of pollen movement in the large, continuous populations that characterize many herbaceous plant species are often technically difficult and biologically unreliable. Here, we studied contemporary pollen movement in four large populations of Trillium cuneatum. Three populations, located in the Georgia Piedmont, are exposed to strong anthropogenic disturbances, while the fourth population, located in the Southern Appalachian Mountains, is relatively undisturbed. Using the recently developed TwoGener analysis, we extracted estimates of the effective number of pollen donors (N(ep)), effective mating neighbourhood size (A(ep)) and the average distance of pollen movement (delta) for each population. We extended the TwoGener method by developing inference on the paternal gametic contribution to the embryo in situations where offspring genotypes are inferred from seeds and elaiosomes of species with bisporic megagametogenesis. Our estimates indicate that maternal plants do not sample pollen randomly from a global pool; rather, pollen movement in all four populations is highly restricted. Although the effective number of pollen donors per maternal plant is low (1.22-1.66) and pollen movement is highly localized in all populations, N(ep) in the disturbed Piedmont populations is higher and there is more pollen movement than in the mountains. The distance pollen moves is greater in disturbed sites and fragmented populations, possibly due to edge effects in Trillium habitats.

  9. 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

  10. 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

  11. Denied density-dependent seedling recruitment in a fragmented forest does not decrease seedling diversity El denegado reclutamiento denso-dependiente de plántulas en un bosque fragmentado no disminuye la diversidad de plántulas

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    CARLOS E VALDIVIA

    2011-06-01

    Full Text Available Negative density-dependent relationships in plant communities are currently claimed as an important mechanism for the maintenance of plant diversity. However, anthropogenic perturbations such as forest fragmentation might modify such relationships. We evaluated density-dependent relationships between seed and seedling abundance of a tree assemblage in a fragmented forest for estimating seed-to-seedling transitions and their effects on seedling richness. In continuous forest, two out of four and one out of four species presented significant or a tendency to exhibit negative seedling recruitment which is in agreement with other temperate and tropical forests. In forest fragments (1-6 ha, however, this relationship was uncoupled. Seedling richness and diversity, assessed through Shannon-Wiener Index, did not differ between both types of sites. Therefore, forest fragmentation negatively affected seedling recruitment by uncoupling seed-to-seedling transitions, but not by diminishing seedling diversity. This leads to considering the role of density-dependent relationships for the maintenance of plant diversity in communities and claims for including forest fragments into conservation programmes.Las relaciones denso-dependientes negativas en las comunidades vegetales son actualmente señaladas como un importante mecanismo para la mantención de la diversidad de plantas. Sin embargo, las perturbaciones antropogénicas como la fragmentación del bosque podrían modificar este tipo de relaciones. Evaluamos las relaciones denso-dependientes entre las abundancias de semillas y plántulas en un ensamble de árboles en un bosque fragmentado para estimar las transiciones de semillas a plántulas y sus efectos sobre la riqueza de plántulas. En el bosque continuo tres de cuatro especies presentaron reclutamientos de plántulas negativos, lo cual se condice con otros bosques templados y tropicales. En los fragmentos de bosque (1-6 ha, no obstante, estas

  12. SEASONAL VARIATION OF AVIFAUNAL COMPOSITION AND COMMUNITIES IN FOOTHILL GALLERY FOREST FRAGMENTS IN THE MANZANARES RIVER MEDIUM BASIN, STATE OF SUCRE, VENEZUELA

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    Marín-Espinoza, Gedio

    2011-07-01

    Full Text Available This study examined the seasonal variation of avifaunal composition and structural community in foothill gallery forest fragments in the Manzanares river medium basin, state of Sucre, Venezuela, at two sectors: Guaranache-Cancamure (GC y Tataracual-Cangrejal (TC, during february-may (dry period and june-november (rainy period. Birds samples were taken monthly by point counts and mist-nets. Correlation analysis and non parametric tests were estimated to examine differences among seasonal periods. 73 species were recorded and were grouped into 7 feeding guilds. Mean diversity of both periods was high but no significant; although dry period diversity was moderately higher than rainy period. Richness and diversity showed no significant differences among periods, neither showed significant correlation with rainy levels. Occurrence frequency showed unusual > eventual > habitual > prevalent species pattern. Complementary index showed a substantial mean similarity monthly (67%. For both methods species cumulative curves displayed similar growing patterns. Insectivores and frugivores-insectivores were the most diverse feeding guilds. Amazilia tobaci obtained the highest specific importance index. Pitangus sulphuratus was the most persistent species. Community dynamic of avifauna of these riparian landscape would seem be influenced primarily to a suitable resources availability because to vertical and horizontal floristic heterogeneity. Conservation plans for medium basin of Manzanares river should take into account regular deforestation activities, particularly periodic and uncontrolled burnings, which likely would affect more adversely species associated with understory habitats.

  13. 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.

  14. The effects of bark beetle outbreaks on forest development, fuel loads and potential fire behavior in salvage logged and untreated lodgepole pine forests

    Science.gov (United States)

    B. J. Collins; C. C. Rhoades; M. A. Battaglia; R. M. Hubbard

    2012-01-01

    Recent mountain pine beetle infestations have resulted in widespread tree mortality and the accumulation of dead woody fuels across the Rocky Mountain region, creating concerns over future forest stand conditions and fire behavior. We quantified how salvage logging influenced tree regeneration and fuel loads relative to nearby, uncut stands for 24 lodgepole pine...

  15. Foraging behavior of pileated woodpeckers in partial cut and uncut bottomland hardwood forest

    Science.gov (United States)

    Newell, P.; King, Sammy L.; Kaller, Michael D.

    2009-01-01

    In bottomland hardwood forests, partial cutting techniques are increasingly advocated and used to create habitat for priority wildlife like Louisiana black bear (Ursus americanus luteolus), white-tailed deer (Odocoileus virginianus), and Neotropical migrants. Although partial cutting may be beneficial to some species, those that use dead wood may be negatively affected since large diameter and poor quality trees (deformed, moribund, or dead) are rare, but normally targeted for removal. On the other hand, partial cutting can create dead wood if logging slash is left on-site. We studied foraging behavior of pileated woodpeckers (Dryocopus pileatus) in one- and two-year-old partial cuts designed to benefit priority species and in uncut forest during winter, spring, and summer of 2006 and 2007 in Louisiana. Males and females did not differ in their use of tree species, dbh class, decay class, foraging height, use of foraging tactics or substrate types; however, males foraged on larger substrates than females. In both partial cut and uncut forest, standing live trees were most frequently used (83% compared to 14% for standing dead trees and 3% for coarse woody debris); however, dead trees were selected (i.e. used out of proportion to availability). Overcup oak (Quercus lyrata) and bitter pecan (Carya aquatica) were also selected and sugarberry (Celtis laevigata) avoided. Pileated woodpeckers selected trees >= 50 cm dbh and avoided trees in smaller dbh classes (10-20 cm). Density of selected foraging substrates was the same in partial cut and uncut forest. Of the foraging substrates, woodpeckers spent 54% of foraging time on live branches and boles, 37% on dead branches and boles, and 9% on vines. Of the foraging tactics, the highest proportion of foraging time was spent excavating (58%), followed by pecking (14%), gleaning (14%), scaling (7%), berry-eating (4%), and probing (3%). Woodpecker use of foraging tactics and substrates, and foraging height and substrate

  16. Effects of fuel particle size and fission-fragment-enhanced irradiation creep on the in-pile behavior in CERCER composite pellets

    Science.gov (United States)

    Zhao, Yunmei; Ding, Shurong; Zhang, Xunchao; Wang, Canglong; Yang, Lei

    2016-12-01

    The micro-scale finite element models for CERCER pellets with different-sized fuel particles are developed. With consideration of a grain-scale mechanistic irradiation swelling model in the fuel particles and the irradiation creep in the matrix, numerical simulations are performed to explore the effects of the particle size and the fission-fragment-enhanced irradiation creep on the thermo-mechanical behavior of CERCER pellets. The enhanced irradiation creep effect is applied in the 10 μm-thick fission fragment damage matrix layer surrounding the fuel particles. The obtained results indicate that (1) lower maximum temperature occurs in the cases with smaller-sized particles, and the effects of particle size on the mechanical behavior in pellets are intricate; (2) the first principal stress and radial axial stress remain compressive in the fission fragment damage layer at higher burnup, thus the mechanism of radial cracking found in the experiment can be better explained.

  17. Army ant raid attendance and bivouac checking behavior by Neotropical montane forest birds

    OpenAIRE

    O'Donnell, Sean; Kumar, Anjali; Logan, Corina J.

    2010-01-01

    This is the final version of the article. It first appeared from Wilson Ornithological Society via http://dx.doi.org/10.1676/09-156.1 We quantified resident and migrant bird attendance at army ant swarm raids (n  =  48) in a neotropical montane forest. All observations were during seasons when Nearctic migrant birds are present. Bird species differed in army ant raid-attending behavior. Resident bird species attended 2 to 54% of raids, while migrants attended at lower maximum frequencies (...

  18. Nesting ecology and behavior of Broad-winged Hawks in moist karst forests of Puerto Rico

    Science.gov (United States)

    Hengstenberg, D.W.; Vilella, F.J.

    2005-01-01

    The Puerto Rican Broad-winged Hawk (Buteo platypterus brunnescens) is an endemic and endangered subspecies inhabiting upland montane forests of Puerto Rico. The reproductive ecology, behavior, and nesting habitat of the Broad-winged Hawk were studied in Ri??o Abajo Forest, Puerto Rico, from 2001-02. We observed 158 courtship displays by Broad-winged Hawks. Also, we recorded 25 territorial interactions between resident Broad-winged Hawks and intruding Red-tailed Hawks (Buteo jamaicensis jamaicensis). Broad-winged Hawks displaced intruding Red-tailed Hawks from occupied territories (P = 0.009). Mayfield nest survival was 0.67 across breeding seasons (0.81 in 2001, N = 6; 0.51 in 2002, N = 4), and pairs averaged 1.1 young per nest (years combined). The birds nested in mixed species timber plantations and mature secondary forest. Nests were placed in the upper reaches of large trees emerging from the canopy. Nest tree DBH, understory stem density, and distance to karst cliff wall correctly classified (77.8%) nest sites. ?? 2005 The Raptor Research Foundation, Inc.

  19. Divergence in foraging behavior of foliage-gleaning birds of Canadian and Russian boreal forests.

    Science.gov (United States)

    Greenberg, Russell; Pravosudov, Vladimir; Sterling, John; Kozlenko, Anna; Kontorschikov, Vitally

    1999-08-01

    We compared foraging behavior of foliage-gleaning birds of the boreal forest of two Palaearctic (central Siberia and European Russia) and two Nearctic (Mackenzie and Ontario, Canada) sites. Using discriminant function analysis on paired sites we were able to distinguish foliage-gleaning species from the Nearctic and Palaearctic with few misclassifications. The two variables that most consistently distinguished species of the two avifaunas were the percentage use of conifer foliage and the percentage use of all foliage. Nearctic foliage-gleaner assemblages had more species that foraged predominantly from coniferous foliage and displayed a greater tendency to forage from foliage, both coniferous and broad-leafed, rather than twigs, branches, or other substrates. The greater specialization on foliage and, in particular, conifer foliage by New World canopy foliage insectivores is consistent with previously proposed hypotheses regarding the role of Pleistocene vegetation history on ecological generalization of Eurasian species. Boreal forest, composed primarily of spruce and pine, was widespread in eastern North America, whereas pockets of forest were scattered in Eurasia (mostly the mountains of southern Europe and Asia). This may have affected the populations of birds directly or indirectly through reduction in the diversity and abundance of defoliating outbreak insects. Loss of habitat and resources may have selected against ecological specialization on these habitats and resources.

  20. Forest specialist and generalist small mammals in forest edges and hedges

    OpenAIRE

    Schlinkert, Hella; Ludwig, Martin; Batáry, Péter; Holzschuh, Andrea; Kovács-Hostyánszki, Anikó; Tscharntke, Teja; Fischer, Christina

    2017-01-01

    GermanyAgricultural intensification often leads to fragmentation of natural habitats, such as forests, and thereby negatively affects forest specialist species. However, human introduced habitats, such as hedges, may counteract negative effects of forest fragmentation and increase dispersal, particularly of forest specialists. We studied effects of habitat type (forest edge versus hedge) and hedge isolation from forests (connected versus isolated hedge) in agricultural landscapes ...

  1. 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...

  2. Coleoptera (Insecta as forest fragmentation indicators in the Rio Negro sub-region of the Pantanal, Mato Grosso do Sul, Brazil

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    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.

  3. Behavior of oxidized platinum nanoparticles on an aligned carbon nanotube forest

    Science.gov (United States)

    Matsuda, Keita; Norimatsu, Wataru; Arai, Shigeo; Kusunoki, Michiko

    2016-10-01

    We observed and analyzed the behavior of platinum nanoparticles (PtNPs) supported on aligned-carbon nanotubes (CNTs) at high temperatures by X-ray photoelectron spectroscopy and high-resolution transmission electron microscope observations. We found that the PtNPs moved toward the inner-side along each CNT on which they were deposited. The mechanism of this behavior is related to the redox reaction of Pt with the carbon atoms in the CNT. We also performed in-situ observation of this process at a high temperature using an environmental transmission electron microscope under an oxygen atmosphere. We found that the PtNPs penetrated down into a high-density aligned CNT forest along the tube axis and that the PtNPs changed their shape to fit the structure of the CNTs during their movement.

  4. Assessment of forest geospatial patterns over the three giant forest areas of China

    Institute of Scientific and Technical Information of China (English)

    LI Ming-shi; ZHU Zhi-liang; LU Heng; XU Da; LIU An-xing; PENG Shi-kui

    2008-01-01

    Geospatial patterns of forest fragmentation over the three traditional giant forested areas of China (Northeastern, southwestern and Southern China) were analyzed comparatively and reported based on a 250-m resolution land cover dataset. Specifically, the spatial patterns of forest fragmentation were characterized by combining geospatial metrics and forest fragmentation models. The driving forces resulting in the differences of the forest spatial patterns were also investigated. Results suggested that forests in southwest China had the highest severity of forest fragmentation, followed by south region and northeast region. The driving forces of forest fragmentation in China were primarily the giant population and improper exploitation of forests. In conclusion, the generated information in the study provided valuable insights and implications as to the fragmentation patterns and the conservation of biodiversity or genes, and the use of the chosen geospatial metrics and forest fragmentation models was quite useful for depicting forest fragmentation patterns.

  5. Empirical Prediction of Leaf Area Index (LAI of Endangered Tree Species in Intact and Fragmented Indigenous Forests Ecosystems Using WorldView-2 Data and Two Robust Machine Learning Algorithms

    Directory of Open Access Journals (Sweden)

    Galal Omer

    2016-04-01

    Full Text Available Leaf area index (LAI is an important biophysical trait for forest ecosystem and ecological modeling, as it plays a key role for the forest productivity and structural characteristics. The ground-based methods like the handheld optical instruments for predicting LAI are subjective, pricy and time-consuming. The advent of very high spatial resolutions multispectral data and robust machine learning regression algorithms like support vector machines (SVM and artificial neural networks (ANN has provided an opportunity to estimate LAI at tree species level. The objective of the this study was therefore to test the utility of spectral vegetation indices (SVI calculated from the multispectral WorldView-2 (WV-2 data in predicting LAI at tree species level using the SVM and ANN machine learning regression algorithms. We further tested whether there are significant differences between LAI of intact and fragmented (open indigenous forest ecosystems at tree species level. The study shows that LAI at tree species level could accurately be estimated using the fragmented stratum data compared with the intact stratum data. Specifically, our study shows that the accurate LAI predictions were achieved for Hymenocardia ulmoides using the fragmented stratum data and SVM regression model based on a validation dataset (R2Val = 0.75, RMSEVal = 0.05 (1.37% of the mean. Our study further showed that SVM regression approach achieved more accurate models for predicting the LAI of the six endangered tree species compared with ANN regression method. It is concluded that the successful application of the WV-2 data, SVM and ANN methods in predicting LAI of six endangered tree species in the Dukuduku indigenous forest could help in making informed decisions and policies regarding management, protection and conservation of these endangered tree species.

  6. PHYTOSOCIOLOGICAL STRUCTURE AND SUCESSION CLASSIFICATION OF THE ARBOREOUS COMPONENT IN FRAGMENT OF SEASONAL SEMIDECIDUOUS FOREST IN VIÇOSA – MINAS GERAIS

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    Luiz Carlos Marangon

    2007-06-01

    Full Text Available This paper aimed at understanding the behavior of the arboreal species of “Mata da pedreira” situated at “Estação Experimental Mata do Paraíso” of the Departamento de Engenharia Florestal, Viçosa- MG-, by studying their phytossociological structure and their sucessional classification. The area has 40 ha and the sampled area was of 1 ha, whee were implanted 40 plots with 250 m2 (25,0 X 10,0 m distributed, at the toposequences proporcionally to the area of each one. The level of inclusion was of CAP≤ 15,0 cm, the sucessional classification the species were observed on field, besides the using of bibliography connected to the subject. In phytosociology 1400 individuals belonging to 48 families, 109 genery and 146 species were analized. The species brought up a level of diversity of Shannon-Wiener (H' of 4.25 nats/species and equability of Pielou (J´ of 0,83. These levels of diversity are among the highest ones encountered in Minas Gerais state. In terms of sucessional classification, the area studied is a secondary forest formation, showing itself in a sucessing initial stage, where there has been a high presence of species classified as initial secondary, followed by late secondary and pioneer tree species.

  7. Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

    OpenAIRE

    Habel, JC; Mulwa, RK; Gassert, F; Roedder, D.; Ulrich, W; Borghesio, L; Husemann, M; Lens, Luc

    2014-01-01

    The Eastern Afromontane cloud forests occur as geographically distinct mountain exclaves. The conditions of these forests range from large to small and from fairly intact to strongly degraded. For this study, we sampled individuals of the forest bird species, the Montane White-eye Zosterops poliogaster from 16 sites and four mountain archipelagos. We analysed 12 polymorphic microsatellites and three phenotypic traits, and calculated Species Distribution Models (SDMs) to project past distribut...

  8. Photo-fragmentation behavior of methyl- and methoxy-substituted derivatives of hexa-peri-hexabenzocoronene (HBC) cations

    Science.gov (United States)

    Zhen, Junfeng; Castellanos, Pablo; Linnartz, Harold; Tielens, Alexander G. G. M.

    2016-11-01

    A systematic study, using ion trap time-of-flight mass spectrometry, is presented for the photo-fragmentation of methyl- and methoxy-substituted derivatives of HBC cations, (OCH3)6HBC+ and (CH3)4(OCH3)2HBC+. Both substituted HBC cations fragment through sequential loss of CH3CO units upon laser (595nm) irradiation, resulting in a PAH-like derivative C36H12+ and a methyl-substituted PAH derivative C44H24+ , respectively. Upon ongoing irradiation, these species further fragment. For lower laser energy C44H24+ dehydrogenates and photo-fragments through CH3 and CHCH2 unit losses; for higher laser energy isomerization takes place, yielding a regular PAH-like configuration, and both stepwise dehydrogenation and C2/C2H2 loss pathways are found. C36H12+ follows largely this latter fragmentation scheme upon irradiation. It is concluded that the photo-dissociation mechanism of the substituted PAH cations studied here is site selective in the substituted subunit. This work also shows experimental evidence that photo-fragmentation of substituted PAHs may contribute to the formation in space of smaller species that are normally considered to form by merging atoms and molecules.

  9. Photo guide for estimating fuel loading and fire behavior in mixed-oak forests of the Mid-Atlantic Region

    Science.gov (United States)

    Patrick H. Brose

    2009-01-01

    A field guide of 45 pairs of photographs depicting ericaceous shrub, leaf litter, and logging slash fuel types of eastern oak forests and observed fire behavior of these fuel types during prescribed burning. The guide contains instructions on how to use the photo guide to choose appropriate fuel models for prescribed fire planning.

  10. 美国西部国有森林破碎化模式及其管理含义%Spatio-Temporal Patterns and Managerial Implications of Forest Fragmentation Derived from Three National Parks in the Western United States

    Institute of Scientific and Technical Information of China (English)

    李明诗; 明莉; 樊鸣鸣; 沈文娟; 孙力

    2012-01-01

    以美国西部3个著名的国家公园(黄石、洛基山和大峡谷)及其缓冲区为研究对象,以空间分辨率30m的3期美国国家土地覆盖数据库(National Land Cover Databases,NLCD 1992\\2001 \\2006)为数据源,采用森林破碎化分析模型与景观指数相结合的方法刻画国家公园及其缓冲区内森林破碎化及干扰模式的时空差异,并有效分离导致森林破碎化的人为干扰和自然干扰贡献份额.结果表明:美国西部国家公园内森林因严格保护而破碎化程度较低且森林状态保持稳定,主要的干扰形式是自然干扰并伴有少量的城市土地利用类型的空间交互.而在缓冲区,由于存在相对宽松的森林经营活动森林破碎化程度较高,森林受自然干扰和人为干扰共同作用,其中农业土地利用扮演主要角色.这些差异主要归因于美国西部陡峻的地形、土地所有权及民众的生活方式.为了有效改善中国森林及国家公园的管理水平,可充分借鉴美国国家公园管理过程中的先进的经营理念、法律依据、管理机制、资金机制和监督机制等,并应在森林经营实践中确保森林保护政策有效执行.%A forest fragmentation model in concert with geospatial metrics was employed to characterize the spatio-temporal variability in forest fragmentation and disturbance patterns within three national parks (Yellow Stone, Rocky Mountains and Grand Canyon) and their transition zones in the western United States based on the triple-temporal national land cover databases (NLCD1992/2001/2006) in a spatial resolution of 30 meters. Contributions of anthropogenic and natural disturbances to fragmentation were effectively separated via the fragmentation model to highlight areas with high priority of conservation or remediation. Results showed that the forest in the national parks had a low fragmentation due to its rigorous forest conservation practice and the forest status remained relatively

  11. Phytosociological importance of an ombrophilous forest fragment in the State of Roraima, Brazil = Importância fitossociológica de um fragmento de floresta ombrófila densa no estado de Roraima, Brasil

    OpenAIRE

    Luiz Fernandes Silva Dionisio; Osmar Serra Bonfim Filho; Bruno Roberto de Souza Crivelli; Jefferson Peixoto Gomes; Marcelo Henrique Silva de Oliveira; João Olegário Pereira de Carvalho

    2016-01-01

    The aim of this study was to characterise the phytosociology of a fragment of native forest in the town of Caroebe, in the State of Roraima, Brazil. All trees with a DBH ≥ 15 cm were inventoried in 18 permanent plots of 15 x 20 m (300 m²). There were 175 individuals indentified, distributed across 17 botanical families, 37 genera and 45 species. The genera with the greatest floristic richness were Protium, Vantanea and Couratari. Among the families, Fabaceae and Lecythidaceae showed the great...

  12. 基于遥感及景观破碎化分析的县域森林保护%Forest Conservation at County Scale Based on RS and Landscape Fragmentation Analysis

    Institute of Scientific and Technical Information of China (English)

    马庆申; 吴国平; 徐峰; 赵明亮; 王建

    2013-01-01

    以山东省费县北部沂蒙山区为研究区域,以1990、2001和2009年Landsat TM/ETM+影像为原始数据,采用面向对象分类方法提取了研究区域的森林覆盖数据。选取景观特征指标对研究区19年间(1990-2009)森林覆盖变化及破碎化特征进行了定量分析。结果表明:1990-2009年研究区内森林覆盖呈现先减少后增加,总体增加的特点。研究期间森林及其核心区破碎化程度较强且呈加重趋势,2001-2009年有所减缓。确定了研究区内森林优先保护区域。%Taking the northern mountainous area of Fei County in Yimeng Mountain as the study area, Landsat Thematic Mapper (TM) or Enhanced Thematic Mapper Plus (ETM+) images of 1990, 2001 and 2009 as the original data, we used the ob-ject-oriented classification method to extract forest cover data of the study area.We selected landscape feature index to quantitatively analyze the forest cover change and characteristics of fragmentation during 19 years (1990-2009 ) .The for-est cover in the study area decreased in 1990-2001 , and then increased in 2001-2009 , however , it showed increased trend in all years.During the study period, the fragmentation degree of the forest and its core area is strong and it tends to be worse.But from 2001 to 2009, the pace of fragmentation was slowing down.Therefore, the priority forest conservation area can be determined in the study area.

  13. Applying Behavioral Ecology and Behavioral Economics to Conservation and Development Planning: An Example from the Mikea Forest, Madagascar.

    Science.gov (United States)

    Tucker, Bram

    2007-09-01

    Governments and non-govermental organizations (NGOs) that plan projects to conserve the environment and alleviate poverty often attempt to modify rural livelihoods by halting activities they judge to be destructive or inefficient and encouraging alternatives. Project planners typically do so without understanding how rural people themselves judge the value of their activities. When the alternatives planners recommend do not replace the value of banned activities, alternatives are unlikely to be adopted, and local people will refuse to participate. Human behavioral ecology and behavioral economics may provide useful tools for generating and evaluating hypotheses for how people value economic activities in their portfolios and potential alternatives. This is demonstrated with a case example from southwestern Madagascar, where plans to create a Mikea Forest National Park began with the elimination of slash-and-burn maize agriculture and the encouragement to plant labor-intensive manioc instead. Future park plans could restrict access to wild tuber patches, hunting small game, and fishing. The value of these activities is considered using observational data informed by optimal foraging theory, and experimental data describing people's time preference and covariation perception. Analyses suggest that manioc is not a suitable replacement for maize for many Mikea because the two crops differ in terms of labor requirements, delay-to-reward, and covariation with rainfall. Park planners should promote wild tuber foraging and stewardship of tuber patches and the anthropogenic landscapes in which they are found. To conserve small game, planners must provide alternative sources of protein and cash. Little effort should be spent protecting lemurs, as they are rarely eaten and never sold.

  14. Forest insurance market participants’ game behavior in China: an analysis based on tripartite dynamic game model

    OpenAIRE

    Ning Ma; Yang Zuo; Kaili Liu; Yue Qi

    2015-01-01

    Purpose: In forest insurance market, there are three main participants including the insurance company, the forest farmer and the government. As different participant has different benefit object, there will be a complex and dynamic game relationship among all participants. The purpose of this paper is to make the game relationship among all participants in forest insurance market clear, and then to put forward some policy suggestions on the implementation of forest insurance from the view of...

  15. Ranging behavior of eastern hoolock gibbon (Hoolock leuconedys) in a northern montane forest in Gaoligongshan, Yunnan, China.

    Science.gov (United States)

    Zhang, Dao; Fei, Han-Lan; Yuan, Sheng-Dong; Sun, Wen-Mo; Ni, Qing-Yong; Cui, Liang-Wei; Fan, Peng-Fei

    2014-04-01

    Generally, food abundance and distribution exert important influence on primate ranging behavior. Hoolock gibbons (genus Hoolock) live in lowland and montane forests in India, Bangladesh, Myanmar and China. All information about hoolock gibbons comes from studies on western hoolock gibbons (Hoolock hoolock) living in lowland forest. Between August 2010 and September 2011, we studied the ranging behavior of one habituated group of eastern hoolock gibbon (H. leuconedys) living in a seasonal montane forest in Gaoligongshan, Yunnan, China. Results show that the study group did not increase foraging effort, calculated in this study as the daily path length, when fruit was less available. Instead, the gibbons fed more on leaves and decreased traveling to conserve energy. They relied heavily on a single food species in most study months which was patchily distributed within their total (14-month) home range, and during most months they used only a small portion of their total home range. In order to find enough food, the group shifted its monthly home range according to the seasonal availability of food species. To satisfy their annual food requirements, they occupied a total home range of 93 ha. The absence of neighboring groups of gibbons and the presence of tsaoko cardamom (Amomum tsaoko) plantations may also have influenced the ranging behavior of the group. Further long-term studies of neighboring groups living in intact forests are required to assess these effects.

  16. Guidelines of handling and management of forest fragments in the municipality of Murcia; Directrices de manejo y gestion de sistemas forestales en el Municipio de Murcia

    Energy Technology Data Exchange (ETDEWEB)

    Zapata Perez, V. M.; Robledano, F.; Jimenez, M. V.; Farinos, P.

    2009-07-01

    Most forest systems in the municipality of Murcia are old afforestations with Pinus halepensis. In many sites, the unsuitability of the habitat for this species has led to a poor tree development, and to a strong competence for resources that increases environmental stress. We have studied patches of forests protected by the municipality of Murcia (Forest Parks of Majal Blanco, Montepinar and Los Polvorines) and other unprotected patches close to these. The objective was to study their composition, structure and ecological dynamics. (Author) 3 refs.

  17. The Interplay among Acorn Abundance and Rodent Behavior Drives the Spatial Pattern of Seedling Recruitment in Mature Mediterranean Oak Forests.

    Directory of Open Access Journals (Sweden)

    Pau Sunyer

    Full Text Available The patterns of seedling recruitment in animal-dispersed plants result from the interactions among environmental and behavioral variables. However, we know little on the contribution and combined effect of both kinds of variables. We designed a field study to assess the interplay between environment (vegetation structure, seed abundance, rodent abundance and behavior (seed dispersal and predation by rodents, and rooting by wild boars, and their contribution to the spatial patterns of seedling recruitment in a Mediterranean mixed-oak forest. In a spatially explicit design, we monitored intensively all environmental and behavioral variables in fixed points at a small spatial scale from autumn to spring, as well as seedling emergence and survival. Our results revealed that the spatial patterns of seedling emergence were strongly related to acorn availability on the ground, but not by a facilitation effect of vegetation cover. Rodents changed seed shadows generated by mother trees by dispersing most seeds from shrubby to open areas, but the spatial patterns of acorn dispersal/predation had no direct effect on recruitment. By contrast, rodents had a strong impact on recruitment as pilferers of cached seeds. Rooting by wild boars also reduced recruitment by reducing seed abundance, but also by changing rodent's behavior towards higher consumption of acorns in situ. Hence, seed abundance and the foraging behavior of scatter-hoarding rodents and wild boars are driving the spatial patterns of seedling recruitment in this mature oak forest, rather than vegetation features. The contribution of vegetation to seedling recruitment (e.g. facilitation by shrubs may be context dependent, having a little role in closed forests, or being overridden by directed seed dispersal from shrubby to open areas. We warn about the need of using broad approaches that consider the combined action of environment and behavior to improve our knowledge on the dynamics of natural

  18. Sobrevivência em viveiro de mudas de espécies nativas retiradas da regeneração natural de remanescente florestal Survival in nursery of native species saplings obtained from natural regeneration of forest fragments

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto Gorne Viani

    2007-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a sobrevivência em viveiro de plântulas retiradas da regeneração natural de remanescente de Floresta Estacional Semidecidual, localizado em Bofete, SP. Indivíduos com até 30 cm de espécies arbustivo-arbóreos foram coletados em parcelas instaladas previamente em remanescente florestal, transplantados para viveiro sob sombrite 50%, e avaliados periodicamente durante nove meses. Ao todo foram transferidos para o viveiro 2.424 indivíduos, pertencentes a 110 espécies. A taxa média de sobrevivência foi de 69%, com variação nos resultados para as diferentes espécies, famílias e classes de altura dos indivíduos. Embora espécies pioneiras tenham apresentado taxa de sobrevivência significativamente maior que não pioneiras, várias espécies não pioneiras apresentaram elevada taxa de sobrevivência. Muitas das espécies sobreviventes não são encontradas nos viveiros florestais do Estado de São Paulo. A produção de mudas por meio da transferência da regeneração natural de áreas naturais é uma estratégia complementar viável, que eleva a riqueza de espécies dos viveiros florestais.Seedling survival was evaluated regarding transplanted saplings obtained from natural regeneration of a Semideciduous Seasonal Forest fragment, located at Bofete, São Paulo State, Brazil. Shrub and trees species seedlings up to 30 cm height were collected from samples sited on a forest remnant, transplanted to a nursery under 50% shade tissue, and evaluated periodically during nine months. A total of 2,424 seedlings, belonging to 110 species were transferred to the nursery. Average survival reached 69%, although this survival rate was quite variable according to the species, families and height classes of the evaluated individuals. In spite of the fact that pioneer species presented higher survival rate, several non-pioneer species also obtained high values of survival. Besides, many of the survivor species are

  19. Composición, riqueza de especies y abundancia de insectos defoliadores de actividad nocturna asociados a Aristotelia chilensis (maqui en el bosque maulino fragmentado Composition, species richness and abundance of nocturnal folivorous insects associated with Aristotelia chilensis (maqui in the fragmented Maulino forest

    Directory of Open Access Journals (Sweden)

    XAVIERA DE LA VEGA

    2008-06-01

    , herbivory upon Aristotelia chilensis (maqui is negatively affected by forest fragmentation, being higher in the continuous forest than in the small remnant fragments, particularly at the beginning of the growing season (spring. This phenomenon may be attributable to changes in the population dynamics of herbivores, mostly insects. In this work, the effect of the Maulino forest fragmentation on the abundance, species richness and composition of nocturnal defoliating insects associated with A. chilensis was evaluated. The insects associated with A. chilensis were sampled monthly, between August 2005 and February 2006, in 32 trees located in a continuous forest (600 ha and in 32 trees located in eight forest fragments (0.4-20 ha. Insect sampling was carried out during the first five night hours. 890 folivorous insects from 17 families and 77 species of Coleóptera, Orthoptera and Lepidoptera were collected. All species were native. The total abundance did not vary with habitat fragmentation. Nevertheless, some species increased their abundance with fragmentation, while others were depressed. The species richness of folivorous insects per tree did not vary with forest fragmentation, though the total number of species was considerably higher in the forest fragments. The species similarity was higher within the continuous forest than between the continuous forest and fragments or among fragments. At the beginning of the season (September, the abundance of Sericoides obesa was significantly higher in the continuous forest than in the forest fragments. Later in the season, Sericoides viridis became more abundant in the forest fragments. Because of the body size and the voracity of Sericoides sp., these insects seem to be responsible of the herbivory patterns of A. chilensis at the Maulino forest.

  20. 集体林权改革后农户林地流转行为影响因素分析--以云南省景洪市为例%Peasant Households Forest Land Circulation Behavior Influence Factor Analysis after Collective Forest Tenure Reform--Taking Jinghong city as an example

    Institute of Scientific and Technical Information of China (English)

    李娅

    2013-01-01

      Based on field survey data of 50 peasant households in 5 villages of Jinghong City, Yunnan Province, the influence factors of peasant household circulation behavior are taken factorial analysis and binary logistic regression analysis. Study results show that household characteristics (household labor population, household members, household forestry income proportion), the head of household characteristics (age, education level), peasant household production characteristics (arable land, forest area, forest land fragmentation level)are the main factors affecting peasant household forest land circulation behavior, and their influence degrees decline.%  基于云南省景洪市5个村50个农户的实地调研数据,对影响农户流转行为的因素进行因子分析、二元Logistic 回归分析,结果表明:家庭特征(家庭劳动力人口数、家庭人口数、家庭林业收入比重)、户主特征(户主年龄、受教育程度)、农户生产特征(耕地面积、林地面积、林地破碎度)是影响农户林地流转行为的主要因素,且对农户林地流转影响程度递减。

  1. [Diversity of Hemiptera Auchenorrhyncha in citrus, coffee and a fragment of native forest of the state of São Paulo].

    Science.gov (United States)

    Giustolin, Teresinha A; Lopes, João R S; Querino, Ranyse B; Cavichioli, Rodney R; Zanol, Kety; Azevedo Filho, Wilson S; Mendes, Miguel A

    2009-01-01

    The population of Hemiptera Auchenorrhyncha was studied in sweet citrus groves (Citrus sinensis), coffee plantations (Coffea arabica) and a semi-deciduous seasonal forest with shrub physiognomy in Bebedouro, SP, to evaluate the influence of the natural ecosystem on the species composition of the agroecosystems. Monitoring was carried out by using yellow stick cards, which were replaced every 15 days and all Auchenorrhyncha collected were counted and identified. Seven families, 11 subfamilies and 98 species were collected, with Cicadellidae being the most abundant. The native forest presented larger wealth, diversity and equitability of Auchenorrhyncha species, demonstrating to be more stable than the other habitats. The high values of similarities obtained between the agroecosystems and the forest demonstrated that great part of Auchenorrhyncha species occurring in the agricultural habitats was also occurring at the forest, indicating that the last may serve as reservoir of species. The abundance of the taxonomic groups of Auchenorrhyncha collected varied with the evaluated habitats, with Proconiini being the most abundant in the coffee plantation next to the forest, Athysanini, Scaphytopiini, Neocoelidiinae and Coelidiinae in the orange orchard and coffee plantation distant from the forest; Cicadellinae and Agalliinae were not related to any of the habitats. The presence of vector insects and possible vectors of plant diseases in the appraised habitats indicate the need of the implementation of strategies for landscape management.

  2. Behavioral ecology of Heteragrion consors Hagen (Odonata, Megapodagrionidae: a shade-seek Atlantic forest damselfly

    Directory of Open Access Journals (Sweden)

    Geovanni Ribeiro Loiola

    2011-09-01

    Full Text Available Behavioral ecology of Heteragrion consors Hagen (Odonata: Megapodagrionidae: a shade-seek Atlantic forest damselfly. The intensity of the inter and intra-sexual selection can affect male behavioral traits as territorial fidelity and aggressiveness allowing the existence of different strategies. However, its differential success could be affected by environmental - as the diel variation in temperature - and physiological constrains - as the variation in thermoregulatory abilities. In this context, we present a behavioral analysis of Heteragrion consors (Zygoptera, Megapodagrionidae trying to characterize its mating system, diel activity pattern, temporal budget, territoriality and reproductive biology. These data were obtained based on field observations using the focal individual method and mark-recapture techniques in 120 m of a shaded Atlantic Forest stream in Brazil. The males of this species were territorial, varying in its local fidelity, while the females appear sporadically. Males were perched in the majority of the time, but were also observed in cleaning movements, longitudinal abdominal flexion, wing flexion and sperm transfer during perch. The males presented a perched thermoregulatory behavior related to an exothermic regulation. Foraging and agonistic interactions were rare, but dominate the other behavioral activities. Abdominal movements associated to long lasting copula pointed to the existence of sperm competition in this species. Males performed contact post-copulatory guarding of the females. These observations pointed to a non-resource mating system for this species.Ecologia comportamental de Heteragrion consors Hagen (Odonata: Megapodagrionidae: uma libélula de áreas sombreadas da Floresta Atlântica. A intensidade de seleção inter e intra-sexual deve afetar características comportamentais dos machos como fidelidade a territórios e agressividade possibilitando a existência de diferentes estratégias. No entanto, seu

  3. Agricultural crops in the diet of bearded capuchin monkeys, Cebus libidinosus Spix (Primates: Cebidae, in forest fragments in southeast Brazil Cultivares na dieta de macacos-prego barbados, Cebus libidinosus Spix (Primates: Cebidae, em fragmentos florestais no sudeste do Brasil

    Directory of Open Access Journals (Sweden)

    Carlos Henrique de Freitas

    2008-03-01

    Full Text Available Capuchin monkeys occupy a wide range of habitats where they feed on fruits, arthropods, and vertebrates. Their large home ranges (80-900 ha suggest that living in forest fragments may challenge their adaptability. We identified and quantified the main food items of Cebus libidinosus Spix, 1823 in forests fragments (100 ha in southeastern Brazil. We recorded the feeding activities of two groups using scan sampling over a 13-month period. The diet was composed of fruits, crops, animal prey, seeds, plant matter and undetermined. Fruit was eaten more in the wet season than in the dry season, and maize and sugar cane consumption peaked in the early dry season. The proportion of fruit in the diet was positively correlated with fruiting intensity of zoochorous trees. The plant diet included 54 species, with maize, Rhamnidium elaeocarpus, Acrocomia aculeata, Guazuma ulmifolia and Cariniana, being most important. Although dietary composition and diversity were similar to capuchins in larger forest fragments, feeding on crops attained higher percentages at times when zoochorous fruit production was low in fragments.Macacos-prego ocupam uma vasta gama de ambientes onde alimentam-se de frutos, artrópodes e vertebrados. Suas grandes áreas de vida (80-900 ha sugerem que viver em fragmentos florestais pode ser um desafio a sua adaptabilidade. Foram identificados e quantificados os principais itens alimentares de Cebus libidinosus Spix, 1823 em fragmentos florestais (100 ha no sudeste do Brasil. Registraram-se as atividades alimentares de dois grupos usando a varredura instantânea durante um período de 13 meses. A dieta compôs-se de frutos, presas animais, cultivares, sementes, material vegetal e indeterminado. Os frutos foram consumidos mais na estação chuvosa do que na estação seca e o consumo de milho e cana atingiu um pico no início da estação seca. A proporção de frutos na dieta foi positivamente correlacionada com a intensidade de frutifica

  4. The Effects of Habitat Fragmentation on the Behavior of the Cotton Rat (Sigmodon hispidus):Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Barrett, G.W.; Drelin, E.A.; Mabry, K.E.

    2001-07-01

    The authors studied the movements of cotton rats and cotton mice in experimental landscapes at the SRS in order to determine the effects of fragmentation and connectivity between habitat patches on dispersal movements and population dynamics. Densities between connected and isolated patches were not different. Small patches tended to support higher densities. Cotton rats were more common in corridors than expected and cotton mice were more likely to leave by a corridor.

  5. Construction, Expression and In Vitro Biological Behaviors of Ig scFv Fragment in Patients with Chronic B Cell Leukemia

    Institute of Scientific and Technical Information of China (English)

    ZHU Lijuan; LIAO Wenjun; ZHU Huifen; LEI Ping; WANG Zhihua; SHAO Jingfang; ZHANG Yue; SHEN Guanxin

    2006-01-01

    The expression vector of SmIg scFv fragment was constructed in patient with B cell chronic lymphocyte leukemia (B-CLL) and expressed in E. coli to obtain scFv fragment, and the effect of the protein on the proliferation of stimulated peripheral blood mononuclear cells (PBMC) was investigated in vitro. Two pairs of primers were designed, and variable region genes of light chain and heavy chain were amplified by PCR respectively from the pGEM-T vectors previously constructed in our laboratory which containing light chain gene or Fd fragment of heavy chain gene. The PCR product was digested, purified and inserted into pHEN2 vector to construct the soluble expression vector pHEN2-scFv. After the induction by IPTG, the scFv protein was identified by SDSPAGE electrophoresis and purified by Ni-NTA-Chromatography. MTT was used to determine the effect of purified protein on the proliferation of stimulated PBMC in vitro. Plasmid PCR and restriction enzyme digestion of pHEN2-scFv revealed the pHEN2-scFv vector was constructed successfully. Id-scFv protein was expressed in positive clone after induced by IPTG. SDS-PAGE analysis showed that the relative molecular weight of fusion protein was about 30 kD (1 kD=0.9921 ku),which was consistent with the theoretically predicted value. Proliferation of PBMC could be induced by purified Id-scFv. It was suggested that the expression vector of SmIg scFv fragment was constructed successfully, and scFv protein was expressed and secreted from E. coli, which could induce proliferation of PBMC. This may lay an experimental foundation for further research of IdHSP complex vaccine for B-CLL.

  6. Expert Evaluation of Subsidies for the Management of Fragmented Private Forest in Regards to National Biodiversity Goals—The Case of Kochi Prefecture, Japan

    Directory of Open Access Journals (Sweden)

    Dennis Gain

    2017-04-01

    Full Text Available This paper presents an expert evaluation of the subsidy scheme for private forest plantations in Kami City, Kochi Prefecture, Japan, to determine whether the twelve currently available subsidies are designed to realize national biodiversity goals. Subsidies for forestry practices are often criticized for rarely achieving planned outcomes and for environmental threats. Threats to natural balance of private forest have been observed in Kochi Prefecture, suggesting that current forestry subsidies may not be achieving national objectives. The utilization objectives, type of management, requirements, area, intensity, and subsidy rates were contrasted to the three forest multifunctionality objectives of the National Biodiversity Strategy of Japan (NBSJ 2012–2020, to identify subsidy weaknesses. Focus group discussions (FGD were conducted in the study site, as well as Bavaria, Germany and Steiermark, Austria, to get a big picture of how experts in these comparable management areas evaluate the Kochi subsidy scheme. Analyses were performed based on a combination of framework analysis and constant comparison analysis. It was found that realization of vertical multifunctionality is hindered due to lack of site-specific management. A six-point proposal for restructuring the subsidy scheme, leaned on results, and the Bavarian subsidy scheme was made. To improve vertical multi-functionality, subsidy schemes should focus on forest owner integration and site-specific, long-term oriented forest works.

  7. Recreational benefits of urban forests: explaining visitors' willingness to pay in the context of the theory of planned behavior.

    Science.gov (United States)

    Bernath, Katrin; Roschewitz, Anna

    2008-11-01

    The extension of contingent valuation models with an attitude-behavior based framework has been proposed in order to improve the descriptive and predictive ability of the models. This study examines the potential of the theory of planned behavior to explain willingness to pay (WTP) in a contingent valuation survey of the recreational benefits of the Zurich city forests. Two aspects of WTP responses, protest votes and bid levels, were analyzed separately. In both steps, models with and without the psychological predictors proposed by the theory of planned behavior were compared. Whereas the inclusion of the psychological predictors significantly improved explanations of protest votes, their ability to improve the performance of the model explaining bid levels was limited. The results indicate that the interpretation of bid levels as behavioral intention may not be appropriate and that the potential of the theory of planned behavior to improve contingent valuation models depends on which aspect of WTP responses is examined.

  8. Quantum fragmentation

    CERN Document Server

    Peschanski, R

    1993-01-01

    Phenomenological and theoretical aspects of fragmentation for elementary particles (resp. nuclei) are discussed. It is shown that some concepts of classical fragmentation remain relevant in a microscopic framework, exhibiting non-trivial properties of quantum relativistic field theory (resp. lattice percolation). Email contact: pesch@amoco.saclay.cea.fr

  9. Funções de distribuição diamétrica em um fragmento de Floresta Ombrófila Mista Diametric distribution functions in a fragment of Mixed Ombrophylous Forest

    Directory of Open Access Journals (Sweden)

    Sebastião do Amaral Machado

    2009-11-01

    Full Text Available Os objetivos deste estudo foram ajustar e selecionar funções de densidade probabilística que caracterizem a estrutura diamétrica desse fragmento e das espécies: Cedrela fissilis (Cedro, Luehea divaricata (Açoita Cavalo, Gochnatia polymorpha (Cambará, Sebastiania commersoniana (Branquilho e Casearia sylvestris (Cafezeiro de um fragmento de Floresta Ombrófila Mista com 15,24ha, localizado em Curitiba, Paraná. Para avaliar a distribuição diamétrica dessa floresta e das cinco espécies selecionadas, foram ajustadas sete funções probabilísticas para intervalos de classe de 5cm. Segundo os critérios de seleção adotados, o modelo que melhor representou a distribuição diamétrica para toda a floresta, o cedro, o cambará e o branquilho foi o de Weber; para o cafezeiro, a função Gamma (Adaptada foi a mais eficiente e para o açoita cavalo nenhuma dessas funções foi aderente. O branquilho, o açoita cavalo, o cafezeiro e a floresta como um todo apresentaram distribuição em "J" invertido ou decrescente. Entretanto, o cedro e o cambará apresentaram distribuição tendendo à unimodalidade com forte assimetria à direita.The objective of this study was to adjust and select probability density functions that characterize the diametric structure of this forest fragment and for the species: Cedrela fissilis, Luehea divaricata, Gochnatia polymorpha, Sebastiania commersoniana and Casearia sylvestris for a 15.24 hectare fragment of Mixed Ombrophylous Forest, located in Curitiba, State of Paraná. In order to evaluate the diametric distributions of this forest and the five selected species, seven probability functions were adjusted for 5cm class intervals. According to the criteria of selection adopted, the model that best represented the diametric distributions for the whole forest, Cedrela fissilis, Gochnatia polymorpha and Sebastiania commersoniana was the Weber model; for Casearia sylvestris, the Gamma function (adapted was the most

  10. Heterogeneidade estrutural e diversidade de pequenos mamíferos em um fragmento de mata secundária de Minas Gerais, Brasil Structural heterogeneity and diversity of small mammals in a secondary forest fragment of Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    Adriano Pereira Paglia

    1995-01-01

    Full Text Available The aim is to determine the relationship between the diversity of small mammals and the structural heterogeneity and/or secondary successional stages in an Atlantic forest fragment at Viçosa (Minas Gerais. We used Sherman and hook live traps to sample this fauna, monthly from may 1992 to april 1993 in three areas: an abandoned plantation of Melinis minutiflora (campo and two distinct forest areas (capoeira and mata. The structural heterogeneity was determined as a function of the presence of dead trees, pioneer species, epiphytes, the distances between trees, the tree height and basal area measured by a modified quadrant sample method (Cottam & Curtis 1945. lt was sampled a total of 340 individuals belonging to 17 species. The homogeneous plantations had the highest diversity (H' = 1,67. Among the two forests stands the less heterogeneous capoeira had similar diversity (H' = 1,19 than the more heterogeneous stand, the mata (H' = 1,13. The unexpected higher diversity and species richness in the more homogeneous habitat may be explained by some hidden factor which decrease the competition for resources in this community.

  11. Fragmented Authoritarianism or Integrated Fragmentation

    DEFF Research Database (Denmark)

    Brødsgaard, Kjeld Erik

    of these business leaders prompts the question of whether we are seeing the development of distinct interest groups that could challenge Party and state authority and create a fragmented polity. However, through the nomenklatura system the Party has an important instrument of control to wield over business groups...... and the Party-state, I suggest the notion of integrated fragmentation....

  12. A behaviorally-explicit approach for delivering vaccine baits to mesopredators to control epizootics in fragmented landscapes.

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    James C Beasley

    Full Text Available Despite the widespread use of aerial baiting to manage epizootics among free-ranging populations, particularly in rabies management, bait acceptance and seroconversion rates often are lower than required to eliminate spread of disease. Our objectives in this study, therefore, were to evaluate the performance of stratified bait distribution models derived from resource selection functions (RSF on uptake of placebo rabies baits by raccoons (Procyon lotor and Virginia opossums (Didelphis virginiana, as well as the probability of bait uptake as a function of proximity to bait distribution areas in fragmented agricultural ecosystems. Among 478 raccoons and 108 opossums evaluated for presence of Rhodamine B (RB across 8 sites, only 26% of raccoons and 20% of opossums exhibited marking consistent with bait consumption 14-24 days post-baiting. The effective area treated, based on 90% kernel density estimators of marked individuals, ranged from 99-240 ha larger than bait distribution zones, with RB marked individuals captured up to 753 m beyond the bait zone. Despite incorporation of RSF data into bait distribution models, no differences in uptake rates were observed between treatment and control sites. These data likely reflect the underlying constraints imposed by the loss and fragmentation of habitat on animal movement in heterogeneous landscapes, forcing individuals to optimize movements at coarse (i.e., patch-level rather than fine spatial scales in highly fragmented environments. Our data also confirm that the probability of bait acceptance decreases with increasing distance from bait zone interiors, even within the zone itself. Thus, although bait acceptance was confirmed beyond bait zone boundaries, the proportion of vaccinated individuals may comprise a small minority of the population at increasing distances from baiting interiors. These data suggest focal baiting creates a buffered area of treated individuals around bait zones or bait stations

  13. 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

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    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

  14. Assessing the relationship between different forms of landowner assistance and family forest owner behaviors and intentions

    Science.gov (United States)

    Michael A. Kilgore; Stephanie A. Snyder; Derya Eryilmaz; Marla A. Markowski-Lindsay; Brett J. Butler; David B. Kittredge; Paul F. Catanzaro; Jaketon H. Hewes; Kyle. Andrejczyk

    2015-01-01

    In this study, we examine how family forest owners who receive various types of assistance differ from unassisted landowners with respect to their forestland management practices, attitudes and concerns, and future management, use, and ownership intentions. We do so by utilizing a national database containing information on private forest owners and the forestland they...

  15. Predação e remoção de sementes de cinco espécies de palmeiras por Guerlinguetus ingrami (Thomas, 1901 em um fragmento urbano de Floresta Atlântica Montana Predation and removal of seeds from five species of palms by Guerlinguetus ingrami (Thomas, 1901 in an urban fragment of the Montane Atlantic Forest

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    Luci Ferreira Ribeiro

    2010-08-01

    dispersed by squirrels (trees with a high productivity and whose fruits are large, with few seeds covered by rigid endocarps and that are not utilized by other arborean seed predators. Here we describe differences in the frugivory pattern exhibited by G. ingrami towards plants with the same dispersal syndrome. The diaspores of species with larger fruits were removed and cached by the squirrel at rates higher than the palms with small fruits. As a result of the high specificity showed by the squirrel's activities related to seed dispersal, this rodent should be important in compensatory shifts only in small, defaunated forest fragments. Therefore, the selectivity of G. ingrami could indicate that its role as a seed dispersor into small forest fragments would be restricted, due to the grater likelihood of mortality associated to the plants scattered by this species. The role of G. ingrami as a seed predator must be quantified for the effects of its behavioral activities in small fragments to be understood.

  16. Uso de florestas secundárias por aves de sub-bosque em uma paisagem fragmentada na Amazônia central Use of secondary forests by understory birds in a fragmented landscape in central Amazonia

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    João Vitor Campos e Silva

    2012-03-01

    secondary forests that are established in the abandoned areas. The trend is an increase in secondary forests cover, resulting in a mosaic of primary forest (FP and fragments separated by an array of secondary forests (FS. In this scenario, the prediction of a massive extinction could be wrong if many species could survive in the secondary forests. To assess the importance of FS for the understory birds we sampled areas in regeneration and a continuous forest of a fragmented landscape. We conducted mist netting (24 nets/day for six consecutive days/month, for 8 months (May-November in 2009. Some forest species as do not seem to be adapted to the secondary forest environment and their occurrences are restricted to continuous forest environments. But most focal species showed no significant difference in apparent survival rates between the enviroments, suggesting that these species inhabit the secondary forest and the primary forest similarly. Because most of the matrix in fragmented landscapes are composed by secondary forests, such results highlights the conservation value that these habitats present in the long term. Thus, FS should be regarded as dynamic matrix that not only allows the movement of individuals but also function as habitat for many species typical of FP.

  17. Interceptação das chuvas em um fragmento de floresta da Mata Atlântica na Bacia do Prata, Recife, PE Rainfall interception in an Atlantic Forest fragment in the Prata Basin, Recife, PE

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    Albert Einstein Spindola Saraiva de Moura

    2009-06-01

    Full Text Available A mata de Dois Irmãos é uma das poucas áreas remanescentes da Floresta Atlântica no Estado de Pernambuco. Nela estão inseridos os açudes do Meio, do Prata e Dois Irmãos que compõem a bacia hidrográfica do Prata. Este trabalho t