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| Registros recuperados: 39 | |
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| FIGUEIREDO, E. O.; PEREIRA, N. W. V.; WADT, L. H. de O.. |
| O modelo de ocupação da Amazônia, implementado nas últimas décadas, pouco considerou as especificidades dos distintos ecossistemas florestais existentes na região. Quando se considera a dimensão territorial da Amazônia e os impactos decorrentes do desflorestamento e conseqüente processo de fragmentação de florestas, o fato ganha importância global. Este trabalho faz parte do projeto "Efeito do processo de fragmentação florestal na sustentabilidade de alguns ecossistemas periféricos aos eixos rodoviários no sudeste acreano", financiado pelo Programa Nacional de Diversidade Biológica (Pronabio), e foi desenvolvido num fragmento florestal localizado à margem direita da Rodovia Federal BR-364, km 30, sentido Rio Branco/Porto Velho, no município de Rio Branco,... |
| Tipo: Séries anteriores (INFOTECA-E) |
Palavras-chave: Fragmentação florestal; Biomassa aérea; Rio Branco (AC); Acre; Amazônia Ocidental; Western Amazon; Amazonia Occidental; Bosques tropicales; Biomasa aérea; Fragmentación de hábitats; Reservorios de carbono.; Floresta tropical; Ecossistema; Degradação ambiental; Impacto ambiental; Biomassa; Carbono; Estoque; Tropical forests; Habitat fragmentation; Aboveground biomass; Carbon sinks; Environmental impact.. |
| Ano: 2000 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/495836 |
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| Cane, James H; USDA-ARS; jcane@biology.usu.edu. |
| Few studies directly address the consequences of habitat fragmentation for communities of pollinating insects, particularly for the key pollinator group, bees (Hymenoptera: Apiformes). Bees typically live in habitats where nesting substrates and bloom are patchily distributed and spatially dissociated. Bee studies have all defined habitat fragments as remnant patches of floral hosts or forests, overlooking the nesting needs of bees. Several authors conclude that habitat fragmentation is broadly deleterious, but their own data show that some native species proliferate in sampled fragments. Other studies report greater densities and comparable diversities of native bees at flowers in some fragment size classes relative to undisrupted habitats, but find... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Apoidea; Bees; Conservation; Diversity; Habitat fragmentation; Land-use change; Pollination; Pollinator; Statistics; Taxonomy. |
| Ano: 2001 |
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| AMARAL, E. F. do; BROWN, I. F.; MELO, A. W. F. de. |
| O uso da terra na Amazônia está condicionado ao processo de fragmentação florestal. No Acre, o arco do desmatamento é constituído pela BR-364 e BR-317. Este trabalho tem como objetivo avaliar os efeitos do uso da terra nas características químicas e físicas do solo, em uma cronosseqüência de uso em uma área de grande fazendeiro no sudeste acreano. Foi conduzido na fazenda Ponteio, situada às margens da BR-317, no município de Capixaba, sendo georreferenciadas três unidades amostrais, caracterizando o gradiente de pressão antrópica: pasto, capoeira e floresta. Em cada unidade amostral foram retiradas informações sobre o histórico de uso e coletados dados referentes às seguintes características: densidade aparente, resistência do solo até 60 cm... |
| Tipo: Séries anteriores (INFOTECA-E) |
Palavras-chave: Fragmentação florestal; Arco do Desmatamento; Rodovia BR-364; Rodovia BR-317; Fazenda Ponteio; Capixapa (AC); Acre; Amazônia Ocidental; Western Amazon; Amazonia Occidental; Propiedades químicas del suelo; Uso de la tierra.; Fragmentación de hábitats; Propiedades fìsicas del suelo; Uso da terra; Solo; Propriedade Físico-Química; Land use; Habitat fragmentation; Soil chemical properties; Soil physical properties.. |
| Ano: 2001 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/495274 |
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| KELT,DOUGLAS A.. |
| Four recent studies on Chilean vertebrates underscore the very different effects that habitat fragmentation may have under different conditions. In southern Chile, birds exhibited significant species-area relationships, whereas the more depauperate small mammal community did not. The avifauna of highly isolated rainforest remnants in Fray Jorge National Park (IV Región) presented steeper species-area relations than those in southern Chile, reminiscent of land-bridge islands after faunal relaxation. The small mammal results were unexpected but may reflect the reduced vagility and immigration potential of this group. Additionally, the inter-remnant matrix habitat may support large populations of only some species, allowing them to capitalize on resources... |
| Tipo: Journal article |
Palavras-chave: Habitat fragmentation; Valdivian temperate rainforest; Small mammals; Birds; Conservation. |
| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000400005 |
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| THOMAZINI, M. J.; THOMAZINI, A. P. de B. W.. |
| O presente trabalho foi conduzido visando comparar a diversidade e composição de insetos em áreas de floresta contínua, fragmentada, floresta secundária e pastagem no sudeste acreano. Coletas mensais de insetos foram realizadas com armadilha luminosa e rede entomológica, entre abril de 1999 e março de 2000, no interior de um fragmento florestal e em uma área de floresta secundária e pastagem adjacentes ao fragmento, no município de Rio Branco, AC. Também foram realizadas amostragens mensais de cupins com iscas de papelão, em todas as áreas citadas e em uma outra área de floresta contínua, localizada no município de Capixaba, AC. Estimou-se a diversidade das áreas usando-se o índice de diversidade de Margalef. Foram aplicadas medidas de fauna... |
| Tipo: Boletim de Pesquisa e Desenvolvimento (INFOTECA-E) |
Palavras-chave: Floresta contínua; Floresta fragmentada; Termites; Western Amazon; Amazônia Ocidental; Acre; Capixaba (AC); Rio Branco (AC); Termitas; Amazonia Occidental; Comunidades de insectos; Bosques secundarios; Pastizales; Fragmentación de hábitats; Plagas de las plantas; Sondeo de la Población Actual.; Entomofauna; Pastagem; Floresta secundária; Floresta; Levantamento populacional; Cupim; Praga de planta; Isoptera.; Pastures.; Insect communities; Current population survey; Habitat fragmentation; Secondary forests; Plant pests. |
| Ano: 2002 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/496050 |
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| Shine, Richard; University of Sydney; rics@bio.usyd.edu.au; Lemaster, Michael; ; lemasterm@mail.science.orst.edu; Wall, Michael; ; mwall@bio.usyd.edu.au; Langkilde, Tracy; ; langkild@bio.usyd.edu.au; Mason, Robert; ; masonr@science.oregonstate.edu. |
| If animals avoid road surfaces or are unable to follow conspecific trails across such surfaces, previously continuous populations may be fragmented. We gathered data on the effects of a small (4-m wide) gravel road on the behavior and trail-following abilities of garter snakes (Thamnophis sirtalis parietalis) in Manitoba, central Canada. As expected, the road surface had less vegetation cover, a more open canopy and, thus, higher incident radiation than did the surrounding grassland. Contrary to expectations, however, substrate temperatures were lower on the road than in its surrounds, because of the higher reflectivity of the road's surface. On a nearby asphalt road, substrate temperatures were relatively high on the road surface only in the evening, as... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Behavior; Connectivity; Habitat fragmentation; Pheromones; Reproduction; Reptile. |
| Ano: 2004 |
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| Duarte,Marcelo Maisonette. |
| The abundance of soil microarthropods from seven fragments of Araucaria Forest, Muitos Capões, Rio Grande do Sul, Brazil, was compared. The size of the fragments ranged from 0.25 ha to 35 ha, the two largest fragments are situated within the Aracuri Ecological Station and the remaining five are situated in a cattle ranching farm. In June 2000, three plots (10 m x 10 m) were established in the central area of each patch, and three soil cores (7 cm diameter x 6 cm deep) were taken per plot. The abundance of microarthropods in the upper six centimeters (soil + litter) varied between 63209 and 102704 ind.m-2, with oribatid mites (Acari, Cryptostigmata) being dominant in all fragments (between 46.9 % and 61.3 % of total individuals). Most microarthropod groups... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Soil microarthropods; Araucaria forest; Acari; Collembola; Habitat fragmentation. |
| Ano: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212004000200008 |
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| GREZ,AUDREY A.; ZAVIEZO,TANIA; REYES,SUSANA. |
| Habitat loss and fragmentation are considered as the main causes of biodiversity depression. Habitat loss implies a reduction of suitable habitat for organisms, and habitat fragmentation is a change in the spatial configuration of the landscape, with the remaining fragments resulting more or less isolated. Recent theory indicates that the effects of habitat loss are more important than those of habitat fragmentation, however there are few experimental studies evaluating both processes separately. To test the effects of habitat fragmentation per se on the abundance, species richness and diversity of epigeal coleopterans, 15 (30 x 30 m) alfalfa micro-landscapes, distributed in three blocks, were created. On twelve of them, 84 % of the habitat was removed,... |
| Tipo: Journal article |
Palavras-chave: Habitat fragmentation; Habitat loss; Micro-landscapes; Diversity of epigeal beetles. |
| Ano: 2004 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2004000300013 |
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| Tischendorf, Lutz; ELUTIS Modelling and Consulting Inc.; lutz.tischendorf@gmx.net; Grez, Audrey; Universidad de Chile; agrez@uchile.cl; Fahrig, Lenore; Carleton University; lfahrig@ccs.carleton.ca. |
| We conducted a factorial simulation experiment to analyze the relative importance of movement pattern, boundary-crossing probability, and mortality in habitat and matrix on population density, and its dependency on habitat fragmentation, as well as inter-patch distance. We also examined how the initial response of a species to a fragmentation event may affect our observations of population density in post-fragmentation experiments. We found that the boundary-crossing probability from habitat to matrix, which partly determines the emigration rate, is the most important determinant for population density within habitat patches. The probability of crossing a boundary from matrix to habitat had a weaker, but positive, effect on population density. Movement... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Boundary crossing; Emigration; Habitat fragmentation; Immigration; Modeling; Movement; Population density; Simulation; Time scale. |
| Ano: 2005 |
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| Milet-Pinheiro,Paulo; Schlindwein,Clemens. |
| Euglossine bees are known to be long-distance pollinators in tropical rainforests. But there is controversy concerning to the flight ranges of these bees between forest fragments. In an isolated fragment of Atlantic Rainforest in Pernambuco, NE Brazil, surrounded by sugarcane monocultures, it was examined if euglossine males leave closed rainforest to collect fragrances. In a straight-line transect leading from forest into a sugarcane plantation, euglossine males were simultaneously captured by scent baits at seven distinct points: inside the forest, forest edge, outside the forest in the sugarcane fields at distances of 10 m, 50 m, 100 m, 250 m and 500 m from the forest edge. A total of 945 euglossine bees of 16 species were recorded. The results... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Atlantic Rainforest; Habitat fragmentation; Northeast Brazil; Orchid bees; Scent baits. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0101-81752005000400008 |
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| Hames, Ralph S.; Cornell Laboratory of Ornithology; rsh5@cornell.edu; Lowe, James D.; Cornell Laboratory of Ornithology; jdl6@cornell.edu; Swarthout, Sara Barker; Cornell Laboratory of Ornithology; sb65@cornell.edu; Rosenberg, Kenneth V.; Cornell Laboratory of Ornithology; kvr2@cornell.edu. |
| Ubiquitous human-caused changes to the environment act as multiple stressors for organisms in the wild, and the effects of these stressors may be synergistic, rather than merely additive, with unexpected results. However, understanding how focal organisms respond to these stressors is crucial for conservation planning for these species. We propose a paradigm that alternates extensive, broadscale data collection by volunteer collaborators to document patterns of response, with intensive fine-scale studies by professional researchers, to elucidate the processes underlying these patterns. We demonstrate this technique, building on our existing work linking patterns of population declines in the Wood Thrush (Hylocichla mustelina) to synergistic effects of acid... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Multiple scales; Synergistic effects; Citizen science; Habitat fragmentation; Acid rain; Forests; Anthropogenic change; Soil; Calcium; Invertebrates. |
| Ano: 2006 |
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| 浅利, 裕伸; 柳川, 久. |
| We studied the nest types used by Pteromys volans orii in two small, fragmented woods (2.1 ha and 3.1 ha) in Obihiro, Hokkaido from April 2005 to March 2006. Three nest types (cavity, nest box, drey) were used by eight flying squirrels. Each flying squirrel made use of two to eight nest-sites. The flying squirrels in our study area appear to have been restricted as to nest resources, since these woods are fragmented and small, they are surrounded by roads and fields. The preferred nests during snow-free and the snowy season were, respectively, cavity and nest box, and cavity and drey. We suggest that longer and more frequent use of nest boxes during the snow-free season might be related to rises in temperature and numbers of ectoparasites. The use of... |
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Palavras-chave: Habitat fragmentation; Nest site use; Obihiro; Pteromys volans orii; Small wood. |
| Ano: 2008 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/4168 |
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| Santos,André Maurício de Melo; Santos,Bráulio Almeida. |
| Edge influence, or edge effect, drives many biological changes in fragmented landscapes. This has been extensively studied in many forest ecosystems, but it remains to be described for the Brazilian Caatinga. Based on the biotic and physical conditions of the shrubby Caatinga, our prediction a priori was that this type of vegetation is free from edge influence in terms of vegetation structure and composition. We sampled shrubs, cacti and trees in twenty 200 m² plots on old edges (>60 yrs old) and interior of a 690 ha fragment, partially isolated and surrounded by Opuntia ficus-indica cacti. Plant height, stem diameter at ground level, stem density, species richness and diversity were statistically equal between edge and interior habitats. Magnitude of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Shrubs; Edge effect; Habitat fragmentation; Seasonal scrub vegetation. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062008000400018 |
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| Bouchard, Julie; Geomatics and Landscape Ecology Research Lab, Department of Biology, Carleton University; julie.bouchard@mail.mcgill.ca; Ford, Adam T.; Geomatics and Landscape Ecology Research Lab, Department of Biology, Carleton University; atford@gmail.com; Eigenbrod, Felix E; Geomatics and Landscape Ecology Research Lab, Department of Biology, Carleton University; felix.eigenbrod@gmail.com; Fahrig, Lenore; Geomatics and Landscape Ecology Research Lab, Department of Biology, Carleton University; lenore_fahrig@carleton.ca. |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Breeding dispersal; Habitat fragmentation; Highway; Migration; Movement; Road avoidance; Road mortality. |
| Ano: 2009 |
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| van Langevelde, Frank; Resource Ecology Group, Wageningen University; frank.vanlangevelde@wur.nl; Jaarsma, Catharinus F.; Land Use Planning Group, Wageningen University; rinus.jaarsma@wur.nl. |
| A steady growth in traffic volumes in industrialized countries with dense human populations is expected, especially on minor roads. As a consequence, the fragmentation of wildlife populations will increase dramatically. In human-dominated landscapes, typically minor roads occur in high densities, and animals encounter them frequently. Traffic calming is a new approach to mitigate negative impacts by reducing traffic volumes and speeds on minor roads at a regional scale. This leads to a distinction between roads with low volumes as being part of the traffic-calmed area, whereas roads with bundled traffic are located around this area. Within the traffic-calmed area, volumes and speeds can be decreased substantially; this is predicted to decrease the... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Habitat fragmentation; Metapopulation theory; Mitigation; Road ecology; Traffic calming; Transportation planning. |
| Ano: 2009 |
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| Brito,Daniel. |
| Habitat fragmentation may cause population subdivision, affecting genetic variation, leading to heterozygosity loss and increased inbreeding, and contributing to population extinction. However, some genetic models have shown that under some conditions, population subdivision can favor heterozygosity and allelic diversity, and small populations may adapt to inbreeding. Here I investigate the relationship between population subdivision and genetic diversity for the marsupial Micoureus paraguayanus (Tate, 1931) using the program Vortex. Hypothetical populations of 100 and 2000 individuals were partitioned into 1, 2, 5 or 10 populations that were linked by varying rates of dispersal and also by sex-biased dispersal. Results suggested that heterozygosity and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic drift; Genetic load; Habitat fragmentation; Inbreeding; Metapopulation; Population viability analysis. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702009000400013 |
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| Registros recuperados: 39 | |
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