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| Registros recuperados: 38 | |
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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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| 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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| 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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| Simmons, Jody M; Monash University; Australian Centre for Biodiversity; jodymichellesimmons@yahoo.com.au; Sunnucks, Paul; Monash University; Australian Centre for Biodiversity; paul.sunnucks@sci.monash.edu.au; Taylor, Andrea C; Monash University; Australian Centre for Biodiversity; andrea.taylor@sci.monash.edu.au; van der Ree, Rodney; Australian Research Centre for Urban Ecology, Royal Botanic Gardens Melbourne; rvdr@unimelb.edu.au. |
| Habitat fragmentation continues to occur despite increasing evidence of its adverse effects on ecosystems. One of the major detrimental effects of roads and traffic is the creation of barriers or filters to the movement of wildlife, ultimately disconnecting some populations. Our understanding of the extent to which roads reduce the movement of biota is mostly based on field-based observational methods of inferring animal movement, and to a much smaller extent, on allele frequency-based genetic analyses. Field-based methods, as it is typically feasible to apply them, tend to be informative at fine temporal and spatial scales. Allele frequency-based genetic methods are informative at broad geographic scales but at timescales usually greater than recent... |
| Tipo: Peer-Reviewed Insight |
Palavras-chave: Barrier; Dispersal; Gene flow; Genotypic analyses; Habitat fragmentation; Road ecology. |
| Ano: 2010 |
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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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| 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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| 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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| Golden Kroner, Rachel E.; Department of Environmental Science and Policy, George Mason University; Betty and Gordon Moore Center for Science, Conservation International; rachelelizabethgolden@gmail.com; Krithivasan, Roopa; Department of Geography, Clark University; rkrithivasan@clarku.edu; Mascia, Michael B.; Betty and Gordon Moore Center for Science, Conservation International; m.mascia@conservation.org. |
| Protected area downgrading, downsizing, and degazettement (PADDD) has been documented worldwide, but its impacts on biodiversity are poorly understood. To fill this knowledge gap, we reviewed historical documents to identify legal changes that altered the boundaries of Yosemite National Park. We identified two downsizes and five additions between 1905 and 1937 that reduced the size of Yosemite National Park by 30%. To examine the effects of these downsizing events on habitat fragmentation by roads, we compared protected, never-protected, and downsized lands at three spatial scales using four habitat fragmentation metrics: road density, fragment (land surrounded by roads) area-to-perimeter ratio, fragment area, and fragment density. In general, lands that... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Downsizing; Governance; Habitat fragmentation; PADDD; Protected areas; Yosemite National Park. |
| Ano: 2016 |
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| Bastos,Heitor B.; Gonçalves,Evonnildo C.; Ferrari,Stephen F.; Silva,Artur; Schneider,Maria Paula C.. |
| We genotyped 15 microsatellite loci in order to evaluate the effects of habitat fragmentation, caused by flooding of the Tucuruí reservoir, on the genetic structure of Alouatta belzebul in eastern Amazonia. The analysis included two populations sampled in 1984, representing both margins of the Tocantins river, and three populations sampled 18 years later. Minimal differences in the diversity levels between present-day (Ho = 0.62-0.69 and A R = 6.07-7.21) and pre-flooding (Ho = 0.60-0.62 and A R = 6.27-6.77) populations indicated there was no significant loss of genetic variability, possibly because of successful management strategies applied during the flooding. The changes observed were limited to shifts in the composition of alleles, which presumably... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Alouatta belzebul; Amazonia; Conservation; Genetic structure; Habitat fragmentation. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572010000400027 |
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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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| Carvalho,Naira C. de; Bordignon,Marcelo O.; Shapiro,Julie T.. |
| Several factors, such as hunting and the pet trade, are responsible for the worldwide decline of wildlife populations. In addition, fatal collisions with vehicles on highways have also taken one of the largest tolls. This study aimed to quantify the richness and abundance of vertebrate roadkill along highway MS-080 in Mato Grosso do Sul, Central-West Brazil. We compare the amount of roadkill to the distance between cities, moon phases and the flow of vehicles on the highway. Samples were collected weekly between March and September 2011, totaling 257 individuals, belonging to 32 families and 52 species, resulting in an index of 0.13 individuals hit/km. Birds were the most frequently hit taxa, followed by mammals. The most affected species was Cariama... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Conservation; Roads; Roadkill; Urbanization; Habitat fragmentation. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212014000100006 |
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| Registros recuperados: 38 | |
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