نتایج جستجو برای: forest fragmentation
تعداد نتایج: 139402 فیلتر نتایج به سال:
Thekipuka system, anetworkof forest fragments surroundedby lavaßowson the island of Hawaii, offers an opportunity to study the natural, long-term fragmentation of a native ecosystem. We examined the impacts of habitat edges upon the community structure of nocturnally active native spiders, primarily in the genus Tetragnatha.Wemeasured plant and spider species distributions across the edges of f...
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 t...
The forest refuge hypothesis (FRH) has long been a paradigm for explaining the extreme biological diversity of tropical forests. According to this hypothesis, forest retraction and fragmentation during glacial periods would have promoted reproductive isolation and consequently speciation in forest patches (ecological refuges) surrounded by open habitats. The recent use of paleoclimatic models o...
This paper looks at the economics of conversion and fragmentation of forest land. The forestry economics literature has generally focussed on the management of a single stand for timber and non-timber forest benefits with little attention being paid to forest level land use decisions, and in particular forest stand interactions. As noted by Bowes and Krutilla (1989), the focus on a single stand...
The relative influence of habitat loss vs. habitat fragmentation per se (the breaking apart of habitat) on species distribution and abundance is a topic of debate. Although some theoretical studies predict a strong negative effect of fragmentation, consensus from empirical studies is that habitat fragmentation has weak effects compared with habitat loss and that these effects are as likely to b...
Fragmentation of tropical forests affects the viability of primate populations worldwide. A recent assessment of habitat loss in Latin America has estimated that 9.7% of extant forest was lost between 1980 and 1995 (Chapman and Peres, 2001). Forest fragmentation has many causes (e.g., human encroachment for settlements, agricultural practices, logging, and flooding, Alvarez et al., 1986; Cosson...
Land cover and land use surrounding fragmented habitat can greatly impact species persistence by altering resource availability, edge effects, or the movement of individuals throughout a landscape. Despite the potential importance of the landscape matrix, ecologists still have limited understanding of the relative effects of different types of land cover and land uses on species patterns and pr...
The effects of forest fragmentation on bird populations have been studied primarily as static phenomena. Yet when forests are allowed to regenerate, local edge contrast and landscape matrix composition change with time, and we would expect fragmentation effects to change accordingly. Describing this process is critical for the conservation of avian species sensitive to forest fragmentation, inc...
Forest fragmentation may alter host-parasite interactions in ways that contribute to host population declines. We tested this prediction by examining parasite infections and the abundance of infective helminths in 20 forest fragments and in unfragmented forest in Kibale National Park, Uganda. Over 4 years, the endangered red colobus (Procolobus rufomitratus) declined by 20% in fragments, wherea...
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