نتایج جستجو برای: forest fragmentation
تعداد نتایج: 139402 فیلتر نتایج به سال:
Forest fragmentation affects animal population dynamics mainly by loss of habitat and disruption of animal movement. Lizard assemblages are affected by environmental changes, but, depending on their ecological needs, some species might be more vulnerable than others. The southern Amazon suffers accelerated anthropic actions replacing natural environments by farmland (crops and pasture). This re...
Many songbird species have experienced significant population declines, partly because of brood parasitism by the Brown-headed Cowbird (Molothrus ater), which is positively associated with increasing landscape forest cover in the midwestern United States. However, cowbirds are also experiencing long-term population declines, which should reduce parasitism pressure and thus increase productivity...
We conducted a year long survey of the fruit-feeding butterfly fauna of sacred forest groves and forest reserves of Ghana. About one-third of all fruit-feeding species recorded for Ghana were trapped, but our total sample had not yet reached the point of species saturation. Rarefied species richness was higher in the larger forest reserves than in the small sacred groves, as predicted by specie...
As people penetrate the Amazon interior, they build roads and clear large expanses of land. Over time, this process of deforestation creates forest fragments, islands of trees surrounded by a sea of pastures, farmland, and other degraded habitats. Laurance and his colleagues at the Smithsonian Tropical Research Institute are studying what happens to the forests when trees lose ground to agricul...
In recent decades, human development pressures have results in conversions of vast tracts of Amazonian tropical rain forests to agriculture and other human land uses. In addition to the loss of large forest cover, remaining forests are also fragmented into smaller habitats. Fragmented forests suffer several biological and ecological changes due to edge effects that can exacerbate regional fores...
In recent years, forest management has moved towards a landscape approach reflecting a mix of social, environmental and economic values. In this paper, we evaluate the effect on harvesting decisions of the spatial attributes of communal forests in Galicia. We first model the forest landscape management problem within a bioeconomic framework, which allows the identification of optimal clear-cutt...
There has been considerable research concerning the extent and effect of urbanization and fragmentation and the importance of monitoring current and potential magnitudes of change is recognized. However, there are limited guidelines for interpreting fragmentation data or for their application for analysis and statewide planning efforts. In this study we take a first step toward developing a sta...
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...
High-volume horizontal hydraulic fracturing (HVHHF) for mining natural gas from the Marcellus and Utica shales is widespread in Pennsylvania and potentially throughout approximately 280,000 km(2) of the Appalachian Basin. Physical and chemical impacts of HVHHF include pollution by toxic synthetic chemicals, salt, and radionuclides, landscape fragmentation by wellpads, pipelines, and roads, alte...
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