Efeitos a longo prazo da perda de habitat e da caça sobre mamíferos de médio e grande porte na Amazônia Central

Abstract

Forest fragmentation has become one of the most pervasive threats to tropical forest, mainly in the Amazonian forest. Despite its detrimental effects, some mid-sized to large-bodied mammals species can persist in forest remnants. In addition to population reduction and subdivision, mammal persistence in tropical forest fragments is affected by hunting pressure, which is aggravated by the growing human population density in fragmented forest landscapes. This study utilized two approaches to evaluate the value of forest fragments have as units of connectivity among landscapes for mid and large-bodied mammals species in the central Amazon. Using diurnal and nocturnal line-transect censuses, track surveys and other indirect evidence in three areas (continuous forest, fragmented forest and forest fragments isolated by savanna vegetation) in western of Para state (Brazil), next to BR-163 highway in the Central Amazonia, I compared the effects of habitat loss and hunting pressure on the distributions of species in these three areas and in 16 forest fragments isolated by savanna. In the first approach results, based on interviews, indicated that some species were extinct prior to habitat loss except in the fragment forest, caused by the perturbation and hunting in the area. I found that diversity decreases with habitat loss, and the set of species in fragments isolated by savanna was a subset of species in the less disturbed areas. However, among the nine species most frequently recorded, six species were as abundant in the fragments as the other areas, including four locallyhunted species (red brocket deer, collored pecary, nine banded armadillo, and howler monkeys). However the characteristics of forest fragments isolated by savanna (fragment size, tree density and hunting intensity) did not influence species distributions, including species that are hunted. Despite the negative effects of habitat loss, results indicate that these patches have a value as they shelter a subset of the species. Even if only temporarily, they support the region s biodiversity, and even the smallest forest fragments can constitute a unity connecting extant conservation unities. Moreover, a good adequate management plan for part of this fauna can complement the local people s subsistence. This scenario is likely to be realized in the Amazon, mainly in areas around highways such as BR-163 that are experiencing severe deforestation and rise in the local human population.