Composição e ocorrência da assembléia de mamíferos de médio e grande porte em Áreas Protegidas sob distintos impactos humanos na Amazônia Central, Brasil

Abstract

Protected Areas (PAs) are considered essential tools for biodiversity conservation, but their efficiency in maintaining species and their ecological roles has been questioned when such areas are close to human settlements. This critique is especially frequent for taxa considered highly sensitive to human impacts, including many species of medium- and large-sized terrestrial mammals, the target group of this study. Using camera trapping, the current study evaluated site-by-site richness and composition of three PAs (with distinct suites of human impacts and protection issues) near the largest urban center in the Amazon Basin – the city of Manaus (1.8 million inhabitants). We analyzed species occurrence and compared assemblage structure between areas for medium- and large-sized terrestrial mammals, and related these to anthropogenic and environmental factors. For some species, occurrence was most influenced by spatial variations in forest heterogeneity: confirming predictions regarding human impact, the most sensitive species responded negatively to road proximity (accessibility index) and to reserve edges (indicative of higher hunting pressure and forest disturbance). The most compositionally altered was the Ducke Reserve, where these effects were most marked. The reserves had similar richness, though assemblage composition varied. Hence, even though urban proximity influences proportional composition, PAs close to urban centers, such as Ducke, still retain a complete regional mammalian assemblage. Our results emphasize the need to ensure that such areas continue to be connected with adjacent forests, and indicate the need for increased protection and surveillance so that conservation of mammals and other forest species is ensured over the long term.