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| Lyra-Jorge, M.C.; Ribeiro, M.C.; Ciocheti, G.; Reverberi Tambosi, L.; Pivello, V.R. | |
| Influence of multi-scale landscape structure on the occurrence of carnivorous mammals in a human-modified savanna, Brazil | |
| 2010 European Journal of Wildlife Research (56): 359-368 | |
SÆo Paulo is the most developed state in Brazil and contains few fragments of native ecosystems, generally surrounded by intensive agriculture lands. Despite this, some areas still shelter large native animals. We aimed at understanding how medium and large carnivores use a mosaic landscape of forest/savanna and agroecosystems, and how the species respond to different landscape parameters (percentage of landcover and edge density), in a multi-scale perspective. The response variables were: species richness, carnivore frequency and frequency for the three most recorded species (_Puma concolor_, _Chrysocyon brachyurus_ and _Leopardus pardalis_). We compared 11 competing models using Akaike's information criterion (AIC) and assessed model support using weight of AIC. Concurrent models were combinations of landcover types (native vegetation, "cerrado" formations, "cerradÆo" and eucalypt plantation), landscape feature (percentage of landcover and edge density) and spatial scale. Herein, spatial scale refers to the radius around a sampling point defining a circular landscape. The scales analyzed were 250 (fine), 1,000 (medium) and 2,000 m (coarse). The shape of curves for response variables (linear, exponential and power) was also assessed. Our results indicate that species with high mobility, _P. concolor_ and _C. brachyurus_, were best explained by edge density of the native vegetation at a coarse scale (2,000 m). The relationship between _P. concolor _and_ C. brachyurus_ frequency had a negative power-shaped response to explanatory variables. This general trend was also observed for species richness and carnivore frequency. Species richness and _P. concolor_ frequency were also well explained by a second concurrent model: edge density of _cerradÆo_ at the fine (250 m) scale. A different response was recorded for _L. pardalis_, as the frequency was best explained for the amount of _cerradÆo_ at the fine (250 m) scale. The curve of response was linearly positive. The contrasting results (_P. concolor _and_ C. brachyurus _vs_ L. pardalis_) may be due to the much higher mobility of the two first species, in comparison with the third. Still, _L. pardalis_ requires habitat with higher quality when compared with other two species. This study highlights the importance of considering multiple spatial scales when evaluating species responses to different habitats. An important and new finding was the prevalence of edge density over the habitat extension to explain overall carnivore distribution, a key information for planning and management of protected areas. |
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