Padrões de distribuição de mamíferos de médio e grande porte em paisagens fragmentadas
Nenhuma Miniatura disponível
Data
2012-01-03
Autores
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Goiás
Resumo
Habitat fragmentation is defined as the breaking of a continuous habitat in “patches” or
fragments. This process leads to environmental changes capable of affecting communities in
different ways, causing species composition changes. Beta diversity measures can show the
variation between the composition of different communities, where two ecological patterns
can be found: turnover and nestedness. In turnover the variation in community structure is a
consequence of species replacement, while in the nestedness poor communities are nested in
richer communities. Here I tested: (I) how habitat fragmentation affects the presence of large
e medium sized mammals in different functional groups; (II) if the variation in beta diversity
in fragmented landscapes is caused by turnover or nestedness, and (III) if the variation
observed was due to habitat fragmentation. I used 19 Semidecidous Forest patches in the
Brazilian Cerrado, from the State of Goiás. Landscape metrics from 2.5 km around the
patches were obtained from classifications and measurements. For the analyses, I made four
sets based in diet, size, diet amplitude and all previous three together. I calculated the beta
diversity with Sorensen indices, turnover with Simpson indices and nestedness with
Nestedness indices. The natural area size influenced the group B3- felines and the core area
percentage, the groups A1-carnivores, larges and B3-felines. The core area percentages were
the most important character in fragmented landscapes for mammal communities. The felines
were the most sensible group. This group was affected by natural area availability and by the
core area percentage. The beta diversity pattern in the fragmented landscapes was turnover,
but it was not related to environmental variation or spatial distances between the landscapes.
Both nestedness and beta diversity were affected by spatial distance, but beta diversity was
also affected by environmental variation linked to landscape connectivity. The changes in
different landscapes cause different responses in species and allow the creation of a
fragmentation gradient, driving the turnover phenomenon. The carnivores were the species
most sensible to habitat fragmentation, mainly because they need large home ranges. Thus, an
understanding of how diversity reacts to habitat fragmentation may provide support to the
implementation of conservation areas and research upgrading which focus specific species
groups. Managed areas with large core areas and good connectivity should bring desirable
results for large and medium sized mammals conservation status. This affirmative is true,
especially for larger mammals and carnivores.
Descrição
Palavras-chave
Citação
BERNARDO, P. V. S. Padrões de distribuição de mamíferos de médio e grande porte em paisagens fragmentadas. 2012. 99 f. Dissertação (Mestrado em Ecologia e Evolução) - Universidade Federal de Goiás, Goiânia, 2012.