Influência do tipo e do manejo da matriz sobre a diversidade de insetos e suas respostas ao efeito de borda
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Data
2016-07-08
Autores
Ribeiro, Felipe Martello [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
A fragmentação atualmente é uma das maiores ameaças a biodiversidade, reduzindo a quantidade de habitat nativo, dividindo o habitat nativo em fragmentos pequenos e isolados. Apesar de boa parte de estratégias de conservação focarem preferencialmente nos remanescentes das áreas nativas, esta prática ignora a relevância que ambientes antrópicos (matrizes) podem têm para biodiversidade: tipos diferentes de matriz diferentemente os movimentos de organismos entre remanescentes de habitat nativo; provêm certa quantidade de recurso que é utilizada por algumas espécies, assim como criam diferentes áreas de transição com os remanescentes (bordas) que influenciam na biodiversidade encontrada nessas áreas. Nesta tese estudei como matrizes diferentes afetam a diversidade de besouros escarabeídeos e de formigas, dois grupos de insetos com alta biodiversidade, considerados importantes bioindicadores ambientais por serem sensíveis à alterações ambientais, essenciais em diversos processos ecológicos e por representarem eficientemente a resposta de outro organismos à tais alterações. Nos primeiros dois capítulos foquei em entender como os besouros e formigas respondiam à distância de borda em bordas compostas por cerrado e diferentes tipos de matrizes. Como resultados encontrei que a biodiversidade de ambos insetos foi afetada pelo tipo de ambiente que se encontravam (cerrado ou matriz), porém nem sempre suas respostas evidenciaram o efeito de borda. No caso das formigas, pude constatar que o tipo de resposta que as comunidades mostraram foi influenciada pelo tipo de matriz que compunha a borda, sugerindo que a resposta que os organismos têm á borda é dependente dos ambientes que a compõe. No terceiro capítulo procurei mostrar que mesmo ambientes que podem ser considerados como a mesma matriz, nesse caso eucalipto, podem afetar de forma diferente a biodiversidade. Utilizando a riqueza de espécies e medidas de diversidade funcional, descobri que comunidades de formigas em áreas de eucalipto abandonadas por 28 anos tinham a mesma riqueza que comunidades localizadas em mata atlântica nativa, porém uma menor riqueza funcional. Além disso, tais comunidades eram mais similares à aquelas localizadas em plantações de eucalipto manejadas do que as comunidades na mata atlântica. De forma geral, procuro discutir a relevância de se considerar paisagens como ambientes heterogêneos tanto em estudos de fragmentação como em estratégias de manejo, visto que ambientes aparentemente iguais (bordas de cerrado e plantações de eucalipto) podem afetar de forma diferente os organismos.
Fragmentation, nowadays, is one of the major threat to biodiversity, reducing the native habitat amount, separating native habitat in small and isolated fragments. Although most of conservation strategies preferably focus in remnants of native areas, this practice ignores the relevance the relevance that anthropic environments (matrixes) would have for biodiversity: different matrix can facilitates or difficult the movement of organisms between native habitat remaining; it provide resources that is used for many species, as well as create different transitional areas adjacent to the remnants (edges) that influence the. In this thesis I studied how different matrices affect the diversity of dung beetles and ants, two groups of insects with high biodiversity, considered important environmental bioindicators since they are sensitive to environmental changes, essential in many ecological processes and efficiently represent the response of other organisms to environmental changes. In the first two chapters I focused in understanding how dung beetles and ants respond to distance to edge, in transitional areas composed by cerrado (Brazilian savannah) and different types of matrixes. I found that the biodiversity of both insects was affected by the type of environment (cerrado or matrix), but not always their answers showed the presence of edge effect. In the case of ants, I found that the type of response that communities showed was influenced by the type of matrix that composed the edge, suggesting that the answer of organisms to edge distance is specific of the environments that compose it. In the third chapter I showed that even environments that can be regarded as the same matrix, in this case eucalyptus, may affect differently biodiversity. Using species richness and functional diversity indexes, I found that communities of ants located in abandoned eucalyptus plantations for 28 years had the same richness that communities located in the native rain forest, but small functional richness. Furthermore these communities were more similar to those located in managed eucalyptus plantations than communities in the Atlantic. In general, I discussed the importance of considering landscapes as heterogeneous environments both in fragmentation studies and in conservation strategies, since environments apparently similar (savannah edges and eucalyptus plantations) can affect differently the organisms.
Fragmentation, nowadays, is one of the major threat to biodiversity, reducing the native habitat amount, separating native habitat in small and isolated fragments. Although most of conservation strategies preferably focus in remnants of native areas, this practice ignores the relevance the relevance that anthropic environments (matrixes) would have for biodiversity: different matrix can facilitates or difficult the movement of organisms between native habitat remaining; it provide resources that is used for many species, as well as create different transitional areas adjacent to the remnants (edges) that influence the. In this thesis I studied how different matrices affect the diversity of dung beetles and ants, two groups of insects with high biodiversity, considered important environmental bioindicators since they are sensitive to environmental changes, essential in many ecological processes and efficiently represent the response of other organisms to environmental changes. In the first two chapters I focused in understanding how dung beetles and ants respond to distance to edge, in transitional areas composed by cerrado (Brazilian savannah) and different types of matrixes. I found that the biodiversity of both insects was affected by the type of environment (cerrado or matrix), but not always their answers showed the presence of edge effect. In the case of ants, I found that the type of response that communities showed was influenced by the type of matrix that composed the edge, suggesting that the answer of organisms to edge distance is specific of the environments that compose it. In the third chapter I showed that even environments that can be regarded as the same matrix, in this case eucalyptus, may affect differently biodiversity. Using species richness and functional diversity indexes, I found that communities of ants located in abandoned eucalyptus plantations for 28 years had the same richness that communities located in the native rain forest, but small functional richness. Furthermore these communities were more similar to those located in managed eucalyptus plantations than communities in the Atlantic. In general, I discussed the importance of considering landscapes as heterogeneous environments both in fragmentation studies and in conservation strategies, since environments apparently similar (savannah edges and eucalyptus plantations) can affect differently the organisms.
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Palavras-chave
Composição de espécies, Riqueza, Diversidade funcional, Formigas, Besouro