Mirmecofauna em áreas de mata ripária: implicações para conservação e restauração do ecossistema

• Ano de defesa: 2008
• Autor(a) principal: Campos, Renata Bernardes Faria
• Orientador(a): Schoereder, José Henrique
• Banca de defesa: Louzada, Júlio Neil Cassa , Guerra Sobrinho, Tathiana , Krüger, Rodrigo Ferreira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Entomologia
• Departamento: Ciência entomológica; Tecnologia entomológica
• País: BR
• Palavras-chave em Português: Riqueza; Composição de espécies; Ecologia; Formigas; Matas ciliares
• Palavras-chave em Inglês: Richness; Species composition; Ecology; Ants; Riparian forest
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA::ECOLOGIA DE ECOSSISTEMAS
• Link de acesso: http://locus.ufv.br/handle/123456789/856

Riparian forest strips are representative of the endangered vegetation formation, legally stated as permanently protected areas. Most of forestry laws consider only the distance from river course and flora species richness as parameters to restoration or conservation of riparian areas. To some extent, the cause of this oversimplification is the paucity of knowledge of the riparian fauna and its importance for riparian ecosystems, and hence the value of stream forests as shelter and refuge for terrestrial organisms. For that reason different aspects of ant communities were investigated in riparian areas. First we look for disturbance as a determinant of local species richness and composition. Distance and altimetry relative to river course are related to flood and edge effects, hence related to disturbances in riparian forests. These factors exert diverse influences on soil ant community in riparian studied areas. Therefore, idiosyncratic differences among studied areas can be important determinants of riparian ant communities. To arboreal ant species, the distance from the river course is the most important determinant of richness, evidencing possible edge effects. Distance between points affect ant soil similarity at all studied areas, hence species ant composition is more dissimilar in points more distant from each other. Nevertheless, the greater soil ant species similarity found between closer points should not be explained by specialization of ants to a specific habitat, while nest budding in litter ants can help to explain this pattern in litter ant communities. For arboreal ants the absence of similarity response to distance and altimetry difference may be explained by the close relationship between ants and plant species, instead by the influence of river or flooding. Second, we investigated if the riparian mirmecofauna presents a distinctive ant species composition and the community species composition changes as distance form this river increases. Our results does not support tested hypotheses that exists a common typical riparian ant species community in distinct river margins. Each area presents a characteristic ant species composition. Results of comparison among transect within each studied area showed that ant species composition of transects varies only when transects are sufficiently lengthy, which is related to bigger distances from river course and importantly larger number of samples. Differently, of results found for samples close to larger rivers, the species composition among transects at thinner protected riparian areas did not differ significantly. Independently from variations in composition among and inside riparian forests, the similarity in species composition from very close to distant places from river margins does not differ. All studied areas presented the same pattern of similarity, for soil and arboreal ants, evidencing the non existence of particular species close to river courses. Consequently a particular riparian community may not exist and this community also is not the same for all regions in tropical areas. Finally, we look another important aspect relative to riparian areas: restoration. We followed reforested areas by four years since the period of soil preparation for seedlings planting. The aim was to thus understand how the richness and composition of species of ants vary over time, in urban riparian reforested areas. Ant soil species richness changed along the studied period, but this variation can not be explained by reforestation, as the same pattern was found in areas that have not been reforested. For ants tree was not found variation in richness. Changes in the composition of species over the period of study were found in most areas, both for ants collected in soil and in trees. This change occurred both in reforested areas, such as those which did not happen the planting of seedlings. Moreover, there was no increase in the similarity of the composition of species in relation to the reference area along time. If ants have been identified by fast numeric recovering, it is possible that the composition does not behave the same way. Among studied areas, one fragment in natural regeneration throughout approximately two decades was more similar to the reference area thus studies that consider the identity and abundance of species of ants in a greater period of time may prove increase in the similarity between reforested areas and reference. Beyond the possible requirement of long periods to community restoration, if the objective of permanently protected areas is to conservation of biodiversity, the forestry law deserves attention because very small areas associated to narrow rivers appears to be faulty to this end.