Coexistência de espécies do gênero Erythroxylum em fragmento de mata atlântica nordestina

• Autor(a) principal: Dantas, Thais Aparecida Vitoriano
• Data de Publicação: 2020
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/29696
• topic: Nicho ecológico; Competição; Exclusão competitiva; Espécies congenericas; Dispersão de sementes; CNPQ::CIENCIAS BIOLOGICAS

Within the ecology of communities, there are processes at different spatial scales involved in the assembly and structuring of these communities. Among them, ecological processes related to the filtering of species that may persist within these communities based on their tolerances to different environmental conditions and interactions with other species, such as competition, stand out. During these processes of community assembly, the availability of the range of conditions (abiotic and biotic) and resources in time and space are heterogeneous, allowing different points in this space over time to present different sets of conditions, which will be occupied by different species, thus collaborating for their coexistence within the communities. The objective of this dissertation was to understand how three congeneric plant species, belonging to the genus Erythroxylum (Eryhroxylaceae), share the various dimensions of the ecological niche (abiotic and biotic) allowing their coexistence in a relict of Humid Tropical Forest. We divided this work into two chapters: In the first, we investigated how the three species share the dimensions of the abiotic niche, according to the environmental conditions of the places where the collections were made. For our range of data, the three plant species show overlap of part of the niches, since all three occur at all locations of the gradients (there is no part in which they are flagrantly absent). However, the species E. simonis stands out as the strongest competitor, benefiting along all gradients with the increase of its abundance. While E. pauferrense and E. citrifolium demonstrate greater competition. In the second chapter, we evaluated the partitioning of biotic niche, through the dispersal services provided by ants to the diaspora of the species Erythroxylum simonis and Erythroxylum pauferrense. Due to the lack of availability of Erythroxylum citrifolium diaspora, the experiments were carried out only with the fruits of two of the three species. Our results have not demonstrated the partitioning of biotic niche between E. pauferrense and E. simonis species through the axes of richness and composition of ants, intensity of interaction of the ants species with the fruits of the plants and cleaning services and removal of their diaspora. However, it collaborates with information on the dispersal services provided by ant species to the diaspora of these two non-myercocoric plant species, as well as on the importance of these dispersal services in maintaining plant communities. Studies such as these help in understanding the processes of niche sharing and coexistence among phylogenetically close species, and in providing important models for understanding the factors that drive and structure plant communities.