Dispers?o de sementes por formigas em ?reas de diferentes idades de restaura??o na Mata Atl?ntica

• Autor(a) principal: Laviski, Bianca Ferreira da Silva
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/6949
• topic: Intera??o formiga-di?sporo; Restaura??o ecol?gica; Ecologia de comunidades; Ant-fruit interactions; Ecological restoration; Community ecology; Zoologia; Ecologia

Seed dispersal is an essential process in the structuring of plant communities. The current loss of dispersers due to habitat loss and defaunation makes it important to evaluate the execution of this service. Ants are organisms capable of performing primary and secondary dispersal of several plant species, allowing a refinement of primary dispersal. Its presence in diverse terrestrial habitats means that this seed dispersal can occur frequently, including in recently restored areas. The objective was to evaluate how the ecosystem service of seed dispersal performed by ants is recovering in restored areas compared to reference areas. The work was carried out at the Guapia?u Ecological Reserve (REGUA), in Cachoeiras de Macacu, RJ, in restored areas and reference areas for evaluating the secondary dispersal process carried out by ants. The first two chapters analyzed myrmecofauna interacting with natural fruits (chapter 1) and artificial fruits (chapter 2) and the biotic and structural factors influencing these interactions. The third chapter analyzed the effect of Ectatomma permagnum nests on seedling richness and abundance, as well as the physical and chemical soil attributes of these nests and the density and distribution of nests in the areas. Interactions were observed in six areas in a total of four transects of 200 m each, with four restored areas and two reference areas. For interactions with natural fruits, interactions were observed monthly over 12 months. A total of 110 interactions were found between 28 species of plants and 23 species of ants of which 52 interactions occurred in the restored ?reas over a year of observation. With artificial fruits, 251 interactions were observed with 23 species of ants and a total of 103 removals. Networks of restored and reference areas showed similar patterns. Solenopsis invicta was the central species in the interactions with natural fruits, indicating a strong dominance of the species and that the areas are still recovering, with a low number of diaspore removals by ants and few interactions with high quality disperser species. In artificial fruits, there was no difference in richness and removal of fruits in restored and reference areas and absence of influence of structural factors. Species composition was different between restored and reference areas. The indicator species in the reference habitat was Wasmannia auropunctata and in the restored habitat were Pheidole subarmata and Atta sexdens. Interactions may be limited by the recovering community and the strong dominance of some ant species, as in natural fruits. However, the absence of differences between restored and reference habitats in the characteristics studied in the two chapters indicates that the ecological process is carried out at the same level in both and is in the process of recovery. Ectatomma permagnum showed low nest density, being slightly higher in thenewest restored area, indicating that the activity of this species may be higher in recently restored areas. Nest distribution was random, indicating low intraspecific competition. The soil near and far from the nests did not differ in nutrient concentration. Therefore, the species does not seem to favor the recycling of nutrients in the environment under the influence of the nests. However, E. permagnum favored a higher abundance of seedlings in the nests, probably due to the diaspore removal activity of the species. Their activity leads to the increase of seedlings in their nests. Considering that all areas have a considerable restoration time and have nutrients necessary for the good development of seedlings, we can consider the species with a positive effect for seed dispersal and restoration of areas.