Atributos florais, flutuação de recursos e interações ecológicas em áreas tropicais úmidas

Abstract

Variations in the diversity of floral traits and resource availability in plant species shape the structure of interactions in communities and their functioning. In this study, we sought to understand how the variation in the availability of resources and floral traits offered by plant species structure the ecological interactions established in tropical humid areas (Pantanal and Veredas). This study was divided into three chapters: floral characteristics, pollinator groups, and different life forms of aquatic macrophytes in the Pantanal (Chapter 1), flowering phenology, and the availability of resources to pollinators in a vereda formation (Chapter 2), the temporal variation of plant-pollinator interactions in vereda, floral traits, groups of pollinators, and their contribution to the network structure (Chapter 3). According to the results presented in Chapter 1, the species of aquatic macrophytes in the Pantanal are well distributed within the phylogeny, indicating phenotypic plasticity, which may be more related to ecological factors (life form) than phylogenetic factors. The aquatic macrophytes of Pantanal also have a great diversity of floral characteristics and groups of pollinators, in addition to evidence of potential wind pollination. In Chapter 2, the richness and abundance of flowering plants were positively influenced by precipitation and temperature. Although the greatest amount of resources were made available during the rainy season, it is important to highlight that the resources were offered throughout the year in the studied vereda in an almost uniform and non seasonal distribution. Finally, in Chapter 3, a study conducted during two seasons (dry and rainy), the results showed that the dry season networks were significantly more specialized, possibly because of the lower availability of resources as previously found in other studies. Overall, the tree strata were the most important for the structure of the multilayer network. However, when evaluated across seasons, non-tree plants were significantly more important in the rainy season for maintaining pollinator diversity. This study contributes to the understanding of how ecological interactions occur within communities located in humid tropical areas. Furthermore, we emphasize that our research fills important gaps in understanding interactions in humid areas that are subject to constant threats, and have practically no studies on ecological aspects, especially considering mutualistic interactions. Through temporal variations, functional attributes, and resource types, it is possible to understand how the structure of an ecosystem is shaped and its functioning, thus contributing to the conservation of these areas. Therefore, research that contributes to a better understanding of the interaction patterns and their role in the structure of communities in humid tropical areas is urgent and represents a first step toward supporting conservation strategies.