Diversidade funcional de assembleias de plantas aquáticas em lagoas rasas da região semiárida brasileira

Abstract

Climatic seasonality can trigger abiotic changes in aquatic environments in the semiarid region, which influences the occurrence of species and the selection of attributes, as well as the patterns of functional groups. Therefore, we aim with this thesis to analyze the influence of pluviometric seasonality on the richness and functional diversity of aquatic plants, at group and functional trait levels, considering the abiotic changes between the rainy and dry periods, in three shallow permanent lagoons in the Brazilian semiarid region. For this, the hypotheses tested were: a) there is an abiotic change between the periods analyzed, in which there is a greater concentration of nutrients and a reduction in depth in the dry season; b) species richness is lower in the dry season; c) functional groups collapse in the dry season; d) the species will have smaller size with reduced values of size and morphological index, as well as the predominant forms of growth in the dry season will be the free floating ones (submerged and emerging), the therophytic life form, vegetative reproduction and anemochoric dispersion will be more abundant this season; greater dissimilarity between species will also occur in the dry period. From this, we conclude that the functional diversity of the groups and at the trait level is influenced by the abiotic variables, which also undergo changes with the period variation, select certain characteristics that are more abundant in a certain period, and furthermore, that the diversity functional is directly influenced by the species richness, which leads to the collapse of groups when the species richness decreases.