Analysis of Diversity and Characterization of Diaspore Dispersal Syndromes in a Successional Gradient of Hyperxerophilic Caatinga

Abstract

Seed dispersal refers to the removal or release of diaspores from the parent plant and allows fruits and/or seeds to escape being deposited in close proximity to the parent plant, where mortality rates are high. The objective of this study was to analyze the diversity and characterize the dispersal mechanisms of diaspores, along a successional chronosequence. The methodology consisted of dividing three Caatinga areas selected according to their succession stage, where the plot method was used, demarcating two transects of 30 m x 10 m, in each condition, these subdivided into two square plots of 10 m², each one 10 m apart. All individuals of phanerogamous plants, with shrub-arboreal habit, ≥ 30 cm in height, were evaluated. After, there was also the typification and classification of fruits and dispersion syndromes. According to the results obtained, it was observed that the syndrome of dispersion by blastochory stood out in the three successional stages with 46% in the initial, 40% in the intermediate, followed by anemochory 27% in the late. There was also a reduction in the number of dry fruits as the ecological succession progressed, with the opposite occurring with fleshy fruits. It was observed that the process of dispersion of propagules in an area of Hyperxerophytic Caatinga varies according to the environmental changes present in each successional stage analyzed. Thus, in the last stage, the local flora uses fleshy fruits as the most efficient attractant for dispersers, while in the early stages of succession, there was a predominance of dispersion strategies by abiotic vectors, such as anemochory and blastochory.