Padrões de distribuição da diversidade de Collembola (Arthropoda, Hexapoda) no semiárido Paraíba

Abstract

The Domain Caatinga spans much of the Northeast, the semiarid climate and xerophytic vegetation are striking characteristics of this area. Collembola are found in all zoogeographic regions of the Earth, are non-insect hexapods animals, edaphic and highly dependent on soil moisture. The diversity of this group is closely linked to seasonal and environmental characteristics.The aim of this paper was to verify the Collembola distribution patterns in three areas of environmental protection in the semiarid Paraiba, in the cities of São João do Cariri, São João do Tigre and Santa Teresinha. The search was conducted for two seasonal periods of the year, the dry season and rainy season. In each study area, they were drawn ten plots of 100m² and each plot was traced three distant points among themselves five meters for the removal and measurement of litter and phytosociological survey; in each plot was taken a soil sample. The organisms collected were screened and identified the species level. Absolute and relative abundances were estimated richness, diversity indices, equitability and similarity. To analyze the abundance of the regions between the samples was the Kruskal-Wallis test. The representativeness of the inventory was estimated using species accumulation curve. Within the Protected Areas and between areas: alpha diversity and estimated the beta diversity into two distinct scales was quantified. The diversity indices of Shannon-Wiener, α-Fisher, Margalef, Simpson and Whittaker were used; and the evenness index of Pielou. A cluster analysis was performed to verify the formation of groups among the studied areas. Multivariate as Canonical Correspondence Analysis were used to evaluate the composition of communities and associate this composition habitat. It was collected 6,226 individuals of Collembola during the two periods of collections, represented by 24 species, 17 genera and 9 families; where the dry season (PS) were recorded 50 individuals distributed in 4 families, 7 genera and 7 species During the rainy season (PC) were collected 6,176 individuals in nine families, 17 genera and 24 species. The most representative species were Brachystomella purma and B. agrosa totaling 83.74% of the individuals found. According to statistical analysis, areas of São João do Cariri and Santa Teresinha are most closely related and are more homogeneous than the areas of São João do Tigre. Therefore, any strategies for environmental conservation areas studied should take into account the spatial scales presented in this study, since the change in diversity was highest within each study area.