Diversidade de collembola (ARTROPODA: HEXAPODA) epiedáficos em uma mancha de caatinga do Parque Nacional de Sete Cidades, estado do Piauí, Brasil

Abstract

The main aim of this study is to estimate the diversity of epigeic Collembola in spots of Caatinga in the Sete Cidades National Park, Piauí, in the dry and rainy seasons, and to identify the main environmental variables that influence these diversity patterns. Pitfall traps were used to capture the specimens, distributed along a 100-meter transect containing 11 sampling points, with the aid of 400 mL disposable cups containing 70% ethanol buried in the ground with openings and protected with disposable plates suspended above. After collection, the material was taken to the Biology Laboratory of the IFPI – Campus Pedro II and sorted using magnifying glasses. The specimens were mounted on stereomicroscope slides and identified. Some environmental parameters were collected, such as soil moisture, soil temperature, percentage of vegetal cover and height of leaf litter, and their influence on the composition of the fauna was analyzed using Canonical Correspondence Analysis (CCA) and Principal Component Analysis (PCA). We obtained results that the total abundance of individuals was 709 in the rainy season, distributed in 2 orders, 3 families, 16 genera and 14 species, and 8,362 in the dry season, distributed in 2 orders, 5 families, 6 genera and 8 species. The Shannon-Wiener index was 1.79 and 0.22, respectively. In the rainy season, the diversity measured for the area was 1.79, which was not so close to the maximum expected diversity (Hmax), which was 2.89. The Pielou index indicated low equitability in the community sampled. In the dry season, the diversity measured for the area was 0.22, which was explicitly far from the maximum expected diversity (Hmax), which was 2.07. The Pielou index again indicated low equitability in the community sampled. These data show a discrepancy in the diversity and equitability of these individuals in the environment.