Ecologia de colêmbolos (Arthropoda:Hexapoda) epiedáficos em uma área de transição Cerrado-Caatinga: a sazonalidade e o perfil da vegetação afetam as suas comunidades?

Abstract

Springtails are microarthropods widely distributed throughout all terrestrial ecosystems, mainly associated with soil. Despite playing a fundamental role in soil ecosystems, studies on these animals are limited, especially those of a taxonomic nature, already conducted in Brazil. Therefore, the main objective of this study was to compare the community of epedaphic springtails in different phytophysiognomies of the National Park of Serra das Confusões (PNSC - Piauí state, Brazil), namely Floresta Semidecidua (Canion), Savana Estépica (Lajeiro), and Carrasco, evaluating the effects of seasonality, vegetation profiles, and other biotic and abiotic variables on the populations surveyed. For this purpose, two collections were conducted in PNSC, covering two distinct periods: one during the dry season and another in the rainy season. Pitfall traps were used, in addition to measurements of environmental variables such as air temperature, soil temperature, soil moisture, relative air humidity, soil pH, litter height, canopy cover, and plant richness. To recognize which variables, such as air temperature, soil temperature, soil moisture, relative air humidity, soil pH, litter height, canopy cover, and plant richness. In the laboratory, screening, morphotyping, assembly, and identification of specimens were performed. To identify which environmental variables have the highest values among phytophysiognomies and periods, an analysis of environmental characterization was performed through a Permutational Multivariate Analysis of Variance (PERMANOVA). To analyze alpha diversity, abundance, richness, diversity, and evenness were estimated, tested using linear and additive models (GLMM or GAMLSS). Beta diversity, using the Whittaker method, and species composition were tested through PERMANOVA, and this assembly composition was plotted through a Non-Metric Multidimensional Scaling Analysis (NMDS). Indicator species of communities were calculated using IndVal, and finally, to assess the relationship between the abundance of springtail species and environmental variables, a Redundancy Analysis was performed. A total of 29,616 springtail specimens belonging to three orders, 12 families, 31 genera, 42 morphospecies, and 4 nominal species were collected during the two collection periods. Abundance and richness analyses indicated significant differences between the different seasons, with the dry period showing higher values compared to the rainy period. ShannonWiener and Simpson Diversity analyses indicated significant differences in the interaction between the two periods, especially in the Lajeiro phytophysiognomy, with lower diversity in the area, as well as the Pielou evenness index, which also showed significant differences in Lajeiro during the rainy period. The main environmental variables that influenced diversity patterns were canopy cover, litter height, silt percentage, and soil temperature. Finally, the results presented compiled a comprehensive inventory of families and genera for the State of Piauí, resulting in increased knowledge about the group in the region.