Diversidade de Isoptera (Arthropoda, Dictyoptera) e efeito de fatores ambientais sobre sua distribuição em três áreas no município de Cláudia - MT, Amazônia Meridional

Abstract

The loss of environment is one of the most threats to biodiversity. The termites are one of the most abundant arthropods in the soil and have an important role on the nutrient cycling, being responsibles for major part of the soil fertility maintenance. Considering the importance of this insects to the edaphic communities dynamics, this study aims (i) to inventory and analyse the termites diversity in three areas in the same region, and (ii) analyse the influence of environmental variables on the distribution of termites composition and richness in three areas in the Meridional Amazon. This research is inserted in the Program of Biodiversity Research (PPBio) with samplings in three basic units (modules) in amazonic biome. The I and II modules have 12 parcels each, and the III module has eight parcels, uniformly distributed every 1km, and have 250m of length. In total were samplings 31 parcels and 155 subparcels. The termites were colected manually in all microhabitats beings. The environmental variables were colected in prior researches according the PPBio protocols. Were sampled a total of 436 occurences of termites, distributed in 72 species, two families and seven subfamilies, among them 55 species were found in the II module, 44 in the III module and 43 in the I module. The genera with major sampling frequency were Nasutitermes, Embiratermes, Cyrilliotermes, Dolichorhinotermes and Anoplotermes. The ordination of the composition by NMDS it captured 47% of the variation with two axes (Stress = 26,7). The multivariate multiple regression indicated that the species composition in the community was affected by the clay content (p=0,023), and organic matter (p=0,0009), but not was affected by the litter volume (p=0,81). However none of these variables influenced the richness. The high occurence of humivorus species indicates that the sampled areas have character of unfragmented environments. The richness observed corresponded only the 78% of the estimated richness and the rarefaction curve not reached the asymptote. The low similarity between the I and II modules, and II and III, demonstrates that the species composition of these locals are very different. Therefore, the three areas have equal importance to the conservation of natural habitats, mainly by the high quantity of exclusive species found.