Diferenças na Taxocenose de Isoptera em função de alterações ambientais no Cerrado

Abstract

The Cerrado is the second largest biome of Brazil and it is considered one of the biggest world biodiversity hotspot. In this Brazilian savannah, there is a great diversity and abundance of termites (Isoptera), which are considered key-species for maintenance of many ecosystem services. Despite the importance of termites exerted on the ecosystem, little is known about how the composition of species of termites varies depending on the different types of vegetation present in the Cerrado. Termites (Isoptera) are eusocial insects widely dispersed throughout the tropics. Even today, the termites are in the midst of a taxonomic review and, coupled with the low number of taxonomists, there is some difficulty in identifying some species. With this, in this study we elaborated two manuscripts adressing the problems exposed above. The first study aimed to verify the possibility of replacing termite identification to species level by other higher levels, through a sufficient analysis taxonomic. Correlated to species richness, the richness of genres (r = 0.98903) subfamilies (r = 0.7422) and trophic group (r = 0.77808), where we saw that there was a high correlation between the wealth of different levels. It evaluated the correlation between species composition and the other analyzed levels, and we saw that both the Mantel test: species x gender (r = 0.5323), x subfamily (r = 0.2718) x trophic group (r = 0.2847), and by Procrustes: x species genus (m²: 0.6344) x subfamily (m²: 0.8989) x trophic group (m²: 0.8043), the values indicated low correlations between the levels. In this article, we conclude that when working with the species composition, the replacement of identification by other levels would be frustrated by the low found overlapping values. And we find that that relative wealth, the high correlation between species and genera suggests the possibility of replacing the identification of the species level by gender. In the second article, we used termite samples collected in 15 municipalities in the Midwest region of the Cerrado and correlated with environmental variables of altitude, geographic distribution, vegetation index, perimeter and fragment area collected and type of vegetation. We also a discriminant analysis and a partition diversity. In these analyzes, we seek to see whether the species could be grouped according to the type of plant formation and in which spatial scale of diversity would be a greater flow of species. In this study, we concluded that in general there were significant correlations between variables related to vegetation and species composition. Among these correlations, we saw that the characterization of landscape by phytophysiognomies best represents the species composition patterns, then the vegetation index EVI2. We saw in the discriminant analysis that 27% of all samples are restricted to a particular physiognomy. Furthermore, the partition diversity showed that substitution of the species (beta diversity) between latitudinal and longitudinal gradients was higher than that observed in level of parts, types of vegetation and municipalities, suggesting that environmental variations at smaller scales bit representing the changes in the composition the Isoptera communities in the Cerrado biome.