Arthropods mesofauna on leaf litter as an indicator of environmental simplification caused by monodominance of Myracrodruon urundeuva (Engler) fr. Allemão

Myracrodruon urundeuva is a tree species of economic importance due to the quality of its wood and medicinal properties. As a result of its overexploitation, it is now threatened with extinction in some Brazilian regions. However, in the region of Governador Valadares, in the east of Minas Gerais, mastic trees are considered invasive, occurring in large areas in monodominance. This study aimed to test the hypothesis that the mesofauna of the monodominance mastic litter differs in its richness and abundance from that of the Atlantic Forest remnants of the region. Litter samples were collected from three locations under monodominance of mastic trees and from three locations under biodiverse vegetation, without mastic trees. Litter was sampled in three plots at each location, using a metal template (50cm in diameter). Litter was sampled four times at each site during one year, one sample per climate season. The collected animals were stored in 70% alcohol and classified by classes and orders. The data showed that the litter fauna of the forest fragments was more abundant than that of the monodominance of mastic trees, although species richness and composition were similar. The results showed that the monodominance of mastic trees is negatively interfering with the biodiversity of the litter mesofauna and that this monodominance is restrictive to more complex soil animal communities. It suggests that environmental services, such as the decomposition of organic matter and mineralization, may be deficient and that local productivity is lower than in other places with vegetation with greater biodiversity.