Efeitos da exploração de areia em assembleias de formigas de Campinaranas na Amazônia Central

Abstract

The Campinaranas (white-sand forests) have been suffering anthropic pressure and considerable loss of their natural vegetation and are being degraded due to the extraction of sand for civil construction. The assemblies of ants are sensitive to environmental changes, revealing the effects of disturbance and, therefore, are being used as indicators of the state of conservation. The impact of sand exploitation on the richness, abundance and composition of ant species and the relative contribution of the replacement and nestedness of species were compared in 12 pairs of explored Campinarana and an adjacent pristine Campinarana in four municipalities of the Manaus Metropolitan Region. We sampled 68 species and 1,898 individuals belonging to seven subfamilies of ants. The number of species (richness) per transect was similar among the Campinaranas. The frequency (occurrence) was higher in the Campinarana explored. The composition of species was very different among the Campinaranas. Species replacement dominated the beta diversity decomposition between treatments (preserved campinarana and exploited campinarana), representing 90% of the data variation. However, the highest ant species turnover occurred among preserved and exploited Campinaras. Despite representing only 10% of the variation, nestedness was higher in exploited Campinaranas than preserved Campinaranas. Given that Campinaranas grow on poor soil and take a long time to recover from disturbance understanding the relationship between ant diversity and the impact of sand mining has important implications for conservation. As ants interact with many other groups and play essential roles, changes caused by sand mining can affect other ecosystem components.