Environmental monitoring of ants (Hymenoptera: Formicidae) in the influence areas of Santo Antônio Hydroelectric Power-Plant in Rondônia, Brazil.

Biodiversity loss is accelerating rapidly in response to increasing human influence on the Earth’s natural ecosystems. One way to overcome this problem is focusing in places of human interest and monitoring the changes and the impacts on the biodiversity. The study was conducted at six sites within the influence area of Santo Antônio Hydroelectric Power-Plant in the margins of Madeira River, Rondônia. The sites cover a latitudinal gradient of approximately 100 km in the Brazilian Amazon Basin. Sampling design included six sampling modules with six plots each totaling 30 sampling plot. Sampling plots were distrubuted with 0 km, 0.5 km, 1 km, 2 km, 3 km and 4 km, measured perpendiculary from the river margin towards the interior of the forest. To sampling the ground-dwelling ants was used the ALL Protocol (Ants of the Leaf Litter), standardized globally in the inventories of ant fauna. For the purpose of impact indicators, the first two campaigns (September 2011 to November 2011) were carried out in the pre-filling period, while the campaigns three to ten (Febuary 2012 to November 2014) were carried out during and after the filling of the Hydroelectric reservoir. A total of 253 events with a total of 9.165 occurrences were accounted during the monitoring, the ants were distributed in 10 subfamily and 68 genera and 324 species/morphospecies. The impact in the ant biodiversity during the period pre and after-filling were mesuared by ecological indicators, and also by presence and absence of some species/morphospecies. This is the first study with taxonomic and ecological treatment used to monitoring the impact of a hydroeletric power-plant in the ant fauna in the world.