Floral resources used by Tetragonisca angustula (Latreille 1811) in areas under the influence of the breach of the Fundão Dam in Mariana (Minas Gerais, Brazil)

Abstract

The Fundão Dam breach, in November 2015 in Mariana (20º 22ʹ 40″ S, 43º 24ʹ 58″ W), was considered, at that time, the largest environmental disaster in Brazilian history. Meliponiculture was one of the activities pointed out as a way to promote floristic recovery and to generate income for the population, in order to minimise the impact of the disaster. The objective of this work was to identify the plants supplying pollen and nectar for Tetragonisca angustula by means of melissopalynological analysis in areas under the influence of the Fundão Dam breach. The palynological data were evaluated comparing to the floristic survey carried out in the region and using multivariate statistical analysis to verify the pollen similarities between the study sites and to investigate possible impacts caused on the bee flora due to the disaster. The pollen spectra of honey did not show differences among the study sites, since Schinus terebinthifolius Raddi predominated in all samples. Regarding the bee bread, two distinct groups were formed; in the areas affected by the dam breach there was a predominance of pollen from the pioneer heliophytic species of herbaceous or shrub habit such as Baccharis, Crotalaria and Mimosa pudica. In the non-affected areas pollen of Cecropia, Myrsine and Schinus predominated, demonstrating a more established environment in the ecological succession. It is suggested that the results obtained be considered in the restoration projects in the region to assist the development of stingless bee-keeping projects as a tool for environmental recovery.