Communities of ants (Hymenoptera: Formicidae) in fragmented environments.

摘要

The composition and richness of ant species were studied in four fragmented environments (agricultural, pasture, reforestation, and secondary forest), in Dourados, Mato Grosso do Sul, Brazil. Six fortnightly sample collections were conducted. Each collection consisted of twenty pitfall traps randomly placed. Forty-three species belonging to six subfamilies and 17 genera were collected. The highest species richness was found in the fragmented environment covered with the secondary forest. The pasture and agricultural environments had lower species richness and higher densities of captured individuals. The species distribution provided by the multidimensional analysis showed two groups: (1) the samples collected in the secondary forest, and (2) the samples collected in agricultural and pasture areas. Results of the species co-occurrence analysis show that all environments were randomly distributed except in pasture, revealing low species competition in the latter. Our results support the hypothesis that environments with higher structural complexity also have higher richness and diversity of ant species and that fragmentation can affect such situation.