Effects of environmental factors on assemblages of arboreal and epigeic ants in Seasonal Semideciduous Forest

ABSTRACT

The present work aimed to study the factors that influence the assemblages of arboreal and epigeic ants in fragments of the Seasonal Semideciduous Forest in the Rio de Janeiro State. The sampling of the ant assemblages was carried out in three forest fragments located in the municipality of Paraiba do Sul and four in the municipality of Três Rios. The sampling has carried out in each forest remnant with 20 baits (sardine and honey) allocated on the ground and brushed on the trunk of 20 trees, and the ants being collected manually. Environmental variables were obtained to verify its association with the ant species richness and diversity and with the number of guilds per forest remnant. In total, 55 ant species were collected, belonging to 20 genera. The variable that most influenced the richness and diversity of epigenic ant species was the level of isolation of forest fragments, which significantly explained about 68% of the richness variation and about 80% of the diversity variation. The mathematical model with the variables level of isolation of the forest fragments, litter leaf depth, circumference of the tree trunk at breast height (CBH), luminosity and forest fragment area, explained more than 99% of the epigenic ant species richness variation (R²= 99.94%; F= 339.06; P= 0.04). The arboreal ant species richness was significantly influenced by CBH (R²= 67.98%; F= 10.62; P= 0.02), and the arboreal ant diversity was affected by CBH and the size of forest (R²= 81.90%; F= 9.05; P= 0.03). Seven ant guilds were observed, and the number of guilds was influenced by litter leaf depth and luminosity (R²= 77.87%; F= 7.04; P= 0.05). The myrmecofauna of the Seasonal Semideciduous Forest is affected by the landscape and vegetation characteristics related to the successional stage of the forest and with environmental heterogeneity.

Keywords
Biodiversity; Biological indicator; Nature conservation