Structure of ant assemblages and effect of environmental conditions in gallery forests with different conservation status in the Humid Chaco ecoregion of Argentina

Abstract

Environmental fragmentation resulting from human activities has negative consequences, including biodiversity loss and a decline in insect populations, which threatens crucial ecosystem functions. A comparative study was conducted in gallery forests with different conservation status (Good, Intermediate, and Unfavorable) in the Humid Chaco ecoregion, Chaco Province, Argentina. We hypothesize that the conservation status of gallery forests influences the diversity parameters, composition, and structure of ant assemblages because it provides better conditions, thereby increasing diversity parameters and resulting in distinct patterns of ant species composition. Samplings were conducted during the peak ant activity periods in the spring and summer seasons between 2017-2018. We collected 5,363 specimens belonging to 108 species/morphospecies, 36 genera, and nine subfamilies. Furthermore, the effect of environmental variables (leaf litter thickness, distance from the river, canopy coverage, number of seedling trees, human footprint index, temperature, relative humidity, and precipitation) on community structures was assessed. The highest species richness and diversity were recorded in sites with a good conservation status. Our findings highlight the importance of gallery forests as biological corridors for the protection of ant diversity. Additionally, the distinct ant community structures in forests of varying conservation statuses emphasize the need for effective conservation strategies in these types of habitats.