D3219: Two invading ant species affect biodiversity in longleaf pine ecosystems

Longleaf pine savannas are unique and diverse ecosystems, therefore establishment by invasive Red-Imported Fire Ants (RIFA, Solenopsis invicta) and Asian Needle Ants (ANA, Brachyponera chinensis) may have a significant impact on biodiversity. The goal of our research is to survey invasive ant nests and ant diversity to identify changes in nest density, richness, and abundance over time. Surveys of RIFA nests were conducted along belt transects in 2014, 2017, and 2022 in three longleaf pine savannas. Pitfall traps were used to measure the abundance and richness of ants along the transects in 2017 and 2022. Our 2017 findings showed that RIFA was clearly the most abundant species of ant. In 2022 we resurveyed the same sites and our data revealed that 1) the ANA was now the most abundant ant species across sites, 2) RIFA abundance and nest densities decreased, 3) there was a sharp decrease in native ant abundance and richness, 4) and total ant abundance increased by 65% overall, but this was due to large increases in the ANA population. In 2023, we employed additional methods to survey these locations sites on a broader scale.These methods include soil samples, bait traps, leaf litter samples.Longleaf pine savannas are some of the most diverse in terms of fauna and flora in North Carolina, so it is paramount to understand the impact of these invasive ants to mitigate any adverse  environmental effects.