Soil Macroinvertebrate Diversity in Congaree National Park

Quattro, Joseph; Kendrick, Sharon

doi:10.36967/2318306

Soil macroinvertebrates are important regulators of decomposition, nutrient cycling, and soil structure, yet baseline inventories remain limited for many protected areas. We conducted a DNA-based survey of soil macroinvertebrate diversity in Congaree National Park, South Carolina, across bottomland, bluff, and upland habitats. From September 2022 to October 2024, we collected 74 soil, litter, and opportunistic samples using standardized pit excavation and searches of the litter, with the goal of documenting macroinvertebrate occurrence. Individual specimens were identified using standard mitochondrial cytochrome c oxidase I (COI) DNA barcoding, and Shannon diversity indices were used to compare diversity among substrates and habitat types. A total of 766 macroinvertebrates were recovered, of which 537 (70%) were confidently assigned to family, genus, or species. Litter samples yielded more individuals than soil samples (546 vs. 220) and exhibited significantly higher Shannon diversity (mean H = 1.426 ± 0.700 vs. 0.961 ± 0.637; P = 0.008). Diversity also differed among ecotones, with bottomland habitats showing the highest mean diversity (H = 1.682 ± 0.715), significantly exceeding both bluff and upland habitats. Eight firefly larvae were recovered and assigned to the genus Photuris; all were found in litter or opportunistic collections rather than excavated soil. Multiple introduced taxa were also detected, some widespread, including Amynthas corticis, A. gracilis, A. minimus, Brachyponera chinensis, Solenopsis invicta, and Oxidus gracilis. These findings provide the first DNA-based baseline inventory of soil macroinvertebrates for Congaree National Park and show that litter and bottomland habitats support comparatively high diversity. The study also identifies management-relevant taxa, including introduced invertebrates and Photuris larvae, and establishes a foundation for future monitoring of belowground biodiversity across the park.

Soil Macroinvertebrate Diversity in Congaree National Park

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