The American bison (Bison bison) has been described as an ecosystem engineer because of its physical alternation of grassland habitats, in particular the creation of wallows. Bison wallows typically contain different plant communities compared to surrounding grassland habitat, increasing the overall plant diversity within the larger ecosystem. How this change affects consumer abundance and diversity has been poorly studied, although previous work has indicated that active wallows contain lower arthropod abundance and diversity compared to less disturbed surrounding prairie. In this study, we investigated the arthropod community structure in abandoned wallows (i.e. those not being actively used by bison) and compared it to nearby tallgrass prairie habitat.
Results/Conclusions
We found that arthropod abundance and diversity was significantly higher early in the season, but that this pattern switched later in the season when the surrounding grassland areas exhibited higher arthropod abundance and diversity. This trend was particularly pronounced among the herbivorous and detritivorous arthropods, while carnivorous arthropods were similar between locations during the entire season. Our results indicate that abandoned wallows represent unique arthropod communities within the larger tallgrass prairie ecosystem, and during some times of the year, could represent areas of higher resource availability for consumers that feed on arthropods.