Community assembly of prairie farm ponds: build it and they will come, stock it and they won't

Dam construction affects freshwater ecosystems worldwide. While there is much focus on large impoundments, farm ponds are overlooked despite their near-ubiquity across human-altered landscapes. Within the Great Plains of North America, there are millions of farm ponds, yet little is known about the fish communities and factors structuring them. We propose a conceptual model where fish, amphibian, and crayfish abundances differ along a pond size and water permanency gradient and are further influenced by interactions among species. In the summer of 2021, we sampled 100 farm ponds across central Kansas, primarily on private land. Pond size and permanency explained community structure with smaller and less permanent ponds being dominated by amphibians and crayfish while larger ponds were dominated by stocked sportfish. Distribution modeling revealed a negative correlation between stocked fish and other community components indicating potential interactions. If we are to conserve headwater stream species, especially those that are threatened or endangered, strategies that integrate farm ponds seem necessary given their prevalence on the landscape.

Automated summary

Dam construction has a global impact on freshwater ecosystems, and while large impoundments receive significant attention, farm ponds have been overlooked. In North America's Great Plains, millions of farm ponds exist, but there is limited knowledge about the fish communities and factors shaping them. This study proposes a conceptual model where fish, amphibian, and crayfish abundances vary based on pond size, water permanency, and interactions among species. Field sampling in central Kansas in 2021 revealed that pond size and permanency play a role in community structure, with smaller and less permanent ponds being dominated by amphibians and crayfish, while larger ponds are dominated by stocked sportfish. Distribution modeling suggests potential interactions between stocked fish and other community components. To conserve threatened or endangered species in headwater streams, it may be necessary to integrate strategies involving farm ponds due to their prevalence in the landscape.