Searching for the Achilles heel(s) for maintaining invertebrate biodiversity across complexes of depressional wetlands

Abstract

Wetlands are among the most threatened ecosystems worldwide due to climate change and land-use conversion. Regional biodiversity of temporary wetlands is dependent on the existence of habitat complexes with variable hydroperiods. Because temperature and rainfall regimes are predicted to shift globally, together with land-use patterns, different scenarios of wetland loss are expected in the future. To understand how wetland biodiversity might change in the future, it is important to evaluate how the loss of particular hydroperiods will affect overall diversity in a region. Using invertebrate datasets from five wetland complexes distributed across South and North America, we calculated beta diversity metrics for each region. Then we contrasted those metrics to simulations of sequential deletions of subsets (30%) of the long-, moderate- and short-hydroperiod wetlands to assess which wetland class would most affect invertebrate beta diversity in each region. Deletions of the short hydroperiod wetlands led to the most significant decline in beta diversity. However, deletion effects of different wetland classes varied across study regions, with a negative correlation existing between deletions of the long and short-hydroperiod wetlands on invertebrate beta diversity. Our simulations indicate that loss of shorthydroperiodwetlands will have the most significant effects on invertebrate beta diversity, but loss of long hydroperiod wetlands will also be important. Thus, wetlands from both hydroperiod extremes should be considered when assessing potential biodiversity declines associated with habitat loss.