Poster Presentation Freshwater Sciences 2023

Benthic and emergent macroinvertebrate community responses to hydrological variation across geographically isolated wetlands   (#701)

Elizabeth Sicking 1 , Stephen Golladay 2 , Kier Klepzig 2 , Hunter Hodson 1 , Sally Entrekin 1
  1. Virginia Tech, Blacksburg, Virginia, United States
  2. The Jones Center at Ichauway, Newton, Georgia, United States

Geographically isolated wetlands support high invertebrate diversity and secondary production that provides an energetic connection between aquatic and terrestrial landscapes. Annual and seasonal changes in precipitation and temperature are impacting hydrologic regimes and, in turn, the abundance, composition, and emergence timing of macroinvertebrates in isolated permanent and temporary wetlands. However, the impacts of changing hydroperiods on emergence timing and subsequent energy exchange between terrestrial and aquatic ecosystems are understudied. Temporary wetlands are particularly vulnerable to reduced periods of inundation that could eliminate insects that lack adaptations for drying. We will measure how different hydroperiods impact benthic and emergent insect and non-insect macroinvertebrate communities in geographically isolated wetlands on the Gulf Coastal Plain in SE USA. We predict that: 1) the abundance and biomass of emerging insects will increase with hydroperiod length due to greater habitat availability and stability, 2) increased hydroperiod variability will decrease the abundance and biomass of the emergent population because of abbreviated time for growth, and 3) emergence timing will differ depending on hydroperiod length. Benthic and emergence samples will be collected from two types of isolated wetlands (sedge-marsh and cypress-swamp) across the hydroperiod. We will assess richness (S), abundance (N), and biomass (B) within individual wetlands, between wetland types, and between benthic and emergent samples. Hydrological and thermal patterns that influence the composition and life cycle of insects are increasingly changing in isolated wetlands that continue to lack the protective environmental policies afforded to other freshwater habitats. Because of this, it is vital to further investigate the relationship between emerging insects and their surrounding terrestrial habitats, and continue to expand our knowledge of how emergence timing and both insect and non-insect macroinvertebrate communities respond in the face of hydrological variation.