Oral Presentation Society for Freshwater Science 2025 Annual Meeting

Let’s not get bogged down: Full hydroperiod analysis of aquatic insect biomass transport and richness in variable isolated wetlands (118618)

Elizabeth Sicking 1 2 , Kier Klepzig 2 , Steve Golladay 2 , Daniel McLaughlin 1 , Sally Entrekin 1
  1. Virginia Tech, Blacksburg, Virginia, United States
  2. The Jones Center at Ichauway, Newton, Georgia, United States

Around 50% of original global wetland area has been lost in the last few centuries. Changes in temperature, evapotranspiration, and precipitation intensity, frequency, and amount are shifting hydrological norms, and disrupting aquatic insect composition and life cycle patterns. Isolated wetlands are susceptible to these changes due to their reliance on precipitation that governs their annual inundation cycles. The extent to which insect communities living in isolated wetlands are adapted to historical inundation cycles and other environmental characteristics is unknown, creating a gap in predicting how climate change will influence aquatic insect abundance and community composition. We aimed to address this gap by assessing insect community composition and life cycle patterns throughout a hydroperiod in 11 isolated wetlands with unique inundation patterns, vegetation communities, and fire history. We sampled benthic and emergent insect communities in five cypress swamps and six sedge marshes located in the southeastern Coastal Plain of Georgia, USA throughout the 2023 hydroperiod. Our objective was to understand relationships between wetland characteristics and richness, density, and biomass weighted community composition. We hypothesized that marshes historically having a long hydroperiod would have the greatest richness, density, and biomass due to more resource availability and adaptation to a longer growth period. Preliminary results suggest that historical hydrology alone is not a significant predictor of insect community richness and biomass, but the combination of vegetation type and hydrology support distinct composition and patterns of emergence. We are continuing our analysis by assessing the influence of historical inundation cycles on insect community patterns and shifts that include insect vs. non-insect ratios across time, and the energetic contribution of emergent insects to surrounding terrestrial systems.