Patterns of functional community structure in Great Lakes interdunal wetlands

Session: Great Lakes Coastal Wetlands: Innovative Research to Improve Restoration (4)

Christopher Frazier, Western Michigan University, [email protected]
Tiffany Schriever, Western Michigan University, [email protected]

Abstract

Determining how communities are structured and how structure changes over time is a fundamental goal in ecology.  Great Lakes interdunal wetlands can be sampled across an entire successional gradient within a relatively small geographic area, making this habitat ideal for studying temporal changes in community structure.  Our study investigated how the functional structure of macroinvertebrate communities in 11 interdunal wetlands changed over the course of a growing season (Apr-Oct) and over successional time.  We tested several hypotheses of functional change patterns across both temporal scales, including functional turnover and convergence/divergence of trait combinations (Boersma et al. 2016).   We constructed a trait database for 73 collected macroinvertebrate taxa and calculated functional diversity indices (total abundance and functional richness, distance, and dispersion) to test our hypotheses.  There is evidence of functional turnover between habitats separated by successional time, likely associated with changes in resource and niche availability.  On an annual timescale, older wetlands showed no difference in functional community, while young wetlands showed similar trait structure through time but with varied abundances, supporting the equal impact hypothesis.  Our results reveal the varying functional roles wetlands play in the landscape over their lifespan and the importance of protecting wetlands across successional gradients.