Connecting Wetland Flooding Patterns to Insect Abundance Using High-Resolution Inundation Frequency Data

Abstract

Flood dynamics are important drivers of wetland biodiversity. With current climate and land-use changes affecting overall water cycling, many wetland ecosystems are at risk of degradation, affecting biodiversity support negatively. This emphasizes a need for understanding possible correlations between specific hydrological conditions and biodiversity support in wetlands, at least in terms of species composition. In this study, we used high resolution hydrological monitoring of water levels and insect sampling in a depressional wetland to investigate possible correlations between inundation patterns and insect abundance. Our results show that there is a high spatial and temporal heterogeneity in wetland inundation patterns and that this heterogeneity explains variation in insect abundance. This creates episodes of downstream wet and upstream dry conditions. In addition, the spatial variability was high between grid cells of 2 meter’s resolution. There were also indications that distance to stream affected insect community structure. The findings from this work show that that the local hydrological conditions can create heterogeneity in habitat conditions, which in turn lead to refuge habitats for species vulnerable to changes in inundation condition. This study also highlights the importance of acknowledging quantitative hydrological methods when assessing the relation to insect communities.