The Relationship Between Patterns in Flying Adult Insect Assemblages and Vegetation Structure in Wetlands of Ohio and Texas

Author Institution: Wetland & Watershed Assessment Group, EDC, Inc. ; Rettew AssociatesThe success of compensatory wetland replacement is frequently judged on the basis of percent vegetation cover. Measuring percent cover of wetland species, or the survival of planted species, especially only one or two years after construction seems tautological. Aquatic insects have been used for many years as indicators of ecosystem integrity and may be useful as an integrative wetland assessment tool. This study was initiated to determine if adult insect assemblages could be used to differentiate between wetlands and uplands, and to identify site characteristics, especially vegetation, related to patterns in insect assemblages. We collected adult insect assemblages using light traps at wetlands in northeastern Ohio and southeastern Texas. We also measured properties of wetland vegetation structure and composition around the light traps and performed indirect gradient analysis. We found that ordinations of flying nocturnal insect assemblages generally separated upland from wetland sites and that insect ordination patterns were related to vegetation density and predominant vegetation growth forms such as vines, herbs, shrubs and trees