Secondary production and seasonal development of epiphytic Enallagma civile Hagen, 1861 (Odonata: Coenagrionidae) in a newly constructed urban wetland floodway ecosystem

摘要

Secondary production and seasonal development of the damselfly Enallagma civile Hagen, 1861 were determined as part of an epiphytic macroinvertebrate study in the Dallas Floodway Extension Trinity River Project Lower Chain of Wetlands, Dallas, TX, USA. These wetlands were constructed to mitigate flooding of the Trinity River, but also provided quality wildlife habitat and removal of wastewater effluent contaminants. Variations in life history were observed between two macrophytes and three different wetlands of varying age, effluent source, and vegetation establishment. Mean annual production of E. civile was 1393 mg/m(2)/year, standing stock biomass was 1376 mg/m(2)/year, cohort production/biomass (P/B) ratio was 4.30/year, and annual P/B was 10.18/year. These values are in the upper range of known Odonata production values from a lentic system. Enallagma civile biomass growth rates were observed to be higher from populations on the better established macrophyte (Potamogeton nodosus Poiret, 1816) and in the longest established wetland.