Iron Regulation of Wetland Vegetation Performance Through Synchronous Effects on Phosphorus Acquisition Efficiency

Abstract

Iron-rich groundwater flowing into wetlands is a worldwide environmental pollution phenomenon that is closely associated with the stability of wetland ecosystems. Combined with high phosphorus (P) loading from agricultural runoff, the prediction of the evolution of wetland vegetation affected by compound contamination is particularly urgent. We tested the effects of anaerobic iron-rich groundwater discharge in a freshwater marsh by simulating the effect of three levels of eutrophic water on native plants (Glyceria spiculosa (Fr. Schmidt.) Rosh.). The management of wetland vegetation with 1-20 mg/L Fe input is an efficient method to promote the growth of plants, which showed an optimum response under a 0.10 mg/L P surface water environment. Iron-rich groundwater strongly affects the changes in ecological niches of some wetland plant species and the dominant species. In addition, when the P concentration in a natural body of water is too high, the governance effect of eutrophication might not be as expected. Under iron-rich groundwater conditions, the δ 13 C values of organs were more depleted, which can partially explain the differences in δ 13 C in the soil profile. Conversely, the carbon isotope composition of soil organic carbon is indicative of past changes in vegetation. The results of our experiments confirm that iron-rich groundwater discharge has the potential to affect vegetation composition through toxicity modification in eutrophic environments.

Eco-physiological Responses of Carex Schmidtii to Soil Salinization in a Chinese Wetland

“…Dry matter content and specific leaf area were used to indicate blade function. Part of fresh leaf samples was used to determine chlorophyll a, chlorophyll b [15] and malondialdehyde (MDA) contents [16]. Fresh leaves (0.2 g) were soaked in 10 mL of ethanol-acetone (1:1) for two days in the dark and then centrifuged at 2000 rpm for 15 min.…”