Nutrient Resorption from Leaves of Wetland Plants in a Constructed Wetland Depends on Green Leaf Nutrient Content and Life Form

Abstract

Leaf nutrient resorption is a fundamental process, which prevails in nutrient-poor ecosystems. However, few studies have focused on this process in nutrient-rich ecosystems, especially in eutrophic constructed wetland (CWs). Thus, insight into the nutrient resorption processes of different species in CWs might have important implications for wetland restoration and water purification. Here, we assessed the leaf nitrogen and phosphorus resorption efficiencies and proficiencies of 11 plant species (4 floating and 7 emergent plants) from a CW, and related them to both plant functional traits and environmental variables to develop better predictive power of resorption processes across species. Our results showed that emergent and floating plants, respectively, resorbed 37.4% vs. 8.6% N and 50.1% vs. 23.3% P during nutrient resorption in such a nutrient-rich CW. Green leaf nutrient was the best predictor for the nutrient resorption efficiencies and proficiencies in this CW. Interspecific variation in nutrient resorption defines an important strategy for plant nutrient recycling in nutrient-rich wetland ecosystems, and provide a tool for optimizing the efficiency and timing of nutrient capture via foliage harvesting. This link between wetland plant functions and wetland ecosystem services will thus be beneficial for the nutrient management of CWs in future.