Plant diversity increases N removal in constructed wetlands when multiple rather than single N processes are considered

作者：Yan Geng, Ying Ge, Bin Luo, Zhengxin Chen, Yong Ki Min, Bernhard Schmid, Binhe Gu, Jie Chang · 发表于：Ecological Applications · 年份：2019 · DOI：10.1002/eap.1965 · 被引用次数：26 · 研究领域：Constructed Wetlands for Wastewater Treatment、Coastal wetland ecosystem dynamics、Wastewater Treatment and Nitrogen Removal

Biodiversity has a close relationship with ecosystem functioning. For most biodiversity-ecosystem-functioning studies, biodiversity has been linked to a single indicator variable of ecosystem functioning. However, there are generally multiple ecosystem processes contributing to ecosystem functioning and they differ in their dependence on biodiversity. Thus, the relationship between biodiversity and ecosystem functioning can be stronger when multiple rather than single ecosystem processes are considered. Using both mass-balance and stable-isotope approaches, we explored the effects of plant diversity on nitrogen (N) removal sustained by multiple N-cycling processes in experimental microcosms simulating constructed wetlands, an ecosystem treating wastewater with high N loading. Four species were used to assemble different plant communities, ranging in richness from one to four species. The removal of N, indicated by low levels of total inorganic N concentration (TIN) present in the effluent, was considered as an integrated measure of ecosystem functioning, combining three constituent N-cycling processes: plant uptake, denitrification, and substrate adsorption. Our results showed that (1) species richness had a positive effect on N removal, in particular, the four-species mixture reduced effluent TIN to a lower level than any monoculture; however, polycultures (two-, three-, and four-species mixtures) did not outperform the most efficient monoculture when each of the three const...