中国外来入侵水生植物及其在污染水体生态修复中的应用进展

Alien-invasive aquatic plants in China and their application progress in ecological remediation of contaminated water

随着社会经济与工农业的快速发展以及人类活动加剧,外来生物以及以氮、磷为主的富营养化和重金属、有机物等污染物正不同程度威胁中国水生态安全、生物多样性及国民经济高质量发展。相对价格高、工程量大和二次风险高的物理和化学措施,以水生植物为核心的生物-生态法在水生态修复中备受青睐和广泛应用。中国外来入侵水生植物物种多,虽然这些物种入侵程度不同,但其分布相对集中在东部平原区和云贵高原区。过去30年来,中国在防控外来入侵水生植物的同时,挖掘凤眼蓝〔Eichhornia crassipes(Mart.)Solms.〕、喜旱莲子草〔Alternanthera philoxeroides(Mart.)Griseb.〕和大薸(Pistia stratiotes Linn.)等在污染水体生态修复方面的功能和实际应用,取得了一定进展,发现外来入侵水生植物在不同水体和不同污染物类别间有一定的修复差异,且部分物种表现出与本土植物间的比较优势;对水体污染物的去除机制主要包括植物吸收与同化、根系分泌物与根际微生物互作以及植物降解与挥发等。本文全面梳理了中国外来入侵水生植物物种及地理分布,分析了凤眼蓝、喜旱莲子草和大薸等典型外来入侵水生植物修复污染水体的效果与机制,指明外来入侵水生植物的重要研究方向,认为未来在利用外来入侵植物进行水生态修复时,应兼顾防控和资源高值化综合利用及科普教育的协同工作。

With the rapid development of society economic and industry and agriculture as well as the intensification of human activity,alien species,eutrophication mainly caused by nitrogen and phosphorus,and pollutants including heavy metals and organic matters are threatening water ecological security,biodiversity,and high-quality development of the national economy in China to different degrees.Compared with physical and chemical measures with relative high prices,large quantity of engineering,and high secondary risk,the bio-ecological method with aquatic plants as the core is highly favored and widely applied in water ecological restoration.There are many alien-invasive aquatic plant species in China,and although the invasion degrees of these species are different,their distributions are relatively concentrated in eastern plain area and Yunnan-Guizhou plateau area.Over the past three decades,while preventing and controlling alien-invasive aquatic plants,China has explored the functions and practical applications of Eichhornia crassipes(Mart.)Solms.,Alternanthera philoxeroides(Mart.)Griseb.,and Pistia stratiotes Linn.,etc.in ecological remediation of polluted water bodies,and has made some progress,which reveals that alien-invasive aquatic plants have some differences in restoration among different water bodies and different types of pollutants,and some species exhibit comparative advantages over native plants;the main mechanisms for removing pollutants from the water bodies include plant absorption and assimilation,root exudates-rhizosphere microbes interactions,and plant degradation and volatilization.This article comprehensively reviews the species and geographical distribution of alien-invasive aquatic plants in China,analyses the effects and mechanisms of typical alien-invasive aquatic plants such as E.crassipes,A.philoxeroides,and P.stratiotes on restoration of polluted water bodies,indicates the important research directions for alien-invasive aquatic plants,and suggests that in the future,when using alien-invasive plants for water ecological remediation,cooperation of prevention and control,comprehensive utilization of the high-value resource,and popular science education should be considered.