汉江中下游水生植物群落及演替

水生植物是河流生态系统的重要组成部分, 研究河流水生植物群落组成及演替对于河流生态系统健康诊断具有重要意义。该研究采用野外生态学研究方法, 于2013年9月和2014年6月2次对汉江中下游12个典型代表性江段的水生植物群落的组成、分布和生物量等进行调查。调查结果表明, 现阶段汉江中下游的主要水生植物共有69种, 隶属28科49属, 其中优势种主要是穿叶眼子菜(Potamogeton perfoliatus)、竹叶眼子菜(P. malaianus)、芦苇(Phragmites australis)、南荻(Triarrhena lutarioriparia)和喜旱莲子草(Alternanthera philoxeroides)等。结合早期的研究表明, 汉江中游江段沉水植物优势群落变化明显; 下游则呈现出由沉水植物群落向挺水植物群落演替的格局。挖沙和污染等人类干扰以及水位波动、河流底质和植物繁殖策略等自然因素可能是导致汉江中下游水生植物优势种变化和群落演替的主要因素。该研究结果可为汉江中下游的水生植物多样性保护和生态修复提供科学依据。

Community Succession of Macrophytes in the Middle and Lower Reaches of the Hanjiang River

Aquatic plants are an important part of river ecosystems, and study of the composition and succession of river aquatic plant communities is important for diagnosing river ecosystem health. In this study, we studied the aquatic plant diversity in the middle and lower reaches of the Hanjiang River, especially the species and community diversity, by field investigation in September 2013 and June 2014. We found 69 species of macrophytes belonging to 28 families, with 49 genera. The dominant species were Potamogeton perfoliatus, P. malaianus, Phragmites australis, Triarrhena lutarioriparia and Alternanthera philoxeroides. The pattern of macrophyte community succession was from submerged to emergent macrophyte community. The main reasons for species replacement and community succession of aquatic plants were human disturbances such as sand-excavation and pollution and natural factors such as water-level fluctuation, river sediment and reproduction strategy. Our study provides a scientific basis for the protection and ecological restoration of macrophytes and river ecosystem in the middle and lower reaches of the Hanjiang River.