中国洪湖沉水植物群落调查与分析

Survey and Analysis of Submerged Plant Communities in Honghu Lake, China

摘要: 沉水植物是指植物体全部位于水层下面固着生存的大型水生植物，是湖泊生态系统的重要组成部分，具有净化水质、提供饵料、改善生境、营造景观的多重生态功能。洪湖是中国第七大、湖北省第一大淡水湖泊，水生植物十分丰富。按照水生植物调查规范，2017年7月对洪湖沉水植物群落调查，发现洪湖主要建群沉水植物有6科8属15种，包括金鱼藻(Ceratophyllum demersum)、五刺金鱼藻(C. oryzetorum)、黑藻(Hydrilla verticillata)、苦草(Vallisneria natans)、水车前(Ottelia alismoides)、荇菜(Nymphoides peltata)、金银莲花(Nymphoides indica)、狐尾藻(Myriophyllum spicatum)、轮叶狐尾藻(M. verticillatum)、菹草(Potamogeton cristatus)、光叶眼子菜(P. lucens)、微齿眼子菜(P. maackianus)、竹叶眼子菜(P. malaianus)、蓖齿眼子菜(P. pectinatus)和小眼子菜(P. pusillus)。沉水植物组成了7个群丛48个群落，覆盖了洪湖49.14%的面积。分析表明，1960年代洪湖主要优势沉水植物是耐污能力差、饵料价值高的竹叶眼子菜、苦草和黑藻，表明那时的洪湖水质清洁，鱼类饵料丰富、生态系统优良；1980年代，耐污能力强的微齿眼子菜、菹草和金鱼藻占据优势，1990年代一直维持着这个格局，表明1980~2000期间，洪湖水质比较差；本次调查显示，虽然优势沉水植物还是耐污能力比较强的菹草和篦齿眼子菜，但苦草和竹叶眼子菜又重新回到优势种的位置，表明洪湖局部地区水质开始好转，生态健康程度有所回升。为提高生态系统稳定性，建议进一步取缔围网、绞草、拖螺等人为干扰，同时改善入湖水质，增加水体透明度，促进沉水植物的恢复。

Abstract: Submerged plant is a group of aquatic macro plants which are rooted in the bottom of a water course while the leaves remain submerged below the surface of the waters. They are the main components of lake ecosystem and have very important ecological functions in terms of clearing water, providing forage, improving habitant and building landscape. Honghu Lake is the largest fresh water lake in Hubei province, ranking as the seventh largest in China. It carries abundant aquatic plants. Following the guideline for aquatic plants investigation, I surveyed submerged plant communities in Honghu lake in July 2017. Results suggested that there are 15 constructive species in 8 genus belonged to 6 families. Species included Ceratophyllum demersum, C. oryzetorum, Hydrilla verticillate, Vallisneria natan, Myriophyllum spicatum, M. verticillatum, Potamogeton cristatus, P. lucens, P. maackianus, P. malaianus, P. pectinatus and P. pusillus. The submerged plants constructed 48 plant communities classed into 7 community associations. The submerged plant communities covered 49.14% areas of the lake. Analyses showed that in 1960s, constructive species were Potamogeton malaianus, Vallisneria natans and Hydrilla verticillate. These three spe-cies usually have weak pollution resistibility and high forage value, indicating Honghu had clean water, abundant forage and health ecosystem that moment. However, in 1980s the constructive species were replaced by Potamogeton maackianus, Potamogeton cristatus and Ceratophyllum de-mersum, which had higher pollution resistibility. This species structure continued to the end of 1990s. It indicated that during 1980 to 1990, the water quality was quite bad. Our investigation in this research showed that although the dominant species were still Potamogeton maackianus and Potamogeton cristatus, Hydrilla verticillate and Potamogeton malaianus appeared again as the constructive species, indicating that the water quality is starting to recovery and ecosystem is be-coming health. For improving the ecosystem, we suggest that the web fishing, aquatic plant har-vesting and collecting snail should be stopped. Meanwhile, we should improve the water quality in the upper reaches, increase water transparency and promote restoration of submerged plants.