汉阳地区五个湖泊沉水植物分布及富营养化现状

2011年7月—2012年4月对武汉市汉阳地区五个湖泊(后官湖,三角湖,南太子湖,墨水湖和龙阳湖)的水质及沉水植物进行了季节性调查,以了解湖泊富营养化现状及其对沉水植物的影响。结果显示:后官湖为中营养,而三角湖、南太子湖、墨水湖和龙阳湖为重度富营养,其中龙阳湖污染最重。共采集沉水植物7种,隶属于5科5属,主要种类为金鱼藻(Ceratophyllum demersum)、苦草(Vallisneria spiralis)和菹草(Potamogeton crispus)。沉水植物主要分布在后官湖沿岸带,其它四个湖泊中沉水植物已严重退化,仅在部分水域偶见。后官湖沉水植物盖度和生物量最大值出现在10月,分别为67.5%和5.58 kg/m~2,1月份较低,分别为29.3%和1.88 kg/m~2,优势种存在明显的季节更替。结果表明,汉阳地区湖泊沉水植物退化与富营养化引起的水下光照下降和高密度的水产养殖有关。

Distribution of submerged macrophytes and eutrophication status of five lakes in Hanyang region of Wuhan,China

A seasonal survey was conducted on water quality and distribution of submerged macrophytes in fives lakes ( Houguan Lake, Sanjiao Lake, Nantaizi Lake, Moshui Lake and Longyang Lake) in Hanyang region of Wuhan, China in July, 2011—April, 2012. The objective is to understand the eutrophication status of these lakes and its effects on sub-merged macrophytes. The results showed that Houguan Lake was mesotrophic, while the other four lakes, especially Longy-ang Lake, were severely eutrophic. Altogether seven species, five genera and five families of submerged macrophytes were identified. Ceratophyllum demersum, Vallisneria spiralis and Potamogeton Crispus dominated the community of submerged macrophytes. Submerged macrohphytes were mainly distributed in the lakeshore areas of Houguan Lake. While they were greatly degraded in other four lakes and might be observed occasionally. The maximum cover ( 67. 5%) and biomass (5. 58 kg/m2 ) of submerged macrohphytes were observed in October, and the relative lower cover (29. 3%) and biomass (1. 88 kg/m2 ) were observed in January. The dominant species showed a significant seasonal succession. Decreased under-water light climate associated with increased lake eutrophication and intensive aquaculture might be responsible for degrada-tion of submerged macrophytes in the lakes of Hanyang region.