2009年秋季武汉大东湖北湖水系水生植物调查

摘要

Beihu Watershed of East Lake area, Wuhan, consists of five lakes: Lake Beihu, Lake Yanxi, Lake Yandong, Lake Zhuzi and Lake Qingtan. The aquatic macrophytes were investigated in the lakes of Beihu Watershed in the autumn of 2009. The results showed that the distribution of macrophytes covered an area of 3.89 km2 , accounting for 14.8％ of the whole lake area with a total biomass (fresh weight) of 17834.28t. 49 species of macrophytes were observed, belonging to 36 genera and 20 families,and the dominant species were Vallisneria spiralis, Myriophyllum spicatun, Nelumbo nucifera, etc. , while V. spiralis was the absolute dominant species. Among the 4 life-type macrophytes, distribution area of submerged plant community was 74.33％ of the total area of macrophytes and the standing crop was 67.25％ of the macrophytes, which were both dominant, those of the emergent plant community were 22.86％ and 28.43％ , and floating-leaved plant community were 2.79％ and 4.31％ , respectively; The percentages of freely floating plant community were 0.02％ and 0.01％ , respectively. Macrophytes mainly distributed in Lake Yandong and Lake Yanxi and were sparse in other lakes. The submerged macrophytes in Lake Yandong were abundant, while the community structure was simple with few species. Species diversity and community composition varied in Lake Yanxi, whereas the macrophytes just distributed near the lake shoreline. Comparing with East Lake, the macrophyte in lakes of Beihu Watershed was more abundant and diversified. But owing to the reclaiming, fishery and deterioration of water quality, the distribution of macrophyte community already showed a tendency to decline, and its structure and function degraded, too. According to the situation,more effort should be taken to protect or restore the macrophyte in the lakes of Beihu Watershed in the Large East Lake Ecological Water-net Engineering Project.%武汉大东湖北湖水系包括北湖、严西湖、严东湖、竹子湖、清潭湖.2009年秋季对北湖水系湖区水生植物调查结果表明,水生植物分布面积达3.89km2,占整个水域面积的14.8%,总现存量(鲜重)为17834.28t;现有水生植物49种,隶属于20科36属,苦草(Vallisneria spiralis)、穗花狐尾藻(Myriophfllum spicatum)、莲(Nelumbo nucifera)等为优势种,其中苦草为绝对优势种.四种生活型水生植物中,沉水植物分布面积和现存量占水生植物总量的74.33%和67.25%,其次是挺水植物,分别占22.86%和28.43%,浮叶植物分别占2.79%和4.31%,漂浮植物的面积和现存量分别占0.02%和0.01%.在整个北湖水系湖泊中,水生植物集中分布在严东湖、严西湖,其他湖泊只有少量零星分布.严东湖水生植物比较丰富,但种类单一,植物群落结构层次较为简单;严西湖植物群落结构层次较为复杂,物种组成比较丰富,但分布仅局限于沿岸带.与东湖相比,北湖水系水生植物分布范围相对较广,但由于围垦、渔业、水质恶化等的影响,水生植物分布呈下降趋势,群落结构与功能退化.针对上述情况,大东湖生态水网工程应尽力保护与恢复北湖水系的水生植物资源.