不同地表水水位下莫莫格湿地植物群落物种组成和数量特征

Species Composition and Quantity Characteristic of Plant Communities in Momoge Wetlands under Different Water Levels of Surface Water

在莫莫格湿地,选择常年积水、季节性积水和常年无积水的3块湿地作为采样点,进行地表水水位观测和植物群落调查。结果表明,莫莫格湿地植物群落物种组成和数量特征受地表水水位的显著影响。常年积水的哈拉塔采样点的植物以水生植物为主,形成单优物种的芦苇(Phragmites australis)群落,其群落高度和平均生物量显著高于其它两个采样点(p<0.05);季节性积水的哈尔挠采样点以湿生植物为主,物种丰富度和群落密度都高于其它两个采样点(p<0.05);而地表湿润的哈拉火烧采样点的植物生长缓慢,其群落高度、盖度和生物量都较低。另外,莫莫格湿地植物群落组成和数量特征季节变化明显。哈拉塔和哈尔挠采样点的物种丰富度在7月(水位最高时)达到最高,而后开始降低。与此同时,哈尔挠采样点优势种由小叶章(Calamagrostic angustifolia)取代薹草(Carex sp.),生物量降低,水位高度与物种多样性显著正相关(R2=0.519,p<0.05)。莫莫格湿地不同区域的地表水水位差异导致植物群落的物种组成和数量特征发生改变。

In Momoge wetlands, Halata, Haernao and Halahuoshao sampling sites with different water levels of surface water were selected to observe the water level of surface water and plant community. The results showed that species composition and quantity characteristics of plant communities were pronouncedly affected by the water level of surface water. In the Halata site with perennial waterlogging, plant community dominated by Phragmites australis had the highest plant height and greatest biomass. Plants in the Haernao site with seasonal waterlogging were main hygrophytes, with the higher species richness and plant density than those in the other two sites(p<0.05). In the Halahuoshao site with limited surface water, plants grew slowly.The plant height, coverage and biomass were lower than those in the other sites. In addition, the composition and quantity characteristics of plant communities changed seasonally. Plant richness in Halata and Haernao sites was the highest when water level achieved to the climax in July, and then tended to decrease. At the same time, Calamagrostic angustifolia occupied the dominant position instead of Carex sp. in Haernao site, and the biomass of vegetation was consequently decreased. There was a significant relationship between water level and species richness in Haernao site(R2=0.519, p<0.05). The differences of the water levels of surface water among the sites in Momoge wetlands resulted in the variations of species composition and quantitative characteristics of plant communities.