三江平原湿地同江地区水域夏季浮游植物群落结构特征

2012年6月对三江平原湿地同江地区水域浮游植物群落结构进行了初步研究。设置了13个采样点,生境类型包括大型开阔水体、小型封闭水体、湿地型水体以及河流型水体。结果在该水域发现浮游植物共计312个分类单位,包括276种33变种3变型,隶属于8门10纲21目36科92属。浮游植物细胞密度变化范围为2.68×104–2.53×106 cells·L–1。大型开阔水体种类丰富,细胞密度最大,以绿藻为优势种群;小型封闭水体中藻类的适应性强,群落结构最为复杂;湿地型水体受人为活动影响较大,发现了一些耐有机污染的种类;在河流型水体中,有一些适低温的隐藻出现并成为优势种,如啮蚀隐藻(Cryptomonas erosa)等。此外,在三江平原湿地同江地区还发现了大量β-中污染指示种类。经聚类和多维尺度分析,将不同采样点各生境水体的浮游植物群落分为4组。综合多样性指数表明,同江地区水域浮游植物群落结构较丰富且稳定性较好。

Community Structure Characteristics of Phytoplankton in Tong-jiang of the Sanjiang Plain Wetland

We examined the phytoplankton community structure in the Tongjiang area in the Sanjiang Plain Wetland in summer （June） of 2012 with 13 sampling sites consisting of large open-water bodies, small closed-water bodies, wetland water bodies, and river water bodies. We identified 312 taxa （including 276 species, 33 varieties and 3 forms） belonging to 8 divisions, 10 classes, 21 orders, 36 families, and 92 genera. The phytoplankton abundance varied from 2.68×10^4 to 2.53×l0^6 cells·L^-1. The abundant species and highest cell densities occurred in large open-water bodies, and Chlorophyta was the dominant group. In small closed-water bodies, algae adaptability was strong, and algal community structures were the most complex in all habitats. The water bodies were influenced by human activities, and we found several indi- cator species of organic pollution, such as Trachelomonas oblonga and T. hisoida. Some taxa that were characteristic of low-temperature habitats, such as Cryptomonas erosa, were identified in river water bodies and were dominant species. Meanwhile, we found a large increase in the number of β-mesosaprobic-zone indicators. Cluster and non-metric multidimensional scaling analysis divided the phytoplankton community composition into 4 groups. The Margalef index ranged from 0.41 to 5.47, the Shannon-Wiener index from 1.22 to 3.58, and the Simpson and Pielou indexes were higher. Diver- sity indexes showed that the phytoplankton community structure was relatively abundant and stability varied in the Tong- jiang area of the Sanjiang Plain Wetland.