三江平原湿地同江地区水域夏季浮游植物群落结构特征

Community Structure Characteristics of Phytoplankton in Tongjiang of the Sanjiang Plain Wetland

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。

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.