白马湖浮游动物生态位及其生态分化影响因子

基于2018年1月至12月在白马湖进行的12次浮游动物调查数据，采用K-优势度曲线法对浮游动物种（类）群进行排序计算白马湖浮游动物优势种（类）群的生态位宽度值（），并通过冗余分析（RDA）研究其生态位分化状况。结果表明: 白马湖浮游动物共出现优势种（类）群20种，依据白马湖浮游动物优势种（类）的生态位宽度值，可以分为以下3个类型：广生态位种（类）群、中生态位种（类）群和窄生态位种（类）群三大类群。广生态位种（类）群如针簇多肢轮虫、桡足幼体、无节幼体等，在各个季节均出现且在大部分的站位点都有较高的个体百分比，生态位宽度值全年均较高，表明这些种类的浮游动物的生态适应能力较强。窄生态位种（类）群如懒轮虫、等刺异尾轮虫、褐砂壳虫等，对环境的适应性较差，其丰度相对较小，并且一年中分布不均匀或者只在个别季节少量出现。RDA分析表明，总氮、氨氮、pH和溶解氧对浮游动物时空生态分化有直接影响，而高锰酸钾、总磷的影响次之。

Zooplankton Ecological Niche and Factors Affecting Ecological Differentiation in Baima Lake

Based on 12 zooplankton surveys conducted in Baima Lake from January to December 2018, the niche width()of dominant zooplankton species (groups) in the lake was calculated by using the K-dominance curve method, and the niche differentiation was studied by using the redundancy analysis (RDA). The results showed that there were a total of 20 dominant species (groups) in the lake. According to the niche width of the dominant species (groups) in the lake, the zooplankton could be divided into three types: wide niche groups, medium niche groups and narrow niche groups. The wide niche species (groups), such as Polyarthra trigla, Copepods, and Nauplius, all appeared in each season and had a high percentage of individuals in most of the stations, and the niche width values were high throughout the year, indicating that these species had strong ecological adaptability. Nnarrow-niche species (groups), such as Rotaria tardigrada,Trichocerca similis and Difflugia avellana, have poor adaptability to the environment. Their abundance is relatively small, and they are distributed unevenly throughout the year or appear only in a few seasons. RDA analysis showed that total nitrogen, ammonia nitrogen, pH and dissolved oxygen had a direct effect on the spatial and temporal ecological differentiation of zooplankton, while potassium permanganate had a direct effect on the spatial and temporal ecological differentiation of zooplankton. The effect of total phosphorus was the second.