赤水河春季浮游植物群落结构变化及其优势种生态位分析

基于2011-2016年春季对赤水河4个断面浮游植物的调查，分析其群落结构变化及优势种生态位，揭示浮游植物群落变化规律、优势种的生态位分化及其环境适应性，可为赤水河浮游植物群落结构特征研究提供基础资料。结果显示，6年间在赤水河共采集到浮游植物7门、68属、233种（变种），主要为硅藻，占比超过60%；浮游植物细胞密度在（17.28～136.68）×104个/L，各段面浮游植物密度年际间变化无显著差异，群落组成时间异质性较空间异质性明显，时空方差分解显示，时间变异可解释总变异的24.5%，空间变异仅解释总变异的2.0%；浮游植物多样性指数显示，2014年和2016年赤水河处于轻污或无污染状态，2011-2013年和2015年受到中度人为影响。2011-2016年春季赤水河共出现优势种31种（变种），主要为广生态位和中生态位种，生态位重叠指数在同一门类物种中最高，在不同门类物种中最小。研究表明，赤水河春季浮游植物对水生态环境的适应能力强，对水环境变化有较好的适应性。

Spring Phytoplankton Community Structure and Niche Analysis of Dominant Species in Chishui River

The phytoplankton community structure and dominant species niche were analyzed based on the survey of phytoplankton in 4 sections of Chishui River during spring from 2011 to 2016. The law of phytoplankton community changes in spring, the niche differentiation of dominant species and their environmental adaptability were revealed to provide basic data for the study of the characteristics of the phytoplankton community structure in the Chishui River. A total of 233 species (variants) of 68 genera and 7 phyla of phytoplankton were collected in Chishui River from 2011 to 2016. Bacillariophyta are the most, accounting for more than 60.51%. The phytoplankton density fluctuates between 17.28~136.68×104cells/L. There is no significant difference in the inter-annual phytoplankton density of each section, and the temporal heterogeneity of phytoplankton community composition is more obvious than the spatial heterogeneity. The decomposition of temporal and spatial variance shows that temporal variability can explain 24.5% of the total variability, while spatial variability only explains 2%. Based on the evaluation of the phytoplankton diversity index, the Chishui River was in a light or no pollution state in 2014 and 2016, and it was moderately affected by humans from 2011 to 2013 and 2015. A total of 31 dominant species (variants) appeared in Chishui River in the spring of 2011-2016. The niche types of the dominant species of phytoplankton in Chishui River are mainly broad and middle niche. The average niche overlap index of dominant species is the highest among species in the same category and the smallest among species in different categories. The analysis results show that the phytoplankton in the Chishui River has a strong adaptability to the water ecological environment in spring, and has a good adaptability to the changes of the water environment.