三环泡湿地浮游动物功能群季节变化及其影响因子

为了研究寒区湿地浮游动物功能群的季节变化以及水环境等因素的影响,对淡水浮游动物进行了功能群划分,以北方寒冷地区沼泽型湿地三环泡国家级自然保护区为例,于2014年春季(5月)、夏季(7月)和秋季(9月)对三环泡国家级自然保护区15个采样点进行了浮游动物采样,系统分析了浮游动物功能群的组成特征。结果表明:三环泡国家级自然保护区浮游动物功能群共划分为7个功能群,春季以功能群RF占优势,为83.82%;夏季以功能群RC、PF、RF和LCC占优势,分别为34.15%,19.58%,18.49%和10.54%;秋季以功能群RC和RF占优势,分别为71.94%和17.86%。浮游动物功能群季节变化表现为RF→RC+PF+RF+LCC→RC+RF的特点,表明春季功能群RF对浮游植物起到了很好的滤食作用,夏季和秋季功能群RC对功能群PF和RF捕食压力较大。通过Pearson相关分析和RDA多元统计分析表明,种间竞争、氯离子(Cl-)、总氮(TN)、总无机碳(IC)和生物耗氧量(BOD5)是影响三环泡国家级自然保护区浮游动物功能群的主要影响因素,除功能群RF外,其它功能群同氯离子(Cl-)、总氮(TN)和总无机碳(IC)显著正相关,同生物耗氧量(BOD5)显著负相关,SCF、MCF、MCC和LCC由于食物竞争和捕食之间的关系表现出极显著的相关性,同为捕食关系的RC和RF、PF则没有表现出明显的相关性。种间竞争、浮游植物上行效应和营养盐是影响寒区沼泽型湿地浮游动物功能群季节变化和生物量的主要因素。

Seasonal dynamics of zooplankton functional groups and their relationships with environmental factors in the sanhuanpao wetland reserve

We classified the zooplankton functional groups in a freshwater ecosystem, the Sanhuanpao Wetland Reserve, to determine the seasonal variation related to the environmental factors. We investigated the zooplankton in spring, summer, and autumn, and identified seven functional groups during the study period. Group RF (Rotifers filter feeders) was dominant in spring and was important to control the phytoplankton. Groups RC (Rotifers carnivore), PF (Protozoas filter feeders), RF, and LCC(Large copepods carnivore) were dominant in summer, whereas groups RC and RF were dominant in autumn. Group RC obviously inhibited the growth of PF and RF in summer and autumn. The results from Pearson and RDA analyses revealed that interspecificcompetition, Cl^-(Chloride ion), TN(Total nitrogen), IC (Total Inorganic Carbon), and BOD₅ (Biological oxygen demand) were the most important factors affecting zooplankton functional groups in the Sanhuanpao Wetland Reserve. Cl^-, TN, and IC showed a positive relationship with all the zooplankton functional groups except RF, whereas BOD₅ showed a negative relationship with all the zooplankton functional groups except RF. The functional groups SCF, MCF, MCC, and LCC had a positive relationship with each other, whereas group RC showed no relationship with groups PF and RF. Interspecific competition, bottom-up effects of phytoplankton and nutrients were the most important factors affecting the seasonal variation and biomass of zooplankton functional groups in cold region of marsh wetland.