生态学报2017，Vol.37Issue(23)：8029-8038,10.DOI:10.5846/stxb201610232158
汀棠湖轮虫主要食性功能群及其优势种群的周年动态对水环境变化的响应
Reponses of the annual dynamics of functional feeding groups and dominant populations of rotifers to environmental factors in Lake Tingtang
摘要
Abstract
To study the ecological mechanisms underlying the responses of the functional feeding groups and dominant populations of rotifers to environmental factors in a slightly eutrophic lake,zooplankton samples were collected once weekly during July 2011 and June 2012 from Lake Tingtang,located in Wuhu City,Anhui Province,China.We also identified and analyzed annual variations in the density of each functional feeding group,the dominant populations,and the egg ratios of the dominant populations of rotifers.Simultaneously,physicochemical variables of water samples collected from Lake Tingtang,including water temperature,chlorophyll a (Chl-a) concentration,transparency,pH value,TN,NO3--N,NH4+-N,TP,and PO43-were measured.The Chl-a concentration in each water sample was measured in two fractions:one filteredthrough a 25 μm plankton net (Chl-a ＜ 25 μm) and another unfiltered (Chl-a),which were used as biomass indicators ofthe algae with a smaller volume and all phytoplankton,respectively.On the basis of Pearson correlation and multiple linearregression analyses,the relationships between the densities of each rotifer functional group and dominant population andeach of the environmental factors (abiotic factors,such as water temperature,food resources measured by the Chl-aconcentrations of the algae with different cell volumes,and biotic variables of potential competitors,such as cladocerans andpredators,including copepods and carnivorous Asplanchna rotifers) were analyzed.The main results were as follows.(1)Among the four dominant rotifer species occurring in Lake Tingtang,Polyarthra trigla was considered as a raptorial species,whereas Brachionus diversicornis,Anuraeopsis fissa,and Filinia longiseta were classed together as filter-feeding species.Suckers such as Trichocerca spp.were not considered in the present study because of their extremely low density.(2)Principal component analysis (PCA) showed that water temperature,Chl-a concentration,the densities of cladocerans,copepods and their nauplii,and Asplanchna were crucial for determining the dynamics of rotifer community structure in Lake Tingtang.Water temperature and Chl-a concentration of all phytoplankton was the most important factor shaping the annual dynamics of the filter-feeding and raptorial rotifers in Lake Tingtang,respectively.However,interspecific competition and predation pressure were not the key factors controlling the seasonal dynamics of any functional feeding groups.(3)Interspecific competition and predation pressure were also not the key factors affecting the annual dynamics of dominant populations of filter-feeders.Water temperature and the Chl-a concentration of algae with a smaller volume (Chl-a ＜ 25μm) were positively correlated with the densities of B.diversicornis and F.longiseta,classified as filter-feeders.Furthermore,the seasonal dynamics of B.diversicornis and F.longiseta were principally controlled by Chl-a ＜ 25 μm.In comparison,the density of A.fissa was only affected by water temperature.(4) The egg ratios of filter-feeding rotifers,including B.diversicornis and F.longiseta,and the raptorial species P.trigla were mostly influenced by water temperature.Additionally,the egg ratios of three rotifers decreased with a decrease in water temperature.Taken together,the results indicate that water temperature and food resources are more likely to be the key factors affecting the annual dynamics of filter-feeding and raptorial rotifers than are the other examined variables,such as interspecific competition and predation pressure.关键词
轮虫/食性功能群/优势种群/动态/环境因子Key words
Rotifers/functional feeding groups/dominant populations/dynamics/environmental factors引用本文复制引用
温新利,谢萍,周俊,席贻龙..汀棠湖轮虫主要食性功能群及其优势种群的周年动态对水环境变化的响应[J].生态学报,2017,37(23):8029-8038,10.基金项目
国家自然科学基金(31470015) （31470015）
安徽省高校自然科学研究重点项目(KJ2017A320) （KJ2017A320）
重要生物资源的保护与利用安徽省重点实验室专项基金 （）
