食物和理化因子对浮游甲壳动物群落结构的影响

Effects of food and physicochemical factors on crustacean zooplankton community structure

食物质量和数量对浮游动物群落结构的影响在野外研究中较少涉及.本文通过对湖北省境内14个水体的春季采样,分析了食物质量和数量以及理化因子对浮游甲壳动物群落结构的影响.结果显示,浮游甲壳动物的密度和生物量以及Daphnia的相对生物量百分比与光照漫射衰减系数(Kd)呈显著负相关,与营养盐和叶绿素a(Chl.a)浓度无显著相关性;群落的平均体长随Chl.a浓度的增加而减小.典范对应分析显示,7个因子共解释了优势浮游甲壳动物群落结构变异的37.4%,贡献率排在前4位的是Kd、Chl.a浓度、悬浮物C/N比和C/P比,分别解释了总变异的11.5%、8.9%、5.6%和4.9%.近邻剑水蚤(Cyclops vicinus vicinus)喜好生活在Chl.a浓度高、水下光照弱的水体中,而汤匙华哲水蚤(Sinocalanus dorrii)喜好生活在水下光照较好、Chl.a浓度和悬浮物C/N比较低的水体中.透明蟤(Daphnia hyalina)喜好生活在Chl.a浓度较低、光照良好、悬浮物C/P比较高的水体中,但简弧象皮蟤(Bosmina coregoni)喜好生活在Chl.a浓度高、光照较好、悬浮物C/P比较低的水体中.整体来看,食物因子解释了群落结构总变异的19.4%,理化因子解释了18.0%,还剩下62.6%的变异未被解释,表明还有其他更为重要的环境因子未被纳入到分析之中.

The effects of food quality and quantity on zooplankton community structure are rarely examined in the field study.Here,the relative importance of food quality and quantity as well as physicochemical factors on crustacean zooplankton community was explored in 14 water bodies in spring in Hubei Province,China.The results showed that the density and biomass of crustaceans and the biomass percentage of Daphnia were all significantly and negatively correlated with K d,while the community mean body length decreased with the increasing of chlorophyll-a(Chl.a)concentration.Canonical correspondence analysis showed that 37.4%of the total variation in crustacean zooplankton community was explained by seven factors.The first four most important factors were listed as K d,Chl.a concentration,seston C/N and C/P ratios,accounting for 11.5%,8.9%,5.6%and 4.9%of the total variation,respectively.Cyclops vicinus vicinus was found to be inclined to inhabit in waters with high concentration of Chl.a and low irradiance of light,while Sinocalanus dorrii in habitats with good light irradiance,low concentration of Chl.a and low seston C/N ratio.Daphnia hyalina peaked in waters with low concentration of Chl.a and better light irradiance as well as high seston C/P ratio,but Bosmina coregoni liked the habitat with high concentration of Chl.a,better light irradiance and low seston C/P ratio.In general,food factors explained 19.4%of the total variation in crustacean zooplankton community,and physicochemical factors explained 18.0%,while 62.6%were left unexplained,suggesting that there are other important factors that are not involved in the analysis.