CO_2升高对枝角类群落结构影响的原位模拟  

Effects of a simulated increase in atmospheric CO_2 concentration on cladoceran zooplankton collected from Lake Taihu

作　　者：魏利军[1] 汤龙升[2] 李胜男[1] 周建[1] 孔繁翔[1] 史小丽[1] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [2]南京师范大学生命科学学院,南京210046

出　　处：《生态学报》2016年第7期1846-1853,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(31270507;31070420)

摘　　要：分别于春、夏两季在太湖梅梁湾进行原位试验,设置3个CO_2浓度梯度,270、380μL/L和750μL/L,以斜生栅藻作为枝角类的食物,研究了CO_2浓度升高对枝角类群落结构的影响。结果表明高CO_2浓度能促进斜生栅藻生长,显著提高枝角类的食物数量;此外CO_2浓度的变化能显著改变枝角类的群落结构,高CO_2浓度有利于象鼻蟤属、秀体蟤属和春季蟤属的生长,而不利于网纹蟤属的生长。这可能是由于CO_2浓度变化改变了枝角类的食物质量,浮游藻类的C∶P比值随CO_2浓度的升高而增加,从而有利于体内含磷量较低,高C∶P的枝角类生长。因此枝角类的群落结构主要受食物质量的影响而与食物的数量无关。研究为预测未来气候变化对太湖浮游动物的影响提供了一些理论依据。With the increase of global carbon emissions since the industrial revolution,atmospheric CO2 levels are expected to be twice the present level by the end of this century,reaching 750 μL / L. The water carbonate chemistry of the environment may change notably because of this increase in CO2 levels,which would in turn have a dramatic effect on aquatic ecosystems. Studies related to the impacts of atmospheric CO2 elevation on plankton mainly focus on oceanic,rather than fresh water ecosystems. Lake Taihu is a highly eutrophic lake,and carbon limitation due to intense cyanobacterial blooms might develop,even in the presence of high concentrations of dissolved inorganic carbon. Increased atmospheric CO2 concentrations could cause a shift in the chemical equilibrium of aquatic ecosystems. There is increasing evidence that the concentration of dissolved inorganic carbon（ DIC） increases because of the uptake of CO2 from the atmosphere,whereas the p H and CO3^2- concentrations in the water decrease. This change in environmental conditions is likely to affect the physiology of phytoplankton,and has the potential to influence species composition and competition. Furthermore,elevated p CO2 levels are expected to cause an increase in carbon-rich compounds stored within phytoplankton,and a shift in their overall elemental composition toward higher carbon to nutrient ratios. These changes in the carbon / nutrient stoichiometry of primary producers can have cascading effects on zooplankton. The effect of CO2 enrichment on zooplankton communities in eutrophiclakes is an important topic from both scientific and lake management perspectives. Laboratory studies of both the direct and indirect effects of CO2 are particularly suitable for determining the physiological thresholds and mechanisms of the response of plankton to rising CO2 levels,but cannot address how zooplankton respond in their natural environment. In contrast,in situ controlled experiments are an important tool for studying the effects of water acidification on pe

关 键 词：太湖 CO2升高 枝角类 斜生栅藻 

分 类 号：Q958.8[生物学—动物学]