CO_2浓度和辐射强度变化对沙柳光合作用速率影响的模拟研究  

Growth chamber study on the impact of CO_2 concentration and radiant intensity on Salix psammophila photosynthetic rate

作　　者：郭建平[1] 高素华[1] 

机构地区：[1]中国气象科学研究院,北京100081

出　　处：《生态学报》2004年第2期181-185,共5页Acta Ecologica Sinica

基　　金：国家重点基础发展规划研究资助项目 (G19990 43 40 7)~~

摘　　要：沙柳是毛乌素沙地防护林的主要灌木树种 ,模拟研究沙柳对 CO2 浓度和辐射强度的响应有利于准确有效地制定全球变化下的沙漠化防治和水土流失的战略对策。结果表明 ,沙柳的光合作用速率对 CO2 浓度的响应表现为线性关系 ,对辐射的响应表现为对数函数关系。沙柳光合作用速率有随辐射强度增加和 /或 CO2 浓度的升高而增大的变化规律。CO2 浓度越高 ,沙柳的光合作用速率对辐射的反应越明显。同样 ,辐射越强 ,沙柳的光合作用速率对 CO2 浓度的反应越敏感。在高辐射条件下增加大气中 CO2 的“施肥效应”比低辐射条件下要显著。土壤干旱对沙柳的光合和暗呼吸都有抑制作用 ,使沙柳的生理过程受到影响 ,从而使沙柳对 CO2 浓度和辐射的反应规律不如土壤水分适宜时显著。CO_2 in the atmosphere is a necessary substance for plant photosynthesis, and solar radiation is a necessary energy for plant photosynthesis. CO_2 concentration in the atmosphere is increased by human activities, which results in changes in temperature, water and radiation. Studying the impact of changes in CO_2 concentration, soil water, radiation and other eco-environmental factors on plants has been one of the foci in global change studies. S. psammophila is one of the dominant shrubs in Mu Us sandland. The study on the response of S. psammophila photosynthetic rate to CO_2 concentration and radiation change can provide a basis for human intervention to renew and expand natural vegetation, conserve and improve an eco-environment, advance sustainable use of water resources and establish sand plant succession, renewal and sustainable development under global change. The experiment was conducted in growth chambers: the S. psammophila seedlings, one year old, were cultivated in pots under 2 treatments of soil water content and 8 treatments of radiant intensities as well as eight to nine treatments of CO_2 concentrations. Photosynthetic rate was measured by using a Li-6400 portable photosynthesis system. The analysis shows that under constant radiation the response of S. psammophila photosynthetic rate to CO_2 concentration is a linear function, and under constant CO_2 concentration the response to radiation is a logarithm function, under different soil moistures. S. psammophila photosynthetic rate increases with radiant intensity and/or CO_2 enrichment. Under higher CO_2 concentration, the reaction of S. psammophila photosynthetic rate to radiation is more remarkable. Simillarly, for more radiation, the reaction to CO_2 concentration is more sensitive. The “fertilization effect” of atmospheric CO_2 enrichment under strong radiation is therefore more remarkable than under weak radiation. Soil drought influences S. psammophila physiological processes in photosynthesis and dark respiration. Consequently, the resp

关 键 词：沙柳 CO2浓度 辐射强度 生长模拟研究 

分 类 号：S792[农业科学—林木遗传育种]