UV-B增强对土壤-大豆系统CO2排放的影响  

Impacts of enhanced ultraviolet-B radiation on CO_2 emission from soil-soybean system

作　　者：胡正华[1] 蒋静艳[2] 牛传坡[2] 陈书涛[1] 刘巧辉[1] 

机构地区：[1]南京信息工程大学环境科学与工程学院,江苏南京210044 [2]南京农业大学资源与环境科学学院,江苏南京210095

出　　处：《中国环境科学》2009年第4期425-430,共6页China Environmental Science

基　　金：国家自然科学基金资助项目(40605029);中国博士后科学基金资助项目(20070420195);中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室开放课题(0812000053)

摘　　要：采用静态箱-气相色谱法测定CO2排放通量,研究了人工模拟UV-B辐射增强对土壤-大豆系统CO2排放的影响.结果表明,在相同的气象条件和田间管理下,UV-B辐射增强对CO2排放的季节变化模式无明显影响.在植株结荚前,UV-B增强对CO2排放通量没有显著影响,但从植株结荚到成熟,CO2排放通量显著降低,2004和2006年分别降低了49.03%和48.13%;并显著降低了整个生育期的CO2累积排放量,2004和2006年分别降低了43.26%和44.79%.收割实验表明,在分枝开花期,UV-B增强降低了土壤CO2排放,但对植株地上部分的CO2排放没有明显影响;从结荚到成熟,UV-B增强主要通过降低植株地上部分CO2排放通量来降低土壤-大豆系统的CO2排放.UV-B辐射增强降低了大豆生态系统碳固定量,在分枝开花-结荚阶段的固定碳量减少了352.73g/m2CO2,在结荚-鼓粒阶段固定碳量减少了1456.25g/m2CO2.To investigate the impacts of enhanced UV-B radiation on carbon dioxide（CO2） emissions from soil-soybean system,field experiments and outdoor pot experiments were carried out during two growing seasons under the condition of simulating 20% enhancement of UV-B. Carbon dioxide emissions were measured by static chamber-gas chromatograph method. Enhanced UV-B radiation did not change the seasonal pattern of CO2 emission from soil-soybean system but significantly decreased the flux of CO2 during pod-maturity stage（49.03% and 48.13% in 2004 and 2006,respectively） and the cumulative amount of CO2（43.26% and 44.79% in 2004 and 2006,respectively） . In addition,it had no significant impact on CO2 emission before podding. A biomass clipping method was employed to distinguish the influence of enhanced UV-B on CO2 flux from soybean plant and soil in different developmental stages. Both CO2 emissions from soils during the branching-flowering stage and those from soybean plants during the pod-maturity stage were significantly decreased by enhanced UV-B. Agroecosystem CO2 emissions declined by enhanced UV-B radiation were primarily due to the decrease in CO2 emissions from soybean plants rather than from soil. Enhanced UV-B reduced the fixed carbon by 352.73 g/m2CO2 during the branching flowering-podding stage,and by 1456.25g/m2CO2 during podding-seed filling stage. Enhanced UV-B radiation could reduce CO2 emissions fluxes from soybean ecosystem and decrease the fixed carbon.

关 键 词：UV-B辐射增强 土壤-大豆系统 土壤 CO2排放 

分 类 号：X511[环境科学与工程—环境工程]