外来入侵植物飞机草和本地植物异叶泽兰对大气CO_2浓度升高的响应  

Responses of invasive Chromolaena odorata and native Eupatorium heterophyllum to atmospheric CO_2 enrichment

作　　者：柴伟玲 类延宝[1] 李扬苹[1,2] 肖海峰[1] 冯玉龙[3] 

机构地区：[1]中国科学院西双版纳热带植物园,热带森林生态学重点实验室,云南勐仑666303 [2]中国科学院研究生院,北京100049 [3]沈阳农业大学生物科学技术学院,沈阳110866

出　　处：《生态学报》2014年第13期3744-3751,共8页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(30830027;31270582);中国科学院知识创新工程重要方向性项目(KSCX2-YW-Z-1019)

摘　　要：大气CO2浓度升高影响外来植物入侵,研究外来入侵植物和本地植物对大气CO2浓度升高响应的差异,有助于准确预测和管理外来植物入侵。基于封顶式CO2生长室,模拟大气CO2浓度变化(对照和700μmol/mol),比较研究了外来入侵植物飞机草(Chromolaena odorata)和本地植物异叶泽兰(Eupatorium heterophyllum)形态、生长、生物量分配和光合特性对大气CO2浓度升高响应的差异。结果表明:(1)在当前大气CO2浓度下,飞机草总生物量、株高、基径和总叶面积高于异叶泽兰,分枝数低于异叶泽兰;CO2浓度升高,飞机的总生物量、株高、基径、分枝数和总叶面积分别增加了92%、41%、60%、325%和148%,高于异叶泽兰的32%、14%、30%、64%和79%,飞机草生长优势进一步提高。(2)无论在高或低CO2浓度下,飞机草根生物量分数(RMF)都低于异叶泽兰,叶生物量分数(LMF)和茎生物量分数(SMF)都高于异叶泽兰;CO2倍增两种植物RMF均降低,LMF和SMF均升高,但这2个参数对CO2倍增响应的种间差异不显著。(3)无论在高或低CO2浓度下,飞机草和异叶泽兰的净光合速率差异均不显著,CO2倍增对两种植物的净光合速率的促进作用相似。上述结果表明,在未来大气CO2浓度升高的条件下,飞机草的入侵性可能提高,入侵危害将加剧。Atmospheric CO2 concentration had increased from a pre-industrial level of 270 μmol /mol to 350 μmol /mol in2005 and continues to increase at 1. 9 μmol /mol per year on average. It is well known that atmospheric CO2 enrichment may influence the invasiveness of introduced plant species. Identifying the effects of elevated CO2 on invasiveness of exotic plants is very important for improving our ability to predict and control potentially invasive species. Four closed-top chambers were used to control CO2 concentration,ambient atmospheric CO2concentration（ control） and doubled atmospheric CO2concentration（ 700 μmol /mol）. To determine the effects of atmospheric CO2 enrichment on invasiveness of Chromolaena odorata,a noxious invasive perennial herb or subshrub in many countries of Asia,Oceania and Africa,we compared C.odorata and its phylogenetically related indigenous plant Eupatorium heterophyllum in terms of morphology,growth,biomass allocation,and photosynthesis at two CO2 concentrations. Fourteen traits related to morphology,growth,biomass allocation,and photosynthesis were measured when C. odorata and E. heterophyllum were treated for nearly three months.At ambient CO2 concentration,total biomass,height,stem diameter,and total leaf area were significantly higher and branch number were lower for invasive C. odorata than for native E. heterophyllum,which contribute to form dense monoculture for the invader,outshading native plant species. CO2 enrichment significantly increased total biomass,height,stem diameter,branch number,and total leaf area in both species. For C. odorata,total biomass,height,stem diameter,branch number and total leaf area were increased by 92%,41%,60%,325%,and 148%,respectively,much higher than 32%,14%,30%,64%,and 79% for E. heterophyllum. Consistently,growth advantage of the invader over the native became more evident at doubled atmospheric CO2 concentration.CO2enrichment decreased root mass fraction（ RMF） and increased stem mass fraction（ SMF） and leaf mass fraction（ L

关 键 词：CO2浓度升高 飞机草 形态 生长 生物量分配 光合特性 入侵性 

分 类 号：X173[环境科学与工程—环境科学]