摘要
选择造林树种大叶相思(Acacia auriculiformis)和樟树(Cinnamomum camphora)为对象,采用开顶生长箱(open-top chamber,OTC)构建实验林,探讨镉(Cd)胁迫及其与大气CO_(2)浓度升高、氮(N)添加的复合作用对2种树木叶片N、P养分利用策略和Cd积累特征的影响。试验设5个处理:对照(CK)、加Cd[10 kg Cd/(hm^(2)·a)](Cd)、加Cd与加CO_(2)(700μmol/mol)(CdC)、加Cd与加N[100 kg N/(hm^(2)·a)](CdN)、加Cd加CO_(2)加N(CdCN)。处理约2.5 a后,测定两树种的成熟叶和衰老叶中N、磷(P)和Cd含量。结果表明,不同处理对两树种叶片P含量及P回收率均无显著影响,但显著影响叶片N含量及N回收率;CdN处理下两树种叶片N含量升高;Cd和CdN处理下樟树叶N回收率显著降低。Cd、CdC、CdN和CdCN处理下两树种叶片Cd积累浓度及樟树成熟叶中的Cd/N和Cd/P升高。大叶相思叶片N、P回收率显著高于樟树,Cd积累浓度显著低于樟树。速生豆科固氮树种大叶相思比普通非固氮树种樟树具有更好的N、P养分利用策略和抵御叶片积累Cd的能力,表明大叶相思可以作为Cd污染林地土壤生态修复的适宜树种。
In order to investigate the effects of cadmium(Cd)pollution and its combinations with elevated atmospheric CO_(2) concentration and nitrogen(N)addition on N and phosphorus(P)utilization strategies and Cd accumulation in leaves,two afforestation tree species(Acacia auriculiformis and Cinnamomum camphora)were selected,and the open-top chambers(OTCs)was used to construct the simulated experimental forests of the two tree species.The five treatments were control(CK),adding Cd[10 kg Cd/(hm^(2)·a)](Cd),adding Cd and CO2(700μmol/mol)(CdC),adding Cd and N[100 kg N/(hm^(2)·a)](CdN),adding Cd,CO_(2) and N(CdCN).After treatment for about 2.5 years,the mature and senescent leaves of two tree species were collected to measure the concentrations of N,P and Cd.The results showed that the foliar P concentration and P resorption efficiency had no significant changes under different treatments,but the N concentration and N resorption efficiency in leaves were significantly affected.The N concentration in leaves of two species increased under CdN treatment,and the N resorption efficiency in C.camphora leaves decreased significantly under Cd and CdN treatments.Under the treatments of Cd,CdC,CdN and CdCN,the Cd accumulation in leaves of two species,as well as the Cd/N and Cd/P ratios in mature leaves of C.camphora increased.The N and P resorption efficiencies were significantly higher,while the Cd accumulation was significantly lower in A.auriculiformis than those in C.camphora.It was demonstrated that the fast-growing leguminous N-fixing tree species(A.auriculiformis)had better N and P utilization strategies and stronger resistance to Cd accumulation than the common non-N-fixing tree species(C.camphora),suggesting that A.auriculiformis could be suitable for ecological restoration in Cd polluted forest sites.
作者
肖美娟
尧波
张桂华
温达志
XIAO Meijuan;YAO Bo;ZHANG Guihua;WEN Dazhi(Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystem,South China Botanical Garden,Chinese Academy of Sciences,Guangzhou 510650,China;South China National Botanical Garden,Guangzhou 510650,China;University of Chinese Academy of Sciences,Beijing 100049,China;School of Geography and Environment,Jiangxi Normal University,Nanchang 330022,China)
出处
《热带亚热带植物学报》
CAS
CSCD
北大核心
2023年第4期473-484,共12页
Journal of Tropical and Subtropical Botany
基金
国家自然科学基金项目(31570483)
广东省自然科学基金重点项目(2015A030311029)资助。
关键词
镉污染
氮添加
CO_(2)浓度升高
养分回收
化学计量比
Cadmium pollution
Nitrogen addition
Elevated CO_(2)concentration
Nutrient resorption
Stoichiometric ratio