摘要
以黔北槽谷型喀斯特地区三种优势植物化香(Platycarya strobilacea)、马尾松(Pinus massoniana)和烟管荚蒾(Viburnum utile)为研究对象,测定其叶片、枝条和根系的功能性状与C、N、P、Ca、Mg元素含量,分析植物不同器官间功能性状和生态化学计量学的特征与关联,探讨优势物种对槽谷喀斯特环境的适应策略。结果表明:(1)叶片干物质含量在物种间无显著差异,比叶面积、枝干物质含量、枝密度、粗根密度和中根密度在种间差异显著,比叶面积种间变异最大(32.13%),而叶干物质含量种间变异最小(12.76%)。(2)比叶面积与叶干物质含量、粗根和中根密度呈显著负相关,叶干物质含量、枝干物质含量、枝密度、粗根密度和中根密度两两正相关。(3)植物C含量在叶片、枝条和根系中的分配较为均匀,N、P、Mg含量均表现为叶片>枝条>根系,C/N、C/P表现为根系>枝条>叶片;叶片N/P范围为10.89~27.39,平均值为17.75。(4)在相应器官内,N与P元素和N/P显著正相关,C与Ca、Mg元素显著负相关,Ca与Mg显著正相关,叶片Ca与叶片P显著负相关。(5)比叶面积与叶片N、P、Mg含量显著正相关,与叶片C含量显著负相关;粗根和中根组织密度与根Ca含量极显著正相关。这说明黔北槽谷喀斯特地区的优势植物在功能性状上产生分化,减少生态位重叠,以降低资源竞争。为适应干旱贫瘠环境,植物一方面形成低比叶面积、高干物质含量和高组织密度的功能性状组合,另一方面改变器官间的元素分配,增加枝条和根系的投资。
Three dominant woody species(Platycarya strobilacea,Pinus massoniana and Viburnum utile)were selected to determine plant functional traits and C,N,P,Ca and Mg contents of leaves,twigs and roots along an elevation gradient in the Langxi Watershed of northern Guizhou Province,southwestern China.The key features of functional traits and ecostoichiometry among different plant organs and their correlations were analyzed,the adaptive strategies of three dominant species to the trough-valley karst environment were further explored.Results showed that:(1)The leaf dry-matter contents(LDMC)of three dominant species had no significant interspecific variation,but specific leaf area(SLA),twig dry-matter content(TDMC),twig tissue density(TTD),coarse root tissue density(CRTD)and medium root tissue density(MRTD)had significant interspecific variation.The highest interspecific variation occurred in SLA(32.13%)and the lowest one in LDMC(12.76%).(2)SLA and LDMC,CRTD and MRTD had significant negative correlations,but LDMC,TDMC,TTD,CRTD and MRTD had parallel positive correlations.(3)The distribution of C contents in leaves,branches and roots was relatively uniform.N,P and Mg contents had the same trend of leaf>twig>root in three plants,the trend of C/N and C/P was root>twig>leaf,and the leaf N/P ranged from 10.89 to 27.39 with an average of 17.75.(4)In the corresponding plant organs,N was significantly and positively correlated with P and N/P,C was significantly and negatively correlated with Ca and Mg,Ca was significantly and positively correlated with Mg,while Ca was significantly and negatively correlated with P in leaves.(5)SLA had significant and positive correlations with contents of leaf N,P and Mg,but had a significant and negative correlation with leaf content of C.Ca contents in coarse and medium roots had very significant and positive correlations with the tissue densities of roots,indicating that the dominant plants in karst areas of northern Guizhou trough valley differentiated in their functional traits to reduce the overlap of niches and such to reduce the resource competition.In order to adapt the arid and infertile environment,on the one hand,karst plants developed multiple functional traits of lower specific leaf area,higher dry matter content and higher tissue density,on the other hand,they re-allocated the element distribution among organs and increased investments of twig and root.
作者
杨勇
许鑫
徐玥
倪健
YANG Yong;XU Xin;XU Yue;NI Jian(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;Chinese Academy of Sciences,Beijing 100049,China;College of Chemistry and Life Sciences,Zhejiang Normal University,Jinhua Zhejiang 321004,China)
出处
《地球与环境》
CAS
CSCD
北大核心
2020年第4期413-423,共11页
Earth and Environment
基金
国家重点研发计划项目(2016YFC0502304)。
