Variation of carbon and nitrogen stoichiometry along a chronosequence of natural temperate forest in northeastern China  

作　　者：Xingyun Liang Shirong Liu Hui Wang Jingxin Wang 

机构地区：[1]Key Laboratory of Forest Ecology and Environment,China’s State Forestry Administration,Institute of Forest Ecology,Environment and Protection,Chinese Academy of Forestry,No.1 Dongxiaofu,Qinglongqiao,Haidian District,Beijing 100091,China [2]Division of Forestry and Natural Resources,West Virginia University,P.O.Box 6215,Morgantown,WV 26506-6125,USA

出　　处：《Journal of Plant Ecology》2018年第3期339-350,共12页植物生态学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(31290223);the Special Research Program for Public-welfare Forestry of China(201404201);the Ministry of Science and Technology(2015DFA31440,2012BAD22B01);the Lecture and Study Program for Outstanding Scholars from Home and Abroad(CAFYBB2011007);the State Key Laboratory of Forest and Soil Ecology(LFSE2014-01)and the CFERN&GENE Award Funds on Ecological Paper.

摘　　要：Aims Carbon(C)and nitrogen(N)stoichiometry contributes to under-standing elemental compositions and coupled biogeochemical cycles in ecosystems.However,we know little about the temporal patterns of C:N stoichiometry during forest development.The goal of this study is to explore the temporal patterns of intraspecific and ecosystem components’variations in C:N stoichiometry and the scaling relationships between C and N at different successional stages.Methods Along forest development in a natural temperate forest,northeastern China,four age gradients were categorized into ca.10-,30-,70-and 200-year old,respectively,and three 20 m×20 m plots were set up for each age class.Leaves,branches,fine roots and fresh litter of seven dominant species as well as mineral soil at depth of 0-10 cm were sampled.A Universal CHN Elemental Analyzer was used to determine the C and N concentrations in all samples.Important Findings Intraspecific leaf C,N and C:N ratios remained stable along forest development regardless of tree species;while C,N concentrations and C:N ratios changed significantly either in branches or in fine roots,and they varied with tree species except Populus davidiana(P<0.05).For ecosystem components,we discovered that leaf C:N ratios remained stable when stand age was below ca.70 years and dominant tree species were light-demanding pioneers such as Betula platyphylla and Populus davidiana,while increased signifi-cantly at the age of ca.200 years with Pinus koraiensis as the dom-inant species.C:N ratios in branches and fresh litter did not changed significantly along forest development stages.C concentrations scaled isometrically with respect to N concentrations in mineral soil but not in other ecosystem components.Our results indicate that,leaf has a higher intraspecific C:N stoichiometric stability compared to branch and fine root,whereas for ecosystem components,shifts in species composition mainly affect C:N ratios in leaves rather than other components.This study also demonstrated that C and N remain coupl

关 键 词：C:N stoichiometry forest succession isometric scaling plant organs soil temperate forest 

分 类 号：S71[农业科学—林学]