Stem CO_(2) efflux of Abies fabri in subalpine forests in the Gongga Mountains,Eastern Tibetan Plateau

作     者：Guang Zhao Gangcai Liu Wanze Zhu Jixia Zhao Xuemei Wang Yaoyao Wang Min Jia 

作者机构：Institute of Mountain Hazards and EnvironmentChinese Academy of Sciences and Ministry of Water Resources#.9Block 4Renminnanlu RoadChengdu 610041China University of Chinese Academy of Sciences19A YuquanluBeijing 100039China 

出 版 物：《Journal of Plant Ecology》 (植物生态学报（英文版）)

年 卷 期：2017年第10卷第6期

页      面：1001-1011页

核心收录：

学科分类：0907[农学-林学] 08[工学] 0829[工学-林业工程] 09[农学] 

基　　金：This work was supported by National Nature Science Foundation of China(41471232) the Knowledge Innovation Priority Project of the Chinese Academy of Sciences(Grant No.KZCX2-EW-309) 

主　　题：stem cO_(2)efflux Q10 DBH sapwood nitrogen contents subalpine forests 

摘      要：Aims Despite the importance of stem cO_(2)efflux(Es)in ecosystem carbon cycling and energy balance,little is known about temporal variation in the temperature coefficient(Q10)and sapwood nitrogen concen-trations([N])and their intrinsic links with *** objectives of this study were:(i)to examine the response of Es to temperature in a subalpine region and(ii)to explore the influence of stem diameter and[N]on ***,we will test the hypothesis that(i)Es in trees has thermal acclimation and(ii)Es will be well correlated with diameter at breast height(DBH)and[N].Methods Here,a horizontally oriented soil chamber technique was applied to measure Es of Abies fabri in two subalpine forest stands in Southwestern china from May to December *** also exam-ined the variability in Es,Q10 and[N]in trees and monitored the relationship between temperature,[N],DBH and *** Findings During the measurement period,Es showed an apparent seasonal trend,following the change in air temperature,increasing from May and peaking in July,then continuously decreasing until *** mean Es for the growing and dormant seasons were 1.45 and 0.25μmol·m^(−2)·s^(−1),respectively,and Es in the mature forest was sig-nificantly higher than in the immature *** area-based Es was positively correlated with DBH and sapwood width(SW),while volume-based Es showed negative relationship with DBH and *** the five diameter classes,69.8-89.0%of the variation in Es could be explained by air *** temperature sensitiv-ity(Q10)of Es ranged from 2.98 to 5.61 during the measurement period,with a higher Q10 appearing in the growing season than in the dormant *** was a significant linear relationship(P0.01)between[N]and Es(expressed based on two different units).Additionally,exponential models of Es against[N]and air temperature were applied to estimate Es.