青藏高原东南缘植物碳氧同位素对气候及植物生理的表征  

Characterization of carbon and oxygen isotopes of plant on climate and plant physiology at the southeastern margin of Qinghai-Tibet Plateau,China

作　　者：曾慧 杨蕊 王翔[2] 吴琪 王鹏[1] 陈果[1,2] 唐晓鹿 裴向军 ZNEG Hui;YANG Rui;WANG Xiang;WU Qi;WANG Peng;CHEN Guo;TANG Xiaolu;PEI Xiangjun(College of Ecology and Environment,Chengdu University of Technology,Chengdu 610059,China;College of Earth Science,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学生态环境学院,成都610059 [2]成都理工大学地球科学学院,成都610059 [3]成都理工大学地质灾害防治与地质环境保护国家重点实验室,成都610059

出　　处：《应用生态学报》2024年第4期867-876,共10页Chinese Journal of Applied Ecology

基　　金：华能西藏在建工程项目(JC2022/D01)资助。

摘　　要：为探究青藏高原东南缘植物纤维素碳氧同位素组成与气候因子和植物生理指标间的关系,本研究以该区相似纬度、不同经度的8个样地植物为研究对象,通过分析植物叶片纤维素中δ^(13)C、δ^(18)O、分馏值(Δ^(13)C、Δ^(18)O)和水分利用效率(WUE)及环境因子特征,探讨青藏高原东南缘植物碳氧同位素随海拔和经度变化的规律,揭示其对不同环境及植被生理的指示程度,同时采用碳氧双同位素半量化模型,揭示研究区植物在不同环境下的生理适应机制。结果表明:植物纤维素Δ^(13)C、Δ^(18)O均随着海拔和经度的增加而减小,Δ^(13)C受经度的影响较大,而Δ^(18)O更易受到海拔变异的影响;Δ^(13)C、Δ^(18)O与温度(TEM)、降雨量(PRE)、潜在蒸散发(PET)、相对湿度(RH)呈显著正相关,其中PRE为Δ^(13)C的主导气象因子,RH为Δ^(18)O变异的主导气象因子。WUE随海拔和经度的升高而增加,且与Δ^(13)C不同,WUE与海拔的相关性比与经度的相关性更高。碳氧联用模型预测表明,随着降雨和相对湿度的增加,植物气孔导度(g_(s))和最大净光合同化速率(A_(max))减小,随着海拔和经度的增加,植物g_(s)和A_(max)增加。有机物碳氧同位素联用可为青藏高原东南缘的气候追溯及植被生理研究提供更多的环境与气体交换信息。To investigate the correlation between carbon and oxygen isotope compositions of plant cellulose and climatic factors as well as plant physiological indices on the southeastern margin of the Qinghai-Tibet Plateau,we examined plant species in eight sampling sites with similar latitudes and different longitudes in this region.Through the characteristics of δ^(13)C and δ^(18)O values,fractionation values(Δ^(13)C and Δ^(18)O)in leaf cellulose,we discussed water use efficiency(WUE)and the environmental factors,the variation of carbon and oxygen isotopes in the southeastern margin of the Qinghai-Tibet Plateau with elevation and longitude,and revealed the indication degrees of isotopic signals to different environments and vegetation physiology.By using the semi-quantitative model of carbon and oxygen dual isotopes,we investigated the physiological adaptation mechanisms of plants to varying environmental conditions.The results demonstrated that both Δ^(13)C and Δ^(18)O of cellulose decreased with increasing elevation and longitude,and Δ^(13)C was more influenced by longitude,while Δ^(18)O was more susceptible to elevation variation.Additionally,Δ^(13)C and Δ^(18)O were significantly and positively correlated with temperature(TEM),precipitation(PRE),potential evapotranspiration(PET),and relative humidity(RH).PRE was the dominant meteorological factor driving the variation of Δ^(13)C,while RH was the dominant meteorological factor influencing Δ^(18)O variation.In contrast to Δ^(13)C,WUE showed a stronger correlation with elevation than with longitude,which increased as elevation and longitude increased.According to the carbon-oxygen model,plant stomatal conductance(g_(s))and photosynthetic capacity(A_(max))decreased with increasing precipitation and relative humidity,while the values increased with increasing elevation and longitude.The combined analysis of carbon and oxygen isotopes of organic matters would yield additional environmental and gas exchange information for studies on climate tracing and vegetat

关 键 词：碳稳定同位素 氧稳定同位素 水分利用效率 气象因子 半量化模型 

分 类 号：Q948.112[生物学—植物学]