文献类型：期刊文献

中文题名：乌兰布和沙漠北部典型植被的叶蜡正构烷烃特征及指示

英文题名：Characteristics and implications of leaf wax n-alkanes in typical vegetation of the northern Ulan Buh Desert

作者：周尚哲[1,2] 席磊[1,2] 崔梦淳[1,2] 崔桂鹏[1,2,3] 孔维远[1,2,3] 高攀[1,2] 卢琦[1,2,3]

第一作者：周尚哲

机构：[1]中国林业科学研究院,生态保护与修复研究所,北京100091;[2]中国林业科学研究院,荒漠化研究所,北京100091;[3]中国林业科学研究院,三北工程研究院,北京100091

年份：2025

卷号：45

期号：5

起止页码：45-54

中文期刊名：中国沙漠

外文期刊名：Journal of Desert Research

收录：;北大核心:【北大核心2023】；

基金：中央级公益性科研院所基本科研业务费专项资金项目(CAFYBB2024MC020,CAFYBB2024ZA002,CAFYBB2023ZA008-06);国家林业和草原局揭榜挂帅项目(202401);国家自然科学基金项目(32101592,32271966,32201635);科学技术部科技基础资源调查专项项目(2022FY202300)。

语种：中文

中文关键词：正构烷烃;荒漠植物;乌兰布和沙漠;古气候重建;古环境重建

外文关键词：n-alkanes;desert plants;Ulan Buh Desert;paleoclimatic reconstruction;paleoenvironmental reconstruction

分类号：S288

摘要：沉积物中的长链正构烷烃主要来源于高等植物叶蜡,是荒漠区古气候、古环境重建的重要指示物。温度、降水、海拔等环境因子影响了荒漠植物叶蜡正构烷烃的含量和分布特征,但环境因子对荒漠植物叶蜡正构烷烃合成的影响和作用机制尚不清晰。为此,本研究选择对气候环境变化响应高度敏感的乌兰布和沙漠作为研究区,对沙漠北部典型植被的正构烷烃组成、分布以及正构烷烃总量(∑ALK)、平均碳链长度(ACL)和碳优势指数(CPI)指标进行了分析和比较。结果表明:白刺(Nitraria roborowskii)的正构烷烃分布模式以n-C27为主,梭梭(Haloxylon ammodendron)则以n-C27和n-C29为主,而沙冬青(Ammopiptanthus mongolicus)以n-C29为主;梭梭∑ALK和CPI的平均值分别为86μg·g-1和10.4,白刺为410μg·g-1和23.3,而沙冬青为7383μg·g-1和47.1,3种典型植被的正构烷烃特征差异显著且沙冬青表现尤为特殊。乌兰布和沙漠植被叶蜡正构烷烃∑ALK受降水影响较大,总体上,随降水增加∑ALK表现为增大趋势;另外,随着荒漠植物叶片形态对干旱胁迫的适应性变化,即从卵形到披针形,再到鳞片(退化),其叶蜡正构烷烃特征也出现适应性变异,即ACL和CPI指标表现为逐渐减小的趋势。总体而言,乌兰布和沙漠植被的叶蜡正构烷烃∑ALK、ACL和CPI特征能够有效指示该区干湿变化。
Long-chain n-alkane biomarker compounds in sediments are mainly originated from higher plant leaf waxes and are important indicators of paleoclimatic and paleoenvironmental reconstruction in desert areas.Environmental factors such as temperature,precipitation and altitude have a profound impact on the abundance and distribution characteristics of leaf wax n-alkanes in extant desert plants.However,the effects and mechanisms of these environmental factors on the synthesis of leaf wax n-alkanes in desert regions are not yet clear.For this reason,the Ulan Buh Desert,which is highly sensitive to the response to climate and environmental changes,is selected as study area,and the n-alkane composition and distribution,as well as the indicators of total n-alkane abundance(∑ALK),average carbon chain length(ACL),and carbon predominance index(CPI)of the typical vegetation in the northern part of the desert were analyzed and compared.We found that n-alkane distribution pattern of Nitraria roborowskii shows a predominance of n-C27,Haloxylon ammodendron shows a predominance of n-C27 and n-C29,while Ammopiptanthus mongolicus shows a predominance of n-C29;mean values of∑ALK and CPI are 86μg·g-1 and 10.4 for H.ammodendron,410μg·g-1 and 23.3 for N.roborowskii,and 7383μg·g-1 and 47.1 for A.mongolicus,and the n-alkane characteristics differs significantly among the three typical vegetation types,with A.mongolicus being particularly distinctive.We also found that the leaf wax n-alkane∑ALK of Ulan Buh Desert vegetation is strongly influenced by environmental precipitation,and in general∑ALK shows an increasing trend with increasing precipitation;additionally,as the leaf morphology of desert plants adapted to drought stress,i.e.,from ovate to lanceolate,and ultimately to scale(assimilative shoot),the leaf wax n-alkane characteristics also show adaptive variations,i.e.,the ACL and CPI shows a gradual decrease.Overall,the leaf wax n-alkane∑ALK,ACL and CPI characteristics of Ulan Buh Desert vegetation are effective for indicating wet and dry changes in the area.