草地植物多样性沿海拔梯度分布特征及其驱动因素——以天山北坡东段为例  

Distribution characteristics of grassland plant diversity along the altitudinal gradient and its driving factors:A case study of the eastern section of the northern slope of the Tianshan Mountains

作　　者：姜安静 董乙强 周时杰 聂婷婷 吴悦 柳泽宇 单兴芸 雷雅欣 吴凯 安沙舟[1,2,3] JIANG An-jing;DONG Yi-qiang;ZHOU Shi-jie;NIE Ting-ting;WU Yue;LIU Ze-yu;SHAN Xing-yun;LEI Ya-xin;WU Kai;AN Sha-zhou(College of Grassland Science,Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Key Laboratory of Grassland Resources and Ecology,Urumqi 830052,China;Key Laboratory of Grassland Resources and Ecology of Western Arid Region,Ministry of Education,Urumqi 830052,China)

机构地区：[1]新疆农业大学草业学院,新疆乌鲁木齐830052 [2]新疆草地资源与生态自治区重点实验室,新疆乌鲁木齐830052 [3]西部干旱区草地资源与生态教育部重点实验室,新疆乌鲁木齐830052

出　　处：《草业学报》2025年第3期29-40,共12页Acta Prataculturae Sinica

基　　金：国家自然科学基金(32260355);新疆农业大学自治区研究生创新项目(XJ2024G122)资助。

摘　　要：探究山地草地生态系统物种多样性沿海拔梯度的分布规律及其驱动因素,对揭示区域植物的环境适应性、区域多样性的保护及修复治理等具有重要意义。以天山北坡东段奇台县山地草地为研究对象,采用野外原生境实地调查取样的方法,对15个海拔梯度,跨度为1250~3150 m的草地植物群落数量特征和物种多样性进行测定分析,并用随机森林模型以及偏最小二乘路径模型解析海拔、气温、降水以及植物数量特征与植物多样性的关系。结果表明:1)随海拔梯度的增加,草地植物群落盖度和密度均呈极显著增加趋势,而植物高度呈极显著降低趋势,生物量则呈先降后升的趋势(P<0.01);2)植物α多样性指数沿海拔梯度均呈先升后降的“单峰”分布规律(P<0.05),相邻海拔间相似度Sorenson指数整体呈先下降后上升的波动变化,相反物种替代率Cody指数呈先上升后下降的变化趋势;3)植物盖度、生物量以及Patrick指数均与气候呈显著相关关系(P<0.05),植物多样性主要受盖度的直接影响,海拔通过显著影响气温和降水,进而间接影响植物密度,植物密度又显著正向影响植物盖度(P<0.01)。综上,海拔通过影响气候间接影响植物群落特征,使其具有明显的垂直分布特征。Exploring the distribution pattern of species diversity,and its driving factors,in mountain grassland ecosystems along altitude gradients is of great importance to understanding of the environmental adaptability of regional plants,and requirements for the conservation of regional diversity and vegetation restoration and management.In this study,the quantitative characteristics and species diversity of plant communities in Qitai County,on the eastern section of the northern slopes of the Tianshan Mountains,were measured and analysed at 15 sites along altitudinal gradients spanning from 1250-3150 m.We also used the random forest model and the partial least squares path modeling(PLS-PM)to analyse the relationship between altitude,temperature,precipitation,and quantitative characteristics of the plants and plant diversity.The results showed that:1)With increasing altitude,the grassland plant community cover and density showed a highly significant increasing trend,while the plant height showed a highly significant decreasing trend,and the biomass showed an initially decreasing trend and then an increasing trend(P<0.01);2)The α-diversity of plants was maximized(P<0.05)at mid-altitude along the altitudinal gradient,and the Sorenson index between neighboring altitudes showed an overall pattern of initial decrease and then increase with increasing altitude,while the Cody index of species substitution rate showed a tendency of increasing and then decreasing;3)Plant cover,biomass,and Patrick’s index were all significantly correlated with climate(P<0.05),with plant diversity mainly directly affected by cover,and elevation indirectly affecting plant density by significantly affecting temperature and precipitation,plant density also significantly positively affects plant coverage(P<0.01).In summary,altitude indirectly affects the characteristics of plant communities by influencing climate,giving the plant communities a distinct vertical distribution along the altitudinal gradient.

关 键 词：海拔 植物多样性 驱动因素 气候因素 

分 类 号：S812[农业科学—草业科学]