西北荒漠区土壤氮素组分沿干旱梯度的空间变化  

Spatial variation in soil nitrogen content along aridity gradients in the northwest desert region in China

作　　者：杭伟 陆永兴 郭浩[1,2,4] 郭星 张世航 张元明 周晓兵[1,2,3] Wei Hang;Yongxing Lu;Hao Guo;Xing Guo;Shihang Zhang;Yuanming Zhang;Xiaobing Zhou(State Key Laboratory of Desert and Oasis Ecology/,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;Xinjiang Key Laboratory of Biodiversity Conservation and Application in Arid Lands,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院新疆生态与地理研究所,荒漠与绿洲生态国家重点实验室,新疆乌鲁木齐830011 [2]中国科学院新疆生态与地理研究所,干旱区生态安全与可持续发展重点实验室,新疆乌鲁木齐830011 [3]中国科学院新疆生态与地理研究所,新疆干旱区生物多样性保育与应用重点实验室,新疆乌鲁木齐830011 [4]中国科学院大学,北京100049

出　　处：《中国沙漠》2024年第3期259-268,共10页Journal of Desert Research

基　　金：天山英才计划项目(2022TSYCCX0001);新疆维吾尔自治区自然科学基金项目(2022D01D083,2021D01E03)。

摘　　要：旱区面积占比大,对全球气候变化响应敏感。氮素通常被认为是荒漠生态系统的第二大限制资源,存在不同的形态,然而目前尚不清楚干旱程度如何影响土壤氮素的空间分布。本研究基于中国西北荒漠区54个样点的无机氮、有机氮和全氮数据,结合气候环境数据,探究不同干旱程度下,西北旱区氮素组分的空间变化及驱动要素。结果表明:土壤氮素沿干旱梯度的空间变化存在明显的干旱阈值(0.87),土壤氮素组分的空间变化对干旱程度的响应呈现突变特征;在阈值附近,土壤全氮、有机氮含量和有机无机氮比例急速上升,而硝态氮含量快速下降;干旱阈值前后的全氮和有机氮含量均随干旱增加而显著下降;0~10 cm土层内,土壤全氮和有机氮含量随土层的加深而逐渐增加。干旱程度会直接或通过土壤含水率、电导率和pH间接影响氮素组分的空间变化。Dryland area is substantial,and the drylands exhibit great sensitivity to global climate change.Nitrogen,which composed of various nitrogen forms,is generally considered the second most limiting resource in desert ecosystems.However,it remains unclear how different levels of aridity affect the spatial distribution of soil nitrogen.Based on data of inorganic nitrogen,organic nitrogen,and total nitrogen from 54 sampling points in the northwest desert region of China,and coupled with climate and environmental data,we explored the spatial variations in nitrogen components under different levels of aridity and the driving factors.Our results indicated a distinct aridity threshold(0.87)for the spatial variations in soil nitrogen along the aridity gradient,meaning an abrupt change in response to aridity.Near the threshold,soil total nitrogen,organic nitrogen content,and the ratio of organic to inorganic nitrogen exhibited rapid increases,while nitrate nitrogen content showed a rapid decrease.Before and after the aridity threshold,both total nitrogen and organic nitrogen content significantly decreased with increasing aridity.In the 0-10 cm soil layer,soil total nitrogen and organic nitrogen content gradually increased with soil depth.The increase in aridity directly or indirectly affected the spatial variation oin nitrogen components through soil water content(SWC),electrical conductivity(EC),and pH.The study revealed the impacts of aridity on soil nitrogen balance,which are beneficial for prediction on the response of soil nutrients to environmental changes in drylands,and provide crucial support for making scientifically effective environmental decisions.

关 键 词：干旱阈值 西北荒漠区 氮素含量 驱动要素 土层 

分 类 号：S153[农业科学—土壤学]