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
杭伟 1陆永兴 1郭浩 1郭星 1张世航 1张元明 2周晓兵2
作者信息
- 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;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;中国科学院大学,北京 100049
- 2. 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;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;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
- 折叠
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;0～10cm 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.
Abstract
Dryland area is substantial,and the drylands exhibit great sensitivity to global climate change.Nitro-gen,which composed of various nitrogen forms,is generally considered the second most limiting resource in des-ert ecosystems.However,it remains unclear how different levels of aridity affect the spatial distribution of soil ni-trogen.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 varia-tions 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 or-ganic to inorganic nitrogen exhibited rapid increases,while nitrate nitrogen content showed a rapid decrease.Be-fore and after the aridity threshold,both total nitrogen and organic nitrogen content significantly decreased with in-creasing 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 aridi-ty 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Key words
drought threshold/northwest desert region/nitrogen content/driving factors/soil layer引用本文复制引用
基金项目
天山英才计划(2022TSYCCX0001)
新疆维吾尔自治区自然科学基金项目(2022D01D083)
新疆维吾尔自治区自然科学基金项目(2021D01E03)
出版年
2024
NETL
NSTL
万方数据