贺兰山西坡不同海拔土壤有机碳热稳定性  

Thermal stability of soil organic carbon at different elevation on the western slope of Helan Mountain

作　　者：魏佳媛 任侠 袁丽丽 王晓勤 赵娅茹 李慧[3] 李冰[3] 吴梦瑶 陈林[3] 李学斌[3] 庞丹波 WEI Jiayuan;REN Xia;YUAN Lili;WANG Xiaoqin;ZHAO Yaru;LI Hui;LI Bing;WU Mengyao;CHEN Lin;LI Xuebin;PANG Danbo(School of Forestry and Grassland,Ningxia University,Yinchuan 750021,China;Administration of Helan Mountain National Nature Reserve Inner Mongolia,Alxa Left Banner 750306,China;Key Laboratory for Restoration and Reconstruction of Degraded Ecosystem in Northwest China of Ministry of Education,Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwest China,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学林业与草业学院,银川750021 [2]内蒙古贺兰山国家级自然保护区管理局,阿拉善左旗750306 [3]宁夏大学生态环境院,西北土地退化与生态恢复国家重点实验室培育基地,西北退化生态系统恢复与重建教育部重点实验室,宁夏贺兰山森林生态系统国家定位观测研究站,银川750021

出　　处：《生态学报》2025年第4期1999-2010,共12页Acta Ecologica Sinica

基　　金：国家自然科学基金项目(32201631);宁夏重点研发计划项目(2022BSB03069,2021BEG02005);银川市重点研发计划项目(2023SFZD04)。

摘　　要：土壤有机碳热稳定性有助于解析土壤对环境因子的响应、认识土壤有机碳稳定性和热动态特征,从而揭示环境要素对碳循环的影响。以贺兰山西坡不同海拔土壤为研究对象,分析土壤理化性质、盐基离子、热重曲线特征、热稳定性参数及热稳定性驱动因素。结果表明:随海拔升高,土壤理化性质除容重(BD)、pH和有效磷(AP)外均呈现递增的趋势;盐基离子主要富集在低海拔地区;TG(Thermogravimetry,热重)曲线所反映的质量损失速率增大;DTG(Derivative thermogravimetry,热重微分)曲线在中低海拔呈双峰趋势,在高海拔呈现单峰趋势;中低海拔TG-T50(SOC质量减少一半时对应的温度)相对较高;随海拔升高,Exo1/Exot(较低温度分解下SOC/总分解SOC)逐渐增加,而Exo2/Exot(较高温度分解下SOC/总分解SOC)逐渐减少,表明贺兰山西坡低海拔土壤有机碳的热稳定性较高;理化性质和土壤有机碳热稳定性之间的相关性显著水平更高;SOM是影响土壤有机碳热稳定性的主导因素。综上,贺兰山西坡土壤有机碳热稳定性随海拔升高逐渐降低,低海拔土壤有机碳含有更多耐热成分且相对更加稳定。Understanding the thermal stability of soil organic carbon(SOC)facilitates interpreting soil responses to environmental factors,comprehending SOC stability,and its thermal dynamic characteristics,thereby revealing the impact of environmental elements on the carbon cycle.This study focuses on soils at various altitudes on the western slope of Helan Mountain,analyzing soil physicochemical properties,base cations,thermogravimetric(TG)curve characteristics,thermal stability parameters,and drivers of thermal stability.The results indicate that,with increasing altitude,soil physicochemical properties generally show an increasing trend,except for bulk density(BD),pH,and available phosphorus(AP);base cations are mainly concentrated in lower altitude areas;the mass loss rate reflected by the TG curves increases;derivative thermogravimetry(DTG)curves exhibit a bimodal trend at mid and low altitudes and a unimodal trend at high altitudes;the temperature at which SOC mass is halved(TG-T50)is relatively higher at mid and low altitudes;with increasing altitude,the ratio of SOC decomposition at lower temperatures to total SOC decomposition(Exo1/Exot)gradually increases,while the ratio at higher temperatures(Exo2/Exot)decreases,indicating higher thermal stability of SOC in soils at lower altitudes on the western slope of Helan Mountain;the correlation between physicochemical properties and SOC thermal stability is significantly stronger;soil organic matter(SOM)is the dominant factor affecting SOC thermal stability.In summary,SOC thermal stability on the western slope of Helan Mountain decreases with increasing altitude,with lower altitude soils containing more heat-resistant components and being relatively more stable.

关 键 词：土壤有机碳 热稳定性 海拔梯度 盐基离子 贺兰山 

分 类 号：S153.6[农业科学—土壤学]