摘要
[目的]探究干旱河谷区土壤有机碳组分及其稳定性变化特征,明确环境因子与土壤有机碳组分及其稳定性之间的关系,为生态脆弱区固碳减排的系统管理提供依据。[方法]选择西藏波密干旱河谷区不同坡向(阴坡、阳坡、半阴坡、半阳坡)、坡位(坡下、坡中、坡上) 0~30 cm土壤为研究对象,测定土壤理化性质、土壤有机碳及其组分。[结果] 1)阴坡土壤有机碳质量分数为11.37~34.74 g/kg,相较于半阴坡、半阳坡、阳坡分别提高55%、138%、292%。土壤颗粒有机碳、易氧化有机碳、矿质结合态有机碳、可溶性有机碳质量分数随坡向均表现出与有机碳变化一致的趋势。阴坡土壤有机碳稳定性显著高于其他坡向,为54.3%~62.1%,相较于半阴坡、半阳坡和阳坡分别提高6%、12%和30%。2)土壤有机碳质量分数沿坡位分布为坡下(17.29 g/kg)>坡中(13.42 g/kg)>坡上(9.73 g/kg),土壤颗粒有机碳、易氧化有机碳、矿质结合态有机碳、可溶性有机碳质量分数在坡位梯度上随坡位升高而降低。各坡位土壤有机碳稳定性大小为坡下(38.1%~62.1%)>坡中(36.9%~59.9%)>坡上(37.6%~58.7%)。3)影响藏东南干旱河谷区土壤有机碳组分及其稳定性的主要环境因子为坡向、植被盖度、土壤全氮、碱解氮、全磷及黏粒质量分数。[结论]藏东南干旱河谷区土壤有机碳组分及其稳定性在不同坡向和坡位上存在显著差异,环境因子中起主要调控作用的为坡向、植被盖度、土壤全氮、碱解氮、全磷和黏粒质量分数,研究结果可为藏东南干旱河谷区SOC的精准评估和土壤碳库调控提供参考。
[Objective]This study aims to investigate the variation characteristics of soil organic carbon(SOC)fractions and their stability in arid valleys,clarify the relationships between environmental factors and SOC fractions as well as stability,and provide a scientific basis for systematic carbon sequestration and emission reduction management in ecologically fragile areas.[Methods]Soil samples(0―30 cm depth)were collected from different slope aspects(shady,sunny,semi-shady,and semi-sunny slopes)and slope positions(lower,middle,and upper)in the arid valleys of Bomi,Xizang.Soil physicochemical properties,SOC contents,and its fractions were measured.[Results]1)The SOC content on shady slopes ranged from 11.37 to 34.74 g/kg,representing increases of 55%,138%,and 292%compared with semi-shady,semi-sunny,and sunny slopes,respectively.The contents of particulate organic carbon(POC),easily oxidizable organic carbon(EOC),mineral-associated organic carbon(MAOC),and dissolved organic carbon(DOC)all exhibited consistent variation trends with SOC across different slope aspects.SOC stability was the highest on shady slopes(54.3%-62.1%),exceeding that of semi-shady,semi-sunny,and sunny slopes by 6%,12%,and 30%,respectively.2)Along slope positions,SOC content decreased in the order was lower slope(17.29 g/kg)>middle slope(13.42 g/kg)>upper slope(9.73 g/kg).Similarly,POC,EOC,MAOC,and DOC contents all decreased with increasing slope position.The stability of SOC across different slope positions followed the pattern was lower slope(38.1%-62.1%)>middle slope(36.9%-59.9%)>upper slope(37.6%-58.7%).3)The main environmental factors influencing SOC fractions and their stability in the arid valleys of southeastern Xizang were slope aspect,vegetation coverage,soil total nitrogen(TN),alkali-hydrolyzable nitrogen(AN),total phosphorus(TP),and clay content.[Conclusion]Significant differences exist in SOC fractions and their stability across different slope aspects and positions in the arid valleys of southeastern Xizang.The key regulatory factors include slope aspect,vegetation coverage,total nitrogen,alkali-hydrolyzable nitrogen,total phosphorus,and clay content.These findings provide valuable references for accurate SOC assessment and soil carbon pool management in arid valleys of southeastern Xizang.
作者
褚保森
张帅发
刘峰
张鹏程
张智勇
陆子淳
周金星
CHU Baosen;ZHANG Shuaifa;LIU Feng;ZHANG Pengcheng;ZHANG Zhiyong;LU Zichun;ZHOU Jinxing(Jianshui Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;Engineering Research Center of Forestry Ecological Engineering,Ministry of Education,Beijing Forestry University,Beijing 100083,China;State Key Laboratory of Efficient Production of Forest Resources,Beijing Forestry University,Beijing 100083,China)
出处
《水土保持学报》
北大核心
2025年第5期169-178,共10页
Journal of Soil and Water Conservation
基金
国家重点研发计划项目(2022YFF1302900)
北京林业大学“5·5工程”科研创新团队项目(BLRC2023B09)。
关键词
坡向
坡位
土壤有机碳
有机碳稳定性
slope aspect
slope position
soil organic carbon
organic carbon stability
