辽东冰缘地貌表层土壤团聚体活性有机碳分布特征  

Distribution characteristics of labile organic carbon in the soil aggregate in periglacial landforms of eastern Liaoning

作　　者：王琼[1] 范志平[1] 陈寒 韩青 李新仓[1] 李一凡 WANG Qiong;FAN Zhiping;CHEN Han;HAN Qing;LI Xincang;LI Yifan(School of Environmental and Safety Engineering,Liaoning Petrochemical University,113001,Fushun,Liaoning,China)

机构地区：[1]辽宁石油化工大学环境与安全工程学院,辽宁抚顺113001

出　　处：《中国水土保持科学》2023年第6期23-31,共9页Science of Soil and Water Conservation

基　　金：国家自然科学基金“冰缘地貌雪被-土壤界面DON迁移转化过程及其冻融驱动机制”(41977074);辽宁省教育厅面上项目“辽东山地河岸带非生长季氮污染削减效应与机制研究”(LJKZ0380)。

摘　　要：辽东山地冰缘地貌地质条件复杂,影响土壤稳定性和土壤碳汇功能。为揭示土壤碳库稳定性及其调控机理,选择不同海拔的4种典型植被,测定并分析土壤团聚体活性有机碳的变化特征及其相关的植被、物理、化学影响因素。结果表明:4种植被>0.25 mm粒径团聚体中活性有机碳质量分数呈现随海拔降低递减的趋势,即中山草地>天然林>人工林>岸边带;团聚体活性有机碳贡献率在中山草地、天然林和人工林中随团聚体粒径的减小而降低,且粒径>0.25 mm的团聚体贡献率较大;土壤团聚体活性有机碳与土壤总有机碳呈显著正相关,且在大团聚体中相关性更为显著;土壤团聚体有机碳、活性有机碳、非活性有机碳与植被盖度、凋落物生物量、根系生物量及氧化还原电位呈正相关,与土壤总氮量、密度、pH和含水率呈负相关。综上,辽东山地冰缘地貌植被特征、土壤物理和化学特征对土壤团聚体活性有机碳有重要影响。[Background]The stability of soil aggregates,the basic units of soil structure,is a key property for many soil ecological processes and functions such as soil and water conservation and soil carbon sequestration potential.The stability of aggregates is strongly correlated with labile carbon,and soil aggregation is mainly affected by labile organic carbon.The periglacial landform of eastern Liaoning is experiencing severe soil erosion and loss of soil fertility due to its special geological conditions.This study aims to reveal the stability of soil carbon and its regulation mechanism.[Methods]In June 2019,about 1 kg of undisturbed soil blocks were collected at depths of 0-10 cm at 4 vegetation types(mid-mountain grassland,natural secondary forest,larch plantation and riparian grassland)according to elevations in periglacial landforms in the mountain areas of eastern Liaoning.Aggregate distribution and stability were determined using dry-sieving methods:2.000,1.000,0.250 and 0.038 mm mesh sieves from top to bottom.After separation,the fractions of the aggregates were dried at 60℃and then weighed.SOC(soil organic carbon)was determined by the digestion method with K 2 Cr 2 O 7-H 2 SO 4.Labile organic carbon was determined by the oxidation of 333 mmol/L KMnO 4.[Results]The content of labile organic carbon in the soil aggregates with particle size>2.000,>1.000-2.000 and>0.250-1.000 mm of different vegetation types was basically the same,showing the following order:mid-mountain grassland>natural secondary forest>larch plantation>riparian grassland,decreasing with altitude.The contribution rate of soil aggregate liable organic carbon decreased with aggregate size in mid-mountain grassland,natural secondary forest and larch plantation.Nevertheless,the contribution rate of labile organic carbon within aggregate size>0.25 mm was higher,and the contribution rate of>0.038-0.250 mm was lower.The linearly positive correlation was found between content of the soil aggregate labile organic carbon and total organic carbon.And th

关 键 词：冰缘地貌 植被 土壤团聚体 活性有机碳 影响因素 

分 类 号：S152.4[农业科学—土壤学]