贺兰山不同坡向和海拔梯度土壤团聚体组成和稳定性变化特征及其影响因素  

Characteristics and influencing factors of soil aggregate composition and stability under different slope orientation and elevation gradients in Helan Mountain

作　　者：秦崧悦 吴新亮 褚保森 张智勇 郑成浩[1,2] 刘峰 张帅发[1,2] 周金星[1,2] QIN Songyue;WU Xinliang;CHU Baosen;ZHANG Zhiyong;ZHENG Chenghao;LIU Feng;ZHANG Shuaifa;ZHOU Jinxing(Key Laboratory of State Forestry Administration on Soil and Water Conservation,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China;National Location Observation Research Station of Jianshui Desert Ecosystem in Yunnan,Beijing Forestry University,Beijing 100083,China;Institute of Eco-environmental and Soil Sciences,Guangdong Academy of Sciences,Guangzhou 510650,China)

机构地区：[1]北京林业大学水土保持学院,水土保持国家林业和草原局重点实验室,北京100083 [2]北京林业大学云南建水荒漠生态系统国家定位观测研究站,北京100083 [3]广东省科学院生态环境与土壤研究所,广州510650

出　　处：《生态学报》2024年第17期7770-7785,共16页Acta Ecologica Sinica

基　　金：宁夏重点研发计划项目(2021BEG02005)。

摘　　要：认识山地土壤团聚体稳定性的空间分异规律,对山地生态系统功能评估与土壤侵蚀防治具有重要意义。为探究干旱区山地土壤团聚体稳定性空间变化特征及其影响因素,选取贺兰山不同坡向(西北、东南、东北和西南)和海拔梯度(1300—2800 m)的表层(0—10 cm)和表下层(10—20 cm)土壤为研究对象,测定了土壤水稳性大团聚体和微团聚体组成,分析了土壤团聚体稳定性的空间分异特征,揭示了土壤团聚体稳定性与地形,植被和土壤性质之间的关系。结果表明:研究区土壤以>2 mm和0.25—0.05 mm粒级团聚体为主。综合土壤粘粒分散系数(CDC)和粘粒分散率(CDR)分析,东北坡和西南坡土壤微团聚体稳定性较优于西北坡和东南坡。对于土壤水稳性大团聚体稳定性指数,东北坡团聚体平均质量直径(MWD)和几何平均直径(GMD)最低,分别为1.56 mm和0.44mm,土壤水稳性团聚体稳定性最差。随海拔升高,土壤CDC和CDR减小,团聚度(DOA)增大,表层土壤GMD呈上升的趋势,而表下层土壤MWD和GMD值减小。冗余分析表明土壤理化性质是影响不同海拔和坡向下土壤团聚体稳定性的主要因素,其中土壤容重、毛管孔隙度、粘粒含量和交换性Mg2+是主要影响因子。Understanding the spatial differentiation of soil aggregate stability in mountainous areas is of great significance for assessing the function of mountain ecosystems and preventing soil erosion.In order to explore the spatial variation characteristics and influencing factors of soil aggregate stability in arid mountainous areas,surface(0-10 cm)and subsurface(10-20 cm)soils with different slope orientation(northwest,southeast,northeast and southwest)and elevation gradients(1300-2800 m)in Helan Mountain were selected as research objects.The composition of macroaggregate and microaggregate of soil water stability was determined,and the spatial differentiation of soil aggregate stability was analyzed.The relationships between soil aggregate stability and topography,vegetation and soil properties were revealed.The results showed that the soils in the study area were mainly composed of aggregates with grain size>2 mm and 0.25-0.05 mm.According to the analysis of Clay Dispersion Coefficient(CDC)and Clay Dispersion Rate(CDR),the stability of soil microaggregates on the northeast slope and southwest slope was better than that on the northwest slope and southeast slope.For the stability index of large aggregates of soil water stability,the Mean Weight Diameter(MWD)and Geometric Mean Diameter(GMD)of aggregates on the northeast slope were the lowest,which were 1.56 mm and 0.44 mm,respectively.The stability of soil water-stable aggregates was the worst.The CDC and CDR decreased,DOA(Degree of Aggregation)increased,and GMD of surface soil increased,while MWD and GMD of subsurface soil decreased with elevation.Redundancy analysis showed that soil physical and chemical properties were the main factors affecting the stability of soil aggregates at different elevations and downslope,in which soil bulk density,capillary porosity,clay content and exchangeability Mg2+were the main factors.

关 键 词：坡向 海拔 土壤团聚体 团聚体稳定性 山地生态系统 

分 类 号：S157.1[农业科学—土壤学]