藏东南色季拉山不同海拔土壤团聚体特征及影响因素  

Characteristics and influencing factors of soil aggregates at different altitudes in Sygera Mountain,southeastern Xizang

作　　者：郭亮娜 丁慧慧 李江荣[1,2,3,4] Guo Liangna;Ding Huihui;Li Jiangrong(Research Institute of Tibet Plateau Ecology,Tibet Agriculture and Animal Husbandry University,Nyingchi,Xizang 860000,China;Key Laboratory of Forest Ecology in Tibet Plateau,Ministry of Education,Nyingchi,Xizang 860000,China;National Forest Ecosystem Observation&Research Station of Nyingchi,Nyingchi,Xizang 860000,China;Key Laboratory of Alpine Vegetation Ecological Security in Tibet,Nyingchi,Xizang 860000,China)

机构地区：[1]西藏农牧学院高原生态研究所,西藏林芝860000 [2]西藏高原森林生态教育部重点实验室,西藏林芝860000 [3]西藏林芝高山森林生态系统国家野外科学观测研究站,西藏林芝860000 [4]西藏自治区高寒植被生态安全重点实验室,西藏林芝860000

出　　处：《水土保持研究》2025年第3期81-90,共10页Research of Soil and Water Conservation

基　　金：西藏农牧学院人才队伍建设资助项目(XZNMXYRCXM-2024-10);西藏农牧学院研究生创新计划项目(YJS2021-23);西藏自治区科技创新基地自主研究项目(XZ2022JR0007G);科技部国家野外科学观测研究站(生态系统)运行补助项目(2020—2025)。

摘　　要：[目的]探讨山地生态系统中土壤团聚体的空间分异规律及其影响因素,为藏东南区域尺度上的土壤资源合理利用和土壤保护机制等生态研究提供理论支持。[方法]在藏东南海拔3500 m、海拔3900 m和海拔4300 m采集不同土层深度的土壤样品,借助干湿筛法和相关性分析(Pearson)探讨了土壤团聚体特征与土壤理化性质的关系。[结果]土壤容重(BD)、可蚀性K值和分形维数D随着土层的增加呈显著增加的趋势,而非毛管孔隙度(NCAP)、铵态氮(NH_(4)^(+)-N)、硝态氮(NO_(3)^(-)-N)、有机碳(SOC)、全氮(TN)、速效磷(AP)、速效氮(AN)、水稳性团聚体含量(WSA)和平均几何直径(GMD)则随着土层的增加呈显著下降的趋势。WSA、平均质量直径(MWD)、GMD随着海拔的升高呈先上升后下降的趋势,在3900 m达到峰值。分形维数D在海拔4300 m最高。在海拔3900 m VWC与团聚体稳定性呈负相关关系,而AP与团聚体稳定性呈正相关关系,在海拔4300 mm,AP,NCAP,毛管孔隙度(CAP),NH_(4)^(+)-N,TN,SOC,AN与团聚体稳定性呈正相关关系,而NCAP,NH_(4)^(+)-N,TN,SOC,AN与可蚀性K值和分形维数D呈负相关关系。[结论]土壤团聚体稳定性和土壤抗侵蚀能力随着海拔的升高呈先上升后下降的趋势,在3900 m达到峰值,此外,高海拔地区土壤团聚体与土壤理化性质之间的互作关系最紧密和最复杂,AP是影响中、高海拔土壤团聚体稳定性最重要的因素。[Objective]This study aims to explore the spatial differentiation patterns of soil aggregates and their influencing factors within mountain ecosystems,providing theoretical support for ecological studies on the rational utilization of soil resources and soil conservation mechanisms at the regional scale in southeastern Xizang.[Methods]Soil samples from different depths were collected at altitudes of 3500 m,3900 m,and 4300 m in southeastern Xizang.Dry and wet sieving methods,along with Pearson correlation analysis,were used to examine the relationship between soil aggregate characteristics and soil physicochemical properties.[Results]Bulk density(BD),soil erodibility(K value),and fractal dimension(D)significantly increased with increasing soil depth,whereas non-capillary porosity(NCAP),ammonium nitrogen(NH_(4)^(+)-N),nitrate nitrogen(NO_(3)^(-)-N),soil organic carbon(SOC),total nitrogen(TN),available phosphorus(AP),available nitrogen(AN),water-stable aggregate content(WSA),and geometric mean diameter(GMD)significantly decreased with increasing soil depth.WSA,mean weight diameter(MWD),and GMD showed a trend of first increasing and then decreasing with altitude,peaking at 3900 m.The fractal dimension(D)was the highest at 4300 m.VWC was negatively correlated with aggregate stability at 3900 m,while AP was positively correlated.At 4300 m,AP,NCAP,capillary porosity(CAP),NH_(4)^(+)-N,TN,SOC,and AN were positively correlated with aggregate stability,whereas NCAP,NH_(4)^(+)-N,TN,SOC,and AN were negatively correlated with the K value and fractal dimension(D).[Conclusion]The stability of soil aggregates and soil erosion resistance increases with altitude,peaking at 3900 m,and then declined.The interaction between soil aggregates and soil physicochemical properties at higher altitudes is found to be the closest and most complex,with AP identified as the most important factor affecting the stability of soil aggregates at middle and high altitudes.

关 键 词：山地生态系统 森林土壤 海拔 土壤团聚体 理化性质 

分 类 号：S157.5[农业科学—土壤学]