西藏米拉山土壤团聚体垂直地带性特征  

Vertical Zonality of Soil Aggregates at the Top of Mila Mountain in Tibet

作　　者：喻武[1,2] 任德智 杨文姬 宋珺 乔锋[6] 李晶[6] YU Wu;REN Dezhi;YANG Wenji;SONG Jun;QIAO Feng;LI Jing(College of Resource and Environment,Tibet Agriculture and Animal Husbandry University,Linzhi Xizang 860000,China;Research Center of Soil and Water Conservation in Alpine-cold Region,Tibet Agriculture and Animal Husbandry University,Linzhi Xizang 860000,China;Chengdu Academy of Agriculture and Forestry Sciences,Chengdu 611130,China;Shanhelin Company(Beijing)of Soil and Water Conservation Technology,Beijing 100038,China;Development&Reform Department,China Railway Corporation,Beijing 100844,China;Sea-buckthorn Development Center,Beijing 100038,China)

机构地区：[1]西藏农牧学院资源与环境学院,西藏林芝860000 [2]西藏农牧学院高寒水土保持研究中心,西藏林芝860000 [3]成都市农林科学院林业研究所,成都611130 [4]山合林(北京)水土保持技术有限公司,北京100038 [5]中国铁路总公司发展和改革部,北京100844 [6]水利部沙棘开发管理中心,北京100038

出　　处：《西南大学学报（自然科学版）》2022年第7期59-69,共11页Journal of Southwest University(Natural Science Edition)

基　　金：水利部沙棘开发管理中心项目(2017-zg-zx-57);西藏自治区科技厅重点项目(XZ 2018ZR G-34(Z))。

摘　　要：为探明米拉山土壤结构及团聚体稳定性特征,利用野外调查和室内试验相结合的方法,按照200 m梯度,选取研究区海拔4 200~5 000 m间土壤,对>0.25 mm团聚体的含量、团聚体破坏率(PAD)、平均重量直径(MWD)、几何平均直径(GWD)和分形维数(D)等指标进行分析.结果表明:(1)不同海拔土壤基本理化性质差异有统计学意义.总体上,海拔5 000,4 800 m土壤容质量及孔隙度结构均优于4 200~4 600 m,有机质质量分数随海拔降低先减小后增大,4 600 m有机质质量分数显著(p<0.05)小于其余海拔.(2)研究区土壤机械稳定性及水稳性团聚体均以>0.25 mm粒径为主.总体上机械稳定性团聚体及水稳性团聚体均表现为海拔5 000,4 800 m优于4 200~4 600 m,其MWD,GMD值相对较高,PAD值相对较低,但差异无统计学意义.在干筛与湿筛两种条件下的D值随海拔增加而变小.(3)相关分析表明,土壤有机质、容质量及大团聚体含量直接影响团聚体稳定性.海拔是区域土壤理化性质产生差异、导致土壤团聚体稳定性异同的重要因素.(4)海拔通过改变水热条件,间接影响研究区植被覆盖、有机质周转、土壤侵蚀过程,从而导致土壤结构和团聚体稳定性的差异.The objective of this research was to explore the characteristics of soil structure and aggregate stability on the top of Mila Mountain. The content of aggregate >0.25 mm, aggregate destruction rate(PAD), mean weight diameter(MWD), geometric mean diameter(GMD) and fractal dimension(D) at altitude of 4200~5000 m were analyzed by field investigation and laboratory experiment. The results showed that:(1) There were significant differences in the basic physical and chemical properties of soils at different altitudes. In general, soil bulk density and porosity structure at 5000 and 4800 m were better than those of at 4 200-4 600 m. The organic matter content decreased first and then increased with the decrease in altitude. The organic matter content at 4600 m was significantly(p<0.05) less than at other altitudes.(2) In the survey area, both the soil mechanical stability and water stable aggregate mostly are >0.25 mm. In general, both mechanically stable aggregates and water-stable aggregates at altitudes of 5000 and 4800 m were better than those of at 4 200-4 600 m, with relatively high MWD and GMD values, and relatively low PAD values, but the difference was not significant. The D value under the two conditions of dry sieving and wet sieving decreased with the increase of altitude.(3) The correlation analysis showed that soil organic matter, bulk density and macroaggregate content directly affected the stability of soil aggregates. Altitude was an important factor for the differences of soil physical and chemical properties and the stability of soil aggregates.(4) Altitude indirectly affected vegetation coverage, organic matter turnover and soil erosion process through changing water and heat conditions, which lead to differences in soil structure and aggregate stability. Altitude gradient is the most fundamental factor affecting the stability of soil aggregates. The organic matter is an indispensable factor in the formation of aggregates and the improvement of aggregate stability.

关 键 词：米拉山 垂直地带性 土壤团聚体 团聚体稳定性 

分 类 号：S152[农业科学—土壤学]