季节性冻融对色季拉森林土壤团聚体稳定性的影响  

Effect of Seasonal Freeze-Thaw on the Stability of Soil Aggregates in the Forest of Sergyemla Mountain

作　　者：丁慧慧 陈文盛 李江荣[1,2,3,4] DING Huihui;CHEN Wensheng;LI Jiangrong(Research Institute of Tibet Plateau Ecology,Tibet Agriculture&Animal Husbandry University,Nyingchi,Tibet 860000,China;Key Laboratory of Forest Ecology in Tibet Plateau,Ministry of Education,Nyingchi,Tibet 860000,China;National Key Station of Field Scientific Observation&Experiment,Nyingchi,Tibet 860000,China;Key Laboratory of Alpine Vegetation Ecological Security in Tibet,Nyingchi,Tibet 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》2023年第1期120-127,共8页Research of Soil and Water Conservation

基　　金：西藏林芝森林生态站辐射基准站与冻土自动监测系统建设(502219001);科技部国家野外科学观测研究站(生态系统)运行补助项目西藏林芝高山森林生态系统国家野外科学观测研究(2020-2025);西藏农牧学院研究生创新计划项目(YJS2021-23)。

摘　　要：为分析季节性冻融对土壤团聚体稳定性的影响,以藏东南色季拉山森林土壤为研究对象,通过野外控制性试验利用湿筛法测定团聚体组成,分析了0—10 cm, 10—20 cm, 20—30 cm深度土层各粒径团粒结构变化,以及土壤含水量(SWC),0.25 mm水稳性团聚体含量(WSA)、平均质量直径(MWD)、平均几何直径(GMD)、分形维数D、可蚀性K值各指标之间的关系。结果表明:(1)季节性冻融导致大团粒含量减少,小团粒含量增加,土壤结构失调。(2)含水量是影响团聚体稳定性的重要因素之一。(3)季节性冻融作用整体上导致MWD,GMD变小,D值与K值变大,降低了土壤团聚体稳定性。(4)当土壤冻融次数在一定范围内STF-One中,WSA有所增加,土壤稳定性有所增强。(5)土壤团聚体WSA,MWD和GMD均与D值和K值呈负相关。(6)在SFT-Ys类型土壤中土壤结构变化,0.5 mm粒级是重要临界点。综上,研究为季节性冻融对土壤稳定性的影响提供数据支持,为冻土潜在受侵蚀情况提供理论依据。The forest soil of Sergyemla Mountain in southern Tibet was used as the study object to examine the influence of seasonal freezing and thawing on the stability of soil aggregates, and the composition of aggregates was measured by using the wet sieving method in field controlled trials. The structure of each particle-sized aggregate changes, soil water content(SWC), 0.25 mm water stability aggregate content(WSA), mean weight diameter(MWD), geometric mean diameter(GMD), the fractal dimension D, the erodibility index K value, and the relationship between these parameters in 0—10 cm, 10—20 cm and 20—30 cm of the soil layers were analyzed. The results show that:(1) seasonal freezing and thawing resulted in the decrease in the content of big aggregates, the increase in the content of tiny aggregates, and an imbalance in soil structure;(2) water content is a crucial component influencing aggregate stability;(3) the seasonal freeze-thaw effect affected the stability of soil aggregates by decreasing MWD and GMD and increasing D and K values;(4) when the number of soil freezing and thawing events in STF-One fell within a particular range, WSA rose and soil stability improved;(5) correlation analysis of the indicators revealed that the valuses of WSA, MWD, and GMD were negatively linked with the D and K values;(6) the 0.5 mm particle size is an essential key point in the soil structure modification in SFT-Ys type soil. These research results can provide evidence to support the impacts of seasonal freezing and thawing on soil stability as well as a theoretical basis for permafrost erosion.

关 键 词：季节性冻融 土壤团聚体 湿筛法 土壤稳定性 色季拉山 

分 类 号：S152.4[农业科学—土壤学]