基于CT扫描研究灌丛根系对土壤大孔隙的影响
高 宙1,2, 胡 霞1,2

(1.北京师范大学 地表过程与资源生态国家重点实验室, 北京 100875; 2.北京师范大学 地理科学学部自然资源学院, 北京 100875)

灌丛; 根系; 土壤大孔隙; CT扫描

Influence of Shrub Roots on Soil Macropores Using X-Ray Computed Tomography
GAO Zhou1,2, HU Xia1,2

(1.Key Laboratory of Earth Surface and Resource Ecology, Beijing Normal University, Beijing 100875, China; 2.School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China)

shrub; root; soil macropores; CT

备注

为研究灌丛根系对土壤大孔隙形成的影响,选取青海湖流域的金露梅灌丛和内蒙古的小叶锦鸡儿灌丛作为研究对象,利用CT扫描和Avizo软件解译,实现两种灌丛的根系和土壤大孔隙的三维可视化和定量化。结果 表明:金露梅灌丛根系和土壤大孔隙主要分布在0—25 cm土层,土壤中存在较多随机分布的独立大孔隙,大孔隙和根系的相似程度低于小叶锦鸡儿灌丛; 小叶锦鸡儿灌丛根系和大孔隙则是在0—50 cm的范围内均有分布,土壤表层大孔隙集中且杂乱,表层以下大孔隙连通性较好,大孔隙和根系结构有较高相似性。内蒙古小叶锦鸡儿灌丛根系对土壤大孔隙的形成影响较大,而青海湖流域的金露梅灌丛根系对土壤大孔隙形成的影响则相对较小,因此,在不同海拔环境中灌丛根系对大孔隙的形成会因环境差异表现出不同的影响程度。

To study the influence of shrub roots on soil macropores, undisturbed soil columns under shrub canopies were sampled(Potentilla fruticose shrub from Qinghai Lake Basin and Caragana microphylla shrub from Inner Mongolia)and scanned with X-ray computed tomography. Then 3 D soil macropores and root architecture were visualized and quantitated with Avizo software. The results showed that roots and macropores under Potentilla fruticose shrub mainly distributed in the 0—25 cm soil layer. In addition, independent macropores were found much more prevalent, which resulted in a less similarity with the roots compared with Caragana microphylla shrub. By contrast, roots and macropores under Caragana microphylla shrub distributed in the 0—50 cm soil layer. Macropores in the surface layer were concentrated and disorderly, while macropores in subsoil had a good connectivity and high similarity with the root architecture. The roots of Caragana microphylla shrub in Inner Mongolia had a greater influence on the formation of soil macropores, while the roots of Potentilla fruticose shrub in Qinghai Lake Basin had a relatively smaller impact on soil macropores. Therefore, the influence of shrub roots on macropores varies in different environments.