期刊
JOURNAL OF HYDROLOGY
卷 361, 期 1-2, 页码 78-95出版社
ELSEVIER
DOI: 10.1016/j.jhydrol.2008.07.027
关键词
Soil hydrology; Saturated hydraulic conductivity; Tropical montane rainforest; Disturbance and recovery; Landslides; Land use
Tropical montane rain forests are subject to both natural and anthropogenic disturbances, such as shallow landslides and forest-to-pasture conversion. Vegetation regrowth is rapid upon attaining hillslope stability and pasture abandonment, respectively, and apt to affect soil hydrology via changes in soil structure, a sensitive indicator of which is soil saturated hydraulic conductivity (K-s). Our objective was to quantify the influence of these regionally widespread and important disturbances on K-s, and the subsequent recovery of Ks, and to describe the resulting spatial patterns. In a 2 km(2) large research area in southern Ecuador, we used a mixed design- and model-based sampling strategy for measuring K-s, in situ at soil depths of 12.5, 20, and 50 cm (n = 30-150/depth) under landslides of different ages (2 and 8 years), under actively grazed pasture, fallows following pasture abandonment (2-25 years of age), and under natural forest, and for elucidating its spatial patterns. Global means of soil permeability generally decrease with increasing soil depth. K-s, does not differ among landslides and in comparison to the natural forest, which suggests a marginal effect of the regional landslide activity on soil hydrology. In contrast, results from the human-induced disturbance regime show a permeability decrease of two orders of magnitude after forest conversion to pasture at shallow soil depths, and a slow regeneration after pasture abandonment that requires a recovery time of at least one decade. Disturbances affect the K-s, spatial structure, in particular the correlation length, in the topsoil. The largest differences in the covariance parameters, however, are found for the subsoil K-s, where the spatial structure is independent of land cover. This case study suggests a rather disparate soil hydraulic response to regionally important disturbances. Cattle grazing strongly affects the spatial mean of K-s, whereas landslides do not, and both the processes affect the spatial structure of K-s, in the topsoil. (C) 2008 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据