ABSTRACT

Soil productivity is a primary determinant of vegetation restoration and land resources utilization in debris flow deposits. However, little is known on the soil productivity change process of debris flow deposits behind check dams during rehabilitation. To investigate the change process of soil productivity at debris flow deposits behind check dams, soil physicochemical properties were measured in different time of rehabilitation (0, 2, 4, 5, 16, 23, 28, 33, 39, 45 years) in Hunshui gully (HSG). Modified Productivity Index (MPI) model was used to evaluate soil productivity. The results showed that soil organic matter (OM), total nitrogen, total phosphorus, available potassium and clay increased with rehabilitation time, while total potassium, pH and bulk density decreased. OM and MPI exponentially increased with the increase of rehabilitation time from 0.1% to 1.7% and 0.0006 to 0.1423, respectively. The rehabilitation time of 23 years was most likely a threshold time for the restoration of soil productivity at debris flow deposits. The trend of MPI indicated that soil productivity increased slowly in the early stage of ecosystem restoration, followed by a rapid with the increase of vegetation and OM. Our results can provide scientific bases for the effective utilization and restoration of debris flow deposits.

摘要

土壤生产力是泥石流沉积物中植被恢复和土地资源利用的主要决定因素。然而，对于修复过程中坝后泥石流沉积物的土壤生产力变化过程知之甚少。为了解拦河坝后泥石流沉积物土壤生产力的变化过程，测定了浑水不同修复时间（0、2、4、5、16、23、28、33、39、45年）土壤理化性质。沟壑（HSG）。改良生产力指数（MPI）模型用于评估土壤生产力。结果表明，随着恢复时间的延长，土壤有机质（OM）、全氮、全磷、速效钾和粘土均增加，而总钾、pH和容重均降低。OM 和 MPI 随着康复时间的增加分别从 0.1% 到 1.7% 和 0.0006 到 0.1423 呈指数增长。23 年的恢复时间很可能是泥石流沉积物恢复土壤生产力的阈值时间。MPI的变化趋势表明，生态系统恢复初期土壤生产力缓慢增加，随着植被和有机质的增加而迅速增加。研究结果可为泥石流沉积物的有效利用和修复提供科学依据。其次是随着植被和有机质的增加而迅速增加。研究结果可为泥石流沉积物的有效利用和修复提供科学依据。其次是随着植被和有机质的增加而迅速增加。研究结果可为泥石流沉积物的有效利用和修复提供科学依据。