云雾山草地植被恢复过程土壤水库特性及影响因素

Soil Storage Characteristics and Its Influencing Factors during Revegetation in Yunwu Mountains

为了了解植被恢复过程土壤水库特征的变化及其驱动因子,为半干旱典型草原区植被恢复的土壤环境效应提供评价依据,研究了宁南半干旱典型草原区植被恢复80 a对土壤水库库容、实际贮水量和贮水效率的影响及驱动因子。结果表明:土壤水库总库容、吸持库容、实际贮水量、贮水效率以及土壤物理性质均在草原植被恢复25 a内不断提高,经37 a略微下降后随植被演替土壤水库特征和土壤物理性质继续改善。通过逐步回归分析,容重、有机质含量和水稳性团聚体分形维数是影响土壤水库总库容的主要因子,毛管孔隙度则是影响土壤实际贮水量和贮水效率的主要因子。土壤有机质含量与容重、分形维数呈显著负相关(P<0.05),与毛管孔隙度呈极显著正相关(P<0.01)。植被恢复促使有机质积累,从而改善了土壤结构状况,提高了土壤土壤贮水能力、贮水量和贮水效率。可以认为土壤有机质积累是土壤水库功能提高的直接动力。

In order to provide some basic foundation with revergetation and soil reservoir in semi-arid typical grassland areas, we need to deepen our understanding on the change of soil reservoir and its driving factors. We studied the effect of vegetation restoration 80a on soil storage capacity, practical storage and the efficiency of soil storage. The result showed that soil storage capacity, retention storage capacity, practical storage, the efficiency of soil storage and soil physical properties improved constantly, in the plant community which was enclosed 25 years. However they declined slightly at 37 a. Soil storage and soil physical properties improved again after 37 a when the plant community was enclosed. Application of the stepwise regression, we can find that the driving factors of soil storage capacity were bulk density, organic matter content and fractal dimension. The driving factors of Soil practical storage and the efficiency of soil storage were capillary porosity. Correlative analysis show that content of soil organic matter negatively corrleated with bulk density and fractal dimension（P〈0.05）, respectively positive corrleated with capillary porosity（P〈0.01）. Revegetation was precondition of accumulation of organic matter, which improved water storage capacity. Therefore, soil organic matter was basic motive force of soil reservoir function.