火干扰对森林土壤斥水性的影响研究进展

土壤斥水性是指水分不能或很难湿润土壤颗粒表面的现象,很多植被类型及气候带森林存在土壤斥水性。土壤斥水性受水分、温度、干湿交替、土壤质地、植被类型等生物和非生物因子的影响。而火干扰是森林生态系统土壤斥水性的重要影响因子,使森林土壤斥水性增强,渗透率降低,地表截留体减少,从而增加地表径流和土壤侵蚀。就火干扰对土壤斥水性的发生机理及其对水文过程的影响进行了较为全面的总结和讨论,并指出目前存在的问题和未来的研究重点。森林火灾后火烧迹地地表径流和土壤侵蚀显著增加,定量预测火灾后土壤斥水性对径流与侵蚀的影响比较困难,因此,基于不同尺度和自然降雨的火灾后斥水性对地表径流和土壤侵蚀的实验及长期定位观测是今后的研究方向与重点。

Progress of the effects of fire disturbance on forest soil water repellency

Soil water repellency (SWR) is a phenomenon that occurs when the soil particles are unable or hard to be moistened by water. It refers to the inability of water to wet or infiltrate a dry soil, and this phenomenon has been documented in a wide range of vegetation types and climates, especially in soil affected by wildfire. SWR is affected by biotic and abiotic factors, such as water, temperature, alternation of dry and wet seasons, soil texture, vegetation type, etc. Fire disturbance is one of the important factors influencing the SWR of forest ecological system. It enhances the SWR of the forest soil, reducing the permeability and intercept body and increasing the surface runoff and soil erosion. Numerous studies have suggested that SWR is the primary cause of reduced infiltration rates of soils after burning. In order to understand the frontier of research in the field, this paper summarizes the effects of fire disturbance on SWR. Based on the recent achievements, the historical development of the issue was reviewed briefly. Meanwhile, its physical mechanism, influencing factors, as well as its potential effects on eco-hydrological processes before and after the fire, are discussed. The main aims of the future studies on this issue are also pointed out. The runoff and soil erosion increased significantly after forest fire, but it is difficult to predict the quantitative influence of SWR on runoff and erosion after the fire. Therefore, studying the effect of SWR of different scales and natural rainfall after the fire experiments on surface runoff and soil erosion and long-term observation are recommended as the future research direction and emphasis.