亚热带岩质海岸不同类型植被的水土保持效益

通过设立径流小区和多元回归分析等方法, 对亚热带岩质海岸不同植被类型的水土保持效益进行了对比研究。结果表明: 由于林木处于幼龄阶段, 不同植被类型的地表径流量削减率较小, 平均比对照降低9-05 % ; 侵蚀模数比对照平均削减39-29 % 。不同植被类型下的土壤含水率比对照提高17-94 % ; 土壤含水率除了与植被类型有关外, 还与土壤物理特性有较密切的关系; 影响土壤含水率的土壤物理因子主要为土壤容重, 其次为非毛管孔隙度与总孔隙度之比和非毛管孔隙度。影响土壤含水率的主要气象因子为平均气温和降水量。土壤物理特性对地表径流量的影响大于对侵蚀模数的影响。表4 参12

Water and soil conservation effectiveness of different types of vegetation on subtropical rocky coast

Studies on water and soil conservation effectiveness of different types of vegetation on the subtropical rocky coast showed that surface ranoff and erosion modulus in the different types of vegetation consisted of young trees decreased by 9 05% and 39 29%,respectively,compared with those of the controls,and their soil moisture content was 17 94% higher than that of the controls.Soil moisture content had colse relation with the physical properties of soil besides vegetation type.The main physical factor of soil affecting soil moisture content was unit weight of soil,and ratio noncapillary porosity to total porosity were secondary.The main meteorological factors affecting soil moisture content were air temperature and preciptation.The effect of physical properties of soil on surface runoff was greater than that on erosion modulus.