太湖地区森林生态系统的水源涵养功能特征

为客观认识森林生态系统在流域水资源管理中的作用，在总结分析前人研究成果的基础上，该文综合比较了太湖地区主要森林类型中枯枝落叶层和土壤层的涵养水源功能特征。结果表明:太湖地区森林生态系统林下枯枝落叶层现存量平均值为4.68～14.4 t/hm²，持水量为11.6～29.99 t/hm²，持水率为187.24%～246.22%；主要森林类型土壤层的毛管孔隙度变动于39.01%～44.21%，非毛管孔隙度为10.21%～16.53%；而土壤层的初渗率变动于11.94～19.06 mm/min，稳渗率为3.77～6.74 mm/min。总体来看，太湖地区森林枯枝落叶层和土壤层的水源涵养能力指标多低于亚热带平均值。

Characteristics of Water Conservation of Forest Ecosystem in Tai Lake Region

In recent years, the water conservation of forest ecosystem has raised a number of concerns. However, the present studies in Tai Lake Region lack of a comprehensive discussion and analysis on water conservation of forests. This paper reviewed a great deal of forest hydrology studies in Tai Lake Region, and compared the characteristics of water conservation in forest litter and soil layer. Field measurements indicated that, the litter biomass of major forest types ranged from 4.68 t/hm² to 14.4 t/hm², the amount of water interception by litter varied from 11.6 t/hm² to 29.99 t/hm², and the interception ratio of fully water-saturated weight to its dry mass ranged from 187.24% to 246.22%. The forests in Tai Lake Region also had well-developed soil porosity, with non-capillary pores ranging from 10.21% to 16.53%, and capillary pores from 39.01% to 44.21%. In addition, the forest soil permeability capabilities varied with vegetation types. The deciduous broadleaf forest had the largest steady-state permeability of 6.74 mm/min, followed by Chinese fir plantation, bamboo, evergreen broadleaf forest and pine. In sum, more improvement should be done in water conservation functions of forests in Tai Lake Region.