从湖南省天然林的现状分析入手 ,对不同森林类型的水源涵养功能进行了阐述。天然次生林以阔叶林为主 ,生物多样性丰富 ,粗腐殖质层A0 层厚 ,林地土壤有机质含量高 ,与人工林比较 ,乔根重及乔、灌草面积指数高 ,凋落物多 ,森林水文生态功能强。天然次生林一次最大土壤贮水量 13 2 6.5t hm2 比人工林的 70 6.84t hm2 大 87.67%;天然次生林冠一次最大持水量为 6.14 8t hm2 ,比人工林的 3 .0 3 9t hm2 大 2 .0 2倍 ,天然林在防洪蓄水中起着重要的作用 Beginning with the analysis of the current situation of natural forests in Hunan Province, the water conservation functions of different forest types were described. The natural secondary forest is mainly broadleaf forest with rich biodiversity. Thick A0 layer of thick humus layer and high content of soil organic matter in forest land, compared with the plantation, Qiaogenzhong and Qiao, high shrub area index, litter and forest hydrology Strong ecological function. The maximum soil water storage capacity of natural secondary forest was 13 2 6.5t hm2, which was 87.67% more than 70 6.84t hm2 of plantation forest. The maximum maximum water holding capacity of natural secondary forest was 6.14 8t hm2, which was larger than 3.309t hm2 of plantation 2 times, natural forests play an important role in flood control and water storage