The Function On Soil And Water Conservation Of Two Forest Types Around Dongting Lake

DongTingLake is located in the north of HunanProvince, which is one of the most important Eco-functional districts of China. In recent years, The great shrinking of lake areas caused by Irrational human activities, its effects on the change of wetland function and ecological environment. The wetland’s ecosystem degeneration results in serious effect to regional sustainable development. The Three Gorges Project is a huge change for the Yangtze River and DongTingLake, the relationship between river-lake relation thus will enter a new development stage from this.The paper takes two forest types around DongtingLake as the main study subject, it based on actual characteristics, and takes the combination of field monitoring and indoor experiment method for researching the function on soil and water conservation around DongtingLake. Besides, using the principal component analysis to comprehensive appraisal the the function on soil and water conservation. The results show that:(1) The two forest types around Dongting Lake on hydrological processes play an important role in regulating soil conservation.Compared with poplar forests, function on soil and water conservation of Chinese fir forest was stronger than the poplar forest. The water-holding capacity of the layers of shrub-grass and litter is in positively associated with its biomass, and the water-holding capacity of shrub-grass layer change in 0.78～2.70 t·hm-2; the water-holding capacity of Litter layer change in 3.83～5.38t·hm-2. The maximum storage capacity of Woodland soil within 0-45 cm change in 1851.40～2398.83t·h m-2, while the soil effective storage capacity change in 472.37～606.11 t·hm-2.The average of soil effective storage water capacity was Poplar forest (2206.50t·hm-2)< Chinese fir forest (2235.91 t·hm-2).By comparison, the water storage capacity of Chinese fir forest was stronger than the Poplar forest.The Soil loss amount in different forest between in 2.03～4.13 t·hm-2·a-1, and forest soil fixation quantity was 33.45～35.55 t·hm-2·a-1. Owing to the protection of forest vegetation on woodland soil, forest land reduce the loss of organic matter content of539.04 ～658.37kg·hm-2, the total N 26.09～31.06 kg·hm-2, all P16-23.07 kg·hm-2, total 72.06～92.67 kg·hm-2 each year.(2) Within the depth of 0～45 cm, different kinds of woodland’s soil organic matter, total nitrogen, total phosphorus content were decreased with the increase of soil depth, and total potassium content increased with the increase of soil depth.(3) Using the principal component analysis to comprehensive appraisal the the function on soil and water conservation, which show that:Chinese fir forest is greater than the poplar forest.The above results can provide a basal reference data for the research of soil and water conservation function around Dongting Lake, as well as play a role in the theoretical guidance for the construction and protection of the region’s forest resources.