The Study On Hydrological Function Of Different Forest Types At The Headwaters Of QianTang River

Based on the climate characteristics and forest resources survey of KaiHua forestry center at the headwaters of QianTang River, I had analyzed the forest hydrology function.The hydrology processes was divided into canopy interception, litter water-holding, soil water storage and so on. Water quality monitoring section set along Soil - Plant - Atmosphere Continuum (SPAC) system omnidirectionally monitored forest vegetation hydrological functions, and the experimental data for deeply research and analysis. The result of Experiment can contribute to establishmenting strategy of science management about forest of the source head of the QianTang River. This paper provides the scientific theory of sustainable development for forest rational operation, the protection of the natural environment and water resources.Soil is one of the important indicators for measurement of the effects of forest hydrology. The main physical characteristics of the forest soil varied with the different forest types, and changed regularly with depth increasing; the largest precipitation storage of forest soils was mainly affected by non-capillary soil porosity and thickness of the soil; the capacity of forest soil precipitation storage was in the following sequence:Cunninghamia lanceolata forest﹥Pinus elliottii forest﹥Pinus massoniana×Quercus acutissima forest﹥Phyllostachys hterocycla forest﹥Quercus acutissima forest.The forest litter layer reserves in the KaiHua forestry center was between 7.25～18.1 t/hm2, which in the following order: Pinus massoniana×Quercus acutissima forest﹥Quercus acutissima forest﹥Cunninghamia lanceolata forest﹥Pinus elliottii forest﹥Phyllostachys hterocycla forest. The capacity for effective retains and storage of different forest types was: Pinus massoniana×Quercus acutissima forest﹥Quercus acutissima forest﹥Cunninghamia lanceolata forest﹥Phyllostachys hterocycla forest﹥Pinus elliottii forest.It monitored 139 precipitations in the forest center in the year 2007 with total precipitation 1078.6 mm, mainly distributed in the May～August and reached the standards of rainstorm. The rainfall redistribution characteristics for the five main types of forest canopy were studied. Results showed that permeable rainfall within the forest and runoff rainfall along the trunk, which primarily increased with more precipitation, were positively correlated with precipitation; canopy interception became bigger with the increase of rainfall. Whether measured in canopy interception or the canopy interception rates, the order was: Cunninghamia lanceolata forest﹥Pinus elliottii forest﹥Pinus massoniana×Quercus acutissima forest﹥Quercus acutissima forest﹥Phyllostachys hterocycla forest.From the analysis on water quality of the surface runoff, stem flow and through-fall, conclusion is gotten that the water quality situation in Quercus acutissima forest and Pinus massoniana×Quercus acutissima forest is better than Cunninghamia lanceolata forest and Pinus elliottii forest. The pH value of Quercus acutissima forest's stem flow and through-fall is the highest, Pinus massoniana×Quercus acutissima forest's and Phyllostachys hterocycla forest stand's are slightly inferior, Cunninghamia lanceolata forest and Pinus elliottii forest respectively's are seriously acidizing. In order to protect the head water source of QianTang River, it shoud be done that strengthening broadleaf and mixing gasification, reducing the proportion of pure forest, developing the mixed forest actively.