Study On The Hydrology Effect Ot Litter Fall In The Main Forest Types Of Helan Mountain

Helan Mountain in the temperate grasslands of the transition area and the desert area, is a famous mountain in northwest China, one area is a fragile ecosystem, its natural environment, the complexity of the vulnerability of ecosystems are typical representative in China, Been designated as water conservation forest of National Nature Reserve. Therefore, the typical vegetation of Helan Mountain Soil and Water Conservation to carry out the research function is important.Forestry industry with the state public welfare projects, "Shaanxi and Ningxia provinces, autonomous regions Function of Forest Ecosystem Services Monitoring and Assessment Technology"to the Helan Mountains in 4 typical natural forest types (spruce pine forest, mixed oil Matsuyama Yang, pure pine Qinghai spruce forests and pure stands) as the object of its forest litter layer of soil and water conservation features were studied. And a large number of field investigation and laboratory tests, based on the established water holding capacity of litter correlation between the model and the Helan Mountains litter layer of forest vegetation of water conservation were evaluated. The results showed that:(1) In the test, the different vegetation types of helan temporary sample litter reserves made detailed investigations and analysis, research studies found that the different vegetation types woodland helan mountain, the ground litter reserves are quite different. In the four forest Lin minutes, qinghai spruce pure forest litter the reserves of the highest, achieve 32.39 t/hm~2, secondly is mixed and pinus tabulaeformis spruce pure forests, the two vegetation types of litter achieved respectively the standing crop also 25.21hm~2 and 26.6 t/t/hm~2, this research area ShanYang pinus tabulaeformis mixed forest of litter layer savings amount minimum, only 19.74 t/hm~2. Various vegetation types of litter layer natural moisture content is the highest in the pure forests, qinghai spruce 89.72%, second only to reach its moisture content of qinghai spruce pure forest tabulaeformis spruce mixed forest, is also achieved its moisture content, to 83.15% pinus tabulaeformis pure ling ling natural moisture content of litter layer, only for 73.95% lowest.(2) indoor litter immersion test results show that the water holding capacity of litter is with the immersion time increases, the maximum speed of the first 2h in water, followed by a sharp decline, the trend is consistent among forest types, different vegetation types Large difference between the water holding capacity. Yang oil mixed forest in Songshan saturated water highest 1.84 times its own weight, followed by pure stands, spruce pine mixed forest, respectively, 1.53 times its own weight and 1.51 times, Picea Pure lowest, 1.44 times.(3) types of forest vegetation in the forest litter water holding capacity and water holding rate increases with the immersion time increases logarithmically; water absorption rate of the oil Matsuyama Yang showed mixed> Mixed≥pine pure stands of spruce > Qinghai spruce pure forest, and various types of forest litter water absorption rate increased with soaking time down by the power function. Establishment of litter in different forest types of water retention and soaking time, water absorption rate and soaking time correlation model.(4) storing the amount of effective changes in the range of forest types 10.7 ~ 15.73t/hm~2, Matsuyama Yang oil mixed the largest 15.73t/hm~2, pure stands (14.05t/hm~2) and mixed spruce pine (11.98t/hm~2), followed by the smallest of Qinghai spruce pure forest, only 10.7 t/hm~2.