| Principal component analysis and hierarchical clustering method was employed,function on soil and water conservation of the main forest types in five location research stations of qiantang river, Zhejiang Province was studied. It showed:(1) About 50% fine roots of deciduous broadleaf forest are distributed in surface layer of soil,βis 0.9678.From different forest types, bamboo'sβ(0.9684)is the biggest one,young forest is the poorest one.cumulative curve and analog curve are unanimous,βcould better infect root amount of each vegetation types in research area.(2) The dynamic course of water-holding capacity and water absorption rate are similar in different forest vegetation types.with the immersion time extending,the water-holding capacity is increasing,when the litter layer is immerged in the water for 8 hours,the water-holding capacity will reach the bigger value.From then on,with the time extending,the increasing range shows small.The water absorption rate of litter layer changes fastly in the front 6 hours,after then it becomes smooth.The maximum water-holding capacity of deciduous broadleaf forest is biggest,pinetum is smallest.(3) The differences of the main forest types about the soil infiltration was significant. The infiltration property of forest land was better than that of bare land. The infiltration rate of soil surface was higher, which was very important to prevent soil erosion. And the infiltration rate decreased with the increase of soil depth.(4) It was found that >0.25mm,decentralization of conglomeration and water stable index can be regarded as the optimum 3 indexes to express soil anti-erodibility of the main forest types in non-commericial of zhejiang province by means of principal component analysis.There was much variance in soil anti-erodibility of different plots and levels.Soil anti-erodibility of Deciduous broad-leaved forest, evergreen coniferous forest, Moso bamboo stand were high,fir and pinetum were in the middle,Bare land was the poorest one. Soil anti-erodibility changed very much in different levels, especially in the same plot . From the soil surface to the bottom, Soil anti-erodibility reduced to some extend. With analysis, we could get 3 discriminant functions concerning good soil anti-erodibility, medium soil anti-erodibility and poor soil anti-erodibility in zhejiang province.(5) The soil infiltration course of Tonglu,Chunan,Kaihua,Longyou,Panan of zhejiang provine are very different.bamboo,pinetum and broad leaf were analysis by principal component analysis, the infiltration rate of Chunan was highest.and what's more,anti-erodibility of Chunan was highest.(6) Litter layer,physical and chemical soil properties and roots were the most effective in reducing the runoff of vegetations. Especially, roots less than 1mm in diameter had greater influence. There was close relationship between physical and chemical soil properties and roots less than 1mm in diameter. In fact, roots less than 1mm in diameter had great effects on the soil physical and chemical properties.cavity of soil effects the runoff.(7) All the 8 plots could be clustered into 4 kinds based on function on soil and water conservation. The function on soil and water conservation of Deciduous broadleaf forest were the strongest, so this was clustered into the first kind. The second kind was composed of evergreen forest and bamboo. The young forest,fir and pinetum were made up of the third kind.Whereas the fourth kind was made up of commercial forest and bare land,whose function of soil and water conservation were the least one. |
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