北川河流域退耕还林不同配置模式的水文效应

对青海大通北川河流域山地退耕还林不同配置模式的水文效应进行了研究，结果表明，不同配置模式植冠层截留量、枯枝落叶层的容水量、土壤总持水量随着林分植冠层生物量和枯枝落叶层现存量的增加呈上升趋势，同时，在林分总蓄水量中，土壤持水量所占比值较大（〉97％），而土壤稳渗速率随着土壤总孔隙度的增大而增大。其中：（1）在浅山区，植冠层截留量和枯枝落叶层的容水量以模式D（中国沙棘）最大，分别为1．43mm，1．87mm；土壤持水量和林分总蓄水量以模式C（青杨＋枸杞）最大，分别为327．88mm，329．07mm，稳渗速率则以模式A（川赤芍）最大，为4．8mm／min。（2）在脑山区．植冠层截留量、枯枝落叶层容水量、土壤总持水量、林分总蓄水量和稳渗速率均以模式F（青海云杉）最大，依次为2．37mm，6．24mm，323．3mm，331．91mm，6．8mm／min。

Hydrological Effects of Different Species Arrangement Models of Converted Farmland to Forest in Beichuanhe Watershed

After five models of converting cropland to forest in low-mountain and high-mountain areas in Beichuanhe watershed of Datong county of Qinghai province were selected respectively,the hydrology effects were analyzed.The water-holding capacity of the canopy,litter layer and soil in different species arrangement models were increased along with biomass of the canopy and existent mass of litter layer.The water-holding capacity of soil was the biggest(>97%) in the total water-holding capacity of forest.The more the total pore space,the bigger the final infiltration rates.In the low-hill area,the total water-holding capacity of the canopy and litter layer of model D(Hippophae rhamnoides)was the biggest,that was 1.43 mm and 1.87 mm respectively;The total water-holding capacity of soil and forest of model C(Populus cathayana Lycium barbarum),which was 327.88 mm and 329.07 mm respectively,ranks first place in different models of species distribution.The final infiltration rate of model A(Paeonia veitchii) is better than others,which is 4.8 mm/min.In the remote-hill area,the total water-holding capacity of canopy,litter layer,soil and forest of model F(Picea crassifolia) ranks first place in different models, which was 2.37 mm,6.24 mm,323.3 mm and 331.91 mm respectively,and the final infiltration rate of soil is 6.8 mm/min.