| Jinshajiang watershed in Yunnan plateau is located in the upper reaches of the Yangtze river, it plays a special role in the Yangtze river Basin. Because of soil erosion, deforestation, the pattern of land use and forest ecological restoration measures has been widely given attention. Rich variety of forest plant community in Jinshajiang watershed plays a very important role on soil and water conservation, water purification, maintain the benign cycle of ecological system; research and protection of the ecological environment in upper reaches of the Yangtze river in Yunnan plateau mountain Jinshajiang watershed is currently an important task. In this study, the main vegetation in experiment aera, Pinus armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest,P. yunnanensis+Quercus VR mixed forest, Alnus cremastogyne Burk forest, of P. yunnanensis forest, and Sabina chinensis forest were selected as the research objects, with farmland and grassland as contrast land use types, on the basis of the analysis of experiment area rainfall characteristics, from the three vertical activity levels of forest, the canopy, litter layer, soil layer, canopy interception, litter water holding, soil infiltration, soil water retention characteristics, surface runoff and hydrological characteristics were discussed. Using mathematical statistics, correlation analysis, regression analysis, the grey relation methods, the impact of the ecological function and its affecting factors of all levels of forest eco-hydrological functions of different levels were analyzed. At the end of this paper, hydrology ecological function evaluation index system of different forest types was established by applying the AHP method. The function and value of water conservation of different forest types were compared and evaluated, and the hydrological ecological function value of forest in Toutang small watershed was calculated by using shadow engineering method. The results have important theoretical and practical significance to the yunnan plateau mountain forest ecological protection and construction, land use and vegetation restoration. The main results were as follows:(l)By comparison different forest canopy eco-hydro logical functions, the function of P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest was the best. The canopy interception ratio ranged from14.35%to24.84%, the order of the ratio was:P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest(24.84%)> P. yunnanensis+Quercus VR mixed forest(21.77%)> P. yunnanensis forest(20.80%)> Sabina chinensis forest (16.11%)> Alnus cremastogyne Burk forest(14.35%). The relationship between canopy interception rate and rainfall was logarithmic function. By classifying rainfall to comparison the interception rate changes also further indicated that, along with the gradual increase of rainfall level,5kinds of typical forest canopy interception rate gradually reduced. (2)By comparison the eco-hydrological function of litter layer of five forests, the function of P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest was the best. Different forest litter reserves is obviously different, P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest litter reserves were the largest, the order of litter reserves amount of different forest type was:P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest(12.0t·hm-2)> P. yunnanensis forest(8.47t·hm-2)> P. yunnanensis+Quercus VR mixed forest(7.62t·hm-2)> Sabina chinensis forest(4.68t·hm-2)> Alnus cremastogyne Burk forest(5.69t·hm-2). The order of litter return, the maximum water holding capacity and effective retaining content of five forests were as same as the litter reserves, The maximum water-holding percentage of litter layer for different forest vegetation ranged from261.02%to401.03%; effective retaining content of the forests were7.13-37.66t-hm-2, equivalently to0.71-3.77mm of rainfall interception. The retaining capacity of P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest was the strongest in five kinds of forests. This fully shows that the forest litter reserves is an important index reflecting the litter water holding capacity of litter, the litter reserves of forest was bigger, and its water holding capacity was stronger.(3)By comparison the eco-hydrological function of soil layer of five forests, the function of P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest was the best. The difference of soil infiltration in different levels was very big, in addition to grass land, the order of initial infiltration rate and steady infiltration rate were A layer of humus layer>B layer of deposition rock> C layer of Parent rock. The initial infiltration rate order was P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest(14.93mm·-min-1)>P. yunnanensis+Quercus VR mixed forest (6.2mm-min-1)>P. yunnanensis forest(5.75mm-min-1)>P1)>Alnus cremastogyne Burk forest(4.06mm-min-1)>dry land(3.41mm·min-1)>Sabina chinensis forest(2.61mm-min-1)>grassland(2.02mm-min-1), the order of surface soil stable infiltration rate and the initial infiltration rate were the same. Correlation analysis and principal component analysis results showed that the physical and chemical properties of soil water stable aggregates, natural water content, total porosity, organic matter, non capillary porosity, bulk density were the main factors that influenced the permeability characteristics. The order of effective storage capacity per unit area of different kinds was P. armandii Franch+yunnanensis+Coriaria nepalensis mixed forest(512.11t-hm-2·a-1)>P. yunnanensis+Quercus VR mixed forest(250.59t·hm-2·a-1)>Alnus cremastogyne Burk forest(199.26t-hm-29a-1)>P. yunnanensis forest(178.81t·hm-2·a-1)>Sabina chinensis forest(147.66t-hm-29a-1)> slope cultivated land(94.83t·hm-2·a-1)>grassland(86.52t·hm-2·a-1).(4)Combining with the analysis of related data in the rainy season from2001to2013, the rules of the annual runoff and the total runoff depth were:slope cultivated land>grassland>Sabina chinensis forest> Alnus cremastogyne Burk forest> P. yunnanensis forest>P. yunnanensis+Quercus VR mixed forest>P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest. Runoff coefficient for typical stand of different forest types from2001to2013decreased gradually, but the runoff coefficient of grassland and slope farmland increased. In2013, the total surface runoff of slope land was90.36mm and was the most, and that of P. armandii Franch+P.yunnanensis+Coriaria nepalensis mixed forestwas the least, only21.91mm. Using grey correlation analysis method the rainfall factor and60minute rain intensity factor were the most closely factor that affect the runoff coefficient. Through regression analysis, the relationship between runoff and rainfall of different kinds of land use type was three times curve equation, all models could pass the F test. Using the SPSS correlation coefficient analysis to explain effects of on the runoff, the results showed that the relationship between soil physical properties, ground cover and runoff coefficient is positive correlation, and the rules was:canopy> litter reserves> maximum water holding rate> soil water content>non capillary pore filling degree> initial infiltration rate.(5)Using the method of analytic hierarchy process14indicators of hydrological and ecological functions of forests was evaluated. The quantization score order of different forests in comprehensive evaluation of ecological function was:P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest(0.981)>P. yunnanensis+Quercus VR mixed forest(0.730)>P. yunnanensis forest(0.617)>Alnus cremastogyme Burk forest(0.514)>Sabina chinensis forest(0.502).The value of P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forestwas the highest, its water conservation capacity was the strongest,and its hydrological and ecological function was also the strongest.(6)The shadow engineering method is adopted for accounting the value of hydrological ecological benefits of forest ecosystem in regulating the runoff peak. The value order was:P. armandii Franch+P. yunnanensis+Coriaria nepalensis mixed forest>P. yunnanensis+Quercus VR mixed forest>P. yunnanensis forest>Alnus cremastogyne Burk forest>Sabina chinensis forest. The water conservation potential of different forests are large, and the forest plays important ecological and social benefits in the upper reaches Yangtze river Jinsha river basin.
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