Spatial Distributions And Factors Affecting Of Forest Water Conservation In China’s Mainland

Under a scenario of global climatic change,terrestrial water storage depletion and accretion of population,forest water conversation play important roles in interception,storage and redistribution of precipitation.Large-scale spatial estimation of forest water conversation has been studied by some models,such as water-balance model,but its results are lack of verification based on observed data.Therefore,we systematically reviewed relevant peer-reviewed literature and extracted water conservation parameters and their influencing factors from studies performed throughout China using a meta-analysis approach.Empirical models and path analysis were used to explore the spatial distributions of and significant factors affecting the canopy interception capacity,litter maximum water-holding capacity,soil storage capacity and forest water conservation capacity at the national and basin scales.Based on the observed data,significant impact factors were used as ancillary information to predict canopy interception,litter maximum water-holding,soil storage,and forest water conservation using random forests.Spatial distributions of the canopy interception capacity,soil storage capacity and forest water conservation capacity in China revealed that they increased from north to south,but the litter maximum water-holding capacity exhibited the opposite trend.The soil storage capacity values contributed approximately 60-85%to forest water conservation capacity values in the different basins,soil types,and forest types.The canopy interception capacity and amount,forest water conservation capacity and amount of the Temperate deciduous broadleaf forest distributed in Songhua River and Liao River,the Cold and temperate mountainous needleleaf forest distributed in Northwest Rivers,the Temperate needleleaf forest and Temperate deciduous broadleaf forest distributed in Yellow River,the Subtropical and tropical mountainous needleleaf forest and Subtropical evergreen broadleaf forest distributed in Yangtze River,the Subtropical needleleaf forest and Subtropical evergreen broadleaf forest distributed in Southeast Rivers,and the Subtropical evergreen broadleaf forest and Tropical monsoon rainforest distributed in Pearl River were higher than those of other forest types in the same basin.In addition,the soil storage capacity and amount of the Alfisol and Semi-hydromorphic soil in Songhua River and Liao River,the Alpine soil and Pedocal in Northwest Rivers,the Semi-alfisol in Hai River,the Semi-alfisol and Primarosols soil in Yellow River,the Alfisol,Primarosols soil and Ferralsol in Yangtze River,the Anthrosol and Ferralsol in Southeast Rivers,and the Ferralsol in Pearl River were higher than those of other soil types in the same basin.Most of factors had consistent effects on the values of canopy interception capacity,litter maximum water-holding,soil storage capacity and forest water conservation capacity at both national and basin scales in China.However,due to the spatial heterogeneity of different factors...