Water Conserving Function of Pinus Tabulaeformis Litters in Three Regions of Beijing City

Gross litter reserves and hydrological characteristic parameters,such as the maximum water capacity,maximum water holding rate and modified interception amount,were studied through the water holding experiment and litter reserves survey on Pinus tabulaeformis forest stands in the Miyun Reservoir,Badaling Forestry Center and Shisanling Forestry Center in Beijing City.Results showed that the three regions,in order of decreasing gross litter reserve and maximum water capacity,were Badaling Forestry Center,Shisanling Forestry Center and Miyun Reservoir.In addition,the maximum water holding rate,average water absorption rate and modified interception amount were the highest in Shisanling Forestry Center,followed by Badaling Forestry Center,and the lowest in Miyun Reservoir.However,the water conserving function of Pinus tabulaeformis litter was relatively poor in the three regions,especially in the Miyun Reservoir.When rainfall is less than the critical value,the water conserving function of litter was best in Badaling Forestry Center;when rainfall is larger than the critical value,the water conserving function was best in Shisanling Forestry Center.The water conserving function of Pinus tabulaeformis in Shisanling Forestry Center was better than other two regions.