Amount and water holding capacity of forest litter in Three Gorges Reservoir area
WANG Feng-Cheng-； Xiao-Wen-Fa-； Zhang-Shou-Gong-； Shi-Yu-Hu-； Bo-Lei-； Ceng-Li-Xiong-； Mo-Rui
1.Research Institute of Forest Ecological Environment and Protection,Chinese Academy of Forestry,100091,Beijing;2.College of Horticulture & Forestry Sciences,Huazhong Agricultural University,430070,Wuhan;3.Research Institute of Forest,Chinese Academy of Forestry,100091,Beijing;4.Research Institute of Resource and Environment,Forestry Science Institute of Hubei Province,430079,Wuhan: China
Abstract：Based on the data of forest resource inventory,combining with the survey of forest litter amount and experiment of litter immersed,a series of forecast models were established and the amount and water holding characteristics of litter in some vegetation types in Three Gorges Reservoir area were studied.The results showed that: 1) Significant difference was found for the storage of litter in some different forest vegetations.The highest storage of litter was observed in <i>Cunninghamia lancedata</i> forests(11.610 t/hm<sup>2</sup>),in <i>Cupressus funebris</i> forests was the lowest(3.948 t/hm<sup>2</sup>).2) The highest water content of litter was found in bamboo forests(182.9%),the lowest of water content of litter was observed in <i>Cupressus funebris</i> forest(32.2%).3) The water capacity increased with immersing time of litter,and decreased rapidly soon after 2-4 h in all vegetation types.Forest litter was saturated after 48 h of immersing.The highest water effective interception capacity of the litter was found in bamboo forests litter,which was 3.367 times higher than the litter weight,the lowest was that of shrubbery(just 2.089 times).4) The absorption rates of litter were high in initial 2 h,but significant difference was observed among different types.Then decreased sharply,and no longer absorbing water after 48 h.5) Based on the GIS data of forest vegetation and the established models,the litter amount,the potential water-holding capacity and the existing water-holding capacity to saturation of forest litter during single precipitation were calculated in Three Gorges Reservoir area.The values of these parameters were 20.485 7 million t,46.953 4 million t,32.917 5 million t in forest vegetation,respectively.The spatial distribution of potential water-holding capacity and existing water-holding capacity to saturation of litter showed a pattern of high values in southeast area and low values in northwest area.This results provided a basis for scientific evaluating the function of water conservation and for the planning and construction of forest ecological engineering in Three Gorges Reservoir area.
2008, Vol. 6 
