THE RESEARCH ON THE HYDROGRAPHICAL PROPERTY OF THE FOREST LITTER AND DIFFERENT DECOMPOSITION LAYERS IN THE LOWER REACHES OF WUJIANG RIVER

Througn measuring the present content,the moisture rate,the moisture content,the moisture absorbing speed and the effective retaining moisture content of the forest Litter and different decomposition layers in the Lower Reaches of Wujiang River,we have got the following results:l.The present forest Litter content of broad-Leaved forest inthe Lower Reaches of Wujiang River averages about l 6.2t/hm²,of the mixed needle-leaved and broad-leaved forest about l 7.0 t/hm²,of the needle-leaved forest about 9.3t/hm²,of scrub and grass about 5t/hm².Among them,the decomposition degree of the needle-leaved forest litter is the lowest,and that of the broad-leaved forest litter is the highest.2.The absorbing power of each decomposition layer is as follows:Of the broad-leaved forest,it is larger than that of the needle-leaved and broad-leaved mixed forest;of the needle-leaved and broad-leaved mixed forest,it is larger than that of the needle-leaved forest.The higher the decomposition degree,the stronger the moisture retaining capacity.3.The moisture absorbing speed can be grouped into 3 different absorbing stages.Te speeds are respectively:l.5~34g/h,0.03~0.5g/h,and 0.006~0.3g/h.During the 3 stages,all that haven't,been decomposed have absorbing function.4.The effective retaining content of the forest litter in the Lower Reaches of Wujiang River is 0.5~3.0t/hm².