3种生态公益林凋落物的持水特性

Water Holding Characteristics in Three Ecological Forests

对于云勇林场的水源涵养林、风景林和水土保持林的凋落物的储量、持水量、持水率和吸水速率进行了研究。结果表明,水源涵养林的凋落物的干重(2.11thm-2)最大,其次是风景林(2.05thm-2),而水土保持林较小(1.43thm-2)。各林分凋落物的持水量呈现水源涵养林>风景林>水土保持林,最大持水量为水源涵养林6.65thm-2,风景林5.16thm-2,水土保持林4.17thm-2。水源涵养林、风景林和水土保持林最大持水率分别为417%、352%和288%。凋落物持水量和凋落物持水率随着浸泡时间的增加按照对数方程增加。3种林分中水源涵养林的凋落物吸水速率在各浸泡时间后居首位,水土保持林中等,风景林最小,各林分的凋落物的吸水速率随浸泡时间的增长按方程W=a·t-b下降。

The characteristics, such as litter reserves contents water holding capacity, proportional water holding capacity and absorption rates, were studied in water-conservation forest, scenic forest and soil and water conservation forest. The dry litter standing crop of water-conservation forest was largest （2.11 t hm^-2）, followed by the scenic forest （2.05t hm^-2）and the water-conservation forest （1.43t hm^-2）. The order of total water holding capacity of litter was water-conservation forest （6.65t hm^-2）〉scenic forest （5.16t hm^-2）〉soil and water conservation forest （4.17t hm^-2）.The maximum proportional water holding capacity shown as a percentage of the litter dry weight in water-conservation forest,scenic forest and soil and water conservation forest were respectively 417%,352% and 288%.The total water holding capacity and proportional water holding capacity of litter increased logarithmically with the time immersed in water. The water absorption rate of litter in water-conservation forest was highest among three ecological forests, medium for the soil and water conservation forest and lowest for the scenic forest. And water absorption rates of litter in three ecological forests decreased according to equation Y=a＋b·t^-1 with the time immersed in water.