川西亚高山人工针叶林枯枝落叶及苔藓层的持水性能

WATER HOLDING CAPACITY OF MOSS AND LITTER LAYERS OF SUBALPINE CONIFEROUS PLANTATIONS IN WESTERN SICHUAN, CHINA

亚高山针叶林作为”长江上游生态屏障”的主体 ,具有重要的水源涵养和水土保持作用 .本文作者对川西地区典型的不同恢复阶段的人工云杉林、迹地、次生林和原始林下苔藓与枯枝落叶层贮量和持水性能进行了试验研究 .结果表明 ,人工云杉林在生态恢复过程中 ,苔藓与枯枝落叶层的贮量和持水性能均呈现出波动式递增 ,表现为 30a <4 0a <6 0a<5 0a,5 0a云杉林达到最大值 ,苔藓、枯枝落叶层的贮量分别为 10 .96× 10 3 kg/hm2 、76 .9× 10 3 kg /hm2 ,最大持水量分别为 4 4 .77× 10 3 kg /hm2 、182 .5× 10 3 kg /hm2 ,以后略有下降 .枯枝落叶层持水性能优于苔藓 ,说明枯枝落叶层在森林的水源涵养方面发挥了更为重要的作用 .人工林枯枝落叶层贮量和持水性能较天然林有所降低 ,反映了该地区在人工林的建设中应注意其生态功能的恢复 .图 2表 2参

The subalpine coniferous forests in western Sichuan have important functions in head water conservation and water and soil conservation, which can be regarded as 'ecological screen of the upper reaches of the Yangtze River'. The pools and water holding capacity of moss and litter layers of residual stands,secondary forests,natural forests and artificial spruce forests in different ecological restoration stages in western Sichuan were studied in this paper. The results showed that in the course of ecological restoration, pools and water holding capacity of moss and litter layers of artificial spruce forests fluctuatingly increased, in the order of 30 a<40 a<60 a<50 a, which had the maximal amount up to 10.96×10 3 kg/hm 2 and 76.9×10 3 kg/hm 2 for pools, and 44.77×10 3 kg/hm 2 and 182.5×10 3 kg/hm 2 for water holding capacity, respectively, and decreased after 50 a. Water holding capacity of litter layer was stronger than that of moss,indicating that forest litter layer played a much more important role in headwater conservation. Pools and water holding capacity of litter layer of artificial spruce forests as inferior to those of the natural forests, so the restoration of ecological function of artificial forests would be specially important. Fig 2,Tab 2,Ref 8