甘肃省兴隆山天然林下苔藓凋落物蓄积量及持水特性

2010年,采用野外实地观测与室内浸水法,对甘肃兴隆山青杄林、青杄—白桦林林下苔藓和凋落物的累积量、持水量、持水率和吸水速率进行了研究。结果表明:(1)青杄—白桦林和青杄林下苔藓及凋落物层总厚度7.10~8.30cm,总重量24.66~30.69t/hm2,青杄—白桦林均高于青杄林;(2)苔藓层最大持水率明显高于凋落物层,但凋落物层最大持水量是苔藓层的11.15倍;(3)苔藓层和凋落物层持水率在开始浸水时增加较快,0.5h后增幅逐渐减慢,浸水10h后基本趋于某一稳定值;(4)凋落物层最大拦蓄量、有效拦蓄量分别是苔藓层的10.41和10.27倍;凋落物层在对降水二次分配及在吸持降水过程中发挥着重要作用,并且位于主导地位。

Water-holding Characteristics and Accumulation Amount of Moss and Litters Under Two Natural Forests in Xinglong Mountains of Gansu Province

By field survey and soaking extraction in laboratory, the accumulation amount, water-holding capacity, water-holding rate and water-absorption rate of moss and litters were studied under two main natural forests(Picea wilsonii forest and P. wilsonii and Betula platyphylla mixed forest) in the Xinglong Mountains of Gansu Province in 2010. Results showed that: (1) The total thickness was 7.10~8.30 cm and the total accumulation amount was 24.66~30.69 t/hm² for moss and litters of two forests, but the thickness and amount of P. wilsonii and B. platyphlla forest were all greater than those of P. wilsonii forest. (2) The maximum water-holding rate of moss was obviously higher than that of litters, whereas the maximum water-holding capacity of litters was 11.15 times of that of moss. (3) The water-holding rate of moss and litters increased quickly at the beginning of immersion in water, increased gradually after 0.5 h, and tended to a stable value after 10 h. (4) The maximum retain capacity and the effective retain depth of litters were 10.27 times and 10.41 times of that of moss, respectively. Litter layer plays an important role in precipitation secondary distribution, as well as precipitation absorption and holding, and it is in the dominant position.