城市水源地5种森林枯落物水文效应特征

目的]探讨云南省蒙自市菲白城市水源地5种主要森林类型林下枯落物的持水效应特征,为菲白水源地营造水土保持林、水源涵养林提供理论依据。方法]利用样方调查法、烘干法、浸泡法对其枯落物蓄积量、持水量、吸水速率、最大持水能力和拦蓄量等进行了研究。结果]各林分总蓄积量相差较大,依次为:杉木林华山松+杉木人工柏树林青冈栎+云南松人工桉树林;不同森林类型枯落物最大持水量变化范围7.85~13.91t/hm2,最大持水率为165.85%~242.45%,最大拦蓄量为7.48~12.62t/hm2,有效拦蓄量为6.53~11.03t/hm2;5种森林枯落物持水量与时间呈较显著的对数函数关系,各层与浸水时间之间存在着显著的幂函数关系。结论]综合比较5种森林类型的持水性能,杉树的持水能力较好,能够很好地涵养水源。

Water-holding Capacity of Litters in Five Different Typical Forest Types in Urban Water Source

Objective] To clarify the water holding capacity of forest litters of 5 different forest types (Cupressus funebris, Pinus armandii+Cunninghamia lanceolata, Cyclobalanopsis glauca+ Pinus yunnanensis, Eucalyptus robusta, C. lanceolata) in Feibai reservoir area in Mengzi City of Yunan Province in order to provide theoretical basis for constructing the forest of water and soil conservation, and for constructing the forest of conservation of water supply in the study area. Methods] We used the quadrat sampling method, oven drying method and soaking method to determine the litter preservation, water holding capacity, water absorption rate and water interception. Results] The litter amount in different forests followed an order of C. lanceolata(9.48 t/hm²)> P. armandii+ C. lanceolata(7.09 t/hm²)> C. funebris(7.02 t/hm²)> C. glauca+ P. yunnanensis(6.13 t/hm²)> E. robusta(3.20 t/hm²);The maximum water holding volume of different forests litters ranged from 7.85 to 13.91 t/hm², the maximum water holding rate ranged from 165.85% to 242.45%, and the maximum interception amount and the effective interception amount ranged from 7.48 to 12.62 t/hm² and 6.53 to 11.03 t/hm² respectively. The relationships between water-holding rate and immersion time in 5 different forest types were significantly fitted by logarithmic equation. The relationships between water absorption speed rate and soaking time could be described by power function. Conclusion] The comprehensive analysis of water holding capacity of 5 different species indicated that Eucalyptus has a higher water-holding capacity and is more beneficial to the water conservation.