龙门山断裂带主要森林类型凋落物累积量及其持水特性

Accumulation Amount of Litters and Their Water-holding Characteristics Under Main Forest Types in Longmen Mountains Fault Zone

采用野外实地调查与室内控制浸提相结合的方法,对龙门山断裂带常绿阔叶林、落叶阔叶林、针阔混交林、常绿针叶林4种森林类型的凋落物储量、持水量、吸水速率进行了研究。结果发现,不同森林类型凋落物总储量大小顺序为:常绿针叶林(8.26t/hm2)>落叶阔叶林(6.80t/hm2)>针阔混交林(5.52t/hm2)>常绿阔叶林(4.61t/hm2),且未分解层累积量所占比例均小于半分解层。不同森林类型不同分解程度凋落物的持水量和持水率与浸泡时间均呈对数关系,其吸水速率与浸泡时间呈幂函数关系。研究区4种森林类型半分解层凋落物的持水能力均强于分解层,而落叶阔叶林和针阔混交林持水能力较强,其次是常绿针叶林,常绿阔叶林最低。研究表明,在该区森林植被恢复和重建过程中,应充分考虑半分解层凋落物对水土保持的作用,且宜优选落叶阔叶林和针阔混交林模式进行森林植被恢复。

By field investigation in combination of indoor control and leaching, a study was conducted on the accumulation amount, water-holding capacity, water-holding rate and water-absorption rate of the litters under four main forests（evergreen broad-leaved forest, broadleaved deciduous forest, conifer-broadleaf forest and evergreen coniferous forest） in the Longmen Mountains fault zone. The accumulation amount of litters under the forests decreased in the order of evergreen coniferous forest（8.26 t/hm2） 〉 broadleaved deciduous forest（6.80 t/hm2） 〉 conifer-broad leaf forest（5.52 t/hm2） 〉evergreen broad-leaved forest（4.61 t/hm2）, and the storage percentage of semi-decomposed litters was higher than that of un-decomposed litters. The water- holding capacity and water-holding rate of litters at different decomposition degree changed logarithmically, while the water-absorption rate assumed a power function of soaking time. Under the four main forests, the litters in semi-decomposed layer had a stronger water-holding capability than that in decomposed layer, and the water-holding capability of litters under hroadleaved deciduous forest and eonifer-broadleaf forest was stronger than the others, while the litters of evergreen broad-leaved forest had the lowest water-holding ca- pability. The results indicated that we should fully exert the functions of soil and water conservation of the semi-decomposed litters, and select broadleaved deciduous forest and conifer-broadleaf forest needle modes in recovering and reconstructing forest vegetation.