百里杜鹃景区马缨杜鹃林凋落物对土壤蒸发的影响

目的]探究百里杜鹃景区马缨杜鹃林下凋落物覆盖对土壤蒸发的影响,为其林下水源涵养功能的发挥提供科学依据。方法]根据土壤蒸发理论,采用自制微型蒸渗装置进行模拟试验,参照百里杜鹃林下凋落物现存状况,研究不同质量相同比例及相同质量不同比例的凋落物覆盖对土壤蒸发抑制的影响。结果]不同分解程度凋落覆盖比例相同质量不同时,土壤水分蒸发量随凋落物的质量增大而减小;土壤水分蒸发量随着土壤含水率的下降呈递减关系,当含水率每下降0.5%时,60,30和15 g凋落物覆盖的土壤水分蒸发量分别依次减少了0.11,0.49和1.23 g。凋落物覆盖质量相同时,不同分解程度的凋落物对土壤水分蒸发抑制作用不同,表现为:未分解半分解已分解。结论]凋落物覆盖量越多,对土壤蒸发的抑制作用越大;凋落物分解程度越低,对土壤蒸发的抑制作用越好。

Effects of Rhododendron Delavayi Litters on Soil Moisture Evaporation in Baili Azalea Scenic Area

Objective] The effects of litter cover on soil evaporation in the Rhododendron delavayi forest in Baili azalea scenic area were studied, in order to provide a scientific basis for the function of water conservation under the forest.Methods] According to the theory of soil evaporation, a self-made micro evaporation and infiltration device was used to conduct the simulation experiment. The existing status of litter under the Baili rhododendron forest was taken as a reference, to study the effect of litter with different mass and different proportion on the inhibition of soil evaporation.Results] The evaporation of soil water decreased with the increase of litter mass at different decomposition degrees and with the same litter coverage ratio. The evaporation of soil moisture decreased with the decrease of soil moisture contents. When the moisture contents decreased by 0.5%, the evaporation of soil moisture with litter cover of 60 g, 30 g and 15 g decreased by 0.11 g, 0.49 g and 1.23 g, respectively. When the cover quality of litter was the same, the inhibition of litter with different decomposition degrees on soil water evaporation was different, which showed as follows:undecomposed > semi-decomposed > decomposed.Conclusion] The more litter cover, the greater the inhibition of soil evaporation; the lower the decomposition degree of litter, the better the inhibition of soil evaporation.