黄土半干旱区刺槐林地土壤蒸发特性研究

Study on Soil Evaporation of the Robinia pseudoacacia Forest Land in Semi-arid Region of the Loess Plateau

对黄土半干旱区刺槐林内的土壤蒸发状况,进行比较系统的试验研究。试验采用微型蒸发器（Micro-lysimeters,MLS）,人为控制土壤水分梯度,对不覆盖、枯枝落叶物覆盖和苔藓覆盖3种处理的林地土壤蒸发进行了分析。结果表明,在不同土壤水分条件下,利用枯落物覆盖减小林地土壤蒸发效果晴天好于多云天,枯落物覆盖、苔藓覆盖与无覆盖相比,分别减少了20.15%～52.46%和11.11%～36.72%的土壤蒸发,枯落物覆盖效果好于苔藓;林地土壤蒸发量随土壤水分的增加呈上升趋势,当土壤含水量增加到一定临界值以后,林地土壤蒸发量由上升变为下降,表现出土壤水分对林地土壤蒸发具有明显的阈值反应,土壤含水量的临界值分别为14.2%（枯落物覆盖）和16.8%（不覆盖）;基于林地土壤蒸发量（E1）与水面蒸发量（E0）的观测数据,利用STATISTICA软件统计分析,建立林地土壤蒸发模型,可用于林地土壤蒸发量的估算,为林地土壤水分管理提供理论依据。

The paper have taken a systemic study by Micro-ysimeters （MLS） on soil evaporation of the Robinia pseudoacacia forest with no land cover, litter cover and moss cover on the Loess Plateau in semi-arid region, artificially controlling its soil water content level. It has been shown that the effect of soil evaporation with litter cover on sunny weather is better than cloudy weather, soil evaporation with litter cover and moss cover is 20. 15% ～52.46% and 11.11% ～ 36.72 % less than with no cover land respectively under the different soil water soil, the soil evaporation with litter cover is less than with moss cover; the more soil water content, the higher soil evaporation, but until the water content becomes up to limitation, the more soil water content, the smaller soil evaporation, therefore, there is an obvious domain value of 14. 2% and 16.8% respectively. The relationship equation has been buildup, which could be used to calculate soil evaporation and taken as academic gist in soil water management, analyzing the data of evaporation in the forestland and water surface by the software of STATISTICA.