通过对枯落物覆盖下森林土壤蒸发的观测,研究了不同干重及类型的枯落物对土壤蒸发的影响,及其与含水率的关系。结果表明:土壤含水率相同,枯落物覆盖量越大,土壤蒸发量越小;不同类型的枯落物对土壤蒸发的抑制作用不同,在相同干重的枯落物覆盖下,未分解、半分解和分解的枯落物对土壤蒸发的抑制能力依次减弱。土壤蒸发量与枯落物质量呈对数关系。随土壤含水率的降低,土壤蒸发量减少,含水率在41%~38%时,每下降1%,75g、45g、15g枯落物覆盖下的土壤蒸发量依次减少2.38g、1.43g、1.30g,且在土壤含水率下降过程中,覆盖的枯落物分解程度越高,土壤蒸发速率降低越不显著。
By observing the soil evaporation under litter cover in broadleaved Korean pine forest, this paper studied the effects of the litters with different dry weights and at different decomposition stages on the soil evaporation as well as the relations between the soil evaporation and soil moisture content. The results showed that at the same soil moisture contents, the larger the litter cover, the smaller the soil evaporation was. The mitigation effect of the litter cover on the soil respiration differed with the decomposition stage of the litters, being decreased in the order of undecomposed, semidecomposed, and decomposed litters. There existed a logarithm relationship between the soil evaporation and the litter mass. With the decrease of soil moisture content, the soil evaporation reduced. When the soil moisture content was within the range of 38%-41%, each 1% decline of the moisture content induced the soil evaporation under the covering of 75 g, 45 g, and 15 g litters decreased by 2.38 g, 1.43 g, and 1.30 g, respectively, and, during the declining of the moisture content, the higher the decomposition rate of the litters, the lesser the decrement of the soil respiration.