不同植被类型对厚层黄土剖面水分含量的影响

为了研究不同植被类型土壤水分差异和土壤水分的年际变化特征, 对陕西省绥德县境 内的农地、天然草地、人工柠条林、人工侧柏林、人工油松林、人工油松侧柏混交林地0~10 m 土壤剖面的土壤水分含量进行了测定与分析。农地土壤约在3 m 以上、其他植被类型约在 2 m 以上土层的土壤含水量随年降雨量的大小存在年际变化, 且农地土壤含水量显著高于其 他植被类型, 其他植被类型间无显著性差异。0~2 m 土层农地土壤水分在不同测定年份始终在易效水以上, 但其他植被类型的土壤水分随降雨量的不同变化于难效- 无效水与易效水之间。农地3 m、其他植被类型约2 m 以下的土壤含水量无显著性年际变化。农地与天然草地 土壤含水量显著高于其他人工林植被, 但二者含水量之间无显著差异, 土壤水分都属易效水 范围。人工柠条灌木林土壤水分显著低于其他植被类型, 人工侧柏林、人工油松林和人工油 松侧柏混交林之间土壤含水量无显著性差异。人工柠条林土壤水分属于难效-无效水范围, 人工乔木林接近难效-无效水范围。

Effects of Different Vegetation Types on Soil Moisture in Deep Loess Soil Profiles

This study was to examine the effects of main vegetation types on soil moisture and its interannual variations.Soil moisture in 0-10m deep profiles of six vegetation types,i.e.,crop,grass,planted shrub of caragana,planted forests of arborvitae,pine and the mixture of pine and arborvitae were measured in 2001,2005 and 2006.Soil moisture in about 0-3m of cropland and about 0-2m of other vegetation types varied interannually dependent on annual precipitation,but was rather stable interannually below this depth under all six vegetation types.In 0-2m,soil moisture of cropland was significantly greater than those of all other vegetation types,but there were no significant differences among other vegetation types.In 2-10m,there was no significant moisture difference between crop and grass,but the soil moisture of both was significantly higher than planted brush and forests.The planted caragana brush and forests had depleted soil moisture below 2m to or near wilting point,and there were no significant soil moisture differences among different forest types.