Soil moisture of different vegetation types on the Loess Plateau
Soil moisture of different vegetation types on the Loess Plateau
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DOI：
10.1007/s11442-009-0707-7
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发表时间：
2009-12
影响因子：
4.9
通讯作者：
Zhiqiang Wang;Baoyuan Liu;Yan Zhang
中科院分区：
文献类型：
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作者：
Zhiqiang Wang;Baoyuan Liu;Yan Zhang
在黄土高原半干旱地区，深层土壤中储存的水分是调节植被生长的重要资源之一，但人工种植的灌木和森林往往会扰乱自然水分循环，进而影响植物的生长。研究主要植被类型对土壤水分的影响及其年际变化。2001年、2005年和2006年，对作物、牧草、锦鸡儿人工灌木、侧柏人工林、松柏混交林等6种植被类型0~10m土层土壤水分进行了测定。约0-3m农田和约0-2m其他植被类型的土壤水分年际变化取决于年降水量，但在这些深度以下土壤水分年际稳定。在0-2m范围内，农田土壤水分显著高于其他植被类型，其他植被类型之间差异不显著。在2~10m范围内，农田和草地的土壤水分差异不显著，但两者下的土壤水分均显著高于人工灌木和森林。人工种植的灌木和森林将2m以下的土壤水分消耗到永久枯萎点或接近永久枯萎点，不同森林类型之间的水分差异不显著。锦鸡儿灌丛的土壤水分显著低于林地，但绝对差异很小。这项研究的结果表明，种植的灌木和森林已经将深层土壤水分消耗到它们可以提取的最低限度，它们主要依靠当年的降水进行蒸腾。
Water stored in deep loess soil is one of the most important resources regulating vegetation growth in the semi-arid area of the Loess Plateau, but planted shrub and forest often disrupt the natural water cycle and in turn influence plant growth. The purpose of this study was to examine the effects of main vegetation types on soil moisture and its inter-annual change. Soil moisture in 0–10 m depth 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 0–3 m of cropland and about 0–2 m of other vegetation types varied inter-annually dependent on annual precipitation, but was stable inter-annually below these depths. In 0–2 m, soil moisture of cropland was significantly greater than those of all other vegetation types, and there were no significant differences among other vegetation types. In 2–10 m, there was no significant moisture difference between cropland and grassland, but the soil moistures under both of them were significantly higher than those of planted shrub and forests. The planted shrub and forests had depleted soil moisture below 2 m to or near permanent wilting point, and there were no significant moisture differences among forest types. The soil moisture of caragana shrub was significantly lower than those of forests, but the absolute difference was very small. The results of this study implicated that the planted shrub and forests had depleted deep soil moisture to the lowest limits to which they could extract and they lived mainly on present year precipitation for transpiration.