沙地人工小叶锦鸡儿植被根系分布与土壤水分关系研究

Relationship Between Root System Distribution and Soil Moisture of Artificial Caragana icrophylla Vegetation in Sandy Land

采用分层挖取根系方法调查不同年龄人工小叶锦鸡儿固沙植被根系分布,同时测定植被下不同深度土壤的水分含量。结果表明:植被根系主要分布在0～100cm土壤中,占总根系生物量的92.77%以上。地下部与地上部生物量比值以天然植被最高。植被的吸收根系分布对土壤水分具有显著影响,吸收根集中分布区域下层土壤含水量锐减;吸收根集中分布深度的比较发现,天然植被>19年生人工植被>4年生人工植被,成龄人工植被吸收根系分布的浅层化造成降雨无法补充土壤深层水分,植被下土壤形成不透水层,影响主要固沙植被的生长。

The root system distribution of different age artificial Caragana microphylla vegetation was investigated with method of digging root system by layers, determined soil moisture of different layer of soil at the same time.The results showed that: root system of vegetation mostly distributed in 0~100 cm depth of soil, in this layer of soil contained 92.77% of total roots biomass. The inartificial vegetation have maximum ratio of belowground biomass and aboveground biomass in this 3 type vegetations. The absorptive roots of vegetation have markedly affect on soil moisture. Soil moisture rapid decrease under the concentrated distribution area of absorptive roots. The depth of concentrated distribution area of absorptive roots of inartificial vegetation are deepen than 1984(19 years old) established vegetation and 1999 (4 years old)established vegetation. The depth of concentrated distribution area of absorptive roots of grown artificial vegetation showed shallowly, and rainfall can not supply deep layer soil of this vegetation. The soil under vegetation come into being antiwater layer, and effected the growth of plants on sandy land.