沙打旺种群对土壤水分的影响及其调节

Effect of Astragalus adsurgens Population on Soil Moisture and Its Adjustment.

一、前言结合沙打旺种群地上部分生物量形成的研究,观测了2—7年生沙打旺改良草地的土壤水分变化情况,以探索沙打旺种群对土壤生态环境的影响及调节因子。

With its age increasing, A.adsurgens population obviously leads to soil aridification,which is represented by the tendency of moisture content reduction on each horizon of 5m soil layer.In forest-grassland zone,A.adsurgens population of 5—6 years old can reduce the moisture content of 1—3m soil layer nearly to wilting point; 7 years old population can reduce it of whole seil profile to wilting point. In shrub-grassland zone, 4 years old population can reduce the moisture content of whole soil profile to wilting point. The 1—3m soil layer forms a 'low moisture horizon'. To reduce the unfavorable ecological effect, it is necessary to suitably adjust A.adsurgens population, such as control the growth density, harvest timely and practise stripped resowing etc.