半干旱区人工林生长与水分生态研究

对黄土高原半干旱区5种主要造林树种生长状况及土壤水分变化规律进行了研究分析,比较了5种人工林的生长与水分适应性。结果表明:(1)不同人工林生长受坡向、坡位等立地因子影响;几种主要人工林总体生长水平,乔木林山杏>小叶杨,灌木林山桃>沙棘>柠条;(2)不同立地条件下,土壤含水率变化特点为阳坡<半阳坡<半阴坡;不同立地土壤含水率呈现出相同的变化趋势,即随坡位上升土壤水分呈下降趋势,0~200 cm为主要的水分利用层,200 cm以下土壤含水率均为逐渐上升,说明植物根系对水分的吸收在逐渐减弱;(3)不同人工林土壤平均含水率为8%左右,表现出土壤干旱的特点。不同人工林对土壤水分的利用可分为2种情况,山杏、沙棘和柠条,属于对水分利用强度大的树种,而小叶杨和山桃属于水分利用强度较低的树种,水分利用强度由大到小为:柠条>沙棘>山杏>小叶杨>山桃。

Study on Plant Growth and Water Ecology of Some Artif icialForests in Sem-i arid Region of Loess Plateau

The growth and soil water status of five dominate forests in the semi-arid region of Loess Plateau were studied.The analysis of the data showed that(1) the growth status of five dominate forests was: Prunus(armeniaca)>Populus simonii;Prunus davidiana>Seabuckthorn>Caragana korshinskii.(2) The analysis of different site types showed that soil water content among different site types was: semi-shady>semi-sunny>sunny.Different slope directions had a similar changing trend.Soil water content descended with the rise of slope.Soil water content descended below 200 cm,which showed that root absorbing was decline.(3) The average soil water content of different artificial forests was about 8%,which showed the arid characteristic of soil.Totally speaking,soil water content of different artificial forests can be divided into two types.Prunus armeniaca, Seabuckthorn and Caragana korshinskii had a higher usage of soil water,but Populus simonii and Prunus davidiana was lower.The strength of soil water usage was Caragana korshinskii>Seabuckthorn>Prunus armeniaca>Populus simonii>Prunus davidiana.