【摘要】 <正> 对造林地立地质量进行科学的评价是实现科学造林的第一步。在有林区,评价造林地立地质量的方法之一,是采用林分基准年龄时上层木所能达到的平均高度作为评定宜林地立地质量的指标(即立地指数法)。而在环境恶化、干旱贫瘠的宁夏黄土干旱区,仅分布有成片毛条(灌木林或疏林),因此针对该区的实际情况,我们用4年生毛条(CaraganaKorshinskii Kom.)优势丛(地上部分)生物量,作为评定宜林地立地质量指标。宁夏分布的成片毛条林绝大部分是4年生,而且毛条到4年时开始开花结果,有较大的生物量,能更多还原

【Abstract】 In order to evaluate site quality for afforestation in the arid regionof loess covered by low woodland and shrubs mainly consisting ofCaragana korshinskii Kom.a quantitative method was employed.Based onthe quantification of critically ecological factors as independentvariables,which affect the growth of trees,a deterministic mathematicalmodle was established to predict fresh weight of C.korshinskii at the ageof four years through multiple regression analysis.Thus the fresh weightabove ground can be used as criterion to evaluate the site quality beforestarting afforestation.更多还原