长江上游低质低效云杉林的分类与评价

对长江上游林分的生长过程、形成原因和功能特征进行了分析 ,建立了云杉低质低效林综合等级的判别函数 ,将林分划分为四种类型 :极低质低效型、生长潜力型、低质型、综合低质低效型。对林分立地因子的逐步回归分析表明 ,在其分布区域内 ,影响云杉生长的主导立地因子除了海拔外 ,依次为土壤名称、土层厚度和坡位 ,而坡度对其影响较小。它们的组合可以构成不同的立地条件类型。根据对各等级的林分生长过程及其立地特征的分析 ,提出了划分云杉低质低效林的技术参数标准

Classification and evaluation of low - quality and low - benefit Spruce stand of the upper reaches of Changjiang River

Analysis on the growth procedure,the courses that results the stand development and the function features of the stands of the upper reaches of the Changjiang River,we established the judge function of incorporate grades of the low-quality and low-benefit Spruce stands and divided it into four types:the extreme low-quality and low-benefit type,the potential type,the low-quality type and the incorporate low-quality and low-benefit type.Gradual regression analysed on the site factors shows that in the areas the stands growed on it, the main site factors that effected the growth were ordinal the soil name,the soil deep and the stand position besides the altitude above sea level.The combination of them can constituted various site types.Based on the analysis of the stands growth procedure and the site features,we provided the parameter criterion used to sort the low-quality and low-benefit Spruce stands.