【摘要】 运用277个县23个杨树品种的2 980块标准地的调查资料,采用聚类分析方法,把全国杨树栽培范围划分成13个栽培区,并作了生产力评价。更多还原

【Abstract】 Data on the growth condition and related material of 23 Poplar spp. in 277 counties with a number of 2 980 sample plots were analyzed. Cluster analysis was used to divide the whole Poplar cultivation area into 13 divisions, and the evaluation of their productivities has been made.更多还原