全国立木生物量建模总体划分与样本构成研究

结合全国生态地理区域和行政区域,并兼顾立木材积表的建模总体划分,提出了全国立木生物量建模总体划分方案,将全部树种分为34个树种组,全国分为6大地理区域,共划分70个建模总体;通过对已有立木生物量数据进行建模分析,将立木生物量模型的预估精度确定为95%以上,同时根据变动系数分析结果提出合适的建模样本单元数应该在150以上,且要按划定的10个径阶均匀分配,保证每个径阶的样本单元数不少于15个;以第七次全国森林资源清查数据为基础,确定了每一个建模总体的样本结构,将样本单元数全部落实到了各省和各级径阶。研究成果可为推进全国森林生物量调查建模工作提供参考依据。

Population Classification and Sample Structure on Modeling of Single-Tree Biomass Equations for National Biomass Estimation in China

The population classification and sample structure on modeling of single-tree biomass equations for national biomass estimation in China was studied in this paper.Firstly,combining the classification of eco-geographic region and administrative region,a scheme of population classification on modeling of single-tree biomass equations was presented,which is mostly compatible with the population classification on modeling of single-tree volume equations,including 34 tree species or species groups,6 large-scale geographic regions,and a total of 70 populations.Secondly,based on the analysis of variation coefficients derived from one-and two-variable tree biomass models fitted with available tree biomass data of several tree species,it was concluded that prediction precision of tree biomass models could be defined as more than 95%,and at least 150 sample trees are needed for a regional model which should be selected in equal numbers for each diameter class,i.e.,not less than 15 trees in each of 10 diameter classes.Finally,by using the 7th National Forest Inventory data,the sample structure of each population was determined,that is,all the sample tree numbers of 70 populations were specified by province and by diameter class.The results will provide a practical reference for the establishment of generalized single-tree biomass models in China.