Studies on the method of biomass estimation for deciduous broad-leaved forests

在本研究项目中，从长度和重量两个维度对树体进行了详细的测量。本研究的目的是：1.建立落叶阔叶林生物量的估测方法；2.分析落叶阔叶林混交林中乔木的适生几何形态。采伐6种31株阔叶树，测量其直径、长度、干枝叶重等指标，确定各器官的异速生长关系。两个相似林分生物量估测结果的比较表明，采用普通异速生长关系时，相对误差高达16%~19%水平；从树冠形状分析来看，同一林分落叶阔叶树具有不同的生活型。例如，桦树树种的叶重相对较轻，这是由于树冠较小所致。栎属树冠较大，叶重相对较重。树种间的这些差异将影响林分内树木竞争的结果。

In this research project, the measurement of tree body was detaily conducted both in the dimensions of length and weight. The objectives of this study is 1.to establish a proper method to evaluate the biomass of deciduous broad-leaved forests, and 2.to analyze the adaptive geometry of trees in mixed stands.In total, 6species-31 individuals of broad-leaved trees were cut and measured of diameter, length, weights of trunk-branch-leaf, etc. Allometric relationships were determined for each organ. The comparison of biomass estimations between two similar stands showed that the occurrence of relative error was as high as 16-19% level when a common allometric relationship was used.From the analysis of crown shape, the different life forms were detected from deciduous broad-leaved trees studied in a same stand. For example, Betula species showed relatively light leaf weight, which came from the small size of crown. Quercus species had a large crown and so relatively heavy leaf weight. These differences detected among tree species will influence the results of tree competition in the stand.