文献类型：期刊文献

英文题名：Modeling Tree Crown-Tree Size Relationships for Eight Pine Species in China

作者：Zeng, Weisheng[2] Zou, Wentao[1]

第一作者：Zeng, Weisheng

机构：[1] Research Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing, 100091, China; [2] Academy of Inventory and Planning, National Forestry and Grassland Administration, Beijing, 100714, China

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240374031)

语种：英文

外文关键词：Forest ecology - Forestry

摘要：Crown condition may determine the growth vigor of trees, and two key characteristic factors are crown width and crown length. There is a close relationship between crown width (CW) or crown length (CL) and diameter at breast height (DBH) and/or height of trees, but most of the studies in this area have been based on local data, and few studies have been carried out based on large-scale data. Using the measurement data of 1354 representative sample trees of eight pine species collected throughout the China, the relationships between CW or CL and DBH and/or tree height (TH) were studied by using nonlinear regression estimation, mixed model and dummy variable model methods. The results showed that CW was positively correlated with DBH and negatively correlated with the TH-DBH ratio; the linear model based on DBH alone explained 80% of the variation in CW, but adding tree height or the TH-DBH ratio had little effect on the accuracy of the prediction of CW. Moreover, the CW-DBH ratio of young trees was relatively high, but it decreased rapidly with increasing DBH and began to stabilize when the DBH reached 10 cm or greater. CL had a nonlinear correlation with DBH and height, and its R2 value was greater than 0.75. The CL-height ratio was positively related to the DBH and negatively related to the TH. The average ratios of CL-height in all diameter classes had little variation and decreased with increasing DBH below 10 cm but increased slowly when the DBH exceeded 10 cm. Within the same diameter class, the CL-DBH ratio decreased with increasing TH. There were some differences among the eight pine species in the above relationships. The correlations between CW, CL and DBH, TH are of practical significance for further studying forest competition and guiding scientific forest management. ? 2024, The Authors. All rights reserved.