文献类型：期刊文献

英文题名：STEM TAPER EQUATIONS FOR BETULA ALNOIDES IN SOUTH CHINA

作者：Tang, C.[1,2] Wang, C. S.[1] Pang, S. J.[3] Zhao, Z. G.[1] Guo, J. J.[1] Lei, Y. C.[4] Zeng, J.[1]

第一作者：Tang, C.

通信作者：Zeng, J[1]

机构：[1]Chinese Acad Forestry, Res Inst Trop Forestry, Guangzhou 510520, Guangdong, Peoples R China;[2]Shihezi Univ, Coll Agr, Shihezi 832003, Xinjiang, Peoples R China;[3]Chinese Acad Forestry, Expt Ctr Trop Forestry, Pingxiang 536000, Guangxi, Peoples R China;[4]Chinese Acad Forestry, Res Inst Forest Resource Informat Tech, Beijing, Peoples R China

年份：2017

卷号：29

期号：1

起止页码：80-92

外文期刊名：JOURNAL OF TROPICAL FOREST SCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000397050800009)】；

基金：This work was supported by the Ministry of Science and Technology of China (2012BAD21B0102). The authors are grateful to RY Huang, BG Yang and SK Deng of the Experimental Center of Tropical Forestry, Chinese Academy of Forestry and to TL Lin and GM Liang of the Laoshan Forest Farm, Baise City for their assistance in the field.

语种：英文

外文关键词：Non-linear regression analysis; taper functions; variable-form model

摘要：Accurate stem taper functions are necessary for estimating stem diameter, form and tree volume, and are important for wood estimation and timber utilisation. Betula alnoides is a valuable plantation hardwood species under large-scale development in South-East Asia and south China, but no study on its stem taper has been reported yet. Here, 28 well-known taper functions from three groups of models ( single, segmented and variable-form taper functions) were fitted and validated separately with diameter-height datasets from 90 and 29 trees of B. alnoides. All trees were sampled from its 8-36-year-old even-aged plantations in south China. Non-linear regression techniques were applied to estimate the parameters in the taper equations using the fitting data set. Then bias, absolute bias, mean squared error and per cent explained variation were applied to examine model accuracy. Student's paired t-tests for observed and predicted diameters were used to examine the validity of these functions based on the validation data. Of the 28 functions, the Bruce, Max-Burkhart and Muhairwe models were the best single, segmented and variable-form taper equations respectively. In general, variable-form taper equations performed better than simple and segmented functions. The Muhairwe model best estimated stem taper without obvious multicollinearity for this species.