文献类型：期刊文献

英文题名：Effect of Planting Density on Knot Attributes and Branch Occlusion of Betula alnoides under Natural Pruning in Southern China

作者：Wang, Chunsheng[1] Zhao, Zhigang[1] Hein, Sebastian[2] Zeng, Ji[3] Schuler, Johanna[4] Guo, Junjie[1] Guo, Wenfu[3] Zeng, Jie[1]

第一作者：王春胜

通信作者：Zeng, J[1]|[a00059de8a61132fd4ece]曾冀;

机构：[1]Chinese Acad Forestry, Res Inst Trop Forestry, Guangzhou 510520, Guangdong, Peoples R China;[2]Univ Appl Forest Sci, D-72108 Rottenburg, Germany;[3]Chinese Acad Forestry, Expt Ctr Trop Forestry, Pingxiang 536000, Guangxi, Peoples R China;[4]Univ Freiburg, Chair Forest Growth, D-79106 Freiburg, Germany

年份：2015

卷号：6

期号：4

起止页码：1343-1361

外文期刊名：FORESTS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000353775500026)】；

基金：This study was financially supported by the Ministry of Science and Technology of China (2012BAD21B0102). The authors would like to thank the Experimental Center of Tropical Forestry, CAF for providing access to the experiment and machinery for knot dissection. Special thanks to Dr. Khongsak Pinyopusarerk at the Black Mountain Laboratories of CSIRO Plant Industry, Australia and Dr. Bernard Dell at the Institute for Sustainable Ecosystems, Murdoch University, Western Australia for their valuable suggestions and English correction. We are also grateful to Er Sha and Kai-Qin Lin for their assistance on tree growth investigation, sampling and knot dissection.

语种：英文

外文关键词：Defects - Wood products

摘要：Knot-related defects are the major cause of timber quality degradation, and diminishing this kind of defects is an important issue in forest management. For the purpose of clear-wood production, knot attributes and branch occlusion of Betula alnoides under natural pruning were investigated in a 14-year-old experimental plantation with five planting densities ranging from 500 to 3333 stems per hectare in southern China, and a total of 1325 occluded branches from 30 trees were sampled and dissected. The mean occluded branch diameter (OBD), radius of knots and branch insertion angle (IA) decreased significantly with increasing planting density. Planting with high stocking density significantly reduced the frequency of thick occluded branches (diameter >= 20 mm) while increasing the frequency of small ones (diameter < 10 mm). Branch occlusion time (OT) also tended to increase with decreasing planting density. The results of generalized linear mixed models showed that OBD was the major factor influencing OT, radius of dead portion of knot (RDP), total radius of knot (TRK) and IA. In addition, OT was positively correlated with RDP but negatively correlated with stem diameter growth rate during branch occlusion (SDGR). Silvicultural strategies with appropriate planting density for large-diameter clear-wood production of B. alnoides were discussed.