文献类型：期刊文献

英文题名：Natural Pruning and Branch Growth Dynamics of Young Betula Alnoides in Response to Planting Density

作者：Wang, Chunsheng[1] Guo, Junjie[1] Wang, Huan[1] Hein, Sebastian[2] Zeng, Jie[1]

第一作者：王春胜

机构：[1] Research Institute of Tropical Forestry, Chinese Academy of Forestry, Longdong, Guangzhou, 510520, China; [2] University of Applied Forest Sciences, Schadenweilerhof, Rotternberg, 72108, Germany

年份：2024

外文期刊名：SSRN

收录：EI(收录号：20240078893)

语种：英文

外文关键词：Plants (botany)

摘要：Branch development is vital to tree growth and timber quality, it is greatly affected by competition, and has received widely attention in the past decades. Up to date, our understanding of how branch dynamics responds to planting density across crown layers remains unclear yet. Here a study was conducted on a five-year-old Betula alnoides plantation in southern China, with planting densities ranging from 625 to 2500 stems per hectare (sph). Over the course of two years, from April 2017 to April 2019, the growth and status of 1885 branches located in different crown layers (spanning from 1-2 m to 5-6 m) of 54 dominant or co-dominant trees were periodically examined. Branch emergence at the crown’s apex was also recorded at each measurement. Natural pruning rate of B. alnoides was in significantly positive correlation with planting density, and natural pruning predominantly occurred in leaf senescence and shedding season (April to October), particularly from July to October. Branch emergence of B. alnoides appeared to be independent of planting density. Both branch diameter and length increments exhibited an obvious increasing trend with decreasing planting densities across the entire investigation period. This trend was particularly pronounced at the crown layer level. Branch length growth was much more sensitive to planting density than branch diameter growth. Furthermore, branch diameter and length increments were much higher under 833 or 1111 and 1250 sph treatments in the upper crown layers because of the interaction of planting density and crown layer. The dynamics of branch growth were closely linked with the tree's phenological cycle and growth pattern, exhibiting a notably elevated increment during the leaf expansion and maturity period spanning from October through April. The findings highlighted empirically the importance and effectiveness of properly high planting densities on branch development control of B. alnoides. Planting with properly high densities could effectively reduce branch size, and expedite natural pruning at the most valuable stem section without significantly compromising tree growth for dominant and codominant trees at early stage. These are crucial for crop tree management aimed at producing large-sized and high-quality solid wood production of B. alnoides. ? 2024, The Authors. All rights reserved.