文献类型：期刊文献

英文题名：Long-term effects of planting density and site quality on timber assortment structure based on a 41-year plantation trial of Chinese fir

作者：Li, Xiaoyan[1] Duan, Aiguo[1,2] Zhang, Jianguo[1,2]

通信作者：Duan, AG[1]

机构：[1]Chinese Acad Forestry, Res Inst Forestry, State Key Lab Efficient Prod Forest Resources, Key Lab Tree Breeding & Cultivat Natl Forestry, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Collaborat Innovat Ctr Sustainable Forestry Southe, Nanjing 210037, Peoples R China

年份：2023

卷号：12

外文期刊名：TREES FORESTS AND PEOPLE

收录：EI(收录号：20230136415);Scopus(收录号：2-s2.0-85160049148);WOS:【ESCI(收录号:WOS:001002424300001)】；

基金：This work was funded by the Research on Directional Cultivation Technology of Cunninghamia lanceolata Timber Forest program, the National Key R & D Program of the 14th Five Year Plan (Grant Number 2021YFD2201301) .

语种：英文

外文关键词：Chinese fir; Initial planting density; Large-diameter timber; Site index; Timber assortment structure

摘要：Stand density control coupled with site control is a key technique for cultivating large-diameter timber of Chi -nese fir trees, whose yield can be effectively increased by the optimal density and site management mode employed. This study aimed to evaluate the dynamic changes in timber assortment structure under differing initial planting densities and site quality based on growth data of a 41-year trial of Chinese fir plantations. Our results showed that the total timber yield and both large-diameter timber outturn and the outturn rate all increased with better site quality under the same initial planting density. Further, the outturn peak as well as outturn rate peak for both medium-and small-diameter timber was reached sooner with improved site quality. For the same site class, a lower initial planting density augmented the total timber outturn rate, and also resulted in less time required for the total timber outturn rate to reach a constant or maximum value. Finally, the total timber outturn rate of all density plots tended to be nearly identical. Using a high planting density increased the outturn of small-diameter timber, whose outturn peak was delayed in the denser plots. The bolstering effect of low density upon the growth of large-diameter timber was enhanced by higher site quality, with density-induced differences in large-diameter timber more pronounced; conversely, that promoting effect weakened under poor site quality conditions. The interaction between planting density and site index significantly influenced the growth of any timber assortment of Chinese fir in the early stage following its formation. Notably, the significant effect of site index on large-diameter timber lasted longer than that of other timber assortments. The optimal site conditions for cultivating large-diameter timber trees of Chinese fir consist of a site class >= 20 with a planting density limited to no more than 1667 trees/ha, whose stand rotation period should not exceed 26 years, so as to maximize the output of large-diameter timber yield. Our empirical findings will be helpful for the construction of an optimal cultivation mode for the density, site, and rotation age of large-diameter timber in Chinese fir plantations.