六十年代以来,国内外许多学者在早期选择方面作过不少的研究,但无统一认识。Cannell认为,在林冠郁闭前,林木处于开放的生长环境,而在林冠郁闭后,处于竞争的生长环境,因此,树高在林冠郁闭前后可能不相关,甚至为负相关;Franklin的看法与此相似。但是,Lambethc在总结了8位学者对花旗松、北美黄松和火炬松等8种针叶树的研究结果后确信,树高生长的早期选择是有效的;叶培忠等对杉木优树子代和产地测定林的研究表明,早晚生长相关是显著的。油松(Pinus tabulaeformis Carr.)是我国北方主要造林树种之一,生长周期较长。本项研究所用材料是我国定植最早的油松测定林,为了供选择优树和早期预测时参考,缩短育种周期,我们将14年来的工作总结如下。 Since the 1960s, many scholars both at home and abroad have done a lot of research on early choices, but there is no uniform understanding. Cannell argues that forest trees are in an open growth environment before canopy closure and are in a competitive environment after canopy closure, so tree height may not be correlated or even negatively correlated before and after forest canopy closure; Franklin’s view Similar to this. However, after summarizing the results of 8 studies on eight conifers such as Douglas fir, Pinus thunbergii and Pinus taeda, Lambethc is convinced that the early selection of tree height growth is effective. Ye et al. Lin’s research shows that the correlation between morning and evening growth is significant. Pine (Pinus tabulaeformis Carr.) Is one of the main afforestation species in northern China with a longer growth cycle. The material used in this study is the earliest Pinus tabulaeformis forest planted in China. In order to select the optimal tree and early prediction reference and shorten the breeding cycle, we summarize the work done in the past 14 years as follows.