由于树木生命周期长,环境条件复杂,树体高大,延长了选择育种周期,增加了测定工作的困难。为了缩短选择育种周期,加速良种的鉴定和推广,国内外育种工作者都积极探索树木性状的早期予测的方法和途径,为了促进林木速生丰产,研究在苗期进行混合选择的方法。为了估算樟子松生长性状的早、晚相关规律,选择不同地区、不同立地条件和不同栽植密度的几块有代表性的标准地,仅就樟子松高生长速率早晚期相关及在苗圃进行混 Due to the long life cycle of trees, complicated environmental conditions and tall trees, the selection breeding cycle is prolonged, which increases the difficulty of determination. In order to shorten the selective breeding cycle and speed up the identification and popularization of improved elite, breeders at home and abroad are actively exploring ways and means of early prediction of tree traits. In order to promote fast-growing and yield-bearing trees, methods of mixed selection at seedling stage are studied. In order to estimate the early and late related laws of growth traits of Pinus sylvestris var. Mongolica and select representative representative standards in different regions, different site conditions and different planting densities, the correlation between high and low growth rates of Pinus sylvestris var. Mongolica and its nursery mix