杉木种子园的初植密度,我省目前普遍采用的株行距是4×4米或5×5米。由于嫁接株冠幅的扩展较为缓慢,嫁接后头几年接株之间存在较大的空间,同时,雄花不够多,花粉数量较少,这样,种子园中因花粉浓度不足,势必影响植株的结实。另外,种子园内不同无性系雌雄花的盛开期先后不一,差异 The initial planting density of Chinese fir seed orchard, the common row spacing in our province is 4 × 4 meters or 5 × 5 meters. Due to the relatively slow expansion of the crown of the grafted plants, there is a large space between the plants in the first few years after grafting. At the same time, there are not enough male flowers and fewer pollen grains. Therefore, the lack of pollen concentration in the seed orchard will inevitably affect the firmness of the plants . In addition, the seeds of different clonal male and female flower blooming period has one after another, the difference