河北省东北部,特别是承德地区一带,现有人工培育或天然更新的油松林不下二百万亩,约占全部用材林面积的五分之一,这是我省的一笔大财富。油松是华北一带速生的用材树种,成林、郁闭较快,出材多,群众喜欢用来造林。在已成林的林分中,有的过于密集,有的在间伐一部份以后又感到偏稀,长年以来虽有不少部门进行研究,也设置了许多标准地,终以标地数目还不足,疏伐标准问题一直没有很好地解决。 In the northeastern part of Hebei Province, especially in the Chengde area, there are no more than two million mu of existing pine forests with artificial breeding or natural regeneration, accounting for one fifth of the total area of ​​timber forests, which is a big fortune of our province. Pinus tabulaeformis is a fast-growing species of timber in North China. When forests grow, the canopy is closed faster and the timber is more suitable for afforestation. Among the already-forested stands, some are over-intensive and some feel less-developed after they have been partially planted. Although many departments have conducted research for many years, they have also set up many standards and eventually set the number of target places Not enough, thinning standards have not been well resolved.