多年实践表明,评价飞播造林的成效,不仅仅看其出苗率和幼苗保存率,还要看其以后的生长和成林的可能性,因此,研究油松幼苗在播区不同立地条件下的生长和成林过程,对正确选择播区、全面评价飞播造林效果以及合理经营飞播林有着重要的意义。一、试验区自然概况试验是在延安地区宜川县的甘义沟播区(1976年飞播)、圪背岭播区(1977年飞播)和木头沟播区(1978年飞播)进行的。这三个播区均属黄龙山余脉,海拔高900- Years of practice have shown that the evaluation of the effectiveness of aerial seeding afforestation not only depends on its emergence rate and preservation rate of seedlings, but also on the possibility of its subsequent growth and afforestation. Therefore, the study on the growth of Pinus tabulaeformis seedlings under different site conditions in the sown area And the succession process of forests, it is of great significance to correctly select the broadcast areas, comprehensively assessing the effectiveness of aerial seeding and afforestation and the rational management of aerial seeding. First, the natural conditions of the experimental area The test was carried out in the Yanshou County Gannan Gully (Yanfei 1976), Qiantuyuan (1977) and Moguogou (Yanfei 1978) in Yichuan. These three sowing area are the Huanglong Mountains, high altitude 900-