北京西山几年来进行较大面积的雨季造林工作,经过实践证明.在一定的条件下(指降雨量大,蒸发量不,造林技术掌握好等)利用雨期的机会进行造林,是可以成功的。根据我们对历年幼林成活效字的调查结果,油松用3.5—4.5年生苗带上坨栽植,其成活率1952年为98%,1953年为94%,1955为98%。用2.5年生苗带土坨栽植,其成活率1935年为91%,1957年为95%,1958年为95%,用1—5年生苗,根部 In recent years, a large area of ​​rainy season afforestation has been carried out in Xishan, Beijing, and it has been proved that afforestation can be succeeded under certain conditions (referring to the large amount of rainfall, no evaporation, good afforestation techniques, etc.). According to our survey on the results of surviving young forest in the past years, Pinus tabulaeformis was nurtured with 3-5.5-year-old seedlings and its survival rate was 98% in 1952, 94% in 1953 and 98% in 1955. With 2.5 years of seedling with soil lumps planted, the survival rate of 91% in 1935, 95% in 1957, 95% in 1958, with 1-5 years of seedlings, roots