油松是我国北方主要的用材树种,我省素有“油松故乡”之称。建国以来,截止1975年底,我省共营造油松人工林2,485,800亩,占造林总面积的1/3以上。五十年代营造的油松林,早已郁闭成林,急需进行抚育间伐。为了研究油松人工林的抚育间伐起始年限、间伐强度及方法等技术措施,从1975年起,省林科所和太原市林场、安泽县林科所协作,对油松人工林进行了试验研究,铺设了抚育间伐固定标准地22块,1978年对部分标地进行了复查,现将试验情况小结如下: Pinus tabulaeformis is the main timber species in northern China, the province known as “hometown of pine”. Since the founding of the People’s Republic of China, 2,485,800 mu of Pinus tabulaeformis plantation has been made up by the end of 1975, accounting for more than one-third of the total afforestation area. The Pinus tabulaeformis forest built in the 1950s has long been closed to forests and is in urgent need of tending thinning. In order to study the starting age, the thinning intensity and the method of tending the thinning of Pinus tabulaeformis plantation, from 1975, the Forestry Branch of the province and the forest farm of Taiyuan City and the Linke Branch of Anze County collaborated to study the Pinus tabulaeformis plantation In the pilot study, 22 fixed standards of tending and thinning were laid. In 1978, part of the landmarks were reviewed. The test results are summarized as follows: