在北京的造林绿化发展史上,有过三次大规模的绿色行动。第一次是1955-1957年,以解放军为主力,绿化小西山地区,造林5.6万亩,部队出工34万个,占总用工量60万个的56.7％。第二次是1958-1960年,机关分片造林,共组织机关、院校、工业、商业、公安、部队等11个系统248个单位,分别在门头沟、房山、昌平、延庆、怀柔等五个区县, In the history of afforestation in Beijing, there have been three large-scale green initiatives. The first was from 1955 to 1957, with the People’s Liberation Army as the main force, greening the small Xishan area, afforestation of 56,000 mu, and the armed forces leaving 340,000 jobs, accounting for 56.7% of the total workforce of 600,000. The second time was from 1958 to 1960 when the organs were divided into afforestation areas and organized 248 units of 11 systems including organs, institutions, institutions of industry, commerce, public security, and armed forces. They were divided into five units at Mentougou, Fangshan, Changping, Yanqing and Huairou District,