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多年来的林业生产实践证明,抚育幼林是改善土壤水、肥条件,提高造林成果的重要措施。在湿润,半湿润地区幼林抚育的中心任务是消灭林地杂草,如大兴安岭林区营造兴安落叶松人工林,一般是当年进行2—3次抚育,包括培土、踏实、修坝埂、除草松土等措施,第二年抚育两次,第三年以后每年最少一次,直到幼林不受杂草影响为止。在半干旱和干旱区,幼林抚育更显得重要,幼林抚育的中心任务是加强土壤管理,以调节林木对土壤水分的供需关系。在平原农区以哲里木盟保安林场为例,该场在1982年春季以小×美杨树为主营造防护林带,行距3～3.5米,当年5—8月以机械为主进行幼林抚育3—6次。经调查,抚育次数越多,土壤含水量、造林成活率越高,幼林长势也越好。如护牧林带造林后当年抚育6
Over the years, forestry production practice has proved that tending young forests is an important measure to improve soil water and fertilizer conditions and improve afforestation achievements. In moist, sub-humid areas of young forest tending the center task is to eliminate wood weeds, such as Daxinganling forest to build Larix gmelinii plantation, usually in the year to carry out 2-3 times of tending, including earthwork, practical, repair dam 埂, weeding riparian And other measures, the second year of tending two times, the third year after the least once a year until young soils are not affected by weeds. In semi-arid and arid areas, young tending is even more important. The central task of young tending is to strengthen soil management so as to regulate the supply and demand of trees to soil moisture. For example, in the plain farmland, Zheliu League Security Forest Farm was taken as an example. The shelterbelts were mainly made of small poplars in the spring of 1982 with spacing of 3 to 3.5 meters. From May to August of that year, machinery was mainly used for young forest tending 3-6 times. After investigation, the higher the number of tending, the higher the soil water content, the higher the survival rate of afforestation, the better the growth of young forest. For example, in the pastoral forest belt afforestation 6 years