敖汉旗三义井林场,过去栽植的榆树纯林由于没有做到适地适树,加上造林密度大,抚育管理跟不上等原因,二十多年生的榆树树高仅两米多,且已停止生长,处于濒死状态。一九八二年起,该场针对树木生长慢和死亡的现状,进行了林分改造。利用本场研制的JK45—50型开沟犁,在皆伐的榆树地上进行开沟整地,然后选用当年的优质杨树条进行扦插造林,初植密度为每亩八十三株。造林后每年进行一次抚 Ao Han flag Sanyi well forest field, the pasture planted with pure elm tree due to not be properly adapted to tree, with afforestation density, management of tending can not keep up, twenty-year-old elm tree height of only two meters , And has stopped growing, in a dying condition. Since 1982, the site has been rebuilding forests in response to the slow growth and death of trees. Using the field developed JK45-50-type open plow, clear cut elm trees in the ground for dredging, and then use the year’s quality poplar cuttings afforestation, planting density of 83 per acre. After afforestation once a year caress