大兴安岭天然中幼龄林抚育间伐剩余物火烧处理试验研究

到1990年止,大兴安岭林区共完成抚育作业面积66.74万ha。据统计,抚育间伐剩余物每公顷可达25t左右,影响了林内卫生,提高了火险等级。为此,先后在松岭、呼中、十八站、库伦斯林业局和呼玛县林业局的国营林场进行了抚育间伐剩余物火烧处理试验,取得了较好的效果一、试验方法 (一)试验条件的选择初步试验在松岭和呼中林业局的部分林场进行。选择天然中幼龄林的兴安落叶松纯林,落叶松与白桦混交林,林龄Ⅱ、Ⅲ龄级,平均树高8-12m,平均胸径6-12cm,郁闭度≥0.7。标准地面积采用正方形33×33m,剩余物按2m×1m×1.5m、2m×1m×1m、2m×1m×0.5m堆放。剩余物按抚育后的3、6、12个月分别进行火烧处理,以检验剩余物含水量与火烧处理效果的关系。剩余物火烧处理的时间选择在防火安全期内进行,分别在7月15日-9月15日,11月15日至翌年3月10日,夏季试验是在连续10天以上无降水过程中进行,以排除因降水对剩余物含水量的影响。

EXPERIMENTAL STUDY ON BURNING TREATMENT TO TENDING AND THINNING REMAIDERS OF NATURE HALF-MATURE FOREST AND YOUNG GROWTH IN DAXINGAN MOUNTAIN

The remainder left from tending and thinning of the half-mature forest and the young growth not only influence the forest hygiene, but also increa-ses the fire denger rating. Based on a large number of experiments in Daxinganm ountain,the critical facters, which affect fire behaviour and harm growingtrees are the distance from the burning point to the growing trees, the burn-ing season, the piling size and moisture content of the remainder. The feasi-bility of burning treatment in winter is put forword in this paper.