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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。
Until 1990, a total of 667,400 ha of tending operations were completed in Daxinganling Forest Area. According to statistics, tending thinning residue per hectare up to about 25t, affecting the forest health, improve the level of fire insurance. To this end, in Songling, Huzhong, Eighteen Station, Culunsi Forestry Bureau and Huma Forestry Bureau of the state-owned forest farms were carried out tending thinning fire residue treatment, and achieved good results First, the test method (a ) The choice of test conditions Preliminary tests were carried out in some forest farms in Songling and Huzhong Forestry Bureau. Larix gmelinii pure forest and mixed forest of larch and Betula platyphylla in natural medium-aged and young-aged forest were selected. The average age is 8-12m, average diameter at breast height is 6-12cm, and canopy density is 0.7. The standard area of square 33 × 33m, the residue by 2m × 1m × 1.5m, 2m × 1m × 1m, 2m × 1m × 0.5m stacked. Residues after tending 3, 6, 12 months, respectively, fire treatment to test the residual moisture content and fire treatment effect. Residual fire treatment time selection during the fire safety period, respectively, from July 15 to September 15, November 15 to March 10 the following year, the summer test is carried out in more than 10 consecutive days without precipitation To exclude the impact of precipitation on the residual moisture content.