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为准确评价林火在大兴安岭樟子松林中的地位和作用,在大兴安岭呼伦贝尔盟莫尔道嘎林区樟子松林内,利用火疤木解析的方法,确定了3块火疤木集中的样地历史林火发生的年代及每次林火的火焰高度(h);林火强度(I)通过经验公式计算;结合样地每木调查,推算了林火发生后样地林木胸径。研究表明,3块样地自1887~1976年间共发生10次林火,h为0.46~3.32m,I为48~3690kW/m,平均林火间隔期(tMFI)约为19.8a。在樟子松林内高强度的火烧对林分生长造成破坏,迫使林分重新开始更新和演替,中度与低强度火作为一个自然选择力,排除抗火性较樟子松差的树种、灌木和杂草,加速养分循环,使存活下来的樟子松获得更大的存活与发展空间。tMFI与I成反比,因此过分干扰林火发生必将增加发生大火的可能性。
In order to accurately evaluate the position and function of forest fire in Pinus sylvestris var.mongolica forest in Daxinganling Mountains, the samples of firewood were collected in the Pinus sylvestris var. Mongolica forest in Hulunbeier, Daxinganling. The age of the historical forest fire and the flame height of each forest fire (h); The intensity of the forest fire (I) is calculated by the empirical formula; Based on the survey of each plot, the DBH of the sample forest after the forest fire was calculated. The results showed that there were 10 fires occurring in the three plots from 1887 to 1976, h was 0.46 ~ 3.32m, I was 48 ~ 3690kW / m, and the average forest fire interval (tMFI) was about 19.8a. High-intensity fire in Pinus sylvestris var. Mongolica forest caused damage to the stand growth, forcing the forest to restart the renewal and succession. Moderate and low intensity fire as a natural selection force, excluding fire resistant than Pinus sylvestris species, Shrubs and weeds, accelerating the nutrient cycle, the survival of Pinus sylvestris to obtain greater survival and development. tMFI is inversely proportional to I, so overly disturbing the occurrence of forest fires will certainly increase the probability of a large fire.