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在野外调查的基础上,对比研究了北京西山林场4种林分类型火烧迹地与对照林地上植被更新及可燃物负荷量的差异,对更新林分的潜在燃烧性进行了分析。所选择林分为侧柏林、油松林、刺槐林与白蜡林,其中侧柏林和油松林为2003年过火林分,刺槐林和白蜡林为2006年过火林分。火烧后,侧柏林采用人工更新,其它3种林分采用天然更新,研究结果表明:人工更新的火烧迹地上(侧柏林)植被多样性指数减少,总可燃物负荷量增加;而天然更新火烧迹地上(油松林、刺槐林及白蜡林)植被多样性指数增加,但总可燃物负荷量减少;火烧迹地可燃物负荷量的多少与更新时间成正比。总体而言,火烧更新使林地上易燃可燃物负荷量增加,难燃可燃物负荷量减少,从而使更新后林分的潜在燃烧性增加。
Based on the field survey, the differences of the ground vegetation regeneration and combustibles loading of four forest types in Beijing Xishan Forest Farm were comparatively studied, and the potential flammability of the regeneration forest was analyzed. The selected forest is planted as parsley, pinus tabulaeformis, locust forest and white wax forest, of which the forest is Pinus tabulaeformis and Pinus tabulaeformis in 2003 over-burning stand, Robinia pseudoacacia forest and white wax forest over-fire stand in 2006. The results showed that: Artificial regeneration of the burned ground (Platycladus orientalis) vegetation diversity index decreased, the total combustible load increased; and natural renewal of fire burned Vegetation diversity index increased on the ground (Pinus tabulaeformis, Robinia pseudoacacia and Balm forest), but the total load of combustible material decreased. The amount of burnable load on burned ground was proportional to the update time. In general, fire-burning renewal increased the load of flammable combustibles on the forest floor and decreased the load of flammable combustibles, thereby increasing the potential flammability of the newly-reformed stands.