论文部分内容阅读
森林大火是森林生态系统最主要的干扰因素之一,不仅影响着森林生态系统内部的营养物质循环、水分和能量流动、土壤理化性质的变化,而且对冻土环境和冷生土壤和土壤碳库、碳氮循环等生物地球化学过程有着重要影响。随着气候变暖和人为活动不断增强,北方林区火灾日益频繁,对冻土的水热影响显著:活动层加深、薄层冻土退化、浅层有机碳大量快速释放、森林和湿地的逆向演替,导致热融沉陷、滑塌、泥石流等现象发生。通过综述国内外森林大火对冻土环境影响的研究进展,分析指出目前森林大火对冻土环境影响的研究主要集中在火烧之后短时间、小范围的定性描述与推断,缺乏长时间、大范围的定量分析。尤其是在大兴安岭地区,除了20世纪90年代初期的少量研究外,此后这方面研究虽有零星报道,但缺乏长期和系统的观测与模型研究,所以森林大火对冻土环境的研究,可以利用空间代替时间的方法,通过长、短期的野外观测和数值模拟相结合,定量研究森林大火之后,多年冻土的水热状态、过程和变化机制,可以为寒区林区、湿地保护、生态环境修复提供科学依据。
Forest fire is one of the most important disturbance factors of forest ecosystem. It not only affects the circulation of nutrients, the flow of water and energy, the change of soil physical and chemical properties within forest ecosystem, but also affects the permafrost environment and soil carbon pool , Carbon cycle and other biogeochemical processes have an important impact. With the increasing of climate warming and man-made activities, the fires in the northern forest are more and more frequent, and the hydrothermal effects on the frozen soil are significant: the active layer deepens, the thin layer of frozen soil degenerates, the large amount of shallow organic carbon releases rapidly, For heat sink, collapse, debris flow and other phenomena. By reviewing the research progress of the influence of forest fires on the permafrost environment at home and abroad, it is pointed out that the current research on the impact of forest fire on the permafrost environment focuses on the short-term and small-scale qualitative description and inference after fire, lack of long-term and large-scale Quantitative analysis. Especially in the Daxinganling area, apart from a small number of studies in the early 1990s, the research in this area has been sporadically reported since then, but lack of long-term and systematic observation and model studies. Therefore, the study of the frozen forest environment by forest fires can make use of space Instead of time, the hydrothermal status, process and change mechanism of permafrost after quantitative analysis of long-term and short-term field observations and numerical simulations can be used for the protection of forest area, wetland and restoration of ecological environment in cold regions Provide a scientific basis.