冰期—间冰期气候旋回中古火灾的变化规律及其控制因子

The change regularities and control factors of fire in the climate cycle of glacial-interglacial period

火对气候、生物地球化学循环和人类健康产生广泛影响,为了避开人类活动的干扰,在整体上把握古火灾、古植被和古气候之间的相互作用关系,并为进一步的深入研究古火灾提供框架,本文聚焦冰期—间冰期时间尺度,整理了深海沉积、湖泊沉积、黄土等沉积物中的古火灾信息,并与对应的古气候、古植被情况结合讨论,总结归纳在冰期—间冰期尺度上不同地区的火灾机制情况,并分析其异同及原因。全球不同海域的深海沉积物中黑碳记录所指示的古火灾没有统一的规律和解释,自然火灾发生机制存在区域性差异。长时间尺度的湖泊记录反映的冰期—间冰期火灾活动情况较一致,今后更多长时间尺度的湖泊沉积物研究可以为火灾活动的轨道驱动研究增添有力证据。黄土中的冰期—间冰期的火灾演化规律存在不同观点,这可能是选用火灾代用指标不同导致,黄土中的黑碳沉积通量可能更准确的揭示古火灾历史。

Fire has a wide impact on climate, biogeochemical cycle and human health. In order to avoid the interference of human activities, to grasp the true relationship between paleofire, paleo vegetation and paleoclimate as a whole, and to provide a framework for further research, this paper focuses on the glacial—interglacial time scales, collates the paleofire information in deep sea sediments, lake sediments and loess, and discusses them with the corresponding paleoclimate and paleo vegetation conditions. We summarize the fire regime in different regions on the glacial—interglacial time scales, and analyze their similarities and differences and their causes. In deep sea sediments in different seas around the world, there are no uniform rules and explanations of paleofires indicated by black carbon records and there are regional differences in natural fire occurrence mechanisms. The fire activity reflected by the long-term lake records is more consistent, and more long-term lake sediment researches in the future can add strong evidence to the orbital driving research of fire activity. There are different views on the evolution of the glacial—interglacial fire in the loess. This may not be the regional differences in fire performance, but the choice of different fire proxies. The black carbon mass deposition rate in the loess may more accurately reveal the history of ancient fires.