关键词: 全新世, 野火历史, 气候变化, 炭屑, 渭河流域

Abstract:

The carbon in Holocene loess deposition is often used to rebuild wildfire history and its evolution process. Through field investigation and the analysis of carbon dust and the magnetic susceptibility index, the earth’s biological sedimentary evidence of wildfire landscape evolution in Holocene is obtained. With reference to OSL/TL dating,¹⁴C dating and archaeology data, wildfire history and landscape evolution process in the loess plateau of Weihe River basin since Holocene is reconstructed. Results show that from the last glacial period to the Middle Holocene stage (12 000-3 100 a B.P.), wildfire changes in loess plateau area of Weihe River basin are mainly associated with regional seasonal climate differences closely, among which the one thousand-one hundred scale effective humidity and fuel supply area change are the main controlling factors of wildfires. In the Late Holocene, with further drought climate, combined with human farming activities, human land use intensity and space-time distribution have become an important driving force to influence of biomass burning scale. Since 3 100 years ago, farmland landscape in the south area of Weihe River has begun to take shape. About 2 170 years ago, the large-scale land reclamation has expanded to the loess tableland area in the north of Weihe River. Until 1 500 years ago, dry farming landscape in loess high order platform tableland areas of northern Weihe River has basically formed. With a number of ancient ecological records and regional point of comprehensive analysis, it helps to understand the region wildfires history, human land use change and evolution of the social structure.

Key words: Holocene, wildfire history, climatic changes, charcoal, Weihe River basin