中文摘要：

参照OSL测年和考古与历史学断代,利用黄土—土壤剖面沉积物中炭屑和黑碳（焦炭和烟炱）记录,结合磁化率、有机碳等古环境指标,揭示过去12000年火灾历史演变过程。炭屑和黑碳浓度研究结果表明：全新世早期区域野火活动频繁发生,中期火灾很少,晚期本地火灾频率呈现增长态势。黑碳（烟炱和焦炭）和炭屑分析呈现不平行变化趋势,可能是生物质燃烧的物质排放方式和传输过程的区域差异引起。距今3500～2800年间,黑碳和炭屑颗粒浓度峰值与全新世短尺度恶化气候事件具有明显同步性;同期,先周人部落大规模土地开垦发展旱作农业活动加剧。黄土高原千年尺度火灾变化与季风气候变化之间的关系表明：全新世以来,野火频率变化取决于区域气候有效湿度和人类土地利用及其对气候变化的响应。

英文摘要：

A high-resolution sedimentary charcoal and Black carbon（char and soot） records from the loess-soil profile in the western of Guanzhong Basin, combined with Magnetic susceptibility and other paleo-proxies revealed the past wildfire history and the evolution of natural ecological landscape in the past 12 millennium. The results showed that regional wildfire activity was high in the late Holocene; whereas fires were less frequent in the middle Holocene. Local fires were frequently occurred in the late Holocene. Charcoal and black carbon（BC） influxes with peak fluctuations consistently attested to important changes in seasonal precipitation variability and mirror with the gradual climate aridity trend of the entire region during the Holocene which were strongly controlled by global and regional climate dynamics. Meanwhile, the detailed analysis of the BC and charcoal signals were inconsistently attributed to the differences with the process of the carbon deposition and transformation at regional and local scale. Understanding the spatial and temporal fire patterns and vegetation dynamics as possible threshold response of monsoon climate variability to these large-scale forcing would provide essential information for revealing the underlying mechanisms of fire and human activity in response to regional climate change.