自然火是地球系统的重要组成部分，与气候、植被关系紧密。全球增温情景下，自然火增多还是减少？其控制因素如何改变？亟需深入研究。季风区气候变幅大、植被类型丰富，其自然火演化及控制因素具有复杂性，是自然火研究的重要区域。在典型季风区，利用可靠方法，恢复不同增温情景下自然火历史，重建古植被演化序列，并深入探讨自然火和植被演替之间的关系，是自然火研究面临的重要任务。本研究拟以东亚季风边缘区黄土高原西峰剖面为载体，着眼于东亚季风区异常温暖时期（MIS-13、MIS-11、MIS-5）所在的三个间冰期－冰期旋回（S5-L5、S4-L4、S1-L1）和全新世（S0），进行黑碳含量和碳同位素分析，及孢粉组合鉴定。重建自然火历史（频率、强度）和古植被演化序列（C3和C4植物比例、植被种属组成）。深入探讨过去不同增温幅度下自然火与古植被演替之间的联系，为预估未来不同增温幅度下自然火的变化趋势提供重要依据。

Natural fire is an important part of the earth system, and it has close relationship with climate and vegetation. In global warming scenario, is the natural fire increasing or decreasing? How is the change of natural fire controlling factors?All need in-depth researchurgently.Monsoon regions are important research areas of global natural fire, as they have significantly changed climate andabundant vegetation types, and their natural fire evolution and control factors are complex. It’s an important task to use reliable method to restore the natural fire history in different warming periodsin a typical monsoon area, and to reconstruct corresponding paleovegetation, and then to explore the relationship between the natural fire and paleovegetation evolution. In this research, focusing on the glacial-interglacial cycles (S5-L5, S4-L4, S1-L1) corresponding to the abnormally warm periods(MIS-13, MIS-11, MIS-5) and the Holocene, we plan to study the black carbon in Xifeng loess profile in the Chinese Loess Plateau which in East Asian Monsoon marginal region, and to analyze the black carbon content, carbon isotope and pollen. We can reconstruct the natural fire evolution history (frequency, intensity) and paleovegetationevolution sequence (C3 and C4ratio, vegetation species composition), and then to discuss the relationship between the natural fire and vegetation evolution in different warming geological periods. Our study will provide an important reference for accurately estimating the natural fire development trend in future warming scenario.