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干旱区地理 ›› 2026, Vol. 49 ›› Issue (4): 804-815.doi: 10.12118/j.issn.1000-6060.2025.144 cstr: 32274.14.ALG2025144

• 灾害研究 • 上一篇    下一篇

近5000 a来西天山温泉地区古火的定量重建及其驱动机制

刘雅琦(), 李建勇(), 王宁练, 冉艺   

  1. 西北大学城市与环境学院陕西 西安 710127
  • 收稿日期:2025-03-19 修回日期:2025-04-22 出版日期:2026-04-25 发布日期:2026-04-28
  • 通讯作者: 李建勇(1987-),男,博士,教授,主要从事气候变化与植被生态恢复、人类活动与环境相互作用等方面的研究. E-mail: lijy@nwu.edu.cn
  • 作者简介:刘雅琦(2001-),女,硕士研究生,主要从事第四纪地质与环境等方面的研究. E-mail: liuyaqi1@stu.nwu.edu.cn
  • 基金资助:
    国家自然科学基金项目(41801090)

Quantitative reconstructions of paleofire and their driving mechanisms in Wenquan County, western Tianshan Mountains over the past 5000 years

LIU Yaqi(), LI Jianyong(), WANG Ninglian, RAN Yi   

  1. College of Urban and Environmental Sciences, Northwest University, Xi’an 710127, Shaanxi, China
  • Received:2025-03-19 Revised:2025-04-22 Published:2026-04-25 Online:2026-04-28

摘要:

火扰动是调控草原生态系统演替的关键因子。西天山草原带作为欧亚草原的重要组成部分,既承载着农牧文明交互历史,又是西风主导干旱半干旱区中揭示火扰动-气候-植被-人类活动耦合机制的理想场所。然而,关于中国西北草原生态系统近5000 a来关键火情参数(如火频率、回火间隔、火事件及峰值幅度)的定量研究较为缺乏,为填补这一空白,基于温泉县湿地沉积柱芯的4种不同粒径炭屑组分(10~30 μm、30~50 μm、50~100 μm、>100 μm),结合多指标证据,不同时空尺度下古火的定量演变规律及其对环境变化的响应机制得以揭示。结果表明:(1) 温泉县以区域性火事件为主,草本植物为主要燃料来源。(2) 温泉县古火演化可分为4个阶段:低活动期(5000—4500 cal a BP)、发展期(4500—3700 cal a BP)、衰退期(3700—2600 cal a BP)以及高频波动期(2600—746 cal a BP)。(3) 温泉县古火演化主要受控于水分驱动的燃料供应,表现为湿度增加、草本植物生产力提升以及有利于古火发生的气候条件之间的协同作用。(4) 史前农牧扩张伴随的周期性烧荒活动,以及历史时期屯垦制度与绿洲农业扩张等人类活动,促使火事件频发。

关键词: 火历史, 炭屑, 气候变化, 人类活动, 西天山

Abstract:

Fire disturbance is a key driver of ecological succession in grassland ecosystems. As a critical component of the Eurasian steppe, the grassland belt of the western Tianshan Mountains bears the imprint of historical agropastoral interactions and serves as an ideal region for investigating the combined mechanisms of fire disturbance, climate, vegetation, and human activities in the arid and semi-arid zones dominated by westerlies. However, quantitative reconstructions of key fire-regime parameters (e.g., fire frequency, fire return interval, fire episodes, and peak magnitude) over the past 5000 years remain limited across the vast grassland systems of northwest China. To fill this gap, based on four charcoal particle-size categories (10-30 μm, 30-50 μm, 50-100 μm, and >100 μm) from a sediment core in Wenquan County, combined with multi-proxy evidence, the quantitative paleofire evolution patterns across different spatiotemporal scales and their response mechanisms to environmental changes we revealed. The results indicated that (1) Regional fire episodes dominated in Wenquan County, with herbaceous plants serving as the primary fuel source. (2) Paleofire evolution in Wenquan County exhibited four distinct phases: A low-activity phase (5000—4500 cal a BP), a development phase (4500—3700 cal a BP), a decline phase (3700—2600 cal a BP), and a high-frequency fluctuation phase (2600—746 cal a BP). (3) Fire regime in Wenquan County was primarily regulated by moisture-mediated fuel availability, driven by synergistic interactions between increasing humidity, grass productivity, fuel loads, and favorable weather conditions during the fire season. (4) Human activities contributed to frequent fire episodes through periodic slash-and-burn events associated with prehistoric agropastoral expansion, as well as land reclamation and oasis agriculture during historical periods.

Key words: fire-regime, charcoal, climate change, human activities, western Tianshan Mountains