Wildfire evolution and response to climate change in the Yinchuan Basin during the past 1.5 Ma based on the charcoal records of the PL02 core
Wildfire evolution and response to climate change in the Yinchuan Basin during the past 1.5 Ma based on the charcoal records of the PL02 core
复制标题
基于PL02岩心木炭记录的近1.5 Ma银川盆地野火演化及其对气候变化的响应
DOI：
10.1016/j.quascirev.2020.106393
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发表时间：
2020
影响因子：
4
通讯作者：
Shi Wei
中科院分区：
文献类型：
--
作者：
Shi Yulan;Pan Baolin;Wei Mingjian;Li Xinling;Cai Maotang;Wang Junping;Xu Xiangke;Hu Jianmin;Shi Wei
野火活动是自然生态系统的重要组成部分，受气候和植被变化的强烈影响。鉴于此，重建野火历史对于理解过去气候变化和火灾动力学之间的相互关系至关重要，特别是在揭示过去特别重要时期的气候变化特征方面。在这项研究中，我们采用了宏观木炭序列重建在银川盆地（一个干旱和半干旱地区在中国）在过去的1.5马的野火历史。将野火活动对气候和植被变化的响应与其他环境指标如磁化率、陆地盆地岩心（PL 02岩心）中的花粉和海洋岩心（LR 04岩心）中的δ 18 O进行了比较。研究结果表明，在干旱半干旱地区，大型木炭记录是一种有效而敏感的环境演变指示器。木炭浓度和木炭通量的峰值通常出现在气候过渡期，特别是在从潮湿到干旱的过渡期（特别是在MIS 41-MIS 40，MIS 39-MIS 38，MIS 19-MIS 18，MIS 17-MIS 16，MIS 15-MIS 14，MIS 11-MIS 10，MIS 9-MIS 8和MIS 3-MIS 2时间间隔）。此外，我们发现野火中燃烧的生物质（即，木炭浓度的峰值水平表明燃烧的生物量很高）受植被数量的控制，而野火的发生则与气候波动有关。此外，在木炭记录中还发现了一些米兰科维奇旋回（如100 ka旋回、40 ka旋回和20 ka旋回），表明银川盆地野火活动的主要驱动力是地球轨道变化引起的气候变化。其中，40万年的周期消失后0.72 Ma，伴随着野火活动特征的变化。我们还发现400 ka的周期在整个时间内是稳定的。该研究为银川盆地（北方中纬度干旱半干旱区）中更新世过渡（MPT）和中布吕赫事件（MBE）等重要气候事件提供了可靠的证据。
Wildfire activity is an important part of natural ecosystems and is strongly influenced by climate and vegetation changes. Given this, the reconstruction of wildfire history is crucial to understanding the interrelationships between past climate change and fire dynamics, especially in terms of revealing past climate change characteristics during particularly important periods. In this study we employed a macro-charcoal sequence to reconstruct the wildfire history in the Yinchuan Basin (an arid and semi-arid region in China) during the past 1.5 Ma. The responses of wildfire activity to climate and vegetation changes were compared with other obtained environmental indices such as magnetic susceptibility, pollen in the terrestrial basin core (the PL02 core), and δ18O in the marine core (LR04). The results confirmed that macro-charcoal records are an effective and sensitive indicator of environmental evolution in arid and semi-arid areas. The peak values of charcoal concentration and charcoal flux generally occurred during climate transition periods, especially in the transition period from humid to drought conditions (specifically in the MIS41-MIS40, MIS39-MIS38, MIS19-MIS18, MIS17-MIS16, MIS15-MIS14, MIS11-MIS10, MIS9-MIS8, and MIS3-MIS2 time intervals). Furthermore, we found that the biomass burned in wildfires (i.e., the high biomass burned as indicated by the peak levels of charcoal concentration) was controlled by the amount of vegetation, while the occurrence of wildfires was related to climate fluctuations. In addition, some Milankovitch cycles (such as 100-ka cycles, 40-ka cycles, and 20-ka cycles) were evident in the charcoal records, thus indicating that the main driving force of wildfire activity in the Yinchuan Basin was climate change caused by variations in the Earth’s orbit. Among these, the 40-ka cycles disappeared after 0.72 Ma, accompanied by changes in wildfire activity characteristics. We also discovered that the 400-ka cycles were stable throughout time. This study provides reliable evidence for some remarkable climate events, including the Mid-Pleistocene Transition (MPT) and the Mid-Brunhes Event (MBE), from the charcoal records in the Yinchuan Basin (an arid and semi-arid region in the mid-latitudes of the Northern Hemisphere).