Climatic controls of Holocene fire patterns in southern South America
Climatic controls of Holocene fire patterns in southern South America
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DOI：
10.1016/j.yqres.2007.01.012
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发表时间：
2007-07
影响因子：
2.3
通讯作者：
C. Whitlock;P. Moreno;Patrick J. Bartlein
中科院分区：
文献类型：
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作者：
C. Whitlock;P. Moreno;Patrick J. Bartlein
全新世火气候植被的联系，主要是了解在个别网站，通过比较木炭和花粉记录与其他古环境代理和模型模拟。这种规模的重建往往掩盖了过去火灾活动中与区域气候和植被变化有关的大规模模式的检测。从南美洲南部的31个木炭记录的网络进行了检查，以评估火灾的历史沿着从亚热带到亚热带生物群落的横断面。木炭数据表明，火灾活动大于目前在约。12，000 cal yr BP，并进一步增加，并在9500 cal yr BP时广泛分布。火灾活动减少，变得更加空间可变的6000卡年BP，这种趋势继续存在。在最近的大火年的大气环流异常表明，在西风向南移动，和古气候模型模拟和数据合成表明，这种情况可能已经盛行了数千年的全新世早期，当极地到赤道的温度梯度较弱，年温度高于现在，响应轨道时间尺度的日照变化。
Holocene fire–climate–vegetation linkages are mostly understood at individual sites by comparing charcoal and pollen records with other paleoenvironmental proxy and model simulations. This scale of reconstruction often obscures detection of large-scale patterns in past fire activity that are related to changes in regional climate and vegetation. A network of 31 charcoal records from southern South America was examined to assess fire history along a transect from subtropic to subantarctic biomes. The charcoal data indicate that fire activity was greater than present at ca. 12,000 cal yr BP and increased further and was widespread at 9500 cal yr BP. Fire activity decreased and became more spatially variable by 6000 cal yr BP, and this trend continued to present. Atmospheric circulation anomalies during recent high-fire years show a southward shift in westerlies, and paleoclimate model simulations and data syntheses suggest that such conditions may have prevailed for millennia in the early Holocene when the pole-to-equator temperature gradients were weaker and annual temperatures were higher than present, in response to orbital-time-scale insolation changes.