Precipitation variability, vegetation turnover, and anthropogenic disturbance over the last millennium in the Atacama highlands of northern Chile (19°S)
Precipitation variability, vegetation turnover, and anthropogenic disturbance over the last millennium in the Atacama highlands of northern Chile (19°S)
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DOI：
10.1177/09596836231151834
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Alejandra I. Domic;M. E. de Porras;J. Capriles;Andrés Zamora-Allendes;S. Ivory;A. Maldonado
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文献类型：
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作者：
Alejandra I. Domic;M. E. de Porras;J. Capriles;Andrés Zamora-Allendes;S. Ivory;A. Maldonado
阿塔卡马沙漠的水文气候变化的晚全新世历史提供了降水和人类对世界上最极端干旱地区之一的生态系统的影响的见解。然而，了解区域降水变化对当地生态压力的影响仍有待充分解决。在这里，我们提出了一个基于花粉的定性降水重建来自化石啮齿动物的垃圾桶恢复从两个网站附近的拉古纳罗哈（LRO; n = 25）和Isluga（ISL; n = 15）在阿塔卡马高地（19°S）的北方智利。在LRO，化石花粉记录显示，在过去的一千年中，多百年水文气候异常，与潮湿比现在的阶段在1155-1130，865-670，215-80卡年BP，和类似的条件之间的1005和880卡年BP。与此相反，ISL记录显示，在1115-840 calyrs BP的湿相，这表明，中生态过程的植被周转区域水文气候异常一样重要。来自LRO的潮湿条件与中世纪气候异常（865-670 cal yrs BP）和小冰期（215-80 cal yrs BP）的最后部分重叠。此外，没有强烈的人为信号被确定可能与记录的远程位置有关。孢粉多样性分析证据增加多样化的植物群落在潮湿的事件在这两个网站。在相关的现有区域水文气候记录从西安第斯山脉，我们的降水重建验证百年尺度的变化，在南美洲夏季风（SASM）的强度和厄尔尼诺（ENSO）条件的部分影响驱动植被周转在阿塔卡马沙漠在过去的千年。
The Late-Holocene history of hydroclimatic variability in the Atacama Desert offers insights into the effects of precipitation and humans on ecosystems in one of the most extremely arid regions of the world. However, understanding the effects of regional precipitation variability in relation to local ecological stressors remains to be fully resolved. Here, we present a pollen-based qualitative precipitation reconstruction derived from fossil rodent middens recovered from two sites near Laguna Roja (LRO; n = 25) and Isluga (ISL; n = 15) in the Atacama highlands (19°S) of northern Chile. At LRO, the fossil pollen record shows multi-centennial hydroclimatic anomalies during the last millennium, with wetter than present phases at 1155–1130, 865–670, and 215–80 cal yrs BP, and similar to present conditions between 1005 and 880 cal yrs BP. In contrast, the ISL record shows a wet phase during 1115–840 cal yrs BP, suggesting that meso-ecological processes were as important in vegetation turnover as regional hydroclimate anomalies. Wetter conditions derived from LRO partially overlap with the Medieval Climate Anomaly (865–670 cal yrs BP) and with the latest part of the Little Ice Age (215–80 cal yrs BP). Furthermore, no strong anthropogenic signal was identified possibly related to the remote location of the records. Palynological diversity analyses evidence increasing diversification of plant communities during wet events at both sites. In correlation to existing regional hydroclimatic records from the Western Andes, our precipitation reconstruction verifies that centennial-scale changes in the strength of the South American Summer Monsoon (SASM) and partial influence of El Niño-like (ENSO) conditions drove vegetation turnover in the Atacama Desert during the last millennium.