Environmental Dynamics in the Southern Maya Lowlands: A Network of High-Resolution, Multi-Proxy Reconstructions of Prehispanic Biomass Burning and Environmental Change

在国家科学基金会的支持下，考古学家Francisco Estrada-Belli和地理学家David Wahl和Lysanna Anderson将对危地马拉东北部的玛雅生物圈保护区森林的环境和气候变化动态以及人与环境的相互作用进行跨学科研究。直到1000年前，这个地区一直是玛雅人聚居最密集的地区之一。这项研究将有助于建立一个高分辨率重建环境变化和土地利用实践的网络，该网络基于跨越数千年的玛雅低地的生物燃烧、气候变化、植被变化和聚落历史的多条证据。环境变化，无论是人为引起的和/或与自然气候变化有关的，都被认为是导致南部玛雅低地人口显著下降的两个时期的原因。第一次事件发生在公元前200年左右，被认为影响了一些大型的前经典时期(公元前2000年-公元前2500年)的中心。第二次发生在古典时期(公元前250-900年)末期，通常被称为“玛雅崩塌”，中断了玛雅南部低地大多数遗址2000年的占领。对于这两种情况，气候变化和环境退化都被认为是人口大规模下降的主要原因。火在景观管理和建筑活动中对玛雅人来说当然很重要，尽管它被使用的程度在很大程度上仍不清楚。此外，拉美裔前时期环境变化的年表和原因的全貌还没有出现。到目前为止制作的许多记录都是不安全的，缺乏关键的文化区，或者缺乏足够的时间分辨率来准确确定事件和变化的时间。对这些景观的逐一研究将为获得对动态气候/环境和人/环境关系的新见解奠定基础。这项研究将提供位于霍尔穆尔地区的埃克纳布湖人类占领和环境变化的详细记录，该地区是玛雅低地的一个地区，公元前1000年开始定居，公元前2500年至公元前900年，大城市中心蓬勃发展。该湖位于两个主要中心之间：西瓦尔在前古典主义时期(公元前300年-公元前250年)被占领，维茨纳在古典主义时期(公元前250-900年)占领达到顶峰。为了模拟环境退化和/或气候变化对该区域文化轨迹的影响，这项研究将结合详细的聚落历史使用广泛的古环境指标。高分辨率化石木炭分析将用于重建生物质燃烧，花粉将用于指示附近的农业活动，稳定同位素将作为气候变异性的替代，沉积物特征将用于评估水文和沉积制度的变化。考古调查和核心遗址附近的选择性挖掘将增强环境问题的解释能力。这项研究的更广泛影响在于：1)提供玛雅文明史上人与环境相互作用的详细记录，将人类影响与气候变化分开，并评估与定居点废弃的任何相关性；2)填补我们在支持人类活动数千年的脆弱湿地环境地区的景观演变和气候变化方面的重要空白；3)生成关于玛雅低地定居的基线考古数据。

With the National Science Foundation support, archaeologist Francisco Estrada-Belli and geographers David Wahl and Lysanna Anderson will conduct an interdisciplinary research study into the dynamics of environmental and climate change, and human-environmental interaction in the Maya Biosphere Reserve forest in northeastern Guatemala. This area was among the most densely settled by the Maya until 1000 years ago. The study will contribute to an ongoing effort to create a network of high-resolution reconstructions of environmental change and land use practices based on multiple lines of evidence for bio-mass burning, climate change, vegetation change, and settlement history for the Maya Lowlands spanning several millennia. Environmental change, either anthropogenically induced and/or associated with natural climate variability, has been posited as contributing to two periods of marked population decline in the southern Maya Lowlands. The first episode occurred ~200 CE and is thought to have affected a number of large Preclassic period (2000 BCE-250 CE) centers. The second occurred at the end of the Classic period (250-900 CE) and is commonly referred as the "Maya Collapse" having interrupted 2000 years of occupation at most sites in the southern Maya lowlands. For both cases, climate change and environmental degradation have been proposed as the primary causes of extensive demographic decline. Fire was certainly important to the Maya in landscape management and building activities, although the extent to which it was used remains largely unknown. Moreover, a full picture of the chronology and causes of environmental change during the Pre-Hispanic period has yet to emerge. Many of the records produced so far are insecurely dated, are lacking from key cultural zones, or lack sufficient temporal resolution to precisely date the timing of events and changes. Examination of these landscapes on a case-by-case basis will provide a foundation for gaining new insights into the dynamic climate/environment and human/environment relationships.This study will provide a detailed record of human occupation and environmental change from Lake Eknaab, located in the Holmul region, an area of the Maya Lowlands where settlement began at 1000 BCE and where large urban centers flourished from 250 BCE to 900 CE. The lake is situated between two major centers: Cival, which was occupied in the Preclassic period (300 BCE- 250 CE) and Witzna whose occupation peaked in the Classic period (250-900 CE). In order to model the effects of environmental degradation and/or climate change on the cultural trajectory of the region, this research will use a wide range of paleoenvironmental indicators in conjunction with detailed settlement history. High-resolution fossil charcoal analysis will be employed to reconstruct biomass burning, pollen will be used to indicate nearby agricultural activity, stable isotopes will serve as a proxy for climate variability, and sediment characteristics will be used to assess changes in hydrology and sedimentation regimes. Archaeological surveys and selective excavations near coring sites will augment interpretive capability of environmental proxies.The broader impact of this study lies in its ability to 1) provide a detailed record of human-environment interactions in the history of Maya civilization, separating human impacts from climate change, and evaluate any correlation with settlement abandonments; 2) fill an important gap in our knowledge of landscape evolution and climate variability in an area of fragile wetland environments that supported human activities for millennia; 3) generate baseline archaeological data on the settlement of the Maya Lowlands.