Ancient Maya wetland fields revealed under tropical forest canopy from laser scanning and multiproxy evidence
Timothy Beach, Sheryl Luzzadder-Beach, Samantha Krause, Tom Guderjan, Fred Valdez Jr., Juan Carlos Fernandez-Diaz, Sara Eshleman, and Colin Doyle
PNAS first published October 7, 2019 https://doi.org/10.1073/pnas.1910553116
Abstract
We report on a large area of ancient Maya wetland field systems in Belize, Central America, based on airborne lidar survey coupled with multiple proxies and radiocarbon dates that reveal ancient field uses and chronology. The lidar survey indicated four main areas of wetland complexes, including the Birds of Paradise wetland field complex that is five times larger than earlier remote and ground survey had indicated, and revealed a previously unknown wetland field complex that is even larger. The field systems date mainly to the Maya Late and Terminal Classic (∼1,400–1,000 y ago), but with evidence from as early as the Late Preclassic (∼1,800 y ago) and as late as the Early Postclassic (∼900 y ago). Previous study showed that these were polycultural systems that grew typical ancient Maya crops including maize, arrowroot, squash, avocado, and other fruits and harvested fauna. The wetland fields were active at a time of population expansion, landscape alteration, and droughts and could have been adaptations to all of these major shifts in Maya civilization. These wetland-farming systems add to the evidence for early and extensive human impacts on the global tropics. Broader evidence suggests a wide distribution of wetland agroecosystems across the Maya Lowlands and Americas, and we hypothesize the increase of atmospheric carbon dioxide and methane from burning, preparing, and maintaining these field systems contributed to the Early Anthropocene.
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查了一下原文的摘要,说的跟本文根本就不是一回事。
环保婊是真可恶。
长期以来,考古学界关于玛雅文明为何突然灭亡有种种不同的说法,如严重旱灾和族群之间的暴力冲突等。美国得克萨斯州大学的科学家最近提出新的研究结论,认为玛雅人自1800年前以来的传统耕种方式破坏了环境,导致“玛雅版气候变化”,造成严重旱灾,玛雅文明因此灭亡。
科学家研究了玛雅传统耕地遗址,发现玛雅耕种方式对环境的重大影响。
得州大学科学家提姆·比奇(Tim Beach)博士率领的科研小组研究了中美洲国家伯利兹多处遗址,深入了解了玛雅人传统耕种方式及其对环境的重大影响。
科研小组以航拍方式扫描了伯利兹西北部一处名为“天堂鸟”(the Birds of Paradise)的湿地,惊讶地发现这里原来是玛雅人长久以来的耕地,面积比科学家原来预想的要大五倍。
比奇博士带领的科研小组以航拍方式扫描了玛雅传统耕地,这里用于灌溉的沟渠运河密布。
扫描结果显示,目前掩埋在地表以下的玛雅传统耕地遍布着灌溉用的沟渠运河。
比奇博士率领的科研小组认为,如此大面积的耕地必须要通过烧荒,即焚毁大片热带雨林来营造。
科研小组还在其他地方发现了面积更为广阔的耕地遗址。
科研小组推测,在1800年前到1000年前的数百年时间里,玛雅人的这种耕种方式对环境造成了灾难性的影响,比科学家先前推测的要严重得多。
玛雅传统耕种方式导致该地区温室气体增多,造成严重旱灾,最终毁灭了玛雅文明。
科研小组认为,耕地中密布的沟渠运河会产生大量甲烷,而大面积焚烧雨林更会产生大量二氧化碳。长此以往,玛雅传统耕种方式导致该地区温室气体增多,造成严重旱灾,最终毁灭了玛雅文明。
“我们现在开始理解人类对热带雨林的重大影响,”比奇博士说,“如此大面积和复杂的湿地耕种系统在工业化以前的长久岁月里可能改变了气候条件,局部地区的气候变化也对地球发出了警告。”
比奇博士及其科研团队认为,玛雅文明的灾难正好是“人类世”(the Anthropocene)的起始阶段,“人类世”指的是人类对自然环境造成严重影响的历史阶段。
“我们的研究提供了新的证据,证明人类对全球热带地区早期的广泛影响。”比奇博士说,“我们推测,烧荒、耕地和灌溉造成大气中二氧化碳和甲烷的增多,导致了早期人类世的情况。”
据悉,《科学》杂志2018年发表的一篇论文指出,玛雅文明灭亡之前,当地的年降雨量已经比早期下降了54%。
严重干旱造成庄稼收成锐减,食品短缺,最终造成玛雅文明的灭亡。
编译/采写:南都记者陈林