A TALE OF TWO COLLAPSES: ENVIRONMENTAL VARIABILITY AND CULTURAL DISRUPTION IN THE MAYA LOWLANDS

Nº 41, 2013. Páginas 171-183 Diálogo Andino A Tale of Two Collapses: Environmental Variability and Cultural Disruption in the Maya Lowlands Historia de dos colapsos: Variabilidad ambiental e interrupción cultural en las Tierras Bajas mayas Nicholas P. Dunninga, Timothy Beachb, Liwy Grasiozo Sierrac, John G. Jonesd, David L. Lentze, Sheryl Luzzadder-Beachf, Vernon L. Scarboroughg, Michael P. Smythh An expanding array of data is becoming available on past climate changes affecting the Maya Lowlands region. We examine the strengths and weaknesses of these data sets, both in terms of identifying general trends and specific events. We then use these data to develop a model based on adaptive cycles that addresses both environmental and cultural changes that occurred in the Terminal Preclassic and the Terminal Classic periods in several areas of the Maya Lowlands. In particular, we compare the variable experiences and trajectories of several ancient communities located in the elevated interior region with others situated on lower elevation coastal plains. In general, communities in lower elevation areas proved more resilient to environmental and cultural perturbations than those in the higher elevation interior. Key words: maya lowlands, maya archaeology, paleoclimate. Un expansivo ordenamiento de la información sobre los pasados cambios climáticos que afectaron a la región de las tierras bajas mayas se está haciendo disponible. Examinamos las fortalezas y debilidades sobre estos conjuntos de datos, tanto para identificar corrientes generales como eventos específicos. Posteriormente utilizamos esta información para desarrollar un modelo basado en ciclos adaptativos que tratan de cambios ambientales y culturales que ocurrieron durante los períodos Preclásico Terminal y Clásico Terminal en algunas áreas de las tierras bajas mayas. En particular, comparamos las experiencias y trayectorias variables de algunas comunidades antiguas localizadas en la región elevada del interior con otras situadas en elevaciones más bajas de las planicies costeras. En general, las comunidades en las áreas de elevaciones de menor altura probaron tener mayor habilidad de recuperación y adaptación a las perturbaciones ambientales y culturales que aquellas situadas en lugares con mayor altura del interior. Palabras claves: tierras bajas mayas, arqueología maya, paleoclima. Introduction: Lowland Maya Civilization in Environmental Context Ancient Maya civilization has grown in the popular imagination since the 19th century, often filled with images of crumpling temples covered by tropical forest, and produced numerous theories about the fate of Maya civilization. More recently, the Classic Maya “collapse” has been used, along with other examples from the ancient world, as a warning for modern civilization (e.g. Diamond 2005). For nearly a century, scholars have debated the role that climate or environmental change may a b c d e f g h have played in the course of Maya civilization (e.g. Huntington 1917). These debates have progressed from highly speculative to increasingly sophisticated as the number of paleoenvironmental proxies being analyzed had grown, the precision of these analyses has increased, and Maya archaeology became increasingly scientific. Since the early 1990s, evidence has mounted linking climate change, especially drought, to the Classic collapse as well as earlier and later downturns in the course of Maya civilization. Each proxy data set has its own strengths and weakness for identifying either general trends or specific events within the paleoenvironmental University of Cincinnati, Department of Geography, Estados Unidos. Correo electrónico: Georgetown University, Science, Technology, and International Affairs, Estados Unidos. Correo electrónico: beachtp@ gmail.com Museo Miraflores, Guatemala. Correo electrónico: Archaeological Consulting Services, LTD, Arizona, Estados Unidos. Correo electrónico: University of Cincinnati, Department of Biological Sciences, Estados Unidos. Correo electrónico: George Mason University, Department of Geography and Geoinformation Science, Estados Unidos. Correo electrónico: University of Cincinnati, Department of Anthropology, Estados Unidos. Correo electrónico: University at Buffalo, Foundation for Americas Research, Inc. Estados Unidos. Correo electrónico: Recibido: 10 de diciembre de 2012. Aceptado: 6 de abril de 2013. 172 N.P. Dunning, T. Beach, L.G. Sierra, J.G. Jones, D.L. Lentz, S. Luzzadder-Beach, V.L. Scarborough, M.P. Smyth record. After briefly reviewing these data below, we propose a broad model of environmental change in the Maya Lowlands and examine how it intersects with trends in Maya civilization. Our study suggests that while Maya communities shared a set of common vulnerabilities to environmental hazards, communities in some regions were considerably more vulnerable, and others more resilient to changing environmental conditions. Ancient lowland Maya civilization spanned a period from about 1000 BC to 1500 AD. Over the course of millennia, Maya civilization experienced several periods of growth and decline, often with highly different trajectories in various regions (Marcus 1993; Dunning and Beach 2010). The Maya Lowlands region comprises the carbonate Yucatan Platform and contiguous areas of Mexico and Central America and includes a mosaic of habitats created by variation in precipitation, drainage, and edaphic patterns. At the heart of the region is an area ranging from 40 to 300 m in elevation and often delimited by geologic scarps that we have elsewhere named the Elevated Interior Region or EIR (Figure 1) (Dunning, Beach, LuzzadderBeach 2012). Drainage is largely internal, except along the southern periphery of the EIR where Figure 1. Map of the Maya Lowlands showing the location of the Elevated Interior Region (EIR) and sites mentioned in the text. rivers with large inputs of groundwater drain the margins of the interior. This region was the focus of spectacular periods of cultural development as expressed in monumental architecture both early and late in the course of Maya civilization including the Late Preclassic (BC 300 - AD 150) apogee in the Mirador Basin and the Late/Terminal Classic (AD 700-925) florescence in the Puuc Hills, regions that were also the scene of dramatic examples of cultural collapse and depopulation. For the Maya Lowlands region, the key climate drivers are shifts in the Intertropical Convergence Zone (ITCZ) and subtropical high pressure masses that create a highly seasonal annual rainfall pattern, as well as a generally north to south rainfall gradient from about 1000 mm to nearly 3000 mm. Changes in the pattern of ITCZ migration have also been linked to longer term climate changes and drought cycles (Haug et al. 2001). The size, Failure of the ITCZ to effectively push northward is strongly linked to periods of increased aridity that at times plague the Maya Lowlands. Soils across the Maya (...truncated)