Episodes of population loss and cultural change, including the famous Classic Collapse, punctuated the long course of Maya civilization. In many cases, these downturns in the fortunes of individual sites and entire regions included significant environmental components such as droughts or anthropogenic environmental degradation. Some afflicted areas remained depopulated for long periods, whereas others recovered more quickly. We examine the dynamics of growth and decline in several areas in the Maya Lowlands in terms of both environmental and cultural resilience and with a focus on downturns that occurred in the Terminal Preclassic (second century Common Era) and Terminal Classic (9th and 10th centuries CE) periods. This examination of available data indicates that the elevated interior areas of the Yucatán Peninsula were more susceptible to system collapse and less suitable for resilient recovery than adjacent lower-lying areas.

The access to water and the engineered landscapes accommodating its collection and allocation are pivotal issues for assessing sustainability. Recent mapping, sediment coring, and formal excavation at Tikal, Guatemala, have markedly expanded our understanding of ancient Maya water and land use. Among the landscape and engineering feats identified are the largest ancient dam identified in the Maya area of Central America; the posited manner by which reservoir waters were released; construction of a cofferdam for dredging the largest reservoir at Tikal; the presence of ancient springs linked to the initial colonization of Tikal; the use of sand filtration to cleanse water entering reservoirs; a switching station that facilitated seasonal filling and release; and the deepest rock-cut canal segment in the Maya Lowlands. These engineering achievements were integrated into a system that sustained the urban complex through deep time, and they have implications for sustainable construction and use of water management systems in tropical forest settings worldwide.archaeology | resilience | intensification | tropics | paleoecology H ow human populations have used currently threatened environments in a sustainable and managed manner over time can be addressed through archeology and its multidisciplinary collaborations (1). Today, in the geographical core of Classic Maya civilization (A.D. 250-800)-the tropical forest of Petén, Guatemala (a subtropical moist forest in the Holdridge system) (2)-short-fallow slash-and-burn agriculture, logging, and cattle ranching have significantly affected portions of the ecosystem and limited access to potable water (3, 4). Nevertheless, within this biophysical context, one of the earliest and most long-lived tropical civilizations flourished. Maya water and land uses were significantly affected by highly seasonal precipitation and karst physiography, which accommodated little perennial surface water. In response, the ancient Maya developed a complex system of water management dependent on water collection and storage devices. The hydraulic system was cleverly tailored to the biophysical conditions and adaptively engineered to the evolving needs of a growing population for more than 1,000 y (5-7). By identifying how a tropical setting was altered using a Stone Age technology, methods and techniques associated with long-lived and sustainable landscape engineering are revealed. Establishing baseline assessments of human impact on an environment before the extraction and depletion of resources by recent technological advancements may allow an evaluation of current technology's effects and the origins of unintended ecological as well as social consequences.The ancient low-density urban community of Tikal, Guatemala, was recently examined by way of water and landscape assessments (8-10).* Our intent was to document the evolution of a tropical wet-dry engineered landscape (11) and the manner in which the site was altered from its initial colonization (Middle to Late Preclassic, 600 B.C. to A.D. ...

The conjunctive use of paleoecological and archaeological data to document past human-environment relationships has become a theoretical imperative in the study of ancient cultures. Geographers are playing leading roles in this scholarly effort. Synthesizing both types of data, we argue that large karst depressions known as bajos in the Maya Lowlands region were anthropogenically transformed from perennial wetlands and shallow lakes to seasonal swamps between 400 bc and ad 250. This environmental transformation helps answer several questions that have long puzzled scholars of Maya civilization: (1) why many of the earliest Maya cities were built on the margins of bajos, (2) why some of these early centers were abandoned between 100 bc and ad 250, and (3) why other centers constructed elaborate water storage systems and survived into the Classic period ( ad 250-900). The transformation of the bajos represents one of the most significant and long-lasting anthropogenic environmental changes documented in the pre-Columbian New World.

No abstract

No abstract

a b s t r a c tThe measure of the "Mayacene," a microcosm of the Early Anthropocene that occurred from c. 3000 to 1000 BP, comes from multiple Late Quaternary paleoenvironmental records. We synthesized the evidence for Maya impacts on climate, vegetation, hydrology and the lithosphere, from studies of soils, lakes, floodplains, wetlands and other ecosystems. Maya civilization had likely altered local to regional ecosystems and hydrology by the Preclassic Period (3000-1700 BP), but these impacts waned by 1000 BP. They altered ecosystems with vast urban and rural infrastructure that included thousands of reservoirs, wetland fields and canals, terraces, field ridges, and temples. Although there is abundant evidence that indicates the Maya altered their forests, even at the large urban complex of Tikal as much as 40% of the forest remained intact through the Classic period. Existing forests are still influenced by ancient Maya forest gardening, particularly by the large expanses of ancient stone structures, terraces, and wetland fields that form their substrates. A few studies suggest deforestation and other land uses probably also warmed and dried regional climate by the Classic Period (1700-1100 BP). A much larger body of research documents the Maya impacts on hydrology, in the form of dams, reservoirs, canals, eroded soils and urban design for runoff. Another metric of the "Mayacene" are paleosols, which contain chemical evidence for human occupation, revealed by high phosphorus concentrations and carbon isotope ratios of C 4 species like maize in the C 3 edominated tropical forest ecosystem. Paleosol sequences exhibit "Maya Clays," a facies that reflects a glut of rapidly eroded sediments that overlie pre-Maya paleosols. This stratigraphy is conspicuous in many dated soil profiles and marks the large-scale Maya transformation of the landscape in the Preclassic and Classic periods. Some of these also have increased phosphorous and carbon isotope evidence of C 4 species. We synthesize and provide new evidence of Maya-period soil strata that show elevated carbon isotope ratios (d 13 C), indicating the presence of C 4 species in typical agricultural sites. This is often the case in ancient Maya wetland systems, which also have abundant evidence for the presence of several other economic plant species. The "Mayacene" of c. 3000 to 1000 BP was thus a patchwork of cities, villages, roads, urban heat islands, intensive and extensive farmsteads, forests and orchards. Today, forests and wetlands cover much of the Maya area but like so many places, these are now under the onslaught of the deforestation, draining, and plowing of the present Anthropocene.

The Petexbatun region has a series of upland ridges surrounded by lowland wetlands. In Preclassic times, ancient Maya peoples began colonizing the region along waterways. Although few in number, they cleared large areas of upland tropical forest for agriculture and induced significant soil erosion. Population contracted in the region during the Early Classic, and mature tropical forest growth returned. During the Late Classic, population expanded rapidly across the region, forest clearance resumed, and desirable, intensively cultivated, upland areas were divided by an elaborate wall system. Upland agriculture during the Late Classic included the use of several types of terracing that significantly checked soil erosion during this period. Considerable variation may have existed between the urban agriculture practiced in the region's three major centers—Dos Pilas, Tamarindito, and Aguateca.

No abstract