title: Forests, fields, and the edge of sustainability at the ancient Maya city of Tikal.
abstract: Tikal has long been viewed as one of the leading polities of the ancient Maya realm, yet how the city was able to maintain its substantial population in the midst of a tropical forest environment has been a topic of unresolved debate among researchers for decades. We present ecological, paleoethnobotanical, hydraulic, remote sensing, edaphic, and isotopic evidence that reveals how the Late Classic Maya at Tikal practiced intensive forms of agriculture (including irrigation, terrace construction, arboriculture, household gardens, and short fallow swidden) coupled with carefully controlled agroforestry and a complex system of water retention and redistribution. Empirical evidence is presented to demonstrate that this assiduously managed anthropogenic ecosystem of the Classic period Maya was a landscape optimized in a way that provided sustenance to a relatively large population in a preindustrial, low-density urban community. This landscape productivity optimization, however, came with a heavy cost of reduced environmental resiliency and a complete reliance on consistent annual rainfall. Recent speleothem data collected from regional caves showed that persistent episodes of unusually low rainfall were prevalent in the mid-9th century A.D., a time period that coincides strikingly with the abandonment of Tikal and the erection of its last dated monument in A.D. 869. The intensified resource management strategy used at Tikal-already operating at the landscape's carrying capacity-ceased to provide adequate food, fuel, and drinking water for the Late Classic populace in the face of extended periods of drought. As a result, social disorder and abandonment ensued.
authors.affiliation: Department of Biological Sciences, david.lentz@uc.edu.
authors.forename: David L
authors.initials: DL
authors.lastname: Lentz
authors.affiliation: Department of Geography, and.
authors.forename: Nicholas P
authors.initials: NP
authors.lastname: Dunning
authors.affiliation: Department of Anthropology, University of Cincinnati, Cincinnati, OH 45221;
authors.forename: Vernon L
authors.initials: VL
authors.lastname: Scarborough
authors.affiliation: Department of Geography, and.
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Magee
authors.affiliation: Department of Biological Sciences.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Thompson
authors.affiliation: Department of Geography, and.
authors.forename: Eric
authors.initials: E
authors.lastname: Weaver
authors.affiliation: Department of Geography, and.
authors.forename: Christopher
authors.identifier: http://orcid.org/0000-0001-8891-5923
authors.initials: C
authors.lastname: Carr
authors.affiliation: Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT 84602;
authors.forename: Richard E
authors.initials: RE
authors.lastname: Terry
authors.affiliation: El Colegio de la Frontera Sur, Unidad Chetumal Herbario, Chetumal, AP 424 Quintana Roo, Mexico;
authors.forename: Gerald
authors.initials: G
authors.lastname: Islebe
authors.affiliation: Department of Anthropology, University of Cincinnati, Cincinnati, OH 45221;
authors.forename: Kenneth B
authors.initials: KB
authors.lastname: Tankersley
authors.affiliation: La Escuela de Historia, Universidad de San Carlos de Guatemala, Guatemala City, 01012 Guatemala;
authors.forename: Liwy
authors.initials: L
authors.lastname: Grazioso Sierra
authors.affiliation: Archaeological Consulting Services, Ltd., Tempe, AZ 85282;
authors.forename: John G
authors.initials: JG
authors.lastname: Jones
authors.affiliation: Software Engineering Institute, Carnegie Mellon University, Pittsburgh, PA 15213;
authors.forename: Palma
authors.initials: P
authors.lastname: Buttles
authors.affiliation: Department of Anthropology, University of Texas, Austin, TX 78712; and.
authors.forename: Fred
authors.initials: F
authors.lastname: Valdez
authors.affiliation: Departamento de Monumentos Prehispanicos, Instituto de Antropología e Historia de Guatemala, Guatemala City, 01001 Guatemala.
authors.forename: Carmen E
authors.initials: CE
authors.lastname: Ramos Hernandez
mesh_terms: D002962:Civilization; D065928:Forests; D049690:History, Ancient; D049691:History, Medieval; D006801:Humans; D008800:Mexico; D014506:Urban Renewal / Q000266:history*
keywords: Neotropics; irrigation; paleoecology; paleoethnobotany; root crops