ON THE MAYACOLLAPSE RobertS. Santley,Thomas W. Killion, and Mark T. Lycett Departmentof Anthropology,University of NewMexico, Albuquerque,NM 87131 The collapseof Late ClassicMaya civilizationinvolved more than the disintegrationof politicalstructure. It involveda totalsystem failure in whichboth centers and dependent villageswere abandoned by elitesand commonersalike. The lowlandrainforest habitat whereMaya civilizationdeveloped was not significantlyreoccupied until comparatively recenttimes. The collapse was differential,in thatcenters in coastalareas or drierregions suchas northernYucatan were not depopulatedto thesame degree. The collapse of many Mayacenters in theforested interior is hereattributed to threeinteracting sets of variables: (1) nutritionalstress, disease, and demographic instability; (2) agriculturalintensification, monocropping,and degradationof the agrarianlandscape; and (3) the relativeabsence of macroregionalresource extraction structures. These factors had littleimpact on Maya populationsliving near the coast or in lowlandareas not originallycovered by tropical rainforests. BETWEENA.D. 300 AND800 the ancientMaya developed a complex, hierar- chicallyorganized society in an environmentwe know todayto be highlysus- ceptible to environmentaldegradation and characterizedby slow natural regeneration(R. E.W. Adams 1977; Culbert 1973; Gomez-Pompa and Vasquez- Yanez1981; Rice and Rice 1984; Wilkerson1985). In the Late Classicperiod (A.D. 600-800) substantialparts of the MayaLowlands were denselyoccupied by populationsof peasant farmers. Because most cultivablesections of the Peten and adjacentregions alreadyhad been broughtunder intensive culti- vation,these farmingpopulations made great demandson their tropicalrain- forest habitat. Classic populationscombined dense settlement and intense agriculturalproduction in physiographicregions as diverse as the Pasionand Usumacintariver drainages, the bajosand lakes of the centralPeten, slopelands in the Rio Bec region, the river valleysand wetlandsof Belize, andthe drier regions in the northernsection of the YucatanPeninsula (Figure 1). It now seems likelythat the very success of the ClassicMaya at settlingand developing the Lowlandforest laid the foundationfor the collapseof southernLowland Mayacivilization at the end of the Late Classicperiod. The growthand rapid decline of Mayacivilization in the southernLowlands providea sharpcontrast with other areas where ancient civilizations developed. In semiaridregions such as CentralMexico, the Andes, and greater Meso- potamia,periods of relativelysustained growth and development,separated by phases of politicalfragmentation, appear to be the norm throughoutthe prehistoricsequence. The sociopoliticalsystems of these areas all faced the problem of provisioning increasingly larger populations on circumscribed ag- riculturallandscapes. The trajectory of culturaldevelopment in the Maya Low- lands, however, was different.The fluorescenceof Classicperiod Maya civilization in the Peten and adjacent areas was followed not by periods of balkanization 123 124 JOURNALOF ANTHROPOLOGICALRESEARCH Dzibilchaltun Chunchucmil Sayil NMayapan 0 50 100 200 Northern Lowlands KM Edzna " Gulf of Mexico Becan Candelaria SCalakmul Central Lowlands f/Pulltr:usdrSwamp Palenque Uaxactn Barton Ramie SAguadasN Tikal - Yaxha , Southern Lowlands PasionR. Caribbean Sea Altar de Sacraficios Seibal Southern Highlands 0 Copan The Maya Area - -.TWK Figure1. Mapof the MayaRegion andregrowth but by wholesalesystem collapse,with major parts of the Low- landsabandoned until comparatively recent times. In the Maya case we will arguethat the need to sustainprogressively larger populations placed severe constraintson the foodproduction base whichprecluded further development, renderedthe system inviable,and preventedrecovery. In this paperwe will focus on the problemof maintainingintensive sustained-yield agroecosystems in a rainforestenvironment. Agricultural utilization and degradation of the trop- ical forest habitatby growingpopulations of peasantfarmers have evidently been a commonfeature of landuse fromprehistoric times to the present. The ONTHE MAYA COLLAPSE 125 fallof ClassicMaya civilization in the ninthcentury, then, is seen here as the negativeoutcome of a series of interrelatedbiological, demographic, and so- cioenvironmentalproblems faced by all archaiccivilizations and is an important objectlesson for the contemporaryuse and developmentof the tropics. Argumentsconcerning causes of the Mayacollapse have includedsuch fac- tors as inherentenvironmental limitations of the rainforesthabitat, climatic perturbations,soil exhaustion,famine, disease, civilstrife, andforeign invasion (Culbert1973). As Lowe (1985) has recently pointedout, these arguments are generallyinadequate because they lack systemic character.Other more integrativemultifactor models of the collapse have been criticizedfor their inabilityto explainknown patterns of variabilityin the MayaLowlands. One of the most intriguingaspects of the Maya "experiment"in civilizationwas the initialgrowth and success of Classicpopulations at utilizingthe Lowlandtropical rainforestand transforming it intoa highlyproductive agroecosystem. Evidence for landscapemodification and sustainedagricultural intensification continues to accumulatefor the Maya Lowlandsfrom the Preclassicuntil Late Classic times. Whythen did this seeminglysuccessful and long-enduringexperiment in civilizationfinally fail at the end of the Late Classic? It is our positionthat, althoughinitially successful, Maya populations even- tuallyapproached the limitsof the southernLowland resource base at a time whenthe cumulativeeffects of malnutritionand disease madethe maintenance of an elaborateagrotechnology increasingly difficult. The combinedeffects of environmentaldegradation due to the slow regenerativecapacity of Lowland forests and soils, physiologicalstresses related to inadequatenutrition and disease infestations,and the relativeabsence of regionalresource extraction networksled to demographicinstability, the collapseof the agriculturalsystem, andthe eventualabandonment of a majorityof the southernLowland centers by elites andnonelites alike.' Another property of the Mayacollapse is that it was spatiallyrestricted. In contrastto morelandlocked portions of the southern Lowlands,populations located in coastalareas where marineresources pro- vided an importantcomponent to subsistence(e.g., Belize), in areas where soils were less susceptibleto degradationand/or had a higherregenerative capacity(e.g., highlandGuatemala), or in areas where alternativeresources such as salt were available(e.g., northernYucatan) were not disruptedto the samedegree. Becausethe structureof the resourcebase utilizedby populations inhabitingthese areas was different,a collapse phenomenonwould not be expected,although rearrangements in localsystem organizationmight be. This is preciselywhat the archaeologicalrecord indicates. STRUCTUREOF THE LOWLANDMAYA RESOURCE BASE Our treatment of the structure of the LowlandMaya resource base is divided into three parts. First, we present data on Maya settlement patterns which indicate that populationdensities reached peak levels throughoutthe Lowlands in the Late Classic. Next, we discuss both archaeologicallyknown and potential 126 JOURNALOF ANTHROPOLOGICALRESEARCH modesof agriculturalproduction, focusing on agrotechnologiesapplied to slope- land, riverine, lake margin,and bajo environments.Third, we look at the locationand availabilityof other resources, particularlyhunted game, which may have providedcritical dietary supplements. Inherent difficulties faced by growingfarming populations utilizing the tropicalforest are discussed.These difficultiesare related to the inabilityof the agroecosystemto sustain high productionlevels over time withoutdegradation. Settlementand PopulationDensity Table 1 providessettlement densities and populationestimates based on house-moundcounts for a broadsample of Lowlandsites. The evidence of highpopulation densities surrounding Classic Maya centers shows that exten- sive, shiftingcultivation probably could not have supportedmore than a fraction of the Mayapopulation. Studies of contemporaryswidden cultivators document that shiftingcultivation in the Mayaarea normallysupports less than eighty persons per squarekilometer (Cowgill 1962; Nationsand Nigh 1980). This figurefalls well below Classicperiod population estimates for the Lowlands basedon surveydata from Maya centers and their rural sustaining areas. While some scholars(e.g., Sanders 1973) have suggested that all house mounds mightnot have been occupiedsimultaneously, little actualevidence exists for noncontemporaneityor for seasonaloccupation of structuresfrom the heart of the southernMaya Lowlands. In fact, the structuralredundancy in the pattern of Mayaresidential settlement from center to more ruralperiphery suggests year-roundoccupation for most Classicresidences. Ceramicevidence from a numberof Lowlandcenters such as Becan (Thomas1981), Tikal(Fry 1969; Culbertand Kosakowsky1985; Puleston1973), Seibal(Tourtellot 1982), and Yaxha(D. Rice 1978; Rice and Rice 1985) indicatesthat populationsreached a peak in the Late Classicwhen most, if not all, structureswere occupied. Highpopulation densities were not restrictedto the largestMaya centers and their immediateperipheries. House-mound counts from survey transectsbe- tween majorMaya centers in the Peten show thatpopulation densities in rural areaswere also high(Culbert n. d.). Settlement-patterndata