Cultural resource databases represent the single largest compilations of archaeological site data, but these databases are seldom used in research because they were designed for management purposes, evolved from paper-based inventories, contain significant interobserver variation, and record information inconsistently. In this paper we present methods designed to alleviate these problems in an analysis of more than 3,000 ancestral Pueblo habitation sites from southwestern Colorado. Our methods draw heavily upon Bayesian statistical concepts and utilize the rich excavation records of our study area to quantify the relationship between surface evidence and excavation results using probabilities. This approach offers a number of advantages over ad hoc, judgmental approaches, and produces a more empirically justified history of ancestral Pueblo settlement in our study area. We believe methods like these have great potential for reconstructing settlement patterns from survey data.
Publications
Using the occupation histories of 3,176 habitation sites, new estimates of maize-agriculture productivity, and an analysis of over 1,700 construction timbers, we examine the historical ecology of Pueblo peoples during their seven-century occupation (A.D. 600–1300) of a densely settled portion of the Mesa Verde archaeological region. We identify two cycles of population growth and decline,the earlier and smaller peaking in the late-A.D. 800s, the later and larger in the mid-A.D. 1200s. We also identify several episodes of immigration. Formation of aggregated settlements, which we term community centers, is positively correlated with increasing population and the time elapsed in each settlement cycle,and it persists during periods of regional population decline, but it does not correlate with climatic variation averaged over periods. Architectural and land-use practices depleted pinyon-juniper woodlands during the first cycle, but more stable field systems and greater recycling of construction timber resulted in more sustainable management of wood resources during the second cycle, despite much higher population densities. Our estimates for maize production are lower than previous estimates, especially for the A.D. 1200s, when population reached its peak in the study area. Even so, considerable potential agricultural production remained unused in the decades that immediately preceded the complete depopulation of our study area.
New archaeological research and computer modeling suggest why Ancestral Puebloans deserted the northern Southwest United States.
Entering Second Phase
The first phase of this project, VEP I, was focused on an 1800-sq-km window of the central Mesa Verde region in Colorado. We are currently working on a final report on that project, to be submitted to the University of California Press, and all of our publications through 2009 result from VEP I research.
In January 2009 we began the Village Ecodynamics Project II, which more than doubles the area under examination in southwestern Colorado and adds a comparative window in the northern Rio Grande region of New Mexico that stretches from the southern border of Bandelier National Monument north to the Chama valley. Fieldwork for this project begins in summer 2009 in Mesa Verde National Park. We expect to report some early results from this new round of research at the 75th Society for American Archaeology meetings in St. Louis in 2010.