Thesis
A low-frequency paleoclimatic reconstruction from the La Plata Mountains, Colorado and its implications for agricultural productivity in the Mesa Verde region
Washington State University
Master of Arts (MA), Washington State University
2006
Handle:
https://hdl.handle.net/2376/101091
Abstract
This thesis presents pertinent data on the low-frequency paleoclimatic regime of the Mesa Verde region in southwestern Colorado from B.C. 100 to the present era. Here, I define lowfrequency climatic changes as climatic changes over periods greater than 20 years. I place interpretive emphasis on the period A.D. 600 - 1300, an era of continuous habitation by ancestral Puebloan farmers in the central Mesa Verde region. These data are intended for use in the Village Project's agricultural paleoproductivity model, which seeks to derive estimates of maize production in the central Mesa Verde region during the 700 years of continuous occupation. Knowledge of low-frequency climatic processes is critical to understanding subsistence practices because they not only establish a region's carrying capacity, but they are also assumed to represent the normative climatic conditions perceived by a population. A tentative comparison of regional paleodemography to low-frequency climate changes suggests that demographic processes are broadly correlated with low-frequency climatic conditions, likely due to associated fluctuations in agricultural productivity. This study consists of an intensive analysis of 72 closely-spaced stratigraphic pollen samples from a subalpine fen in the La Plata Mountains, southwestern Colorado; 16 radiocarbon samples provide temporal control. The results offer data on the most closely sampled and radiometrically dated pollen core of lacustrine sediments from the past 2,100 years in North America. I use these data to reconstruct low-frequency changes in regional temperature, summer precipitation and winter precipitation, all of which are critical to agricultural production in Mesa Verde region. This reconstruction uses five indicator taxa whose existence around the fen is dictated largely by these climatic conditions: Engelmann spruce, ponderosa pine, pinyon pine, sedge and an inclusive category of plants belonging to the Chenopodaceae family and Amaranthus genus. I argue and demonstrate that changes in the proliferation of these taxa around the fen occurred in response to climatic fluctuations that dictate their distribution. Therefore, I interpret changes in the proliferation of these taxa as changes in associated climate variables, and I extrapolate these climate changes into a regional context that includes the Village Project's study area in the central Mesa Verde region.
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Details
- Title
- A low-frequency paleoclimatic reconstruction from the La Plata Mountains, Colorado and its implications for agricultural productivity in the Mesa Verde region
- Creators
- Aaron M. Wright
- Contributors
- John G. Jones (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Anthropology, Department of
- Theses and Dissertations
- Master of Arts (MA), Washington State University
- Publisher
- Washington State University; Pullman, Wash. :
- Identifiers
- 99900525027301842
- Language
- English
- Resource Type
- Thesis