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- All Subjects: Indians of North America
- All Subjects: Soil Ecology
- Creators: Abbott, David R.
Description
The Hohokam of central Arizona left behind evidence of a culture markedly different from and more complex than the small communities of O'odham farmers first encountered by Europeans in the sixteenth and seventeenth centuries A.D. Archaeologists have worked for well over a century to document Hohokam culture history, but much about Pre-Columbian life in the Sonoran Desert remains poorly understood. In particular, the organization of the Hohokam economy in the Phoenix Basin has been an elusive and complicated subject, despite having been the focus of much previous research. This dissertation provides an assessment of several working hypotheses regarding the organization and evolution of the pottery distribution sector of the Hohokam economy. This was accomplished using an agent-based modeling methodology known as pattern-oriented modeling. The objective of the research was to first identify a variety of economic models that may explain patterns of artifact distribution in the archaeological record. Those models were abstract representations of the real-world system theoretically drawn from different sources, including microeconomics, mathematics (network/graph theory), and economic anthropology. Next, the effort was turned toward implementing those hypotheses as agent-based models, and finally assessing whether or not any of the models were consistent with Hohokam ceramic datasets. The project's pattern-oriented modeling methodology led to the discard of several hypotheses, narrowing the range of plausible models of the organization of the Hohokam economy. The results suggest that for much of the Hohokam sequence a market-based system, perhaps structured around workshop procurement and shopkeeper merchandise, provided the means of distributing pottery from specialist producers to widely distributed consumers. Perhaps unsurprisingly, the results of this project are broadly consistent with earlier researchers' interpretations that the structure of the Hohokam economy evolved through time, growing more complex throughout the Preclassic, and undergoing a major reorganization resulting in a less complicated system at the transition to the Classic Period.
ContributorsWatts, Joshua (Author) / Abbott, David R. (Thesis advisor) / Barton, C Michael (Committee member) / Van Der Leeuw, Sander (Committee member) / Janssen, Marcus (Committee member) / Arizona State University (Publisher)
Created2013
Description
Understanding agricultural land use requires the integration of natural factors, such as climate and nutrients, as well as human factors, such as agricultural intensification. Employing an agroecological framework, I use the Perry Mesa landscape, located in central Arizona, as a case study to explore the intersection of these factors to investigate prehistoric agriculture from A.D. 1275-1450. Ancient Perry Mesa farmers used a runoff agricultural strategy and constructed extensive alignments, or terraces, on gentle hillslopes to slow and capture nutrient rich surface runoff generated from intense rainfall. I investigate how the construction of agricultural terraces altered key parameters (water and nutrients) necessary for successful agriculture in this arid region. Building upon past work focused on agricultural terraces in general, I gathered empirical data pertaining to nutrient renewal and water retention from one ancient runoff field. I developed a long-term model of maize growth and soil nutrient dynamics parameterized using nutrient analyses of runoff collected from the sample prehistoric field. This model resulted in an estimate of ideal field use and fallow periods for maintaining long-term soil fertility under different climatic regimes. The results of the model were integrated with estimates of prehistoric population distribution and geographical characterizations of the arable lands to evaluate the places and periods when sufficient arable land was available for the type of cropping and fallowing systems suggested by the model (given the known climatic trends and land use requirements). Results indicate that not only do dry climatic periods put stress on crops due to reduced precipitation but that a reduction in expected runoff events results in a reduction in the amount of nutrient renewal due to fewer runoff events. This reduction lengthens estimated fallow cycles, and probably would have increased the amount of land necessary to maintain sustainable agricultural production. While the overall Perry Mesa area was not limited in terms of arable land, this analysis demonstrates the likely presence of arable land pressures in the immediate vicinity of some communities. Anthropological understandings of agricultural land use combined with ecological tools for investigating nutrient dynamics provides a comprehensive understanding of ancient land use in arid regions.
ContributorsKruse-Peeples, Melissa R (Author) / Spielmann, Katherine A. (Thesis advisor) / Abbott, David R. (Committee member) / Hall, Sharon J. (Committee member) / Kintigh, Keith W. (Committee member) / Arizona State University (Publisher)
Created2013
Description
Microarthropods play important roles in the decomposition process of the detrital food web, where they break down organic matter and return nutrients to the soil. However, only a small percentage of the belowground microarthropod population has been studied or even discovered, leading to a decrease in the knowledge of all of the processes carried out by these organisms and their importance to the soil. This is because microarthropod extraction methods are not 100% effective at collecting specimens. This study aimed to find an ideal quantitative procedure to better record the number of microarthropods existing in the soil and to determine if a seasonal variation exists that effects the success of extraction. Two extraction methods, including dynamic extraction and heptane flotation extraction, were compared across two seasons, a dry season (June) and a wet season (September). Average biomasses and average richness were calculated for four different functional groups, including Prostigmata, Mesostigmata, Cryptostigmata, and Collembola, across the two seasons, and statistical analysis was performed to determine if any differences that existed were statistically significant. Results indicate that the dynamic extraction method was significantly more effective for the collection of microarthropods during the wet season, and the heptane extraction method was significantly more effective during the dry season. In addition, the heptane procedure recovered samples of higher average richness than the dynamic method during both seasons. The heptane procedure works best for extraction during the dry season because it is able to collect organisms that entered into an ametabolic anhydrobiotic state to escape desiccation. These organisms form a protective lipid layer around their exoskeletons to retain water, and the non-polar exoskeletons display a chemical affinity to the heptane fluid, allowing for collection out of the soil and into the heptane layer. Despite these results, no one method is entirely superior to the other, and the most efficacious procedure depends on the researcher's aim of study.
ContributorsAntol, Rachel Lynn (Author) / Sabo, John L. (Thesis director) / Hall, Sharon (Committee member) / Wyant, Karl A. (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-12
Description
This study investigates the vulnerability of subsistence agriculturalists to food shortfalls associated with dry periods. I approach this effort by evaluating prominent and often implicit conceptual models of vulnerability to dry periods used by archaeologists and other scholars investigating past human adaptations in dry climates. The conceptual models I evaluate rely on an assumption of regional-scale resource marginality and emphasize the contribution of demographic conditions (settlement population levels and watershed population density) and environmental conditions (settlement proximity to perennial rivers and annual precipitation levels) to vulnerability to dry periods. I evaluate the models and the spatial scales they might apply by identifying the extent to which these conditions influenced the relationship between dry-period severity and residential abandonment in central Arizona from A.D. 1200 to 1450. I use this long-term relationship as an indicator of potential vulnerability to dry periods. I use tree-ring precipitation and streamflow reconstructions to identify dry periods. Critically examining the relationship between precipitation conditions and residential abandonment potentially sparked by the risk of food shortfalls due to demographic and environmental conditions is a necessary step toward advancing understanding of the influences of changing climate conditions on human behavior. Results of this study support conceptual models that emphasize the contribution of high watershed population density and watershed-scale population-resource imbalances to relatively high vulnerability to dry periods. Models that emphasize the contribution of: (1) settlement population levels, (2) settlement locations distant from perennial rivers, (3) settlement locations in areas of low average annual precipitation; and (4) settlement-scale population-resource imbalances to relatively high vulnerability to dry periods are, however, not supported. Results also suggest that people living in watersheds with the greatest access to and availability of water were the most vulnerable to dry periods, or at least most likely to move when confronted with dry conditions. Thus, commonly held assumptions of differences in vulnerability due to settlement population levels and inherently water poor conditions are not supported. The assumption of regional-scale resource marginality and widespread vulnerability to dry periods in this region of the U.S. Southwest is also not consistently supported throughout the study area.
ContributorsIngram, Scott Eric (Author) / Nelson, Margaret C. (Thesis advisor) / Abbott, David R. (Committee member) / Kintigh, Keith W. (Committee member) / Kinzig, Ann P. (Committee member) / Redman, Charles L. (Committee member) / Arizona State University (Publisher)
Created2010