Overview Getting Here Accomodations Registration Explore the Area

Overview | Program | Session 1 | Session 2 | Session 3 | Session 4 | Poster Abstracts

Session 2

Historical Ecology in the Southwest: Long-term Adaptation and Extreme Events

Organizer: Ronald Towner, University of Arizona Laboratory of Tree-Ring Research

Historical ecology is the study of past human/environment interaction over long time scales. In the Southwest, we have excellent paleoclimatic and cultural data that can be used to address significant issues regarding human/environment interaction. Both ecological (sediments, floral, faunal) and cultural (artifactal, architectural, land-use) data illuminate long-term, gradual aspects of human ecology at multi-generational time scales. An important component of both cultural and ecological change, however, is extreme events—climatic, environmental, socioeconomic, and demographic. These rapid changes may be "tipping points" if they result in new cultural trajectories. Alternatively, these rare events, though significant, may not be of of sufficient duration to leave an archaeological trace. if not, may simply be rare events of little significance. The temporally and spatially broad papers in this session delineate long-term human/environment interactions, but also examine the role extreme events have played in changing those interactions at specific times and places.

********* Return to top ********

Session Abstracts

Sunset Crater and Little Springs Volcano Eruptions:
Hazards Management in the 11th Century A.D. Prehistoric Southwest

Mark D. Elson, Desert Archaeology, Inc., Tucson
Michael H. Ort, Northern Arizona University, Flagstaff
Kirk C. Anderson, Museum of Northern Arizona, Flagstaff

Volcano eruptions are some of the most powerful natural phenomena, with impacts extending far beyond the zone of physical destruction. As ethnographic and archaeological data attest, volcano eruptions can act upon social groups as catalysts, as processes, and sometimes as terminating factors.

Within the span of at most 100 years, two volcanoes – Sunset Crater and Little Springs -- situated only 200 km apart, erupted in the prehistoric northern Southwest. Both areas were inhabited by small groups of similar pueblo-building dry-land farmers, living in the transitional pinyon-ponderosa pine forests of northern Arizona.

Sunset Crater has long been posited to have played a significant role in post-eruptive social, demographic, and technological change, including large-scale migration. The volcano refugees who left the Sunset Crater area and settled at Wupatki soon constructed the largest and most complex sites in the region. Recent research shows that the Little Springs eruption also played a significant role in migration and settlement restructuring, but instead of abandonment, the lava flows became a defensive refuge. This paper discusses the differences in adaptive behavior between local populations in the Sunset Crater and Little Springs areas. Major catastrophic events permanently alter natural and cultural landscapes, requiring significant behavioral change for survival.

********* Return to top ********

The Changing Landscape of Protohistoric New Mexico:
Settlement, Subsistence, Ethnicity, and Fauna

Emily Lena Jones, University of New Mexico, Albuquerque

The 17th century brought a large number of changes to New Mexico, many of which could be expected to have left a signature on New Mexican landscapes. Old World domesticates such as sheep and cattle became well-established members of New Mexico's faunal community; indigenous populations may (or may not) have undergone radical demographic shrinking due to new diseases; settlement patterns and strategies shifted for many indigenous groups; and a number of new ethnic groups, including the Spanish, moved into the area with their own distinct subsistence and settlement practices. Some or all these factors may have impacted New Mexican landscapes – but which ones, and how? This paper uses faunal data from raptor-generated microfaunal assemblages to assess human impacts –both direct and indirect – on New Mexican landscapes in the 17th century.

********* Return to top ********

Bigger Isn't Always Better:
The Role of Extreme Events at an Early Agricultural Period Village

Fred Nials, Desert Archaeology, Inc, Tucson

The site of Las Capas is situated on the Santa Cruz River floodplain in one of the most favorable locations in the Tucson Basin for availability of irrigation water and irrigable land. Rapid aggradation of the floodplan (as much as 5m during occupation) was a factor in preservation of more than 750 individual border-basin fields and 180 or more canals and ditches of various sizes at the site. Despite frequent flooding, formation of arroyos, and loss of farmland through other processes, fields and canal systems were re-constructed at least 7 times. The site appears to have been abandoned ca. 800 BC. The role of high-frequency and extreme event-related environmental factors in site abandonment is examined.

********* Return to top ********

Terminal Pleistocene Paleoindian Ecology and Demography:
A View from the Southwestern United States
Mary M. Prasciunas, Westland Resources, Tucson
Vance T. Holliday, University of Arizona, Tucson
Jesse A. M Ballenger

Terminal Pleistocene Paleoindian foragers of North America faced unique ecological circumstances that would not be seen again during the course of human history on the continent. The terminal Pleistocene saw not only the entry of colonizing human populations into an otherwise unoccupied landscape, but also the onset of the Younger Dryas Chronozone (YDC). The YDC was marked by changing climatic conditions in some parts of the continent and may have posed adaptive challenges for Paleoindian populations and their animal prey, ultimately causing significant demographic and cultural change. However, the link between human behavior and environmental change is obscured by the variable character, magnitude, and tempo of terminal Pleistocene environmental changes across the continent. In many regions the paleoenvironmental record is also unclear owing to ambiguities in proxy environmental indicators. Additionally, links between cultural, demographic, and environmental change are further hampered by inadequate temporal resolution and an ambiguous archaeological record. With the complexity of these issues in mind, this paper examines the adaptive response of Paleoindians to the special set of ecological circumstances at play during the terminal Pleistocene, as illustrated by the archaeological record of the southwestern United States.

********* Return to top ********

Fire, Climate, and Society in Ancient Southwestern Forests and Woodlands
Christopher I. Roos, Southern Methodist University, Dallas

Wildland fires rarely feature in the narratives of Southwestern prehistory but they almost certainly affected ancient Southwesterners. Understanding how past societies adapted to changing fire activity or how human behaviors impacted the resilience of fire-prone ecosystems to climate change is key for fostering sustainability. In light of recent scholarship on the fire-climate-society nexus in Southwestern forests and woodlands, I suggest rephrasing our research questions to evaluate the role of human activities in ecosystem feedbacks and tipping points. Although this approach is decidedly non-anthropocentric, it creates a necessary place for archaeology in the emerging interdisciplinary field of applied historical ecology.

********* Return to top ********

Historical Ecology and Tree-Rings in northern New Mexico
Ronald H. Towner, Laboratory of Tree-Ring Research, University of Arizona, Tucson
Matthew W. Salzer, University of Arizona, Tucson

Since the late 1970s, tree-ring reconstructions of precipitation have contributed significantly to our understanding of human ecology in the Southwest. Most reconstructions have examined long-term precipitation variability and, by necessity, the effects of drought on past human populations. This paper uses multiple, independent tree-ring chronologies from northern New Mexico to (a) illuminate aspects of long-term precipitation variability, (b) delineate specific extreme years and events, and (c) identify "hinge points" when such extremes may have shifted the long-term trends, We use these independent data sets to examine precipitation variability spatially and relate it to cultural phenomena, with particular emphasis on the protohistoric and early historic periods.

********* Return to top ********