Research on the Colorado Plateau

Bryce Canyon National Park, Utah. Photo © 1999 Ray Wheeler.

The landscape of the Colorado Plateau, with its rich natural and cultural history, has been a source of scientific inquiry for well over one hundred years. Answers to questions concerning the region's geology, flora, fauna, and people have been sought through numerous research projects. How did the many spectacular canyons, mountains, and high tablelands of the Plateau form? How long have people lived in different areas on the Plateau and how did they go about their lives in this stark, semi-arid landscape? What impacts have humans recently had on the region's plant and animal life?

Click on a topic of interest from those listed below to see selected summaries of current scientific research on the Colorado Plateau.

Research Summaries:

The Spread of Maize to the Colorado Plateau. Migration theories have become an essential part of our understanding of Anasazi origins. The convergence of archaeological research on the Colorado Plateau and elsewhere in the Greater Southwest demonstrates that the traditional view of Anasazi development as essentially independent of Mexico is clearly no longer viable. A synopsis of current research by R.G. Matson.

The Social and Ecological Consequences of Early Cattle Ranching in the Little Colorado River Basin. Examines the early development of cattle ranching in the Little Colorado River Basin, the various factors which contributed to overgrazing in the region, and the pervasive effects that early commercial cattle ranching had on the local environment. Adapted from a published journal article by Dr.William S. Abruzzi.

Ecology and Mormon colonization in the Little Colorado River Basin, Arizona. The successful agricultural settlement by Mormon pioneers of the arid and climatically variable Colorado Plateau was eventually achieved by a system of tithing redistribution. An original land-use essay for CP-LUHNA by Dr. William S. Abruzzi.

The Changing Physical Environment of the Hopi Indians of Arizona. This abstract from a classic 1942 paper by John T. Hack describes the geomorphology of the Hopi country,  their dry-farming methods, the effects of a recent period of arroyo-cutting, the use of sand dunes as a means of deciphering climatic change, and evidence for the effect of the changing physical environment on ancient farming.

Native Americans and the Environment. A comprehensive survey of twentieth century environmental issues facing Native Americans on the Colorado Plateau and throughout the Southwest, including discussions of agriculture, logging, mining, grazing, water rights, and tourism. Adapted from a published journal article by David Rich Lewis.

Packrat Midden Research in the Grand Canyon. On the Colorado Plateau the ice age (Pleistocene) vegetation of the Grand Canyon has been determined through the analysis of plant fossils preserved in caves and fossil packrat middens.  Large changes occurred as the most recent ice age ended and the Holocene era began. Adapted by Kenneth L. Cole from his journal article.

Paleobotany and Paleoclimate of the Southern Colorado Plateau. The biota of the Colorado Plateau during the middle (50,000-27,500 B.P.) and late (27,500-14,000 B.P.) Wisconsin time periods was dramatically different from that seen today. Differences were primarily a result of major climate changes associated with the last major glacial period. This site examines the environment of the southern plateau during this time. Adapted by R. Scott Anderson from his journal article.

Late Holocene Environmental Change in the Upper Gunnison Basin, Colorado. The Upper Gunnison Basin is a high elevation (3100 to 3600 m) region on the edge of the Colorado Plateau in southwestern Colorado. Its unusual ecological characteristics include an absence of plant and animal taxa that should occur here. Fossil and archaeological evidence indicates that many of the missing species existed in the Basin during the late Pleistocene to middle Holocene. Authored by Steve Emslie.

Fire-Southern Oscillation Relations in the Southwestern United States. A close linkage between fire and climate could diminish the importance of local processes in the long-term dynamics of fire-prone ecosystems. The structure and diversity of communities regulated by fire may have nonequilibrial properties associated with variations in global climate. Successful prediction of vegetation change hinges on a better understanding of climatically driven disturbance regimes and the relative contributions of regional versus local processes to community dynamics. Adapted from a journal article by Thomas W. Swetnam and Julio L. Betancourt.

Changed Southwestern Forests: Resource effects and management remedies. Over 150 years of occupancy by northern Europeans has markedly changed vegetative conditions in the Southwest. Less fire due to grazing and fire suppression triggered a shift to forests with very high tree densities, which in turn contributed to destructive forest fires. Options to deal with these changes include prescribed fire, thinning and timber harvest to mimic natural disturbances and conditions. However, there are barriers to implementing these activities on a scale large enough to have a significant benefit. Adapted from a published journal article by Marlin Johnson.

Contribution of Roads to Forest Fragmentation. Increasingly, previously extensive, continuous tracts of forest are being reduced to widely dispersed patches of remnant forest vegetation by logging and road-building, but few measures of the effects of roads on forest fragmentation are available. This study looks at the importance of roads in delineating and quantifying landscape structure, including the proportion of the landscape occupied by edge habitat, and compares the effects of roads and clearcut logging on forest fragmentation. Adapted from a published journal article by Rebecca A. Reed et al.

Where have all the grasslands gone? Numerous ecological studies across the Southwest have documented the decline in herbaceous vegetation (grasses and non-woody flowering plants) while forests thicken and brush invades. Documenting the changes in the Jemez Mountains of northern New Mexico, ecologist Craig Allen considers the evidence that these patterns are tied to changes in land use history, primarily livestock grazing and fire suppression.

Restoring Ecosystem Health in Ponderosa Pine Forests of the Southwest. Restoration of ecosystem structure and reintroduction of fire are necessary for restoring rates of decomposition, nutrient cycling, and net primary production to natural, presettlement levels. The rates of these processes will be higher in an ecosystem that approximates the natural structure and disturbance regime. Adapted from a published journal article by W. Wallace Covington et al.