Interaction of prehistoric climate, ecology, and cultures: An example from the Dolores River region of southwest Colorado
- Washington State Univ., Richland, WA (United States)
Greenhouse theory suggests global climatic variation will exceed the historical records as the lower atmosphere warms in response to a rise in the concentrations of carbon dioxide, methane, and other gases. The sharp contrast between the large predicted future change and the small climatic changes recorded during the last century indicates that this later period may offer an insufficient basis for appreciating the projected future climate and vegetation changes. Examination of larger-than-historic climatic changes that have occurred in the past (such as those in the Dolores River region) provide a context for evaluating possible future changes and their implications for environmental restoration and land use planning. The zenith of Anasazi Pueblo Indian occupation in the northern Colorado Plateau region coincides with the Little Climatic Optimum (AD 900-1300), and its demise coincides with the Little Ice Age (AD 1250-1300 to AD 1850-1890). Pollen and tree-ring derived indexes of winter and summerprecipitation and growing season length were developed for the La Plata Mountains region of southwestern Colorado. The results show during the height of the Little Climatic Optimum (AD 1000-1100) the region was characterized by a relatively long growing season and by a potential dry farming zone or elevational belt twice as wide as present and supporting Anasazi upland dry farming down to at least 1600 m, an elevation impossible to dry farm today. Between AD 1100 and 1300 the potential dry-farm belt narrowed and finally disappeared with the onset of a period of markedly colder and drier conditions than current. When the Little Ice Age ended in the mid-1800s, another group of farmers (modern Anglos) were able to dry farm. If previous conditions were to return in the near future due to the effects of greenhouse warming, such conditions would be very beneficial to dry farmers.
- Research Organization:
- Rust Geotech, Inc., Grand Junction, CO (United States)
- OSTI ID:
- 198218
- Report Number(s):
- CONF-9409325-; ON: DE96003275; TRN: 96:001174-0009
- Resource Relation:
- Conference: Workshop on climate change in the four corners and adjacent regions: implications for environmental restoration and land-use planning, Grand Junction, CO (United States), 12-14 Sep 1994; Other Information: PBD: Sep 1995; Related Information: Is Part Of Climate change in the four corners and adjacent regions: Implications for environmental restoration and land-use planning; Waugh, W.J. [ed.]; PB: 199 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
Regional hydrology of the Dolores River Basin, eastern Paradox Basin, Colorado and Utah
Early Holocene cold snaps and their expression in the moraine record of the eastern European Alps