Abstract
For over a decade, the Hopi Tribe and Navajo Nation of northeastern Arizona have suffered the effects of persistent drought conditions. Severe dry spells have critically impacted natural ecosystems, water resources, and regional livelihoods including dryland farming and ranching. Drought planning and resource management efforts in the region are based largely on the instrumental climate record, which contains a limited number of severe, sustained droughts. In this study, a new network of moisture-sensitive tree-ring chronologies provides the basis for evaluating the longer-term temporal variability of precipitation in the Four Corners region. By analyzing the earlywood and latewood components within each annual tree ring, we are able to generate separate, centuries-long reconstructions of both cool- (October-April) and warm-season (July-August) precipitation. These proxy records offer new insights into seasonal drought characteristics and indicate that the instrumental record fails to adequately represent precipitation variability over the past 400 years. Through the use of two different analysis techniques, we identify multiyear and decadal-scale drought events more severe than any in the modern era. Furthermore, the reconstructions suggest that many of the historically significant droughts of the past (e. g., 17th century Puebloan drought) were not merely winter phenomena, but persisted through the summer season as well. By comparing these proxy records with historical documents, we are able to independently validate the reconstructions and better understand the socioeconomic and environmental significance of past climate anomalies on the tribal lands of northeastern Arizona.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 457-468 |
| Number of pages | 12 |
| Journal | Climatic Change |
| Volume | 118 |
| Issue number | 2 |
| DOIs | |
| State | Published - May 2013 |
Bibliographical note
Funding Information:Acknowledgements This work was supported by the National Oceanic and Atmospheric Administration’s Climate Program Office through grant NA07OAR4310382 with the Climate Assessment for the Southwest program at the University of Arizona, and by National Science Foundation award number 0823090. We are grateful to personnel of the U.S. National Park Service and to the Navajo Nation for facilitating tree-ring sampling on federal and tribal lands. Thanks to Tom Sheridan and Dale Brenneman for inspiring the use of historical documents, and to Daniel Ferguson and Alison Meadow for facilitating Hopi stakeholder collaboration. Many thanks to Paul Sheppard, Michael Crimmins and two anonymous reviewers for providing constructive feedback that improved this manuscript.