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Accueil du site → Master → Etats Unis → 2010 → A LATE HOLOCENE HISTORY OF VEGETATION, FIRE, AND CLIMATE FROM A DESERT WETLAND IN SOUTHWEST NORTH AMERICA

University of Utah (2010)

A LATE HOLOCENE HISTORY OF VEGETATION, FIRE, AND CLIMATE FROM A DESERT WETLAND IN SOUTHWEST NORTH AMERICA

Blissett Shawn D.

Titre : A LATE HOLOCENE HISTORY OF VEGETATION, FIRE, AND CLIMATE FROM A DESERT WETLAND IN SOUTHWEST NORTH AMERICA

Auteur : Blissett Shawn D.

Université de soutenance : University of Utah

Grade : Master of Science 2010

Résumé
This study presents a late Holocene fi re, vegetation, and climate history from  2500 to 740 cal yr BP of Ciénega de San Be rnardino, a desert wetland in southwestern North America. A high resolution multiple sedimentary proxy approach was used in conjunction with solid chronologi cal control to determine the environmental history of Ciénega de San Bernardino, a wetland on th e international border between extreme southeastern Arizona, United States, and nor theastern Sonora, Mexico. The combined sedimentary proxies of macros copic charcoal particles, pollen, loss-on-ignition, magnetic susceptibility, grain size an alysis, and sound AMS radiocarbon dating was used to reconstruct the pre-European environmental history of this wetland. Results reflect a relatively stable wetland ecosystem within a fluctuating but con tinuously depositional environment for the approximately 1800 year record. Sediment proxies show this ecosystem to be sensitive enough to record changes in surface hydr ology, vegetation, and fire regime. Of special intere st is a rapid, large, and sustai ned change in the fire regime of this site which temporally coincides w ith the Medieval Climat e Anomaly. This study shows that these perennially wet ecosystems ar e effective and important archives of past environmental conditions and change. The information presented here can be used to inform land managers of the pre-European settlement environmental conditions in southwestern lowland deserts, and the likely response of these systems to future climate change.

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Page publiée le 16 mai 2011, mise à jour le 22 février 2019