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Show THE UNIVERSITY OF UTAH RESEARCH POSTERS ON THE HILL 2013 FIRE AND SEDIMENT HISTORY OF A DESERT WETLAND IN NEW MEXICO Vanessa Chavez (Andrea Brunelle) Department of Geography (Environmental) University of Utah f A -14,500 YEAR FIRE A N D SEDIMENT HISTORY OF A DESERT WETLAND IN N E W MEXICO Vanessa Chavez & Andrea Brunelle Department of Geography u T H E U N I V E R S I T Y OF U T AH Results Boca Negra Wash, N M Methods •Magnetic Susceptibility (MS) i with which sediment takes a charge •LOW M S = More organic-rich sediments •HIGH M S = erosion into the basin •Charcoal analysis is used to create a fire history •Higher quantities of charcoal indicate a fire event •Stratigraphy •A lithostratigraphic column was created using corrected depths from (Holliday et al. 2006) •Age Control •A model was created using available radiocarbon dates from depths below 43 i from (Holliday etal 2006) in R i from the surface Future Work Acknowledgements ik Vance HolDday EPA SCERP ( Sediment samples from the archeological site at Boca Negra Wash N e w Mexico are being examined in order to construct a prehistoric fire history for this area. This record is reconstructed using magnetic susceptibility, loss on ignition, and charcoal analysis. The first will serve as a proxy for productivity of the area (when M S is low) or an indicator of high surface erosion (when M S is high). Loss on ignition will also provide information on the productivity of the area by measuring percent water, organic, and carbonate content of the sediment. Variation in fire occurrence for the area will be determined through charcoal analysis. Of particular interest is the fire history, which will provide critical information on the climate during the period of time when this site was a wetland. Understanding past disturbance processes provides a baseline for protecting and restoring desert wetlands through the application of appropriate land management. •Insignificant fire activity until -6900 years BP • Similar onset of fire as other desert wetland cites in the southwest (Brunelle et al. 2010) •Consistent with the onset of E N S O (Moy et al 2002; Conroy et al. 2008 and others) •Sediment •High M S readings are consistent with sandy layers •Unconformity identified at -43 c m (-2000 cal yr BP) •General Conclusions •Fire in deserts dependent on winter precipitation •ENSO a strong factor in desert fire regimes even out of the core area of influence •Future management in these areas must consider how E N S O will respond to warming climate 'Analysis •Magnetic Susceptibility •Charcoal Analysis •Loss on Ignition •Pollen Analysis •Radiocarbon Dating •ENSO •Further investigation concerning the relationship between desert wetlands. E N S O and climate change 7 |