charcoal
; article
; atmosphere
; biomass
; climate change
; drought
; ecosystem fire history
; environmental impact
; fire
; forest
; Little Ice Age
; Medieval Warm Period
; priority journal
; seasonal variation
; temperature
; United States
; vegetation
; Biomass
; Charcoal
; Climate Change
; Droughts
; Fires
; Geologic Sediments
; History, 15th Century
; History, 16th Century
; History, 17th Century
; History, 18th Century
; History, 19th Century
; History, 20th Century
; History, 21st Century
; History, Ancient
; History, Medieval
; Human Activities
; Humans
; Southwestern United States
; Temperature
; Trees
英文摘要:
Understanding the causes and consequences of wildfires in forests of the western United States requires integrated information about fire, climate changes, and human activity on multiple temporal scales. We use sedimentary charcoal accumulation rates to construct long-term variations in fire during the past 3,000 y in the American West and compare this record to independent firehistory data from historical records and fire scars. There has been a slight decline in burning over the past 3,000 y, with the lowest levels attained during the 20th century and during the Little Ice Age (LIA, ca. 1400-1700 CE [Common Era]). Prominent peaks in forest fires occurred during the Medieval Climate Anomaly (ca. 950-1250 CE) and during the 1800s. Analysis of climate reconstructions beginning from 500 CE and population data show that temperature and drought predict changes in biomass burning up to the late 1800s CE. Since the late 1800s , human activities and the ecological effects of recent high fire activity caused a large, abrupt decline in burning similar to the LIA fire decline. Consequently, there is now a forest "fire deficit" in the western United States attributable to the combined effects of human activities, ecological, and climate changes. Large fires in the late 20th and 21st century fires have begun to address the fire deficit, but it is continuing to grow.
Marlon, J.R., Department of Geography, University of Wisconsin, Madison, WI 53706, United States; Bartlein, P.J., Department of Geography, University of Oregon, Eugene, OR 97403, United States; Gavin, D.G., Department of Geography, University of Oregon, Eugene, OR 97403, United States; Long, C.J., Department of Geography and Urban Planning, University of Wisconsin, Oshkosh, WI 54901, United States; Anderson, R.S., School of Earth Sciences and Environmental Sustainability, Northern Arizona University, Flagstaff, AZ 86011, United States; Briles, C.E., School of Geography and Environmental Science, Monash University, VIC 3800, Australia; Brown, K.J., Canadian Forest Service, Victoria, BC V8Z 1M5, Canada; Colombaroli, D., Oeschger Centre for Climate Change Research, Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland; Hallett, D.J., Biogeoscience Institute, University of Calgary, AB T2N 1N4, Canada; Power, M.J., Natural History Museum of Utah, Department of Geography, University of Utah, Salt Lake City, UT 84112, United States; Scharf, E.A., Department of Anthropology, University of North Dakota, Grand Forks, ND 58202, United States; Walsh, M.K., Department of Geography, Central Washington University, Ellensburg, WA 98926, United States
Recommended Citation:
Marlon J.R.,Bartlein P.J.,Gavin D.G.,et al. Long-term perspective on wildfires in the western USA[J]. Proceedings of the National Academy of Sciences of the United States of America,2012-01-01,109(9)