title: Multiscale perspectives of fire, climate and humans in western North America and the Jemez Mountains, USA.
abstract: Interannual climate variations have been important drivers of wildfire occurrence in ponderosa pine forests across western North America for at least 400 years, but at finer scales of mountain ranges and landscapes human land uses sometimes over-rode climate influences. We reconstruct and analyse effects of high human population densities in forests of the Jemez Mountains, New Mexico from ca 1300 CE to Present. Prior to the 1680 Pueblo Revolt, human land uses reduced the occurrence of widespread fires while simultaneously adding more ignitions resulting in many small-extent fires. During the 18th and 19th centuries, wet/dry oscillations and their effects on fuels dynamics controlled widespread fire occurrence. In the late 19th century, intensive livestock grazing disrupted fuels continuity and fire spread and then active fire suppression maintained the absence of widespread surface fires during most of the 20th century. The abundance and continuity of fuels is the most important controlling variable in fire regimes of these semi-arid forests. Reduction of widespread fires owing to reduction of fuel continuity emerges as a hallmark of extensive human impacts on past forests and fire regimes.This article is part of the themed issue 'The interaction of fire and mankind'.
authors.affiliation: Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA tswetnam@ltrr.arizona.edu.
authors.forename: Thomas W
authors.identifier: 0000-0001-7268-2184
authors.initials: TW
authors.lastname: Swetnam
authors.affiliation: Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Farella
authors.affiliation: Department of Anthropology, Southern Methodist University, Dallas, TX, USA.
authors.forename: Christopher I
authors.identifier: 0000-0001-8754-7655
authors.initials: CI
authors.lastname: Roos
authors.affiliation: Department of Anthropology, Harvard University, Cambridge, MA, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Liebmann
authors.affiliation: Laboratory of Tree-Ring Research, University of Arizona, Tucson, AZ 85721, USA School of Natural Resources and Environment, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Donald A
authors.initials: DA
authors.lastname: Falk
authors.affiliation: US Geological Survey, Jemez Mountains Field Station, Los Alamos, NM, USA.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Allen
mesh_terms: D002980:Climate; D057231:Climate Change / Q000266:history*; D005390:Fires / Q000266:history*; D065928:Forests; D049668:History, 15th Century; D049669:History, 16th Century; D049670:History, 17th Century; D049671:History, 18th Century; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D049691:History, Medieval; D006801:Humans; D009516:New Mexico; D009656:North America; D041604:Pinus ponderosa / Q000254:growth & development*
keywords: Pueblo people; archaeology; dendrochronology; fire history; land uses; ponderosa pine forest