title: Fire, climate and vegetation linkages in the Bolivian Chiquitano seasonally dry tropical forest.
abstract: South American seasonally dry tropical forests (SDTFs) are critically endangered, with only a small proportion of their original distribution remaining. This paper presents a 12 000 year reconstruction of climate change, fire and vegetation dynamics in the Bolivian Chiquitano SDTF, based upon pollen and charcoal analysis, to examine the resilience of this ecosystem to drought and fire. Our analysis demonstrates a complex relationship between climate, fire and floristic composition over multi-millennial time scales, and reveals that moisture variability is the dominant control upon community turnover in this ecosystem. Maximum drought during the Early Holocene, consistent with regional drought reconstructions, correlates with a period of significant fire activity between 8000 and 7000 cal yr BP which resulted in a decrease in SDTF diversity. As fire activity declined but severe regional droughts persisted through the Middle Holocene, SDTFs, including Anadenanthera and Astronium, became firmly established in the Bolivian lowlands. The trend of decreasing fire activity during the last two millennia promotes the idea among forest ecologists that SDTFs are threatened by fire. Our analysis shows that the Chiquitano seasonally dry biome has been more resilient to Holocene changes in climate and fire regime than previously assumed, but raises questions over whether this resilience will continue in the future under increased temperatures and drought coupled with a higher frequency anthropogenic fire regime.This article is part of the themed issue 'The interaction of fire and mankind'.
authors.affiliation: Natural History Museum of Utah, Department of Geography, University of Utah, UT, USA mitchell.power@geog.utah.edu.
authors.forename: M J
authors.initials: MJ
authors.lastname: Power
authors.affiliation: Department of Geography, Northumbria University Newcastle, Newcastle-Upon-Tyne, UK.
authors.forename: B S
authors.initials: BS
authors.lastname: Whitney
authors.affiliation: Centre for Past Climate Change, Department of Geography and Environmental Science, University of Reading, Reading, UK.
authors.forename: F E
authors.initials: FE
authors.lastname: Mayle
authors.affiliation: Royal Botanic Gardens, Kew, Richmond, UK.
authors.forename: D M
authors.initials: DM
authors.lastname: Neves
authors.affiliation: Faculty of Geosciences, Department of Geography, Utrecht University, NL, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: de Boer
authors.affiliation: 2C Forthbridge Road, London, UK.
authors.forename: K S
authors.initials: KS
authors.lastname: Maclean
mesh_terms: D044822:Biodiversity; D001838:Bolivia; D057231:Climate Change; D055864:Droughts; D005390:Fires; D065928:Forests; D019015:Geologic Sediments; D010163:Paleontology; D013997:Time Factors; D014197:Trees / Q000254:growth & development; D014329:Tropical Climate
keywords: Chiquitano; Holocene; climate; drought; fire; seasonally dry tropical forest