StJacquesCummingSauchynEtAl2015

Référence

St-Jacques, J.-M., Cumming, B.F., Sauchyn, D.J. and Smol, J.P. (2015) The bias and signal attenuation present in conventional pollen-based climate reconstructions as assessed by early climate data from Minnesota, USA. PLoS ONE, 10(1). (Scopus )

Résumé

The inference of past temperatures from a sedimentary pollen record depends upon the stationarity of the pollen-climate relationship. However, humans have altered vegetation independent of changes to climate, and consequently modern pollen deposition is a product of landscape disturbance and climate, which is different from the dominance of climate-derived processes in the past. This problem could cause serious signal distortion in pollen-based reconstructions. In the north-central United States, direct human impacts have strongly altered the modern vegetation and hence the pollen rain since Euro-American settlement in the mid-19th century. Using instrumental temperature data from the early 1800s from Fort Snelling (Minnesota), we assessed the signal distortion and bias introduced by using the conventional method of inferring temperature from pollen assemblages in comparison to a calibration set from pre-settlement pollen assemblages and the earliest instrumental climate data. The early post-settlement calibration set provides more accurate reconstructions of the 19th century instrumental record, with less bias, than the modern set does. When both modern and pre-industrial calibration sets are used to reconstruct past temperatures since AD 1116 from pollen counts from a varve-dated record from Lake Mina, Minnesota, the conventional inference method produces significant low-frequency (centennial-scale) signal attenuation and positive bias of 0.8-1.7°C, resulting in an overestimation of Little Ice Age temperature and likely an underestimation of the extent and rate of anthropogenic warming in this region. However, high-frequency (annual-scale) signal attenuation exists with both methods. Hence, we conclude that any past pollen spectra from before Euro-American settlement in this region should be interpreted using a pre-Euro-American settlement pollen set, paired to the earliest instrumental climate records. It remains to be explored how widespread this problem is when conventional pollen-based inference methods are used, and consequently how seriously regional manifestations of global warming have been underestimated with traditional pollen-based techniques. © 2015 St. Jacques et al.

Format EndNote

Vous pouvez importer cette référence dans EndNote.

Format BibTeX-CSV

Vous pouvez importer cette référence en format BibTeX-CSV.

Format BibTeX

Vous pouvez copier l'entrée BibTeX de cette référence ci-bas, ou l'importer directement dans un logiciel tel que JabRef .

@ARTICLE { StJacquesCummingSauchynEtAl2015,
    AUTHOR = { St-Jacques, J.-M. and Cumming, B.F. and Sauchyn, D.J. and Smol, J.P. },
    TITLE = { The bias and signal attenuation present in conventional pollen-based climate reconstructions as assessed by early climate data from Minnesota, USA },
    JOURNAL = { PLoS ONE },
    YEAR = { 2015 },
    VOLUME = { 10 },
    NUMBER = { 1 },
    NOTE = { cited By 6 },
    ABSTRACT = { The inference of past temperatures from a sedimentary pollen record depends upon the stationarity of the pollen-climate relationship. However, humans have altered vegetation independent of changes to climate, and consequently modern pollen deposition is a product of landscape disturbance and climate, which is different from the dominance of climate-derived processes in the past. This problem could cause serious signal distortion in pollen-based reconstructions. In the north-central United States, direct human impacts have strongly altered the modern vegetation and hence the pollen rain since Euro-American settlement in the mid-19th century. Using instrumental temperature data from the early 1800s from Fort Snelling (Minnesota), we assessed the signal distortion and bias introduced by using the conventional method of inferring temperature from pollen assemblages in comparison to a calibration set from pre-settlement pollen assemblages and the earliest instrumental climate data. The early post-settlement calibration set provides more accurate reconstructions of the 19th century instrumental record, with less bias, than the modern set does. When both modern and pre-industrial calibration sets are used to reconstruct past temperatures since AD 1116 from pollen counts from a varve-dated record from Lake Mina, Minnesota, the conventional inference method produces significant low-frequency (centennial-scale) signal attenuation and positive bias of 0.8-1.7°C, resulting in an overestimation of Little Ice Age temperature and likely an underestimation of the extent and rate of anthropogenic warming in this region. However, high-frequency (annual-scale) signal attenuation exists with both methods. Hence, we conclude that any past pollen spectra from before Euro-American settlement in this region should be interpreted using a pre-Euro-American settlement pollen set, paired to the earliest instrumental climate records. It remains to be explored how widespread this problem is when conventional pollen-based inference methods are used, and consequently how seriously regional manifestations of global warming have been underestimated with traditional pollen-based techniques. © 2015 St. Jacques et al. },
    AFFILIATION = { Prairie Adaptation Research Collaborative, University of Regina, Regina, SK, Canada; Paleoecological Environmental Assessment and Research Lab, Department of Biology, Queen's University, Kingston, ON, Canada },
    ART_NUMBER = { e0113806 },
    DOCUMENT_TYPE = { Article },
    DOI = { 10.1371/journal.pone.0113806 },
    SOURCE = { Scopus },
    URL = { https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928975516&doi=10.1371%2fjournal.pone.0113806&partnerID=40&md5=c47229733a211c3d830c8d033dbcf7e7 },
}

********************************************************** ***************** Facebook Twitter *********************** **********************************************************

Abonnez-vous à
l'Infolettre du CEF!

********************************************************** ************* Colloque **************************** **********************************************************

1er au 3 mai 2019
UQAC

********************************************************** ************* R à Québec 2019**************************** **********************************************************

********************************************************** ********************* Traits **************************** **********************************************************

********************************************************** ************* Écoles d'été et formation **************************** **********************************************************

Écoles d'été et formations

Cours intensif sur l'analyse des pistes 
6-10 mai 2019, Université de Sherbrooke
Cours intensif : Taxonomie et méthodes d’échantillonnage en tourbières 
6-17 mai 2019, Université Laval
Dendrochronological Fieldweek 2019 
16-21 mai 2019, Station FERLD
Traits Fonctionnels des Organismes - École thématique internationale
19-24 mai 2019, Porquerolles, France
Cours aux cycles supérieurs: Terrain avancé en géographie 
10-15 juin 2019, FERLD, Abitibi-Témiscamingue
École d'été « Drones et télédétection environnementale » 
13-14 juin 2019, Sherbrooke
Ecole d'été en Biologie et Ecologie intégratives 
6-12 juillet 2019, Pyrénées françaises
École d'été en modélisation de la biodiversité 
19-23 août 2019, Orford
Cours aux cycles supérieurs: Aménagement des écosystèmes forestiers 
19-30 août 2019, Station FERLD

********************************************************** ***************** Pub - Carapace ****************** **********************************************************

********************************************************** ***************** Pub - Budworm ****************** **********************************************************

********************************************************** ***************** Pub - Colibri **************************** **********************************************************

********************************************************** ********** Pub 6 - Au coeur de l'arbre *********** **********************************************************

...Une exposition
virtuelle sur l'arbre!

********************************************************** ***************** Boîte à trucs *************** **********************************************************

CEF-Référence
La référence vedette !

Jérémie Alluard (2016) Les statistiques au moments de la rédaction 

  • Ce document a pour but de guider les étudiants à intégrer de manière appropriée une analyse statistique dans leur rapport de recherche.

Voir les autres...