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The potential to strengthen temperature reconstructions in ecoregions with limited tree line using a multispecies approach

Published online by Cambridge University Press:  25 June 2019

M. Ross Alexander
Affiliation:
Harvard Forest, Petersham, Massachusetts 01366, USA Midwest Dendro LLC, Naperville, Illinois 60565, USA
Jessie K. Pearl
Affiliation:
Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona 85721, USA Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA
Daniel A. Bishop
Affiliation:
Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA Department of Earth and Environmental Sciences, Columbia University, New York, New York 10025, USA
Edward R. Cook
Affiliation:
Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA
Kevin J. Anchukaitis
Affiliation:
Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona 85721, USA Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964, USA School of Geography and Development, University of Arizona, Tucson, Arizona 85721, USA
Neil Pederson
Affiliation:
Harvard Forest, Petersham, Massachusetts 01366, USA
Corresponding
E-mail address:

Abstract

Tree-ring reconstructions of temperature often target trees at altitudinal or latitudinal tree line where annual growth is broadly expected to be limited by and respond to temperature variability. Based on this principal, regions with sparse tree line would seem to be restricted in their potential to reconstruct past temperatures. In the northeastern United States, there are only two published temperature reconstructions. Previous work in the region reconstructing moisture availability, however, has shown that using a greater diversity of species can improve reconstruction model skill. Here, we use a network of 228 tree-ring records composed of 29 species to test the hypothesis that an increase in species diversity among the pool of predictors improves reconstructions of past temperatures. Chamaecyparis thyoides alone explained 31% of the variability in observed cool-season minimum temperatures, but a multispecies model increased the explained variance to 44%. Liriodendron tulipifera, a species not previously used for temperature reconstructions, explained a similar amount of variance as Chamaecyparis thyoides (12.9% and 20.8%, respectively). Increasing the species diversity of tree proxies has the potential for improving reconstruction of paleotemperatures in regions lacking latitudinal or elevational tree lines provided that long-lived hardwood records can be located.

Type
Research Article
Copyright
Copyright © University of Washington. Published by Cambridge University Press, 2019 

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