Spatiotemporal Variability in the Climate Growth Response of High Elevation Bristlecone Pine in the White Mountains of California
Final Published version
AffiliationUniv Arizona, Tree Ring Res Lab
Univ Arizona, Sch Geog & Dev
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationBunn, A. G., Salzer, M. W., Anchukaitis, K. J., Bruening, J. M., & Hughes, M. K. ( 2018). Spatiotemporal variability in the climate growth response of high elevation bristlecone pine in the White Mountains of California. Geophysical Research Letters, 45, 13,312– 13,321. https://doi.org/10.1029/2018GL080981
JournalGEOPHYSICAL RESEARCH LETTERS
Rights© 2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractTree-ring chronologies from bristlecone pine (Pinus longaeva) are a unique proxy used to understand climate variability over the middle to late Holocene. The annual rings from trees growing toward the species' lower elevational range are sensitive to precipitation variability. Interpretation of the ring-width signal at the upper forest border has been more difficult. We evaluate differences in climate induced by topography (topoclimate) to better understand the dual signals of temperature and moisture. We unmix signals from trees growing at and near the upper forest border based on the seasonal mean temperature (SMT) experienced by each tree. We find that trees growing in exposures with SMT <7.5 degrees C are limited by temperature, while trees with SMT > 7.5 degrees C are limited by moisture. We demonstrate this independently through analysis of growth in the frequency and time domains and using a process model of xylogenesis. Furthermore, we identify increasing moisture sensitivity in trees formerly limited by temperature. Plain Language Summary Tree rings from ancient bristlecone pines are a remarkable proxy for climate, extending back thousands of years. However, interpreting this record has been difficult because some trees record information on both past temperature and past soil moisture variability. These dual growth responses can be hard to separate. We show that differentiating trees based on relatively small differences in location, determined by their topographical setting and therefore the "local climate" individual trees have experienced, can help unravel these mixed signals and provide a better basis for understanding growth and past climate. We find that even near the alpine treeline, only trees in the coldest settings show ring-width growth that is sensitive to temperature. However, we also show that recent warming might have weakened this temperature response by causing bristlecone pine to switch to a moisture-sensitive growth response.
Note6 month embargo; published online: 29 November 2018
VersionFinal published version
SponsorsNational Science Foundation's P2C2 program [ATM-1203749]; Malcolm H. Wiener Foundation
Except where otherwise noted, this item's license is described as © 2018. The Authors. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs License.