Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America
This is the accepted manuscript of an article published by Wiley. We present a new 23-site network of white spruce ring-width chronologies near boreal treeline in Old Crow Flats, Yukon Territory, Canada. Most chronologies span the last 300 years, and some reach the mid-16th century. The chronologies...
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ftunivtoronto:oai:localhost:1807/73511 2023-05-15T16:55:53+02:00 Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America Porter, Trevor J. Pisaric, Michael F.J. 2011-09-06 http://hdl.handle.net/1807/73511 https://doi.org/10.1111/j.1365-2486.2011.02507.x en_ca eng Wiley Porter, T. J. and Pisaric, M. F. J. (2011). Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America. Glob. Change Biol., 17: 3418–3430. doi:10.1111/j.1365-2486.2011.02507.x http://hdl.handle.net/1807/73511 http://dx.doi.org/10.1111/j.1365-2486.2011.02507.x dendroclimatology ring-width divergence boreal treeline white spruce Old Crow Flats Yukon Territory Article Post-Print 2011 ftunivtoronto https://doi.org/10.1111/j.1365-2486.2011.02507.x 2020-06-17T12:00:29Z This is the accepted manuscript of an article published by Wiley. We present a new 23-site network of white spruce ring-width chronologies near boreal treeline in Old Crow Flats, Yukon Territory, Canada. Most chronologies span the last 300 years, and some reach the mid-16th century. The chronologies exhibit coherent growth patterns before the 1930s. However, since the 1930s they diverge in trend and exhibit one of two contrasting, but well-replicated patterns we call Group 1 and Group 2. Over the instrumental period (1930-2007) Group 1 sites were inversely correlated with previous-year July temperatures while Group 2 sites were positively correlated with growth-year June temperatures. At the broader northwestern North America (NWNA) scale, we find that the Group 1 and Group 2 patterns are common to a number of white spruce chronologies, which we call NWNA 1 and NWNA 2 chronologies. The NWNA 1 and NWNA 2 chronologies also share a single coherent growth pattern prior to their divergence (~1950s). Comparison of the NWNA 1/NWNA 2 chronologies against gridded 20th-century temperatures for NWNA and reconstructed Northern Hemisphere summer temperatures (A.D. 1300-2000) indicates that all sites responded positively to temperature prior to the mid-20th century (at least back to A.D. 1300), but that some changed to a negative response (NWNA 1) while others maintained a positive response (NWNA 2). The spatial extent of divergence implies a large-scale forcing. As the divergence appears to be restricted to the 20th century, we suggest the temperature response shift represents a moisture stress caused by an anomalously warm, dry 20th-century climate in NWNA, as indicated by paleoclimatic records. However, because some sites do not diverge, and are located within a few kilometres of divergent sites, we speculate that site-level factors have been important in determining the susceptibility of sites to the large-scale drivers of divergence. This research was supported by a NSERC Discovery Grant, NSERC Northern Supplement and Government of Canada IPY grant to M. Pisaric; and a NSERC Graduate Scholarship and Northern Scientific Training Program grant to T. Porter. Other/Unknown Material IPY Old Crow Yukon University of Toronto: Research Repository T-Space Canada Old Crow Flats ENVELOPE(-139.755,-139.755,68.083,68.083) Yukon Global Change Biology 17 11 3418 3430 |
institution |
Open Polar |
collection |
University of Toronto: Research Repository T-Space |
op_collection_id |
ftunivtoronto |
language |
English |
topic |
dendroclimatology ring-width divergence boreal treeline white spruce Old Crow Flats Yukon Territory |
spellingShingle |
dendroclimatology ring-width divergence boreal treeline white spruce Old Crow Flats Yukon Territory Porter, Trevor J. Pisaric, Michael F.J. Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
topic_facet |
dendroclimatology ring-width divergence boreal treeline white spruce Old Crow Flats Yukon Territory |
description |
This is the accepted manuscript of an article published by Wiley. We present a new 23-site network of white spruce ring-width chronologies near boreal treeline in Old Crow Flats, Yukon Territory, Canada. Most chronologies span the last 300 years, and some reach the mid-16th century. The chronologies exhibit coherent growth patterns before the 1930s. However, since the 1930s they diverge in trend and exhibit one of two contrasting, but well-replicated patterns we call Group 1 and Group 2. Over the instrumental period (1930-2007) Group 1 sites were inversely correlated with previous-year July temperatures while Group 2 sites were positively correlated with growth-year June temperatures. At the broader northwestern North America (NWNA) scale, we find that the Group 1 and Group 2 patterns are common to a number of white spruce chronologies, which we call NWNA 1 and NWNA 2 chronologies. The NWNA 1 and NWNA 2 chronologies also share a single coherent growth pattern prior to their divergence (~1950s). Comparison of the NWNA 1/NWNA 2 chronologies against gridded 20th-century temperatures for NWNA and reconstructed Northern Hemisphere summer temperatures (A.D. 1300-2000) indicates that all sites responded positively to temperature prior to the mid-20th century (at least back to A.D. 1300), but that some changed to a negative response (NWNA 1) while others maintained a positive response (NWNA 2). The spatial extent of divergence implies a large-scale forcing. As the divergence appears to be restricted to the 20th century, we suggest the temperature response shift represents a moisture stress caused by an anomalously warm, dry 20th-century climate in NWNA, as indicated by paleoclimatic records. However, because some sites do not diverge, and are located within a few kilometres of divergent sites, we speculate that site-level factors have been important in determining the susceptibility of sites to the large-scale drivers of divergence. This research was supported by a NSERC Discovery Grant, NSERC Northern Supplement and Government of Canada IPY grant to M. Pisaric; and a NSERC Graduate Scholarship and Northern Scientific Training Program grant to T. Porter. |
format |
Other/Unknown Material |
author |
Porter, Trevor J. Pisaric, Michael F.J. |
author_facet |
Porter, Trevor J. Pisaric, Michael F.J. |
author_sort |
Porter, Trevor J. |
title |
Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
title_short |
Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
title_full |
Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
title_fullStr |
Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
title_full_unstemmed |
Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America |
title_sort |
temperature-growth divergence in white spruce forests of old crow flats, yukon territory, and adjacent regions of northwestern north america |
publisher |
Wiley |
publishDate |
2011 |
url |
http://hdl.handle.net/1807/73511 https://doi.org/10.1111/j.1365-2486.2011.02507.x |
long_lat |
ENVELOPE(-139.755,-139.755,68.083,68.083) |
geographic |
Canada Old Crow Flats Yukon |
geographic_facet |
Canada Old Crow Flats Yukon |
genre |
IPY Old Crow Yukon |
genre_facet |
IPY Old Crow Yukon |
op_relation |
Porter, T. J. and Pisaric, M. F. J. (2011). Temperature-growth divergence in white spruce forests of Old Crow Flats, Yukon Territory, and adjacent regions of northwestern North America. Glob. Change Biol., 17: 3418–3430. doi:10.1111/j.1365-2486.2011.02507.x http://hdl.handle.net/1807/73511 http://dx.doi.org/10.1111/j.1365-2486.2011.02507.x |
op_doi |
https://doi.org/10.1111/j.1365-2486.2011.02507.x |
container_title |
Global Change Biology |
container_volume |
17 |
container_issue |
11 |
container_start_page |
3418 |
op_container_end_page |
3430 |
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1766046919786758144 |