A narrow window of summer temperatures associated with shrub growth in Arctic Alaska
Gaglioti, Benjamin V
Berner, Logan T
Anchukaitis, Kevin J
Goetz, Scott J
AffiliationUniv Arizona, Lab Tree Ring Res
Univ Arizona, Sch Geog & Dev
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationAndreu-Hayles, L., Gaglioti, B. V., Berner, L. T., Levesque, M., Anchukaitis, K. J., Goetz, S. J., & D’Arrigo, R. (2020). A narrow window of summer temperatures associated with shrub growth in Arctic Alaska. Environmental Research Letters, 15(10), 105012.
JournalENVIRONMENTAL RESEARCH LETTERS
Rights© 2020 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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AbstractWarming in recent decades has triggered shrub expansion in Arctic and alpine tundra, which is transforming these temperature-limited ecosystems and altering carbon and nutrient cycles, fire regimes, permafrost stability, land-surface climate-feedbacks, and wildlife habitat. Where and when Arctic shrub expansion happens in the future will depend in part on how different shrub communities respond to warming air temperatures. Here, we analyze a shrub ring-width network of 18 sites consisting ofSalixspp. andAlnus viridisgrowing across the North Slope of Alaska (68-71 degrees N; 164-149 degrees W) to assess shrub temperature sensitivity and compare radial growth patterns with satellite NDVI (normalized difference vegetation index) data since 1982. Regardless of site conditions and taxa, all shrubs shared a common year-to-year growth variability and had a positive response to daily maximum air temperatures (Tmax) from ca. May 31 (i.e. Tmax similar to 6 degrees C) to early July (i.e. Tmax similar to 12 degrees C), two-thirds of which were significant correlations. Thus, the month of June had the highest shrub growth-temperature sensitivity. This period coincides with the seasonal increase in temperature and phenological green up on the North Slope indicated by both field observations and the seasonal cycle of NDVI (a proxy of photosynthetic activity). Nearly all of the sampled shrubs (98%) initiated their growth after 1960, with 74% initiated since 1980. This post-1980 shrub-recruitment pulse coincided with similar to 2 degrees C warmer June temperatures compared to prior periods, as well as with positive trends in shrub basal area increments and peak summer NDVI. Significant correlations between shrub growth and peak summer NDVI indicate these radial growth patterns in shrubs reflect tundra productivity at a broader scale and that tundra vegetation on the North Slope of Alaska underwent a greening trend between 1980 and 2012.
NoteOpen access article
VersionFinal published version
SponsorsCenter for Hierarchical Manufacturing, National Science Foundation
Except where otherwise noted, this item's license is described as © 2020 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.