NDVI Changes Show Warming Increases the Length of the Green Season at Tundra Communities in Northern Alaska: A Fine-Scale Analysis.
Arctic shrubs
International Tundra Experiment
Normalized Difference Vegetation Index
climate change
experimental warming
phenology
seasonality
Journal
Frontiers in plant science
ISSN: 1664-462X
Titre abrégé: Front Plant Sci
Pays: Switzerland
ID NLM: 101568200
Informations de publication
Date de publication:
2020
2020
Historique:
received:
13
03
2020
accepted:
20
07
2020
entrez:
28
8
2020
pubmed:
28
8
2020
medline:
28
8
2020
Statut:
epublish
Résumé
A warming Arctic has been associated with increases in aboveground plant biomass, specifically shrubs, and changes in vegetation cover. However, the magnitude and direction of changes in NDVI have not been consistent across different tundra types. Here we examine the responsiveness of fine-scale NDVI values to experimental warming at eight sites in northern Alaska, United States. Warming in our eight sites ranged in duration from 2‑23 seasons. Dry, wet and moist tundra communities were monitored for canopy surface temperatures and NDVI in ambient and experimentally-warmed plots at near-daily frequencies during the summer of 2017 to assess the impact of the warming treatment on the magnitude and timing of greening. Experimental warming increased canopy-level surface temperatures across all sites (+0.47 to +3.14˚C), with the strongest warming effect occurring during June and July and for the southernmost sites. Green-up was accelerated by warming at six sites, and autumn senescence was delayed at five sites. Warming increased the magnitude of peak NDVI values at five sites, decreased it at one site, and at two sites it did not change. Warming resulted in earlier peak NDVI at three sites and no significant change in the other sites. Shrub and graminoid cover was positively correlated with the magnitude of peak NDVI (r=0.37 to 0.60) while cryptogam influence was mixed. The magnitude and timing of peak NDVI showed considerable variability across sites. Warming extended the duration of the summer green season at most sites due to accelerated greening in the spring and delayed senescence in the autumn. We show that in a warmer Arctic (as simulated by our experiment) the timing and total period of carbon gain may change. Our results suggest these changes are dependent on community composition and abundance of specific growth forms and therefore will likely impact net primary productivity and trophic interactions.
Identifiants
pubmed: 32849728
doi: 10.3389/fpls.2020.01174
pmc: PMC7412972
doi:
Types de publication
Journal Article
Langues
eng
Pagination
1174Informations de copyright
Copyright © 2020 May, Hollister, Betway, Harris, Tweedie, Welker, Gould and Oberbauer.
Références
Proc Natl Acad Sci U S A. 2015 Jan 13;112(2):448-52
pubmed: 25548195
Oecologia. 2018 Aug;187(4):1009-1023
pubmed: 29955988
Proc Natl Acad Sci U S A. 2017 Apr 18;114(16):4177-4182
pubmed: 28373560
Glob Chang Biol. 2015 Dec;21(12):4520-32
pubmed: 26183112
Glob Chang Biol. 2015 Dec;21(12):4651-61
pubmed: 26216538
Science. 2009 Sep 11;325(5946):1355-8
pubmed: 19745143
Oecologia. 2003 May;135(3):414-21
pubmed: 12721832
Oecologia. 1992 Sep;91(3):346-349
pubmed: 28313541
Am J Bot. 2015 Dec;102(12):2020-31
pubmed: 26672012
Ecol Lett. 2012 Feb;15(2):164-75
pubmed: 22136670
Philos Trans R Soc Lond B Biol Sci. 2013 Jul 08;368(1624):20120481
pubmed: 23836787
Glob Chang Biol. 2013 Feb;19(2):459-72
pubmed: 23504784
Nat Clim Chang. 2018;8:825-828
pubmed: 30319714
Ecol Evol. 2015 May;5(9):1881-95
pubmed: 26140204
Proc Natl Acad Sci U S A. 2006 Jan 31;103(5):1342-6
pubmed: 16428292
Ecology. 2009 Oct;90(10):2657-63
pubmed: 19886474
Glob Chang Biol. 2016 Sep;22(9):2960-2
pubmed: 27095022
Glob Chang Biol. 2013 Jan;19(1):64-74
pubmed: 23504721
Glob Chang Biol. 2014 Oct;20(10):3147-58
pubmed: 24890614
Glob Chang Biol. 2017 Jul;23(7):2660-2671
pubmed: 28079308
Oecologia. 2005 May;143(4):588-97
pubmed: 15812655
Oecologia. 2016 May;181(1):287-97
pubmed: 26747269
Sci Rep. 2018 Feb 5;8(1):2345
pubmed: 29402988
Nature. 2018 Oct;562(7725):57-62
pubmed: 30258229