Divergence of Arctic shrub growth associated with sea ice decline.

Autor:	Buchwal A; Institute of Geoecology and Geoinformation, Adam Mickiewicz University, 61-680 Poznan, Poland; kamzik@amu.edu.pl.; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508., Sullivan PF; Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK 99508., Macias-Fauria M; School of Geography and the Environment, University of Oxford, OX1 3QY Oxford, United Kingdom., Post E; Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, CA 95616., Myers-Smith IH; School of GeoSciences, University of Edinburgh, EH9 3FF Edinburgh, United Kingdom., Stroeve JC; National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder, CO 80309.; Centre for Earth Observation Science, University of Manitoba, Winnipeg, MT MB R3T 2N2, Canada., Blok D; Dutch Research Council (NWO), 93460 The Hague, The Netherlands., Tape KD; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775., Forbes BC; Arctic Centre, University of Lapland, FI-96101 Rovaniemi, Finland., Ropars P; Chaire de Recherche du Canada en Biodiversité Nordique, Université du Québec à Rimouski, QC G5L 3A1 Rimouski, Canada.; Centre for Indigenous Peoples' Nutrition and Environment, McGill University, QC H9X 3V9 Montreal, Canada., Lévesque E; Département des Sciences de l'Environnement et Centre d'Études Nordiques, Université du Québec à Trois-Rivières, QC G8Z 4M3 Trois-Rivières, Canada., Elberling B; Center for Permafrost, Department of Geoscience and Natural Resource Management, University of Copenhagen, DK-1350 Copenhagen, Denmark., Angers-Blondin S; School of GeoSciences, University of Edinburgh, EH9 3FF Edinburgh, United Kingdom., Boyle JS; School of GeoSciences, University of Edinburgh, EH9 3FF Edinburgh, United Kingdom., Boudreau S; Département de Biologie et Centre d'Etudes Nordiques, Université Laval, QC G1V 0A6 Québec City, Canada., Boulanger-Lapointe N; Department of Geography, University of British Columbia, Vancouver, BC V6T 1Z2, Canada., Gamm C; Environment and Natural Resources Institute, University of Alaska Anchorage, Anchorage, AK 99508., Hallinger M; Biology Department, Swedish Agricultural University, SE-750 07 Uppsala, Sweden., Rachlewicz G; Institute of Geoecology and Geoinformation, Adam Mickiewicz University, 61-680 Poznan, Poland.; Department of Health and Environmental Science, Xi'an Jiaotong-Liverpool University, 215123 Suzhou, China., Young A; Toolik Field Station, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775.; Department of Geography, Pennsylvania State University, University Park, PA 16802., Zetterberg P; Laboratory of Dendrochronology, School of Forest Sciences, University of Eastern Finland, FI-80101 Joensuu, Finland., Welker JM; Department of Ecology and Genetics, University of Oulu and UArctic, 90570 Oulu, Finland.; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508.
Jazyk:	angličtina
Zdroj:	Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2020 Dec 29; Vol. 117 (52), pp. 33334-33344. Date of Electronic Publication: 2020 Dec 14.
DOI:	10.1073/pnas.2013311117
Abstrakt:	Arctic sea ice extent (SIE) is declining at an accelerating rate with a wide range of ecological consequences. However, determining sea ice effects on tundra vegetation remains a challenge. In this study, we examined the universality or lack thereof in tundra shrub growth responses to changes in SIE and summer climate across the Pan-Arctic, taking advantage of 23 tundra shrub-ring chronologies from 19 widely distributed sites (56°N to 83°N). We show a clear divergence in shrub growth responses to SIE that began in the mid-1990s, with 39% of the chronologies showing declines and 57% showing increases in radial growth (decreasers and increasers, respectively). Structural equation models revealed that declining SIE was associated with rising air temperature and precipitation for increasers and with increasingly dry conditions for decreasers. Decreasers tended to be from areas of the Arctic with lower summer precipitation and their growth decline was related to decreases in the standardized precipitation evapotranspiration index. Our findings suggest that moisture limitation, associated with declining SIE, might inhibit the positive effects of warming on shrub growth over a considerable part of the terrestrial Arctic, thereby complicating predictions of vegetation change and future tundra productivity. Competing Interests: The authors declare no competing interest. (Copyright © 2020 the Author(s). Published by PNAS.)
Databáze:	MEDLINE
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