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Complexity revealed in the greening of the Arctic

Abstract

As the Arctic warms, vegetation is responding, and satellite measures indicate widespread greening at high latitudes. This ‘greening of the Arctic’ is among the world’s most important large-scale ecological responses to global climate change. However, a consensus is emerging that the underlying causes and future dynamics of so-called Arctic greening and browning trends are more complex, variable and inherently scale-dependent than previously thought. Here we summarize the complexities of observing and interpreting high-latitude greening to identify priorities for future research. Incorporating satellite and proximal remote sensing with in-situ data, while accounting for uncertainties and scale issues, will advance the study of past, present and future Arctic vegetation change.

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Fig. 1: Satellite records indicate greening trends across the circumpolar Arctic.
Fig. 2: Ecological interpretation of trends in NDVI requires a consideration of non-ecological factors.
Fig. 3: Spatial heterogeneity in landcover can influence NDVI–vegetation relationships.
Fig. 4: Satellite-derived estimates do not always match in-situ observations of plant phenology across the growing season.
Fig. 5: Arctic greening is influenced by issues of measurement scale and inference across ecological hierarchies.

Data availability

Data come from publicly available remote sensing and ecological datasets including: MODIS (https://modis.gsfc.nasa.gov/), GIMMS3g.v1 (https://nex.nasa.gov/nex/projects/1349/), the High Latitude Drone Ecology Network (https://arcticdrones.org/), shrub abundance, annual growth ring and phenology datasets (https://github.com/ShrubHub/QikiqtarukHub, https://arcticdata.io/catalog/view/doi:10.18739/A24X0Q, https://arcticdata.io/catalog/view/doi:10.18739/A28Q18, https://arcticdata.io/catalog/view/doi:10.5065/D6542KRH).

Code availability

Code is available in a GitHub repository (https://github.com/ShrubHub/GreeningHub).

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Acknowledgements

We thank the Inuvialuit and Greenlandic People for the opportunity to conduct field research on their land. Data collection on Qikiqtaruk–Herschel Island was funded by the UK Natural Environment Research Council (NERC) NE/M016323/1 (to I.H.M.-S.) and a National Geographic Society grant CP-061R-17 and a Parrot Climate Innovation Grant (to J.T.K.). Data collection at Kangerlussuaq, Greenland was supported by the US National Science Foundation (NSF) grants 0724711, 0713994, 0732168, 0902125, 1107381, 1525636, 1748052 and the National Geographic Society (to E.P.), as well as an Arctic Institute of North America Grant-in-Aid (to C.J.). The sTundra working group was supported by sDiv, the Synthesis Centre of the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig (DFG FZT 118). The Event Drivers of Arctic Browning workshop was funded by P3-Plant Production and Protection (http://p3.sheffield.ac.uk/). Several members of the team are supported by the NASA ABoVE program (https://above.nasa.gov/). Additional funding was provided by the Research Council of Norway grant 287402 (to J.W.B. and H.T.) and 294948 (to F.S., J.W.B., A.B., H.T. and F.-J.W.P.), the NERC doctoral training partnership grant NE/L002558/1 (to J.J.A. and H.J.D.T.), the US NSF grants OPP-15-04134, AGS-15-02150 and OPP-16-03473 (to L.A.-H.), the Natural Sciences and Engineering Research Council of Canada and the Canadian Centennial Scholarship Fund (to S.A.-B.), the Academy of Finland decision 256991 and JPI Climate 291581 (to B.C.F.), the NASA ABoVE grants NNX17AE44G and NNX17AE13G (to S.J.G. and L.T.B.), NSF grants PLR-0632263, PLR-0856516, PLR-1432277, PLR-1504224, PLR-1836839 (to R.D.H.), the US NSF grant PLR-1417745 (to M.M.L.), an NERC IRF NE/L011859/1 (to M.M.-F.), Independent Research Fund Denmark 7027-00133B and Villum Fonden VKR023456 (to S.N.), the Norwegian Research Council grants 230970 and 274711 and the Swedish Research Council registration 2017-05268 (to F.-J.W.P.), University of Zurich Research Priority Program on Global Change and Biodiversity (to G.S.-S.) and the US NSF grants OPP-1108425 and PLR-1108425 (to P.F.S.).

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I.H.M.-S. and J.T.K. conducted the analyses and wrote the manuscript with contributions from all authors. G.K.P., J.W.B. and H.E.E. contributed substantially to early versions of the manuscript. I.H.M.-S., J.T.K., J.J.A., C.J., S.A.-B., A.M.C., H.J.D.T. and E.P. collected drone and in-situ data. This paper results from two collaborations: the sTundra working group at the German Centre for Integrative Biodiversity Research (iDiv) led by I.H.M.-S., S.C.E. and A.D.B., and the ‘Event Drivers of Arctic Browning Workshop’ at the University of Sheffield led by G.K.P.

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Correspondence to Isla H. Myers-Smith or Jeffrey T. Kerby.

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Peer review information Nature Climate Change thanks Matthias Forkel and John Gamon for their contribution to the peer review of this work.

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Myers-Smith, I.H., Kerby, J.T., Phoenix, G.K. et al. Complexity revealed in the greening of the Arctic. Nat. Clim. Chang. 10, 106–117 (2020). https://doi.org/10.1038/s41558-019-0688-1

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