. Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions:

Please contact authors before publishing the data. Please use the following acknowledgements when using/publishing the data from Qikiqtaruk: "We thank the Herschel Island-Qikiqtaruk Territorial Park, Isla Myers-Smith, Cameron Eckert, Richard Gordon, Catherine Kennedy, Dorothy Cooley, and Dr. Jill F. Johnstone for establishing and maintaining the phenology and composition data from Qikiqtaruk. We thank Haydn J.D. Thomas, Meagan M. Grabowski, Sandra Angers-Blondin, Gergana N. Daskalova, Jakob J. Assmann for assisting with the collection and compilation of the data. We thank rangers including Edward McLeod, Samuel McLeod, Ricky Joe, Paden Lennie, Deon Arey, LeeJohn Meyook, Jordan McLeod, Pierre Foisy, Colin Gordon, Jeremy Hansen, Albert Rufus and field assistants including Santeri Lehtonen, William Palmer, Louise Beveridge, Clara Flintrop, John Godlee, Eleanor Walker, Joseph Boyle, Catherine Henry and Anika Trimble. Funding for data collection was provided by Herschel Island-Qikiqtaruk Territorial Park and the UK Natural Environment Research Council ShrubTundra Grant (NE/M016323/1). We thank the Inuvialuit People for the opportunity to collect these data on their traditional lands."

Methodology:

Wood samples were collected in the summer 2015 during an expedition to the four field sites. At each site, square plots ranging from 25 m2 to 100 m2 were established. All shrubs taller than 10 cm within these plots were sampled at the root collar and cross-sectioned with a sledge microtome. Sample preparation and analysis followed procedures described by Myers-Smith et al. 2015 (Earth-Science Reviews). Annual growth rings were measured for the period 1990-2014. The measurements presented are an average of 2-4 radii per individual and represent raw ring width, measured in micrometers.

The coordinates given are the corners of a box encompassing all plots at a given site. Kluane: (60.9585, -138.4202), (60.9585, -138.2698), (61.2213, -138.4202), (61.2213, -138.2698) / Qikiqtaruk: (69.5702, -138.9457), (69.5702,-138.8649), (69.5801,-138.9457), (69.5801, -138.8649) / Umiujaq: (56.5321, -76.5420), (56.5321,-76.4769), (56.5725,-76.5420), (56.5725,-76.4769) / Salluit: (62.1802, -75.6774), (62.1802, -75.6460), (62.1982, -75.6774), (62.1982,-75.6460)

Column definitions:

Height is the maximum height of the shrub. Width1 is the longest width of the shrub and width2 is the width perpendicular to the first width.

Longer time-series from the circumpolar region (up to 2009) can be found at the ShrubRingHub : https://github.com/ShrubHub/ShrubringHub

Data collection:

A sledge microtome was used to section the samples. Ring width was measured with the ImageJ software and the ObjectJ plugin (https://sils.fnwi.uva.nl/bcb/objectj/)

Data quality:

Samples that could not be cross-sectioned or measured reliably (rotten core, heavy wedging/lobing) were not included in the dataset. Remaining samples have an average inter-radii correlation of ca. 75%.