Divergence of Arctic shrub growth associated with sea ice decline

Significance Two defining features of climate change in the Arctic are the rapid decline of sea ice and “shrubification” of the tundra. While previous studies have inferred warming-related linkages between the two, these have been limited to a few locations. Our Pan-Arctic analysis of shrub growth chronologies reveals two important insights. Tundra shrub growth dynamics are associated with sea ice decline throughout the Arctic; however, while shrubs from most locations increased their growth, more than one-third showed evidence of declining growth in response to warming and drying associated with sea ice loss. These results highlight pronounced growth response heterogeneity across the tundra biome that will have important implications for tundra productivity and vegetation–climate feedback.