LAUSR

Increasing air temperatures are driving widespread changes to Arctic vegetation. In the high Arctic, these changes are patchy and the causes of heterogeneity are not well understood. In this study, we explore the determinants of high Arctic vegetation change over the last three decades on Banks Island, Northwest Territories. We used Landsat imagery (1984–2014) to map long-term trends in vegetation productivity and regional spatial data to investigate the relationships between trends in productivity and terrain position. Field sampling investigated vegetation community composition in different habitat types. Our analysis shows that vegetation productivity changes are substantial on Banks Island, where productivity has increased across about 80% of the study area. Rising productivity levels can be attributed to increasing biomass of the plant communities in both upland and lowland habitats. Our analysis also shows that the magnitude of greening is mediated by terrain characteristics related to soil moisture. Shifts in tundra vegetation will impact wildlife habitat quality, surface energy balance, permafrost dynamics, and the carbon cycle; additional research is needed to explore the effects of more productive vegetation communities on these processes in the high Arctic.