The Arctic is warming faster than any other region on Earth. This rapid change is not only transforming Arctic ecosystems, but also has profound consequences for the global climate. Beneath the tundra and boreal soils lies more than twice as much carbon as is currently found in the atmosphere. Whether this carbon remains stored in soils and plant biomass or is released as carbon dioxide (CO2) and methane (CH₄) depends strongly on vegetation. Shifts in the identity and traits of Arctic plant communities therefore have the potential to reinforce or mitigate future climate change. Understanding these processes is crucial to improving climate predictions and informing global climate policy.
Over the past decade, substantial progress has been made in documenting how Arctic vegetation is changing, particularly the expansion of shrubs and trees into tundra habitats. Yet the functional consequences of these shifts remain highly uncertain. Will new species lead to faster litter decomposition, releasing more carbon to the atmosphere? Or will taller, woodier plants store more carbon in long-lived biomass? Will an extended growing season increase productivity, or will stress from changing light and temperature patterns constrain growth? And how will vegetation change affect fire regimes in northern ecosystems? These are among the most urgent questions in Arctic ecology today.
ArcticEDGE addresses these questions by combining trait-based ecology, field and growth chamber experiments, and biome-scale synthesis. The project focuses on three core ecosystem processes that are tightly linked to carbon cycling: litter decomposition, primary production, and fire dynamics. Specifically, we aim to:
1. Quantify how plant traits (e.g. leaf chemistry, height) predict decomposition, productivity, and fire behavior.
2. Assess how quickly these traits are likely to change in response to warming, through species turnover, changes in abundance, plastic responses, or evolutionary adaptation.
3. Determine how observed and projected trait shifts scale up to affect carbon fluxes and carbon storage across the Arctic biome.
4. Deliver outputs that directly inform Dynamic Global Vegetation and Earth System Models, improving their ability to represent Arctic vegetation-climate feedbacks.
The project leverages unique resources: decades of long-term monitoring at over 200 Arctic sites, global plant trait databases, and targeted new experiments. By linking easily measured plant traits to hard-to-measure processes like decomposition and fire, ArcticEDGE will provide the first pan-Arctic, trait-based assessment of how vegetation change affects ecosystem carbon cycling.
The expected impact is twofold. Scientifically, the project will advance fundamental theory on how biodiversity and functional traits shape ecosystem processes under rapid climate change. Societally, it will produce data and model improvements that feed directly into international climate assessments, ensuring more accurate projections of future warming. In doing so, ArcticEDGE will clarify whether Arctic vegetation acts as a brake or an accelerator of climate change—knowledge essential for global climate policy and adaptation strategies.
