Ecology

Fire ecology

Taiga

Fire regime

Biochemistry

Physics

Climate change

Biology

Gene

Geography

Boreal

Forestry

Ecosystem

Flammability

Black spruce

Environmental science

Dominance (genetics)

Thermodynamics

Proceedings of the National Academy of Sciences

Significance Black spruce is the dominant tree species in boreal North America and has shaped forest flammability, carbon storage, and other landscape processes over the last several thousand years. However, climate warming and increases in wildfire activity may be undermining its ability to maintain dominance, shifting forests toward alternative forested and nonforested states. Using data from across North America, we evaluate whether loss of black spruce resilience is already widespread. Resilience was the most common outcome, but drier climatic conditions and more severe fires consistently undermine resilience, often resulting in complete regeneration failure. Although black spruce forests are currently moderately resilient, ongoing warming and drying may alter this trajectory, with large potential consequences for the functioning of this globally important biome.

Increasing fire and the decline of fire adapted black spruce in the boreal forest