Fig. 1: Conceptual overview of hypothesised biome distribution changes.
From: Northern expansion is not compensating for southern declines in North American boreal forests
Each panel represents the latitudinal distribution of the temperate, boreal, and tundra biomes from south (bottom) to north (top). A Representation of the current distributions of biomes. B The boreal biome is expected to move northward with climate change (purple arrows). In the south, the boreal distribution boundary moves northward through tree mortality and reduced recruitment, owing to deteriorating growing conditions. The northern boundary is expected to migrate through dispersal and colonisation into the warming Arctic shrubland and tundra. C Observed shift through changes in tree cover: Tree cover loss in the south is amplified by timber harvests and wildfires. In the north, tree cover within the boreal biome increases by infilling of open areas. However, tree cover expansion into the Arctic is slow. D Over time, the fast tree cover losses in the south and the slow expansion in the north lead to a transient contraction of the boreal biome.
