Figure 7.

(a) Old-growth lichen-spruce woodland more than 2000 years old. Woodland at equilibrium with all-sized and all-aged dead and living spruce trees. (b) Old-growth lichen-spruce krummholz more than 2000 years old with all-sized and all-aged spruce shrubs. Dead tree stems on the ground were growing in the 1400s and 1500s when growth conditions were more favourable than at present (Payette et al. 1989). (c) Clonal black spruce, ca 100 year old, growing in a lichen-heath tundra site. (d) Clonal black spruce, ca 450 year old, growing in a lichen-heath tundra site. Mosaic of post-fire old-growth woodlands and lichen-heath tundras in the background. (e) Pre-fire spruce stems on the ground associated with fire 450 years old. Cross-dating of pre-fire trees was used to date past fire events when fire scar and post-fire tree evidence was lacking. (f) Lichen-heath tundras caused by deforesting fire 450 years ago adjacent to fire-free lichen-spruce woodlands.