Natural seeding as an alternative to planting in black spruce-lichen woodlands

Regeneration failures in the closed-crown boreal forest, which lead to the creation of open lichen woodlands, are expected to increase with climate change due to a rise in burn rates. Past studies have shown that it was possible to restore the productivity of those stands through planting. Since most lichen woodland stands are remotely located, afforestation through planting can be prohibitive. Therefore, the objective of this research was to measure the afforestation efficiency of lichen woodlands through scarification and natural seeding after clear-cutting. Our results showed that clear-cutting, when combined with scarification, promoted seedling establishment more strongly than clear-cutting alone. Scarification was also necessary for creating suitable microsites for germination, which were essentially bare mineral soil and decomposed organic matter. Last, seedling growth was higher in lichen woodlands when logging and scarification were combined, but lower than their counterpart feather moss stands. We conclude that afforestation of lichen woodlands in the closed-crown boreal forest is possible through natural seeding following scarification and could be a cost-effective option compared to planting.

Automated summary

Regeneration failures in the closed-crown boreal forest, resulting in the creation of open lichen woodlands, can be restored through clear-cutting, scarification, and natural seeding. Clear-cutting combined with scarification promotes seedling establishment, and scarification creates suitable microsites for germination. Seedling growth in lichen woodlands is higher when logging and scarification are combined, but lower compared to feather moss stands. Afforestation through natural seeding following scarification could be a cost-effective option for restoring lichen woodlands.