What roles do lichens play in taiga woodlands?

In the taiga, or northern forest, lichens serve as a vital component of the ecosystem, particularly in areas known as lichen woodlands or sparse taiga. Their primary roles include:1

• Food Source: Lichens are a critical food supply for reindeer and caribou, especially during the winter months when these animals migrate to lichen-rich woodlands to graze.23
• Ground and Canopy Cover: Lichens constitute a significant portion of the ground cover in open taiga habitats. Additionally, they are widely distributed on tree trunks and within the canopies of older conifer trees, where they can accumulate in substantial quantities.12
• Ecological Presence: Because they are dispersed by airborne spores, many lichen species are found across the entire circumpolar taiga, contributing to the region's biodiversity.1

While lichens are essential for forage, it is important to note that they are distinct from the underground fungi that form mycorrhizae with tree roots; those underground fungi play a separate, crucial role in forest health by being consumed and dispersed by animals like the northern flying squirrel.3