The lobaria lichens such as lungwort and lettuce-lung play a crucial role in forest ecology. These lichens bear a superficial resemblance to human lung tissue, and so under the medieval medical belief known as “The Doctrine of Signatures”, they were used to treat pulmonary illnesses such as tuberculosis and asthma. Though the benefits of this belief proved to be only of the imagination, these lichens are in fact critical for the health of our planetary “lungs”, the temperate rainforests.
Lobaria lichens are able to accomplish the rare feat of fixing atmospheric nitrogen. Nitrogen is an essential nutrient for plant growth but almost no organisms are able to extract it from the air. These lichens mine this precious nutrient from the atmosphere and when they fall to the forest floor and decay, that nitrogen is made available to the entire ecosystem. These ecologically critical lichens are most abundant in old-growth forests where there may be as much as two tons of lobaria per hectare, all working tirelessly to enrich and fertilize the entire forest ecosystem.
Lobaria lichens are declining globally due to logging and pollution. The coastal rainforests of BC represent a critical global stronghold for these remarkable and ecologically valuable organisms.