Lobaria Pulmonaria - Distribution and Habitat

Distribution and Habitat

It has a wide distribution in Europe, Asia, North America and Africa, preferring damp habitats with high rainfall, especially coastal areas. It is the most widely distributed and most common Lobaria species in North America. Associated with old-growth forests, its presence and abundance may be used as an indicator of forest age, at least in the Interior Cedar-Hemlock biogeoclimatic zone in eastern British Columbia. It is also found in pasture-woodlands. It usually grows on the bark of broad-leaved trees such as oak, beech and maple but will also grow on rocks. In the laboratory, L. pulmonaria has been grown on nylon microfilaments. Various environmental factors are thought to affect the distribution of L. pulmonaria, such as temperature, moisture (average humidity, rapidity and frequency of wet-dry cycles), sunlight exposure, and levels of air pollution. Attempts to quantitatively evaluate the contribution of these factors to lichen growth is difficult because differences in the original environment from which the lichen thalli are collected will greatly affect heat and desiccation tolerances.

Due to declining population, L. pulmonaria is considered to be rare or threatened in many parts of the world, especially in lowland areas of Europe. The decline has been attributed to industrial forestry and air pollution, particularly acid rain. L. pulmonaria, like other lichens containing a blue-green algal component, are particularly susceptible to the effects of acid rain, because the subsequent decrease in pH reduces nitrogen fixation through inhibition of the algal nitrogenase enzyme.