Functional traits of epiphytic lichens respond to alkaline dust pollution

Dust pollution has a harmful impact on the environment and human health. Lichen trait-based metrics are increasingly used to monitor effects of air pollution, but studies using this technique to monitor the effects of dust pollution are still scarce. Functional traits of lichens along a gradient of long-term alkaline dust pollution were investigated. Species composition was affected along this gradient according to two easily identifiable “soft” traits (growth form and main reproductive strategy) and one expert-assessed “hard” trait (species preference for substrate pH). Particularly, crustose species and lichens with sexual reproduction were related to the most polluted side of the gradient and higher pH, while foliose narrow-lobed species and lichens with asexual reproduction were associated with the opposite side.