An unusual growth form of Cladonia furcata: The trampling-resistant primary thallus colonizing a paved pathway

Abstract

Lichens are well known to be susceptible to damage by trampling. Fruticose species, with their highly branched structure, are particularly sensitive and Bayfield et al. (1981) described substantial damage to Cladonia uncialis, C. arbuscula, C. rangiferina, and C. impexa on paths in lichen-rich heath communities in north-east Scotland. Less visible communities, biotic soil crusts in arid and semi-arid areas with their cover of crustose lichens, are also easily disturbed by walking, car driving, or grazing and recovery can take decades. We report here an interesting situation where a lichen (Cladonia furcata) is apparently being maintained and even spread in a habitat because trampling prevents it from completing its monocarpic life cycle.