In lithosere (xerosere or xerarch), the pioneer community is usually constituted by crustose lichens (e.g., Graphis, Rhizocarpon). Foliose lichens (e.g., Dermatocarpon, Parmelia) kill the crustose lichens by shading them, cause deeper depressions and accumulate more soil particles and organic matter. Foliose lichens make the conditions favourable for the growth of hardy mosses (e.g., Tortula, Grimmia).