AbstractIn southern SwedenO. linearegrows in two main habitats, coastal pine forests and planted spruce forests. Within this area, the species colonizes the same kinds of substrate as in other climatically similar areas in Europe, viz. rotten wood, tree bases and, to a lesser degree, bare soil. Only a small proportion of the seemingly available substrate (0.2–8.3%) is colonized, a smaller proportion in the pine forests than in the spruce forests. DECORANA and TWINSPAN analyses of sociological data from random squares indicated that the associationOrthodontietum linearis(Barkman) v. Hübschmann is heterogeneous and that its species composition varies considerably with the habitat.O. lineareseems to be competitively inferior compared with the species commonly found in its habitats and it probably survives in the area due to a high dispersal and colonization capacity.