Corticulous Myxomycetes in three different habitats in southern Finland

Abstract

HARKONEN, M. 1977: Corticolous Myxomycetes in three different habitats in southern Finland.-Karstenia 17: 19-32. Bark from living trees was periodically coilected from three localities in southern Finland : from an urban, air-polluted park, a virgin forest and a managed forest, representing similar boreal coniferous forest areas. In moist chambers 19 species of Myxomycetes appeared on the pieces of bark. Eight are new to Finland: Echinoste-lium minutum deBary, E. cribrarioides Alex., Perichaena chrysosperma (Currey) A. Lister, Stemonitis pal/ida Wingate, Comatricha elegans (Racid.) G. Lister, Paradia-cheopsis fimbriata (G. Lister & Cran) Hertel, P. solitaria (Nann.-Brem.) Nann.-Brem ., Physarum pusil/um (Berk. & Curt.) G. Lister. Six species were abundant: Echinostelium minutum de Bary, Arcyria pomiformis (Leers) Rost., A. cinerea (Bull.) Pers ., Comatricha nigra (Pers.) Schroet., Enerthenema papillatum (Pers.) Rost. and Paradiacheopsisfimbriata (G. Lister & Cran) Hertel. Slime moulds appeared on bark with a wide range of pH, 2-9. Some species, e.g. Comatricha nigra, seemed to prefer an acid substrate, others, e.g. Arcyria cinerea, a less acid one. Among the common species the incubation time needed for fructifica-tions to develop varied from a couple of days to over 40 days. Bark from the urban. locality yielded many fructifications but of only six species. Paradiacheopsis fimbriata was very common and formed large colonies in places inhabited by the lichen Bacidia chlorococca (Stenh .) Lett., which is highly resistant to atmospheric pollution. Bark from the virgin forest produced fewer fructifications, but of many more species (16). Bark from the managed forest had few fructifications and few species (5). With the moist chamber culture method no phenological variation can be shown.