Stjälkröksvamp (Tulostoma brumale) : stora eller små individer?

Abstract: The spatial population structure of the saprotrophic basidiomycete Tulostoma brumale was investigated at a site in south eastern Sweden. Sporocarps were mapped and collected, and somatic incompatibility tests between mycelial cultures cultivated from the sporocarps were used to identify genets. Calculations of the size and numbers of genets and their distribution were performed. The spatial distribution of the tested sporocarps and the identified genets are presented graphically in a grid. The total number of identified genets within the investigated area (1210 m2) was 27 based on 48 tested sporocarps. The size of the genets was calculated by measuring the distance between the furthermost sporocarps with somatically compatible mycelial cultures. 16 of the 27 identified genets displayed 2 or more sporocarps. The most extensive genet, as reflected by the tested sporocarps, was 1.25 meters in diameter. The shortest distance between sporocarps from different genets was 32 cm. The results indicate that the population contains of relatively small, short-lived and spore established genets. A moderate but continuous disturbance by (preferably horse) grazing can maintain open sand bares that probably favour the establishment of new genets from spores. The size, age and life strategies of genets are discussed.