Fungi-vegetation relationships in aPinus sylvestrisforest in central Norway

Abstract

The macrofungal Basidiomycete community of a Pinus sylvestris forest was investigated in 50 plots, 2 × 2 m, to see how vegetation composition and space influenced the distribution of saprotrophic and ectomycorrhizal fungi. Mantel tests and partial Mantel tests revealed a relationship between total cover of the field layer and mycorrhizal fungi, and total cover of the bottom layer and saprotrophic fungi. These results are consistent with the predictions that mycorrhizal fungi are mainly influenced by plant species present in the root zone, whereas saprotrophic fungi are mainly influenced by the plant species of the bottom layer. Variation in the abundance of tree species did not influence the distribution of macrofungal species at this scale. The spatial patterns of fungal distribution found in this study did not deviate significantly from a random distribution. Indirect ordination showed that the ectomycorrhizal fungi mainly responded to a gradient in cover of the field layer, whereas the saprotrophs seemed to respond to a complex gradient of cover of field and bottom layer, moisture, and paludification. A direct ordination using both vegetation and fungi descriptors indicated that some of the covariation in the saprotrophic fungi and the bottom layer might be coordinated responses to changes in the field layer. A considerably higher β diversity was found among the fungi than in the vegetation. Key words: basidiomycetes, saprotrophic fungi, mycorrhizal fungi, fungi–vegetation relationships, Mantel test, ordination.