Species-rich alvar forests represent a rare vegetation type in northern Europe. They grow locally on shallow soils formed on calcareous parent material. The aim of this study was to compare cryptogam species richness and composition on various substrata in alvar forests of different age and management rate. Altogether 101 bryophyte and 54 lichen species were recorded. Substratum explained species variance more than did the stand age or management intensity. Younger and older forests had a different bryophyte and lichen species composition. Decaying wood was the richest as cryptogam species substratum. It had quite a unique bryophyte composition, including a high amount of hepatics. Juniperus communis appeared to be an important substratum for cryptogam species diversity in alvar forests. Bryophyte species composition appeared to be similar on the bases of Pinus sylvestris, Betula pendula and Picea abies and different on J. communis. Most of the recorded threatened bryophyte species grew in old subnatural forests on stones or decaying wood.