• Interactions between vascular plants and bryophytes determine plant community composition in many ecosystems. Yet, little is known about the importance ofinterspecific differences between bryophytes with respect to their effects on vascular plants. We compared the extent to which species-specific bryophyte effects onvascular plant generative recruitment depend on the following underlying mechanisms: allelopathy, mechanical obstruction, soil moisture and temperature control.

• We sowed 10 vascular plant species into monospecific mats of six chemicallyand structurally diverse bryophytes, and examined 1-yr seedling recruitment.Allelopathic effects were also assessed in a laboratory phyto-assay.

• Although all bryophytes suppressed vascular plant regeneration, there weresignificant differences between the bryophyte species. The lack of interactionsindicated the absence of species-specific adaptations of vascular plants for recruitment in bryophyte mats. Differences between bryophyte species were bestexplained by alterations in temperature regime under bryophyte mats, mostly byreduced temperature amplitudes during germination. The temperature regimeunder bryophyte mats was well predicted by species-specific bryophyte cushionthickness. The fitness of established seedlings was not affected by the presence ofbryophytes.

• Our results suggest that climatically or anthropogenically driven changes in thespecies’ composition of bryophyte communities have knock-on effects on vascularplant populations via generative reproduction.