title: How do bryophytes govern generative recruitment of vascular plants?
abstract: Interactions between vascular plants and bryophytes determine plant community composition in many ecosystems. Yet, little is known about the importance of interspecific differences between bryophytes with respect to their effects on vascular plants. We compared the extent to which species-specific bryophyte effects on vascular 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 chemically and 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 were significant differences between the bryophyte species. The lack of interactions indicated the absence of species-specific adaptations of vascular plants for recruitment in bryophyte mats. Differences between bryophyte species were best explained by alterations in temperature regime under bryophyte mats, mostly by reduced temperature amplitudes during germination. The temperature regime under bryophyte mats was well predicted by species-specific bryophyte cushion thickness. The fitness of established seedlings was not affected by the presence of bryophytes. Our results suggest that climatically or anthropogenically driven changes in the species' composition of bryophyte communities have knock-on effects on vascular plant populations via generative reproduction.
authors.affiliation: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
authors.forename: Nadejda A
authors.initials: NA
authors.lastname: Soudzilovskaia
authors.affiliation: Department of Biology, NTNU, Trondheim, Norway.
authors.forename: Bente J
authors.initials: BJ
authors.lastname: Graae
authors.affiliation: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
authors.forename: Jacob C
authors.initials: JC
authors.lastname: Douma
authors.affiliation: Departament de Biologia Vegetal, Universitat de Barcelona, Av. Diagonal 645, ES-08028, Catalonia.
authors.forename: Oriol
authors.initials: O
authors.lastname: Grau
authors.affiliation: Climate Impacts Research Centre, Umeå University, Umeå, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Milbau
authors.affiliation: Research Group Plant and Vegetation Ecology, Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Wilrijk, Belgium.
authors.forename: Anna
authors.initials: A
authors.lastname: Shevtsova
authors.affiliation: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
authors.forename: Loes
authors.initials: L
authors.lastname: Wolters
authors.affiliation: Systems Ecology, Department of Ecological Science, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
authors.forename: Johannes H C
authors.initials: JHC
authors.lastname: Cornelissen
mesh_terms: D000222:Adaptation, Physiological; D056808:Biostatistics; D044002:Bryophyta / Q000737:chemistry / Q000502:physiology*; D018525:Germination; D019684:Magnoliopsida / Q000187:drug effects / Q000254:growth & development*; D010636:Phenols / Q000032:analysis / Q000494:pharmacology; D012621:Seasons; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development*; D012987:Soil; D013045:Species Specificity; D013696:Temperature; D014867:Water
chemical_list: D010636:Phenols; D012987:Soil; D014867:Water