Bryophyte community assembly on young land uplift islands – dispersal and habitat filtering assessed using species traits

Aim: To assess habitat filtering and dispersal limitation in spore plant community assembly using bryophytes on recently emerged land uplift islands as study system.

Location: Gulf of Bothnia, northern Europe.

Taxa: Bryophytes, including the spore plant phyla Bryophyta (mosses) and Marchantiophyta (liverworts).

Methods: The species compositions of 20 coastal land uplift islands differing in age, area, connectivity, and habitat composition were recorded in the field. In addition, we compiled a list of the regional species pool (446 species) and gathered data on species traits related to habitat affiliations (substrate, light, moisture, and pH) and dispersal capacity (regional abundance, spore size, sporophyte frequency, sexual system, vegetative propagules). For the 420 species with available trait data, we used multivariate generalized linear models to compare trait effects on species occurrence probabilities on the islands.

Results: Occurrence probabilities depended strongl...