The roles of bryophyte propagule sources in community composition and structure are poorly understood, but regeneration processes may be critical to the conservation of severely disturbed communities such as those in Acadian forests managed for timber production. Our research objectives were to 1) describe the compositions of the aerial diaspore rain and the buried propagule bank at two locations, 2) compare compositional turnover (β-diversity) among assemblages (i.e., changes in composition across sample units), and 3) investigate potential temporal variability across a growing season within the aerial diaspore rain. A case study approach was used to 4) determine the potential recovery of two extant communities based on available propagules. Compositions of propagule sources were determined by emergence and compared to that of the extant community sampled intensively, i.e., within two grids (1 m² and 1.69 m²) of contiguous 100 cm² cells established on the forest floor of mature mixed forests in southeastern New Brunswick, Canada. Overall, 51 taxa (0–12 taxa per 100 cm²) were found in the aerial diaspore rain and buried propagule banks, 36 taxa (0–9 taxa per 100 cm²) in the extant community. High degree of turnover among sample units and seasonal variability within the aerial diaspore rain indicate that a very intensive sampling protocol is necessary for accurate description of bryophyte propagule sources. We also argue that the emergence method is essential, given the taxonomic richness of these propagule sources. Of the two sources of propagules, the aerial diaspore rain across the growing season was more similar to the composition of the extant community than was the buried propagule bank.