Abstract Detail

Bryological and Lichenological Section/ABLS

Barbé, Marion [1], Fenton, Nicole [2], Bergeron, Yves [2].

So close and yet so far away: the role of local and regional propagule dispersal in re-assembling bryophyte communities.

How do source populations at different distances influence bryophyte community regeneration? Answering this question is key to species conservation in disturbed bryophyte communities such as those in boreal forests exploited for timber production. In this study, our objectives were: 1. To characterize the α diversity of the aerial propagule rain (PR) by taxonomic, habitat and life strategy groups, and to compare it to that of the extant community (EC) 2. To compare compositional turnover (β diversity) between the two community types among habitat types in a disturbed landscape (i.e. disturbed matrix, edge and core of residual habitat) 3. To identify potential dispersal patterns of bryophytes at different spatial scales by comparing PR and EC at different distances (meters to hundreds of kilometers) at the community (similarity indices) and species level (presence). PR composition was determined by the emergence method using Petri plates filled with Parker Thompson nutrient agar. PR was trapped (spring and fall; 2013, 2014) in three fires, in three residual forest patches per fire, with sampling at the core and the edge of each patch. Three plots in the fire matrix were also sampled in each fire. EC was sampled in the same plots as PR as well as on three others plots along a linear transect across each residual forest patch. The α diversity of PR differed neither among residual patches nor positions, and was mainly composed of pioneer-colonist species and acrocarpous species. Both specific richness and abundance of bryophyte differed significantly between PR and EC. Clustering analysis indicated that PR and EC from patches as well as EC from fires formed distinct groups with their own species assemblage. PR communities were more similar among themselves than to other assemblages. Similarity indices did not provide clear dispersal patterns of bryophytes due to the marked differences of diversity and abundance between EC and PR. In contrast, at the species level, comparisons between EC and PR suggested that propagule exchanges were more regional than local. Identifying the characteristics of residual patches that enhance the similarity between EC and PR is a priority in order to maintain sources of specific species able to efficiently recolonize the disturbed matrix. Unlike what was expected, the present conclusions indicate that residual patches are mainly sources of propagules at large scale rather than small scale for bryophyte dispersal. The paradigm regarding the poor dispersal capacity of bryophytes is once more open to discussion.

1 - Université du Québec en Abitibi-Témiscamingue, IRF, 445, boul. de l'Université, 5, Rouyn-Noranda, Quebec, J9X 4E5, Canada
2 - Université du Québec en Abitibi-Témiscamingue, IRF, 445, boul. de l'Université, Rouyn-Noranda, Québec, J9X 4E5, Canada

Keywords:
Residual patches
boreal ecosystems
Community ecology
Propagule rain
Dispersal patterns.

Presentation Type: Oral Paper:Papers for Sections
Session: 38
Location: Salon 8/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 10:30 AM
Number: 38008
Abstract ID:235
Candidate for Awards:A. J. Sharp Award,Cinq Mars Award