Assemblages of native bryophytes in secondary forests with introduced <i>Quercus rubra</i>
2 June 2016
Woziwoda, Beata; Staniaszek-Kik, Monika; Stefańska-Krzaczek, EwaThe diversity of bryophytes was studied in the post-agricultural forests that were planted in Central Poland at the sites that are suitable for a mesic coniferous forest (abbreviation: CFS) and for a mesic broadleaved forest (abbreviation: BFS), and which were dominated by the native Scots pine Pinus sylvestris and the alien (North American) red oak Quercus rubra. The structure and composition of the bryophyte assemblages were analysed in terms of the forest site and substrata availability. Special attention was paid to introduced Q. rubra as a host species for native bryophytes.
A total of 54 bryophyte species, 9 liverworts and 45 mosses were found on the 90 plots (= phytosociological relevés, 10 x 10 m in area; 45 at each forest site) that were studied. DCA analysis showed that the bryophyte assemblages of the P. sylvestris-Q. rubra secondary forest community significantly varied at CFS and BFS; the similarity of the composition of bryophyte species was 36.8%. The substrate preferences (epigeic, epixylic, epiphytic) as well as the growth form and the life form of the recorded bryophytes were also different at CFS and BFS, while the proportion of bryophytes that had a characteristic life strategy was very similar.
The introduced Q. rubra was inhabited by 28 bryophyte species, including two liverworts. This tree hosted 64% of CFS and 47% of BFS bryophyte flora and as a host for epiphytes, the species successfully fulfilled the functional role of the native oaks (Q. robur and Q. petraea). The introduction of Q. rubra may contribute to the restoration of post-agricultural forests and to the conservation of epiphytic bryophyte species. On the other hand, the negative impact of the introduced tree that was observed on the ground flora (including bryophytes) questions the benefits of Q. rubra for the conservation of native biodiversity in general.