Format: ORAL

H.A.C. Dilrukshi1, S.C.K. Rubasinghe2*, N.C.S. Ruklani2

1 Postgraduate Institute of Science, University of Peradeniya, Kandy, Sri Lanka 2 Department of Botany, Faculty of Science, University of Peradeniya, Kandy, Sri Lanka

Epiphytic bryophytes stand out as vital indicators of ecosystem transformations in rainforests due to their heightened sensitivity to environmental shifts. Succession, the gradual evolution of plant communities over time leading to the establishment of a mature and stable ecosystem, can be effectively monitored by tracking the presence and abundance of specific species. This study aims to investigate the response of epiphytic bryophytes to forest succession in three lowland rainforests in the Southern Province of Sri Lanka; Wilpita, Kottawa, and Pituwala. The assessment of bryophytes on 135 trees across three succession stages (early, intermediate, late) in each forest site was conducted, and the impacts of forest succession stage, tree species richness, and diameter at breast height on epiphytic bryophyte species richness per plot were analyzed using generalized linear mixed models. Results revealed the identification of 73 bryophyte species across the three forests. The diversity of epiphytic bryophytes exhibited a pattern, being highest in late succession stages and lowest in early succession stages across all three forest sites. The families Calymperaceae, Sematophyllaceae, and Jungermanniaceae emerged as the most abundant among bryophytes in the three lowland rainforests. A significant revelation of this study is the identification, for the first time, of the pivotal role played by tree species richness in influencing the richness of epiphytic bryophytes in the Kottawa, Pituwala, and Wilpita forests. Notably, higher tree species diversity in late succession forests is found to be a key factor contributing substantially to the conservation of epiphytic bryophytes in lowland rainforests. This study underscores the importance of exploring epiphytic bryophytes in tropical lowland rainforests in Sri Lanka, offering valuable insights into successional processes and ecosystem dynamics. The obtained information holds crucial implications for the formulation of effective conservation and management strategies, particularly in light of the persisting environmental changes.