Open access freely available online Nat. Life Sci. Commun. 2023. 22(2): e2023022 1 Natural and Life Sciences Communications: https://cmuj.cmu.ac.th Effects of Forest Restoration Age on the Species Diversity of Epiphytic Bryophyte Communities Puwadol Chawengkul 1 , Pranee Nangngam 1 and Stephen Elliott 2,* 1 Department of Biology, Faculty of Science, Naresuan University, Phitsanulok 65000, Thailand 2 Forest Restoration Research Unit and Environmental Science Research Centre, Biology Department, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand. We examined recovery of bryophyte diversity during forest restoration by the framework species method (FSM), as a component of overall biodiversity recovery—one of the defining indicators of restoration success. The epiphytic bryophyte communities in FSM trial plots (13 and 21 years since tree planting), were compared with those of old-growth forest in the upper Mae Sa Valley, northern Thailand. Bryophytes were surveyed in June 2019, on the bark of 3 framework tree species: Archidendron clypearia, Erythrina subumbrans and Sarcosperma arboreum. Fifteen species were recorded, representing 14 genera and 12 families in 3 morphological groups: acrocarpous mosses 4 species (27%), pleurocarpous mosses 5 species (33%) and leafy liverworts 6 species (40%). Within 13 years after restoration initiation, bryophyte species richness had increased to the same level as that recorded in old-growth forest. Furthermore, the bryophyte community species composition of the older restoration forest was more similar to that of natural forest than was the bryophyte community species composition of younger forest. We conclude that the FSM effectively recovers bryophyte diversity and directs the successional trajectory of the bryophyte community towards that of old growth forest within an acceptable time span. The use of bryophytes as indicators of forest restoration progress is discussed. Keywords: Conservation, Framework species method, Liverwort, Moss, Species richness Funding: Chiang Mai University funded the work of SE on this project. Citation: Chawengkul, P., Nangngam, P., and Elliott, S. 2023. Effects of Forest Restoration Age on the Species Diversity of Epiphytic Bryophyte Communities. Nat. Life Sci. Commun. 22(2): e2023022. Research article Editor: Wasu Pathom-aree, Chiang Mai University, Thailand Article history: Received: July 19, 2022; Revised: December 16, 2022; Accepted: December 26, 2022; https://doi.org/10.12982/NLSC.2023.022 Corresponding author: Stephen Elliott, E-mail: stephen_elliott1@yahoo.com Open Access Copyright: ©2023 Author (s). This is an open access article distributed under the term of the Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author (s) and the source. ABSTRACT