Baseline Survey of Lichen Flora in the Montane Forests of Mt. Mayo Range, Tarragona, Davao Oriental

This study presents a baseline survey of lichen flora in the montane forests of Mt. Mayo Range, Tarragona, Davao Oriental, an understudied region in southeastern Mindanao, Philippines. Lichens, known bioindicators and key ecological contributors, are increasingly threatened by deforestation and climate variability, yet little is known about their distribution in many Philippine montane ecosystems. Using a transect walk sampling method, 54 lichen specimens were collected, of which 16 species were identified across 7 families and 11 genera, indicating moderate species richness. Lobariaceae and Parmeliaceae showed the highest genus richness (3 genera each), while Physciaceae exhibited the greatest species count within a single genus (4 species), suggesting adaptability and ecological resilience. Diversity indices—Shannon (H = 1.787), Simpson’s dominance (D = 0.188), and Evenness (E = 0.918)— revealed a moderately diverse and balanced community structure. These results highlight the ecological stability of Mt. Mayo's montane habitat and its potential for hosting diverse lichen communities. This initial inventory fills a critical data gap and underscores the need  for  extended  lichenological  surveys  and conservation strategies across Mindanao’s unexplored forest ecosystems. The findings provide foundational data for future ecological assessments, conservation planning, and possible ethnobotanical applications of lichens known for their bioactive compounds.