Diversity and Distribution Patterns of Lichens in Different Ecological Conditions in the Garhwal Himalaya, Uttarakhand

This study investigated the distribution and diversity of lichens across different elevational zones in the Madhyamaheshwar Valley, Garhwal Himalaya. A total of 77 lichen species from 22 families and 52 genera were recorded across three altitudes: lower (1600–2300 m ASL), middle (2600–3100 m ASL), and higher (3200–3600 m ASL). Lichen diversity increased with elevation, with 48 species recorded at higher elevation sites, Madhyamaheshwar and Budha Madhyamaheshwar, 17 at middle elevation sites, Maikhamba-Chatti and Koonchatti, and 12 at lower elevation sites, Goundar Village, Lower Bantoli, Upper Bantoli, Khadarakhal, and Nanuchatti. Temperature and humidity were identified as significant factors influencing lichen diversity, with cooler conditions at higher elevations supporting more diverse communities. Slope and cardinal directions also influenced species distribution, with gentler slopes and southern cardinal directions supporting higher diversity. Lichens have a preference for tree bark as a substrate, with certain species exhibiting greater host specificity. These findings underscore the crucial role of environmental factors in shaping the distribution of lichen communities across elevational gradients in the valley.