Colonization Dynamics of Lichens Along Altitudinal Gradients in the Kumaun Himalaya, India

Despite ecological relevance and susceptibility to environmental change, the Kumaun Himalaya, a biologically rich region of Uttarakhand, has received scant attention on the diversity and dynamics of lichens. In this context, the goal of this study was to examine the distribution and variety of lichens in the Hawalbagh block region of Kumaun Himalaya. For this purpose, lichen samples were collected between 1400 and 2200 m in altitude to document their diversity and distribution patterns using a stratified random sampling method. The study area was categorized into three elevation zones: lower elevation (1000-1400 m) dominated by pure pine forest; middle elevation (1400 - 1800 m) was characterized by pine-oak mixed forest, and the higher elevation (100-2200) forest zone was dominated by oak trees. An extensive field survey was conducted to collect primary data. During the study, a total of 46 species of lichen belonging to 29 genera and 12 families were encountered. Maximum 60.87% species were found as foliose, followed by crustose (19.57%) and fruticose (15.22 %) lichens. Whereas dimorphic, squamulose, and fruticose forms of lichen contributed 2.17 %, respectively. A single species of dimorphic type ( ) was observed on the soil surface in the higher region. During the field survey, it was Cladonia verticillata
also observed that lopping of trees for fuel and fodder, increasing tourism activity, construction of motorable roads Quercus
and resorts, particularly in the high-altitude region at Shitlakhet-Syahi Devi, frequent occurrence of forest fire, and grazing at middle and lower altitudes in pine forests, provide a threat to the lichen taxa of the region. Besides heavy anthropogenic activities, lichens on soil and rock surfaces, even on lower regions of tree trunks, are also threatened by their survival. This study suggests that habitats should be protected to support the lichen flora along with other vegetation of the region. It would be helpful to prevent the colonisation of several terricolous and saxicolous lichens on ground and rock surfaces, which are declining due to frequent occurrence of forest fires in the lower reaches of the study area.