Baseline Inventory, Taxonomic Identification and Characterization of Lichens at Sophia Point Rainforest Research Centre, Essequibo River, Guyana

Lichens are good indicators of environmental conditions, yet their diversity in inland Guyana remains poorly documented. This study identified and characterized lichens at the Sophia Point Rainforest Research Centre located near the confluence of the Essequibo, Mazaruni, and Cuyuni rivers. A quantitative, non-experimental observational approach was used. Suitable host trees were purposively selected, and lichen communities were examined within a standardized bark zone approximately 1.5 m above ground level. Field identification was based on thallus morphology, growth form, colour, attachment, lobation, surface characteristics and reproductive structures, while representative specimens were examined in the laboratory and chemical spot tests were applied where necessary. Sixteen lichen taxa were recorded, representing a broad range of foliose, crustose, fruticose and crustose-leprose growth forms. Foliose taxa were the most conspicuous component of the assemblage. Chemical spot testing provided additional diagnostic information, with species displaying distinctive K, C, KC and P reactions as well as predominantly negative profiles. The observed diversity suggests that the bark substrate provides heterogeneous microsites capable of supporting lichens with contrasting structural and reproductive characteristics. The study establishes a baseline for lichen diversity at Sophia Point and contributes to the body of lichenological knowledge from inland Guyana. Continued inventories across additional host species, habitats and seasons, supported by detailed taxonomic verification, are recommended to improve understanding of lichen diversity, distribution and ecological significance and conservation in Guyana.