Diversity of lichens at Mount Cameroon, South West Region, Cameroon

Concern about maintaining the biodiversity of lichen communities’ species has been an issue with lichenologists for many years. Many of the understudied regions face increasing threats from urban development, pollution, and potentially climate change, among other factors. The objective of this study was to examine the diversity of lichens on Mt. Cameroon. To achieve this objective, eight collection sites were surveyed on two flanks of the mountain at elevations ranging from 3 to 2178 m above sea level. The visual estimate sampling method using circular plots was adopted for the survey. Voucher specimens were collected in triplicate and deposited in the herbaria in Limbe and the University Buea. Lichens were identified by studying the morphology and chemical spot test. The morphology of the thallus and reproductive structures were examined under the stereomicroscope at 10×. The K-test, C-tests and KC-spot test were performed for each specimen with KOH and Ca(OCl) 2 . The abundance rating scale, species diversity, similarity and richness indices were computed. Identification by molecular, morphological and chemical spot tests produced a total of 89 species, 22 site-specific species, 52 genera belonging to 27 families and 11 orders. Four lichen specimens were identified to genus level and eighty-five to species level. According to the Cameroon lichen database, 82 of these are new discoveries. Parmeliaceae, Heterodermia, Usnea and Dirinaria applanata dominated the area. The identified species occurred in six growth forms and from nine substrates types. Foliose and corticolous lichens were most represented. Among the sites surveyed, Upper Buea situated on the leeward flank at high altitude >1000 m, recorded the highest diversity and site-specific species.