Lichen Inventory of an Urban Ecosystem: A Case Study from Ngaoundere, Cameroon

Lichens have proven to be excellent bio indicators. An inventory of the lichens present in an area is an important step in assessing pollution. It is to assess the extent of air pollution that an inventory of the different species of lichens in an area along the heavy axis of the city of Ngaoundere was carried out from June to August 2023. The 3 study stations are located along the Ngaoundere – Garoua, Ngaoundere – Toubora and Ngaoundere – Meiganga highways at Tchabbal, Borongo and Wakwa respectively. The relative abundance and frequency of different species, thallus type and phorophytes were calculated at the three stations as well as the Shannon diversity index. The inventory identified 25 species in 15 genera and 9 families. The abundant species are Physconia detersa, Permotrema austrosinense and Hypotrachya livida with a frequency of 11.93%, 11.85%, 11.73% respectively. The least abundant species is Physcia apolia with a frequency of 0.41%. The most abundant and diverse family is Permeliaceae with 1382 individuals, including 11 species and 5 genera. Foliaceous are the most abundant with a frequency of 69.02% and fruity are the least present with a frequency of 7.6%. Abundance and diversity varies according to the stations. The Wakwa station is the least rich in lichen, followed by the Borongo station. The Tchabbal station is the most diverse in lichens and this can be explained by the relative weakness of road traffic and consequently of air pollution of this station.