LICHEN AS BIO-INDICATORS OF ATMOSPHERIC POLLUTION AT AKWA IBOM STATE UNIVERSITY MAIN CAMPUS

The essence of this study was to assess the diversity and abundance of lichens in Akwa Ibom State University Main Campus with respect to Nitrogen abundance in the area. Eight (8) trees were selected for sampling and three (3) lichen species were found which includes; Phlyctis argena, Hyperphyscia adglutinata, and Graphis scripta belonging to 3 different families. Phlyctis argena had the highest number of occurrences on tree trunks and on the branches and also the most common species found in Akwa Ibom State University Main Campus. Lichen biodiversity count for the month of May was 377 for tree trunks and 112 for branches. June recorded 327 and 116 lichen count for trunks and branches respectively which showed a slight decline from the previous survey. For the month of July, lichen biodiversity count was 410 (tree trunks) and 162 for branches. All the species found during the 3 months survey were N-sensitive. Lichen species occurring mostly on the dominant tree species in the study area are (Wadyetia bifurcate, Caesalpinia pulcherrima and Mangifera indica). Lichen growth substrate analysis revealed that the growth substrate is acidic (pH range 4.59 – 5.89) and PM2.5 (21.1 – 28.2) for the 3 months of survey. Lichen Indicator Score (LIS) for tree trunk and tree branches recorded 47.13 and 14.00 respectively for the month of May which is above the Nitrogen Air Quality Index (NAQI) chart valuation of 0 - >1.25 which indicates that the air quality of the survey area for the 3 month were very N polluted. This study also shows that lichens can be used as prevention systems to protect public health, in particular diseases related to air pollution and as a potential alternative or complement to expensive chemical monitoring equipment.