lichen inventory and species diversity at coastal ecosystems at No. 63 Benab, Berbice, Guyana

This study evaluates and compares lichen diversity at two coastal sites at No. 63 Benab, Berbice, Guyana. The study was completed in three phases. Phase one included the collection of the lichen specimens from the sites; Phase two consisted of the identification of the lichen specimens obtained from field visits and Phase three included the analysis of the data done on R version 4.2.2 (R-Studio) and Microsoft Excel to determine which of the sites had the highest lichen diversity. Sampling plots of 2000 meter square (2000 m2) for each of the two agroecosystems was demarcated and at both locations, 50 m x 40 m study plots were established, and samples of healthy mature trees were identified from each plot to determine species richness, evenness, and diversity of the lichen communities. The trunks of 40 healthy individual trees were intercepted with twine in the North, South, East, and West quadrants (each measuring 50 by 100 cm). A total of fifty-two thousand three hundred eleven (52,311) lichens were identified belonging to fifteen (15) families, twenty-three (23) genera and thirty (30) species. This research based on the available literature has reported seventeen (17) new species of lichens from eleven (11) families as first-time record of species that were not previously identified for Guyana and so adds to the biodiversity of lichen flora in the country. First time records for Guyana included four (4) species of lichens from the family Parmeliaceae; one (1) species from the family Chrysotrichaceae; one (1) species from the family Teloschistaceae; two (2) species from the family Lecanoraceae; one species from the family Arthoniaceae; two (2) species from the family; one (1) species from the family Stereocaulaceae; two (2) species from the family Phlyctidaceae; one species from the family Collemataceae; one species from the family Cladoniaceae and one species from the family Lichinaceae. The lichen communities were compared using the Simpson's Diversity Index, Shannon Diversity Index, Menhinick's Index and Pielou's Index. Statistical analyses were executed with the help of the R and Excel software and it was possible to distinguish between the two sites' species distribution, diversity, and abundance. The results showed that site # 1 lichen community had a higher species richness, species evenness, species diversity and abundance than site # 2. Four (4) species of lichens showed specificity towards twelve (12) species of host trees.