Relationship Underlying Seedlings Composition and Abundance of Mature Tree Species at Coral Rag Forest of Mnarani Ruins

Abstract

The tropical regions have a rich diversity of tree species which provide the basis for a number of different forms and scales of economic activity. This study therefore was conducted with an aim of enhancing the knowledge of tree species diversity (seedlings and mature trees), and their relationship at the site. The experiment was laid out in three transects and quadrants in the forest: for mature trees the transects measured 100 m by 20 m, whereas for the seedlings quadrants measured 5 m by 5 m. That is along the ocean (T1), along human settlement (T2) and along the forest path (T3). Data was collected by counting mature trees species and seedlings. Data was analysed using R software 3.4.4 and results showed that a total of 22 tree species were recorded in the forest. In T1, the highest (22) species richness was recorded with 4 tree species restricted to the site (Bourellia nemoralis, Flueggia virosa, Turraea wakefieldii and Eryithrinia abyssinica). Combretum schumanii was most abundant in mature trees (89) followed by Lecaniodiscus fraxinifolius (36), Ochna thomasiana (21) and Adansonia digitata (14). All the above abundant species except Adanosnia digitata (2) were also abundant in seedlings with (189), (11) and (21) seedlings respectively. In T2, 9 tree species were recorded. Azadirachta indica was the most dominant in both mature trees (40) and seedlings (261) while Sterculia appendiculata recorded the lowest (1) and (0) respectively. T3 was rich with three exotic tree species namely Delonyx regia, Azadirachta digitata and Lannea schweinfurthii. Lecaniodiscus fraxinifolius was the most common with (35) followed by Combretum schumanii (11). While the seedlings were (23) and (67) respectively. In conclusion, it was evident that anthropogenic factors reduced species richness and the corag rag forest had more indeginous tree species and good seed recruitment.