ASSESSMENT OF TREE BIODIVERSITY OF TWO TROPICAL RAINFOREST IN CROSS RIVER STATE, NIGERIA [ ]


In this study, the status of biodiversity conservation was assessed. Multistage sampling technique was used for the study. The sampling entailed primary, secondary and tertiary sampling units. Tree identification and detailed growing stock were determined within the tertiary sampling plots (40m x 50m). Biodiversity status was assessed using Shannon-Wiener diversity (H'), species evenness (E) and Simpson dominance index. In addition, species similarity index of the two forest reserves was determined using Sorensen’s indix (based on qualitative and quantitative data). The study revealed that dominant families in Afi River Forest Reserve are Caesalpinioideae, Mimosoideae, Euphorbiaceae and Meliaceae while for Oban Forest Reserve, Caesalpinioideae, Mimosoideae, Moraceae and Papilionoideae were the dominant families. The species similarity index of the two forest reserves was 84%, implying very high floristic similarity in their constituent tree species. The species richness index were 10.44 and 10.61 for Afi River and Oban Forest Reserves respectively while the values of Shannon-Wiener diversity index (HI) for Afi River Forest Reserve and Oban Forest Reserve were 3.827 and 3.795 respectively. The species diversity was higher in Afi River Forest Reserve than Oban Forest Reserve. More studies aimed at providing qualitative and quantitative assessments are required in order to further close the existing information gap in the study area.