Population frequency, density, abundance and diversity of tree species in ten communal forests of northern Cross River State, Nigeria

Due to the high rate of deforestation and degradation activities carried out by local people on forest ecosystem, this study assessed the tree species population frequency, density, abundance and diversity in ten communalforests (two each) of the five Local Government Areas (Ogoja, Yala, Bekwarra, Obudu and Obanliku) of Northern Cross River State, Nigeria using the modified Whittaker method. The study was carried out from (November, 2015 – May, 2016). In each site a 30 × 90 m plot was laid out in a spoke design and tree species present on the plots were recorded. Survey results revealed a total of 143 trees belonging to 45 families in the study area. The relative frequency and abundance of the tree species under study varied across the study sites. The highest percentage frequency of the tree species was 24% while the lowest was 6%. The highest population density recorded for the tree species was 2 stem/ha while the lowest was 0.1666 stem/ha. Abundance results show that the species were mostly low in their distribution with abundance of (1.00≤AB≤2.99) except in Bechevie and Sankwala forest where there were occasional (3.00≤AB≤3.33). Results from the study area show that Sankwala (8.18) had the highest species richness index while Omulako (4.63) had the lowest. Sankwala forest had the highest diversity index value of 2.12 while Omulako (1.21) had the lowest. This study shows that majority of the trees were low in their distribution and are declining in the study area. Appropriate decisions and measures in sustainable forest management are strongly recommended so that the forests would continue to provide goods and services for communities around the forests.