The use of Shanon Weiners diversity index in the assessment of floral diversity and equitability of Neni–Nimo Watershed in Anaocha L.G.A. of Anambra State, Nigeria

The study on the floral diversity of Neni-Nimo watershed in Anaocha L.G.A. of Anambra State was conducted between November 2009 and July 2020. The aim of the study was to find out the species richness and the floral biodiversity of the watershed. In this study, the watershed was divided into three sites, the forested site, the fallow site and the current usage site. The experiment was laid out in a Randomized Complete Block Design. The ecological methods used in this study are the Point Centred Plotless Count sampling technique for areas dominated by trees while the Plot Count technique using quadrats were used for sampling the areas dominated by forbs, shrubs, climbers and grasses. The vegetation data collected was used to estimate the species richness of the different plant growth forms, the diversity and equitability of the various growth forms encountered were calculated using Shanon Weiners diversity index. The Shanno Weiners diversity index shows that the forested areas had the highest floral biodiversity than the fallow and current usage area. Regression analysis shows that a significant relationship exists between species abundance and floral biodiversity at a p-value of <0.05 for all plant growth forms in the watershed except for grasses and as abundance increases, diversity also increases.