Data Analysis

Statistical analysis on species richness, species abundance, evenness, species diversity and habitat similarities or differences in all the zones were examined and computed. Data from all the zones were pooled to obtain total diversity of insects for the entire study site and sampling period. Three diversity indices were computed using PRIMER 6 & PERMANOVA+ to compare data from all three zones. These were preferred because they allowed for qualitative assessment of sites by comparing their diversity indices (Chao et al. , 2005) which were treated for biodiversity assessment (Marshall et al ., 2006). Diversity indices (Margalef index, Shannon-index, Simpson index and Evenness) were calculated and compared between all three zones.
1. Species richness (Margalef): \(d\ =\ (S-1)/Log\ (N)\) - This is a measure of the number of species present, making some allowance for the number of individuals.
2. Pielou’s evenness: \(J=\frac{H^{\prime}}{In(S)}\) - this is a measure of equitability, a measure of how evenly the individuals are distributed among the different species
3. Shannon-Wiener index: \(H\ =-\ \Sigma\ pi\ ln(pi)\) – incorporates both species richness and equitability components.
4. Simpson index (D): It is influenced by dominant species (Measures dominance and evenness).
ni = the number of individual species in the sample,\(\Sigma\ ni\ =\ N.\ pi\ \)= the proportion of individual species in the sample, \(pi\ =\ ni/N\). S=the number of species in the sample, N= the total number of individuals in the sample.