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.