Gaolathe Tsheboeng, Mike Murray-Hudson, Keotshephile Kashe, and Anastacia Makati
Braun-Blanquet, Cluster analysis, Disturbance
This study aimed to determine the influence of flooding frequency on the species composition and distribution of riparian woodland vegetation in the Okavango Delta. Sampling was done in 20m × 50m plots in the Panhandle, Seronga, Jao, Moremi and Boro. Plant cover, seedling density, species richness and diversity were determined at each site. Plant cover was estimated using the modified Braun-Blanquet cover/abundance scale. Annual flooding frequency was also determined at each site. Plant species fell into two assemblages occurring at each site. There was spatial variation in mean cover, density, species diversity and richness in the Okavango Delta. ANOVA followed by Tukey post hoc analysis showed that in Seronga mean seedling density was significantly higher than in Boro and Moremi. In the Panhandle, seedling density was higher (p<0.05) than in Boro while in Jao it was higher (p<0.05) than in Moremi. Species richness was higher (p<0.05) in Seronga, Jao and Panhandle than in Moremi. Species diversity was higher (p<0.05) in Boro, Jao, Panhandle and Seronga than in Moremi. This study has shown that there is a potential to use riparian vegetation to reconstruct historical hydrological gradients.