Herbaceous plant species richness and composition in moist Midlands Mistbelt Grasslands in KwaZulu-Natal: is there a relationship to veld condition?

Abstract

This study investigated the relationship between grazing veld condition and herbaceous plant species richness in the moist Midlands Mistbelt Grassland in KwaZulu-Natal. The observed herbaceous plant species richness and composition of 12 sample plots (50 m × 50 m) was determined in three study sites using quadrat samples (50 cm × 50 cm in size) and the estimated species richness was determined using the jacknife estimate of species richness. Grazing veld condition was established using the spike-point sampling technique and the benchmark method for data analysis. The relationship between the herbaceous plant species richness and the veld condition scores was determined using the linear and curvilinear correlation analysis. Veld condition scores for the 12 plots ranged from 2.43% to 120.65%, whereas the species richness ranged from 46 to 107 (observed) and 60 to 136 (estimated) species per plot. There was no relationship between herbaceous plant species richness and grazing veld condition scores (r = −0.2723, P = 0.392, df = 10, n = 12). Therefore, veld condition scores cannot be used as a surrogate for species diversity and vice versa. There was a positive curvilinear relationship between observed grass and forb species richness (r = 0.5478, P = 0.0652, df = 10, n = 12).