Responses of Karoo plants to hail damage near Williston, Cape Province

Abstract

Although hail contributes occasionally to the water budget in the Karoo, it may also cause localized, extensive damage to plants. A comparison was made between damaged and undamaged vegetation to assess the recovery of species, growth forms and palatability classes following a hail event during autumn (April 1988) in natural veld on a farm near Williston, Cape Province. Grazing stock had been withdrawn for the fourteen months between the time of the damage and the study. There was no significant long-term reduction in species diversity, growth form richness, percentage plant cover and growth form richness in the hail-damaged vegetation. There was a significantly lower cover of palatable plants in the hail-damaged area. It is concluded that the supposed long-term effects of hail damage on vegetation composition may be seriously overstated and that alleviating grazing pressure during the year following hail damage may contribute greatly to successful recovery.