Consequences of protection from grazing on diversity and abundance of the coastal lowland vegetation in Eastern Saudi Arabia

Fourteen years of protection against grazing and human impacts of the coastal lowland vegetation in Eastern Saudi Arabia (an experimental site in the vicinity of Al-Hassa region) has led to an increase of 68% in the total cover, 33% in species richness and 32% in species relative evenness. Many of the species with significantly higher abundance in the protected area are important forage and/or fuel plants. Soil salinity and important soil nutrients (N, K, Mg and Na) are significantly higher in the free grazing area which may be attributable to the fact that the passage of herbage through the grazing animals often enhances nutrient availability.