Biodiversity

Biography

Biography: Ali El-Keblawy

Abstract

Plant communities of the arid deserts are facing several stresses, such as high temperatures, repeated draught and overgrazing. The impacts of protection from grazing for two years on plant diversity, richness, abundance and community structure were assessed in sand dunes and gravel plains of Dubai Desert Conservation Reserve. During the two years, the study area received significantly less rainfall than the average and consequently was a good chance to assess the impact of draught and protection from grazing on community attributes of the two substrate types. Protection for two years significantly increased plant diversity, abundance and sizes in sand dunes. In gravel plains, however, protection resulted in the reduction of most of the community attributes. The reduction was significant in the grazed, but not in the protected sites, indicating that grazing exaggerated the negative effects of drought in gravel plains. The positive effect of protection from grazing in sand dunes indicates that many of sand dune plants are less affect by draught; many of them were grown nicely after very little showers. Water irrigation was provided for both protected and grazed sites on sand dunes. Species richness and abundance in the irrigated exclosures were twice that in the irrigated open grazed sites. In addition, species richness, plant abundance and average plant sizes attained significantly greater values in the irrigated than in non irrigated plots. The results conclude that both rainfall and grazing are limiting factors in shaping plant community and their impact is dependent on the soil type