Abstract
Inland desert dunes are regarded as the most fragile ecosystem in arid regions. A field study was conducted to evaluate the effect of human recreational camping on vegetation assemblages at four sites belonging to none, low, moderate and heavy recreational intensities on the sand dunes of Al-Ghada Nature Reserve. In each study site, four 10 x 100 m transects were established in the four cardinal directions to measure the different vegetation attributes. The results showed that all recreational levels significantly reduced the total vegetation cover, plant density, number of species, as well as Shannon-Wiener diversity and evenness indices. Heavy recreational intensities decreased the cover of the woody and grass species, and increased that of annual and weedy species. Non-metric Multidimensional Scaling ordination (NMDS) of vegetation presented a clear spatial separation of the four sampling sites reflecting their differences in vegetation association according to the recreational pressure. Indicator species value analysis (INDVAL) showed that the four recreational intensities were characterized by different indicator species with highest constancy and fidelity. The study concluded that recreational pressure significantly alters vegetation structure and diversity, and recreation activities should be restricted to conserve the ecosystem function of desert dunes that are sensitive to disturbance.