Response of shrubs and under-shrubs to protection againts grazing in two islands of lake bardawill, mediterranean coast of Egypt

الملخص EN

The effects of grazing by livestock on three palatable under shrubs (Convolvulus lentos Vahl, Moltkiopsis ciliate (Forssk) I.

M.

Johnst and Echiochilon fruticosum Desf) and three shrubs (Artemisia monospermous Del., Thymelaea hirsuta (L.) Endle and Zygophyllum album L.) were studied in two islands at Zaranik, Lake Bardawil (northern Sinai) on the Mediterranean coast of Egypt.

For the under-shrubs, seventeen years of protection against grazing has led to an increase in their vigor, cover and density.

The density of the palatable shrub Artemisia monospermous was greater in the heavily grazed area, while its cover and vigor were higher in the unglazed area.

Thymelaea hirsute and Zygophyllum album were more abundant in the heavily grazed area than in the protected area.

Soil fine fractions were higher in the protected areas, while soil salinity and organic carbon were higher in the heavily grazed areas.

The three shrubs showed positively skewed size distributions in both protected and heavily grazed sites.

Recruitment occurred through vegetative sprouts only for the three palatable under-shrubs under the heavy grazing intensity and through both seedlings and vegetative sprouts in the protected areas except for Convolvulus lunates.

Results obtained indicate that the three grazing tolerant under-shrubs were under pressure and there is likely to be a decline in their vigor, cover and density unless active grazing control is initiated.