A study was conducted on the hills of Ulukigla (a county of Nigde Province) central-south Turkey. The area comprises typical steppe (1,350 m altitude) with a semiarid climate. Floristic composition and vegetation yield was compared in a 36,690 ha area protected from grazing since 1947 (i.e. 30 years at the time of study), with an adjacent public grazing area heavily grazed by livestock.
Four different slope aspects in both areas were selected to represent the soil moisture gradient present.
Vegetation data were collected at the beginning of grazing period in spring 1980, and at the end of the grazing seasons in 1979 and 1980. On each slope, eight 20-m long transects were established. Vegetation cover, composition and species frequency data were recorded at intervals along each transect. Herbage yields were estimated by cutting plants at ground level in 20 randomly thrown 0.1 m² quadrats at each location. Crude protein content of the dried material was determined.
Soil infiltration rate was measured at each location by a double ring infiltrometer.
Total vegetation ground cover (less than half that in the grazed, average 12.5%, than in the ungrazed, average 26.7%, area), composition, and dry forage yields were significantly less on the livestock-grazed hills. Two grasses (sheep’s fescue Festuca ovina and the annual, bulbous meadow-grass Poa bulbosa var. vivipara),a sage shrub Salvia criptantha and a perennial forb Asphodeline isthmocarpa were the species responsible for the the main differences in the ground cover.
Salvia criptantha (5.9% in the grazed area; 1% in ungrazed area)and thyme Thymus squarrosus (2.4% in grazed area; 4.3% in ungrazed area)dominated the grazed area vegetation, and F.ovina and P.bulbosa dominated the protected area.
These results indicate that palatable forage grasses were replaced by less palatable shrub species in the heavily grazed area, and that secondary succession was still taking place in the protected area.
The grazed and ungrazed areas did not differ significantly in infiltration rate averaged across all slope aspects (protected - 20.5 cm/h; grazed - 22.1 cm/h).
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