Effects of Cattle Grazing on a Perennial Legume, Bitumen Trefoil (Bituminaria bituminosa (L.) Stirton), in a Mediterranean Grassland

Effects of Cattle Grazing on a Perennial Legume, Bitumen Trefoil (Bituminaria bituminosa (L.) Stirton), in a Mediterranean Grassland

A six-year study was conducted in a Mediterranean grassland in north-eastern Israel to investigate the effects of cattle grazing management on a perennial legume, Bitumen Trefoil (Bituminaria bituminosa (L.) Stirton). The relationship between grazing pressure and its relative plant cover was studied in the context of inter-annual variation in rainfall. Treatments included manipulations of stocking rates (moderate, heavy and very heavy) and of grazing regimes (continuous vs. seasonal), in a factorial design. The results showed that inter-seasonal rainfall variation was a dominant factor in the expression of plant cover changes of this species. Grazing showed no significant effect on plant cover of this species even under very heavy grazing pressure. The importance of this species as complementary forage at the end of the grazing season and its resistance to grazing is discussed within the framework of persistence of dominant species, despite wide variation in grazing regimes and climatic condition.