The effect of grazing on the abundance of wild wheat, barley and oat in Israel

Abstract

Differences in percentage cover of wild cereal species between the two sides of fences with different intensities of cattle grazing were recorded at 14 sites in mediterranean grasslands in northern Israel where these species are native. The cover of the tall wild cereal grasses ( Triticum dicoccoides, Hordeum spontaneum, Avena sterilis), individually and combined, was in most sites significantly and substantially higher on the protected or more lightly grazed side of the fence, and showed a strong negative correlation with grazing intensity. It was also negatively correlated with perennial grass cover. The results support the hypothesis that the distribution of the wild progenitors of cereals in the Middle East has been restricted by millenia of heavy livestock grazing to refuge habitats, and suggest that an important mechanism has been the relative vulnerability of these grasses to close grazing in the growing season. It is suggested that considerable variation in attributes affecting tolerance of grazing or clipping may be found among present wild populations. In any in situ conservation programmes the effects of grazing management on both abundance and genetic diversity of the populations will have to be considered.