Two sites, both affected by grazing but under different climatic conditions, were selected in Israel to study the effect of grazing on soil degradation. One site was selected in the Judean Desert, a dry environment (260 mm mean annual rainfall) with a long history of overgrazing and very little vegetative cover. The second site was selected in the Galilee Mountains where the climate is of Mediterranean type (650 mm mean annual rainfall) and the vegetative cover is much greater in spite of the

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... azing. Simulated rain experiments were performed in the field and in the laboratory in order to evaluate differences in hydrological and erosional response to rainfall between the two sites. The results show a clear difference between these two ecosystems. In the Judean Desert, where vascular plant cover is sparse, a crust was developed which enhanced overland flow and erosion. In the Mediterranean environment the overland flow and erosion were negligible under shrubs and relatively high at the intershrub corridors. At the hillslope scale a mosaiclike pattern of water and soil contributing and accepting patches was developed. Such a pattern usually protect the hillslope from being eroded. Runoff and erosion rates luere very high in the Judean Desert and negligible in the Galilee Mountains.[fr] Afin d'étudier l'effet du pâturage sur la dégradation des sols, deux zones de caractéristiques climatiques différentes soumises au pâturage ont été sélectionnées en Israel. L'une de ces zones se trouve située dans le désert de Judée, un milieu très aride (260 mm de précipitation annuelle moyenne) avec un couvert végétal peu dense et une longue influence du surpâturage. La deuxième zone se trouve sur les montagnes de Galilée, caractérisées par un climat méditerranéen (650 mm de précipitation annuelle moyenne) et un couvert végétal bien plus dense et ce malgré l'influence du pâturage. Afin d'évaluer le comportement hydrologique et érosif des sols de ces deux zones, des expériences ont été réalisées sous pluie simulée sur le ter [...]