ENVIRONMENTAL CORRELATES OF GEOGRAPHICAL-DISTRIBUTION OF TERRESTRIAL VERTEBRATES IN ISRAEL

Species richness in Israel was studied by correlating the number of sp ecies of mammals, birds, and reptiles in 30 x 30 km squares with sever al environmental factors. The most diverse areas in Israel (in terms o f number of species) were transition zones between the Mediterranean, Irano-Turanian, and Saharo-Arabian regions. For mammals and birds, the factors best correlated with species richness were, in decreasing ord er: number of isohyets per square, mean annual precipitation, and numb er of plant communities. These factors are highly correlated with lati tude, hence a very high correlation exists between latitude and specie s richness. For reptiles, species richness was significantly correlate d with the number of soil types, followed by mean annual evaporation a nd mean August temperature. Most environmental factors examined were h ighly correlated among themselves, hence no definite conclusion as to the most important factor can be drawn. For terrestrial vertebrates wi thin Israel, species richness declines from north to south, and its va riation is predominantly explained by abiotic and vegetation factors.