Ecophysiological strategies were examined for some species colonizing the different habitat types of north Egypt, namely, saline flat covered by sand sheets, a transitional area between the saline flat and rocky ridge, rocky ridge covered by gravely sand deposits and a non-saline depression. These habitats are characterized by marked soil variations which affect species tolerance. Water content, relative water content, pH, dry matter percentage, chlorophyll content, proline and carbohydrates varied in the species characteristic of each habitat type. Such information has made it possible to identify the most suitable habitat for each species within the range of habitats where they occur. (C) 1996 Academic Press Limited