Selecting species for recharge management in Mediterranean south western Australia – some ecophysiological considerations

This paper makes a case for coupling quantitative relationships between plant function and environment with an understanding of local hydrology as a basis for selecting species for recharge control and salinity management in the cropping zone (rainfall < 500 mm per year) of south western Australia, a region with a Mediterranean-type climate. This case is made in two parts: (a) A review of some physiological responses of trees to drought and trends in these responses in relation to the rainfall patterns across the natural distribution of species. In general low-rainfall species use less water during winter and early spring and have greater physiological activity during summer than high-rainfall communities. Trends in leaf water relations and stomatal responses to soil drying are consistent with this observation; species from lower rainfall environments have lower leaf water potential at the turgor loss point and weaker stomatal responses to soil drying than those from high rainfall areas. (b) A physiological growth model for Eucalyptus globulus is used to demonstrate how a quantitative description of key plant-environment interactions may be used to analyse the growth and mortality risk for combinations of site, climate and stand management.