NUTRITIONAL ADAPTATIONS OF CAPER SHRUB (CAPPARIS-OVATA DESF) TO ENVIRONMENTAL-STRESS

Capparis ovata, a prostrate shrub found in most arid zones of Mediterranean countries, has been cultivated extensively for the last ten years, although its physiology is unknown. To test the effect of fertilization on Capparis, two year old seedlings were grown in pots, and doses of nitrogen (N), phosphorus (P), and potassium (K) were added in a factorial design. Total biomass production, nutrient concentration and uptake, and allocation patterns were studied. Fertilization induced an increase in productivity and nutrient tissue concentrations of both N and P. Capparis showed characteristics of a plant adapted to poor soils, where water and nutrients are strongly limiting. Increased K and Ca uptake to maintain the hydric balance, thorny stems and a heavy investment in chemical defences to prevent grazing, and a deep mycorrhizal root system allow Capparis to grow successfully in very infertile soils and to endure environmental stress.