Correlations between the concentrations of bio-elements in several Mediterranean plant species.

Correlations between foliar concentrations of main bio-elements (C, N, Ca, P, K) in several Mediterranean plant species have been studied, considering the life forms and substratum status (calcareous or siliceous soils) in th e sampling sites of the plants. For all the study plants, in all life forms , phosphorus concentrations are positively correlated with those of nitroge n. By contrast, when grasses are disregarded, concentrations in calcium and phosphorus are negatively correlated with those of carbon. In some species of plants (particularly the nanophanerophytes growing on siliceous soils) the concentrations in potassium and phosphorus are positively correlated wi th those of calcium; whereas concentrations of these two elements are negat ively correlated with the carbon concentrations. Element concentrations are not strictly linked with substratum types, but more to the life forms of p lants. Plants growing in different environments can have similar element co ncentrations.