Stoichiometry and Nutrition of Plant Growth in Natural Communities

Stoichiometric relations in plants, with emphasis on C:N:P, are reviewed. Both theoretically and empirically it is found for whole plants as well as for different tissues that nitrogen concentrations increase slower than phosphorus concentrations. A lack of data prevents the establishment of relations between nitrogen and other elements. Optimal element ratios where elements are simultaneously limiting growth can be established. There is a considerable variability around these optimal ratios in observed values. Conclusions about the ecological significance of stoichiometric relations based on these observations may therefore be biased. The significance of this variability remains to be established.