Correlations between concentrations of elements in plants

Abstract

INTEREST in the cycling of the elements through ecosystems has increased in recent years, and numerous plant species have been analysed. It can be assumed that elements do not cycle independently in vegetation because they are involved in the basic structure and function of cells, which have similar biochemical pathways. Thus concentrations of different elements must be correlated. Little attention has been given to the relationships between concentrations of elements within or across a variety of species. This is undoubtedly because the chemical composition of individuals within a species may vary considerably from one site to another1. The ratio of different elements may be relatively unaffected by this geographic variation because natural vegetation can absorb and accumulate nutrients selectively2 maintaining a balance of intracellular concentrations to optimise metabolism, protein synthesis and tissue production. If concentrations of elements were correlated across a variety of species from different sites, this would indicate a relatively constant ratio between concentrations of elements among plant cells. I report here correlations between concentrations of nitrogen, phosphorus, magnesium, calcium and potassium, across a variety of species, which seem to be based on biochemical similarities between elements in cell metabolism.