The relationship between Sr and Ca accumulation in the major constituents of a terrestrial community resident on a celestitic (Sr SO4) soil in S.W. England

Stable Sr and Ca concentrations were determined in natural populations of a plant species (Urtica dioica) and several invertebrate groups (isopods, earthworms, gastropod molluscs and a chilopod) from a celestite (SrSO4)-rich site near Yate, S.W. England. Sr concentrations were not biomagnified in successive trophic levels. Sr concentrations were higher in organisms with mineralized skeletons such as isopods, compared with soft-bodied lumbricid worms. There were significant differences in Sr burdens between closely-related species with known differences in Ca physiology, notably between endogeic and epigeic earthworms. However, Sr:Ca ratios provided strong evidence for Sr discrimination, relative to Ca, particularly in those groups with high Ca requirements.