BIOCHEMICAL UPTAKE OF MAGNESIUM AND OTHER TRACE ELEMENTS IN SERPENTINE ENVIRONMENTS

The common element magnesium (Mg), is abundant in many terrestrial Earth environments and it is a major constituent in life forms from bacteria to man. Serpentinites and soils derived from these rocks (serpentine soils) contain elevated total and exchangeable Mg concentrations often exceeding 5 Wt. % (total) and 3000 mg kg-1 (exchangeable). Paradoxically, these ‘serpentinite environments' are obvious as ‘barren' spots with low levels of plant species and suppressed vegetative growth. In addition to abundance of Mg, serpentine soils contain high concentrations of biologically toxic elements including Cr, Ni, and Cd and limited plant nutrients (Ca, P, N, K, and potentially carbon). Despite the adverse chemical conditions, these locales are where endemic plant species thrive and demonstrate well-adapted selective uptake processes with regards to Mg as well as other trace metals that allow them to succeed where many other non-endemic plants fail. Studies of worldwide serpentinite localities, especially in California, document the unique chemical characteristics of these environments. New information on selective uptake and/or suppression of Mg and other trace elements into endemic vegetation biomass relative to the availability of the element in the serpentine soil allows us to question adaption strategies for non-endemic vegetation. These ‘serpentinite environments' present opportunities for cross-disciplinary investigations uniting transfer of nutrients from soils, airborne materials, into biota whose mechanisms may be applicable in other biological, and perhaps human, systems.