Salinity affects ph and lead availability in two mangrove plant species

Abstract

Some tropical coastal areas that include mangroves are highly polluted by heavy metals, where lead (Pb) is prevalent. Few studies document how environment affects soil physicochemical characteristics and the availability of heavy metals. This study evaluated how different salt concentrations influenced the accumulation of Pb in plants of Avicennia germinans and Laguncularia racemosa and how salinity modified the substrate pH. Under unsalted conditions, Pb accumulation occurred continuously, mainly in L. racemosa, which was more tolerant to its toxic effects. Salt led to a decreased Pb uptake by the roots and an increase in the substrate pH. In addition, salinity also caused an increase in the translocation of Pb to the leaves. Because L. racemosa was tolerant to Pb, this species could be a better candidate for possible remediation and restoration programs in mangrove areas.