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Presence of metal-rich rhizoconcretions on the roots of Spartina maritima from the salt marshes of the Tagus Estuary, Portugal

1990; Elsevier BV; Volume: 97-98; Linguagem: Inglês

10.1016/0048-9697(90)90265-v

1879-1026

Carlos Vale, Fernando Catarino, C CORTESAO, Isabel Caçador,

Aluminum toxicity and tolerance in plants and animals

A striking feature of southern and eastern intertidal areas in the Tagus Estuary is the presence of hollow sediment-cylinders, ranging from 0.5 to 15 mm both in length and diameter, around the roots and rhizomes of the vascular plant Spartina maritima. The weight fraction that makes up these cylinders varies between 0% near the sediment surface and 8% in deeper layers. Compared with the surrounding sediment, the structures are enriched in some metals, particularly Fe (11%). The concentration of Mn is also high (1496 μg g−1). Trace metals Zn, Cu, Cd and Pb vary widely, with the highest concentrations in the thinnest rhizoconcretions.