Affiliations: Environmental Impact Assessment Division, Sálim
Ali Centre for Ornithology and Natural History (SACON), Anaikatty (PO),
Coimbatore-641 108, India
Abstract: The present work provides the baseline information on concentrations
of select transition metals (iron, manganese, copper, zinc, nickel, lead and
chromium) in seven macrophytes and their changes in the course of their
decomposition in the wetlands of Keoladeo National Park, Bharatpur, India.
Litterbag experiments were carried out in nylon litterbags of two different
mesh sizes (0.14 and 0.375 mm) in the field and in the laboratory water tanks.
The macrophytes selected for the study were Paspalum distichum, Paspalidium
punctatum, Cyperus alopecuroides, Pseudoraphis spinescens, Ipomoea aquatica,
Neptunia olearhiza and Hydrilla verticillata, which dominate the aquatic
vegetation of the wetland system. On the whole there was no notable influence
of mesh size on the release of metals from the decomposing plant matter. In
field condition the level of Cr, Ni and Pb in plant matter at the end increased
while their levels decreased in water indicating the uptake and accumulation of
metals in plants from the surrounding water column during decomposition.
