Cobalt Uptake by Nyssa aquatica, N. sylvatica var. biflora, and Taxodium distichum Seedlings
Kenneth W. McLeod and Thomas G. Ciravolo
Savannah River Ecology Laboratory, University of Georgia, Aiken, South
Carolina 29802, USA
Abstract
Cobalt is a minor contaminant in wetlands that has been linked to
accumulation by Nyssa species for many years, though the evidence
is largely anecdotal. We examined cobalt uptake characteristics from cobalt-enriched
potting soil by Nyssa aquatica (water tupelo), N. sylvatica
var. biflora (swamp tupelo), and Taxodium distichum (baldcypress),
codominant canopy species of wetland forests of the southeastern United
States. Seedlings were grown in 10 l pots for two growing seasons. Cobalt
additions (up to 100 mg/pot) did not affect biomass production of leaves,
stems, or roots of the three species. Height was significantly different
among treatments within a species, but no treatment was different from
the control treatment with no added cobalt. Leaf cobalt concentrations
were greater in N. sylvatica var. biflora than N.
aquatica during the first year, but similar during the second year.
Cobalt concentrations declined from the first to second years for T.
distichum leaves. In the 100 mg/pot treatment, leaf cobalt concentrations
of both Nyssa species during the second year were 150 times greater
than that of T. distichum. Elevated cobalt uptake by Nyssa
species is apparently a function of special mechanisms of the genera and
not a habitat characteristic.
Key Words: cypress, environmental contamination, plant production,
tupelo
SREL Reprint #3031
McLeod,
K. W. and T. G. Ciravolo. 2007. Cobalt Uptake by Nyssa aquatica,
N. sylvatica var. biflora, and Taxodium distichum
Seedlings. Wetlands 27(1):40-43.
