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Selection of Native Wetland Plants for Water Treatment of Urban Runoff
Eliska Rejmankova, University of California, Davis
David E. Bayer, University of California, Davis
Water Resources Center Technical Completion Report W-769
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ABSTRACT: Field sampling was conducted in relatively undisturbed wetlands as well as in
wetlands impacted by urban runoff to obtain information on ranges of biomass, nutrients and
heavy metals accumulation in different type of common wetland plant species. The above
ground biomass of erect emergent macrophytes, tules and cattails, (Scirpus spp., Typha
spp.) ranged from 560 g to 3015 g of dry mass per square meter with the average nitrogen
concentration of 0.9%. The creeping or soft emergent macrophytes such as water primrose,
water cress and pennywort (Ludwigia peploides, Nasturtium aquaticum, Hydrocotyle
verticillata, Sagittaria latifolia) usually reached significantly lower biomass (average of
about 450 gm-2) but the biomass was richer in nitrogen (3%). Representatives of the
second group were also characterized by significantly faster decomposition rates. Methods of
propagation of plants from rhizome and stem cuttings were elaborated. A greenhouse
experiment carried out to determine the dependence of growth characteristics on water level
showed that Hydrocotyle verticillata seemed to be most sensitive to low water levels followed
by Nasturtium aquaticum. Ludwigia peploides grew well at all five tested water levels. Both
Hydrocotyle verticillata and Nasturtium aquaticum were more sensitive to high nitrogen
concentrations than Ludwigia peploides. The mesocosm experiment studying the effect of four
different water levels on the growth and biomass allocation in tall erect emergents (Scirpus
californicus, S. acutus, Typha domingensis, Phragmites australis) and short emergents
(Polygonum sp., Scirpus robustus, Sagitta ria latifolia and Ludwigia peplaides) showed that
with the exception of Typha domingensis, Sagitta ria latifolia and Scirpus robustus, all other
species allocated more biomass into belowground organs in the low water level treatment
than in the high water treatment. Results of this experiment in combination with the
observations from the field are crucial for proper species selection for various treatment
purposes.
Five species, Scirpus californicus, S. acutus, Typha domingensis, Sagitta ria latifoia
and Ludwigia peploides, were grown in outdoor hydroponic cultures in a heavy metal
experiment. Zinc, lead, cadmium and copper in the concentrations of 0.1, 1 and 10 ppm of
were added to the nutrient solution in the cultures. After two weeks of exposure to the heavy
metals, plants were measured, harvested, biomass was sorted into roots, rhizomes, stems
and leaves, dried and analyzed for concentrations of individual metals. There were no
statistically significant differences in the growth expressed as the percentage increment of
total length between the control and all concentrations of all metals. However, there were
species and organ specific differences in the accumulation of individual metals. Most metals
were accumulated in roots, specifically adventitious roots. Ludwigia peploides seemed to be
the most efficient in the accumulation of all metals tested.
SUGGESTED CITATION:
Eliska Rejmankova and David E. Bayer,
"Selection of Native Wetland Plants for Water Treatment of Urban Runoff"
(January 1, 1995).
University of California Water Resources Center.
Technical Completion Reports.
Paper 769.
http://repositories.cdlib.org/wrc/tcr/769
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