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An investigation into the effect of metals on chlorophyll content and photosynthesis activity of the wetland plant phragmites australis in the lower Diep River, Milnerton, Cape Town

Thesis (MTech (Environmental Management)))--Cape Peninsula University of Technology, 2011. / A study involving a wetland plant, common reed (Phragmites australis L.) was carried
out along the bank of the lower Diep River and the adjacent soil samples from four
different sites (Milnerton Lagoon, Lower Estuary, Milnerton Bowling Club and
Woodbridge Island), Cape Town, South Africa. The aim was to determine the extent of
metal contamination and its impact on physiological indices.
Results showed that among the metals evaluated, AI and Fe were consistently higher in
all the soil samples (from both river bank and the adjacent soil) followed by Zn, Mn, Pb,
Cu, Cd, Co, Cr and Ni. The concentrations of AI in the river banks ranged between
1214.1 - 3176 mg.kg-1 compared with the adjacent soils, where AI concentration ranged
from 434.8 - 2445.4 mg.kq". The Fe concentrations from the river bank values ranged
from 1136.4 - 4897.2 mg.kg-1 compared with Fe concentrations of the adjacent soil
samples which ranged from 402.2 - 2459.8 mg.kg-1
. Generally, Zn ranged from 2.4 -
211.5 mq.kq"; Mn: 5.5 - 48.05 mg.kq': Pb: 0.97 - 71.7 mg.kq"; Cu: 0.3 - 45.9 mg.kq';
Cd: 0.0 - 9.3 mg.kq": Co: 0.2 - 2.7 mg.kq': Cr: 0.3 - 2.1 mg.kg-1
; and Ni: 0.02 - 2.6
mg.kg-1.
Overall, Ni had the lovest concentrations in the ecosystem. Results also showed that the abundance of metals from plant samples were in the order
of AI > Pb > Cd > Co > Ni > Cr; and for micronutrients, Fe > Mn > Zn > Cu both in the
shoots and roots sampled from all the sites investigated. The values of chlorophylls a, b
and total chlorophyll as well as photosynthesis were significantly higher in the P.
australis plant samples and from the adjacent soil compared with those from the river
bank. These results suggest that contamination of soils and wetland ecosystem by
metals over and above plant requirements may affect the chlorophyll and photosynthesis
rate of the plant thereby undermining the physiological functioning of plants growing
along river systems.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:cput/oai:localhost:20.500.11838/2016
Date January 2011
CreatorsAyeni, Olutoyosi Olaide
ContributorsNdakidemi, PA, Snyman, RG, Odendaal, JP, Ndakidemi, PA, Snyman, RG, Odendaal, JP
PublisherCape Peninsula University of Technology
Source SetsSouth African National ETD Portal
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Rightshttp://creativecommons.org/licenses/by-nc-sa/3.0/za/

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