coaltech upper olifants river catchment wetland inventory ...

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Pans may contribute to groundwater recharge. This outward seepage from the pans may help to regulate the build-up of dissolved solids in the system. When the deposited material is not transported out of the system they redissolve after a rainfall event and contribute to the saline nature of the pans. Phosphates in the pans convert from absorbed to soluble and back on a regular basis. Plants should be harvested for the removal of phosphate (Palmer et al 2002, Allan et al 1995). 3.5.2.3 Toxicant removal The reduction or transformation of sulphate in wetlands is an important process in the wetland biochemistry. This process requires the presence of sulphate reducing bacteria. The bacteria occur in sediment and micro zones in plant litter. The process requires an environment with low oxidation potential (-120mV) and the presence of organic matter. Once the sulphate has been reduced other processes are required to immobilise or remove the sulphur compounds from the system (Palmer et al 2002, Kotze 2000, Kotze et al 2000, Brady & Weil 1999). The removal of metals takes place through precipitation, absorption and plant uptake. The metals can enter the wetland system in particulate form or in a dissolved state. Metals associated with mine water often precipitates out. The precipitation of metals are influenced by the pH and redox potential present at a particular moment. The oxidation potential varies between and within wetlands. This is greatly influenced by the wetland species present, since plants have the ability to aerate soils. Although the precipitation of metals is an important process in wetlands the metal uptake by plants also plays an important role. The dominant species in wetlands in the UORC receiving mine drainage are Typha capensis and Phragmites species. These species are metal accumulators, thereby allowing the plants to grow in areas with high pollution. The level of metal accumulation by plants is very low (Palmer et al 2002, Kotze 2000, Kotze et al 2000, Brady & Weil 1999). Wetland Database for UORC - 36 -
More important in the removal of metals is the role played by algae. Algae are manganese accumulators and can accumulate other metals as well. The metal uptake ability of algae is controlled by the specific bioaccumulation and physical-chemical factors present. Although algae can accumulate vast amounts of metals in relation to mass, the distribution of algae in wetlands is limited and therefore the total metal uptake by algae in the wetland. The most important role of plants in the removal of metals from the system are therefore not in the accumulation of metals, but in changing the environment to that more suitable for the removal of toxicants (Palmer et al 2002, Kotze 2000, Kotze et al 2000). Acid mine drainage has entered the Kromdraaispruit wetland (located approximately 20 km north-west of Witbank) for 20 years, a wetland with distinct morphological zones. The Kromdraaispruit wetland is located in the Kromdraaispruit, a tributary of the Zaalklapspruit, flowing into the Wilge River. Vegetation in the wetland removes high percentages of influent metals. The accumulation of iron and manganese takes place in the roots and aerial parts (stems and leaves) of the wetland vegetation (Limpitlaw 1995). It was determined that the biochemical water quality of acid mine drainage passing through a wetland improves with distance moved through the wetland. It was also determined that the concentration of sulphate-reducing bacteria increases with distance away from the pollution source (Limpitlaw 1996). The immobilisation of metals was best in the areas of optimal organic adsorption of metals (Limpitlaw 1995, 1996). Permanently wet seeps can function to reduce nitrate, sulphate, iron and manganese. Where there are both nitrates and sulphates in the groundwater competition occurs for the available carbon and reduction is therefore a slower process. Similar processes occur in the seasonal seeps, but the leaching of immobilised substances can occur before soil saturation, thereby affecting changes to the redox potential and pH of the site. Organic materials in the wetland are lost when the water levels drop (Palmer et al 2002). Wetland Database for UORC - 37 -
Page 1 and 2: COALTECH UPPER OLIFANTS RIVER CATCH
Page 3 and 4: The following aspects are included
Page 5 and 6: The most common wetland types in th
Page 7 and 8: The attributes allocated based on t
Page 9 and 10: 6. DATABASE CONSTRAINTS............
Page 11 and 12: Addendums Addendum A - Plant specie
Page 13 and 14: Figure 1. Extent of the UORC (refer
Page 15 and 16: The aim of the wetland layer is to
Page 17 and 18: 3.3 Wetland biodiversity Wetlands p
Page 19 and 20: Table 1: Species of concern Species
Page 21 and 22: Species name Common name Hottentot
Page 23 and 24: Species name Common name Cordylus g
Page 25 and 26: 3.3.2 Birds Various bird species ut
Page 27 and 28: 3.3.6 Fish The UORC has a low diver
Page 29 and 30: Figure 2. Schematic illustration of
Page 31 and 32: 3.4.1.2 Floodplain riparian Floodpl
Page 33 and 34: 3.4.4 Other non-riparian wetlands O
Page 35: 3.5.1.2 Groundwater recharge Variou
Page 39 and 40: The flow velocity in the channel of
Page 41 and 42: The most important fishing activity
Page 43 and 44: 3.5.6.3 Livestock Diseases Various
Page 45 and 46: 3.6.2 Mining and Quarrying There is
Page 47 and 48: • Dwars-in-die-wegspruit at the l
Page 49 and 50: 3.6.4 Burning Wetlands are burnt on
Page 51 and 52: 3.6.9 Alien Fauna and Flora 3.6.9.1
Page 53 and 54: Category 3 plant invaders are plant
Page 55 and 56: o The Fish Assemblage Integrity Ind
Page 57 and 58: Figure 4. The ecoregions of the Oli
Page 59 and 60: Sixteen fish species (four of which
Page 61 and 62: Figure 5. Extent of the UORC accord
Page 63 and 64: 3.9 Common wetland types in UORC Ac
Page 65 and 66: In a wetland assessment conducted a
Page 67 and 68: In a wetland study at Douglas Colli
Page 69 and 70: Figure 8. Status of assessed wetlan
Page 71 and 72: Figure 9. Portion of the wetland la
Page 73 and 74: Figure 11. Portion of the water bod
Page 75 and 76: Figure 13. Portion of the separated
Page 77 and 78: Figure 15. Portion of the wetland l
Page 79 and 80: Since the field verification site v
Page 81 and 82: Figure 18. Portion of the final wet
Page 83 and 84: Upon a request from DWAF the status
Page 85 and 86: 5.8 Functions The functions likely
Page 87 and 88:
5.11 Wetland types The entire catch
Page 89 and 90:
6. DATABASE CONSTRAINTS The greates
Page 91 and 92:
Figure 21. The wetland in the UORC
Page 93 and 94:
8.2 Mapping o Small wetlands (of le
Page 95 and 96:
The attributes in the attribute tab
Page 97 and 98:
10. REFERENCES Abbott Grobicki (Pty
Page 99 and 100:
Goudie, A.S. & Thomas, D.S.G. 1985.
Page 101 and 102:
Merot, P., Squividant, H., Aurousse
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Wilson, R.T. 2003. Animal health an
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Addendum A - Plan species list Wetl
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var. lachnantha Lamiaceae Ajuga oph
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Asteraceae Berkheya onopordifolia B
Page 111 and 112:
Poaceae Chloris pycnothrix Chloroph
Page 113 and 114:
Poaceae Boraginaceae incompletus Cy
Page 115 and 116:
Poaceae Echinochloa cruspavonis * *
Page 117 and 118:
Asteraceae Gamochaeta subfalcata Y
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Sterculiaceae Sterculiaceae Poaceae
Page 121 and 122:
Cyperaceae Kyllinga erecta Kyllinga
Page 123 and 124:
Asteraceae Nidorella anamola Nympho
Page 125 and 126:
Polygonaceae Apiaceae Poaceae Apiac
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Brassicaceae Rorippa nudiuscula * *
Page 129 and 130:
Poaceae Setaria verticillata * Malv
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Asteraceae Ursinia nana * * * Lenti
Page 133 and 134:
Addendum B - Mammal species list We
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Cynictis Yellow Carnivora penicilla
Page 137 and 138:
Addendum C - Bird species list Wetl
Page 139 and 140:
Actitis hypoleucos Actophilornis Co
Page 141 and 142:
Ceryle rudis Nectarinia Pied Kingfi
Page 143 and 144:
Eremopterix verticalis Estrilda ast
Page 145 and 146:
Netta erythrophthalma Numida meleag
Page 147 and 148:
Spizocorys conirostris Pinkbilled L
Page 149 and 150:
Addendum D - Reptile species list W
Page 151 and 152:
Elapidae Naja haje Egyptian cobra X
Page 153 and 154:
Group Species name Common name Pipi
Page 155 and 156:
Addendum F - Fish species list Wetl
Page 157 and 158:
Austroglansis sclateri X X Barbus a
Page 159 and 160:
Phylum Group Species name Common na
Page 161 and 162:
Arachnida Tanycypris obtusa Hydroze
Page 163 and 164:
gibba Daphnia pulex Simocephalus ca
Page 165 and 166:
Ischnura senegalensis Pseuddgrion s
Page 167 and 168:
Micronecta sp. Micronecta piccanin
Page 169 and 170:
Hydraenidae Hydrophilida e Berosus
Page 171 and 172:
MOLLUSCA Simulium adersi Simulium ?
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