Ecosystem Guidelines for Environmental Assessment

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LOWLAND FYNBOS INCORPORATING SAND FYNBOS AND LIMESTONE FYNBOS LOWLAND FYNBOS ECOSYSTEMS LOWLAND FYNBOS ECOSYSTEMS Nick Helme, Pat Holmes and Tony Rebelo What are the key ecological “drivers” in terms of maintaining ecosystem function, pattern or structure Limestone Fynbos and Sand Fynbos often occur in a matrix, and ecological processes that affect the one may be closely inter-related with the other. Fire frequency must ensure sufficient seed-set in slow-maturing species such as the Proteaceae. This can be up to 30 years in arid areas. The appropriate seasonal fire regime must be retained. Fire should occur in summer to early autumn (December to March). Under natural regimes fires are slow moving, ignition is extremely rare (most fires start "elsewhere") and fires burn unimpeded over large areas. End boundaries of fires are usually other vegetation types and young veld. Allow <strong>for</strong> sufficient seed-set in slow-maturing species. In Limestone Fynbos and Sand Fynbos, there can be a high incidence of species turnover along habitat or environmental gradients, i.e. beta diversity is high. Many edaphic gradients are found on edges of Limestone Fynbos and Sand Fynbos communities. Subtle edaphic variations, such as the depth of overlying sand, have a dramatic effect on community structure. There are also substantial unexplained variations in species richness, and concentration of rare and endemic plants, from area to area. Patch size and connectivity with other limestone outcrops may be important to retain certain species. Seasonal wetlands and seeps are important to retain certain distinct communities. Regional and local natural water drainage patterns are thus also important drivers of biodiversity pattern. Natural grazing and physical soil disturbance by fauna may be important to retain a high incidence of spring annuals, which is unusual in fynbos. What are the key issues, vulnerabilities and threats There can be a very high occurrence of rare and regionally endemic plant species in Limestone Fynbos and Sand Fynbos, many of which are very localised within what might appear to be fairly homogenous habitat. In Sand Fynbos, the incidence of rare and endemic plant species is particularly high in the South. Vulnerable habitats include wetlands, sink-depressions and moister soil facies. These ecotypes are at risk due to their higher agricultural potential. Both Limestone Fynbos and Sand Fynbos are vulnerable to changes in the natural fire regime (to promote grazing, <strong>for</strong> example) and invasion by alien plants. They are also at risk from veld clearance and ploughing, over-harvesting of species (flowers and whole plants), and changes in water availability due to abstraction of groundwater. Limestone Fynbos is highly susceptible to invasion by rooikrans Acacia cyclops, especially on deeper sands in valleys between rocky outcrops. However, in areas of severe invasion even the rocky pavements are affected. Besides being vulnerable to rooikrans, Sand Fynbos is also susceptible to invasion by Port Jackson Acacia saligna, Eucalyptus gomphocephala and Leptospermum laevigatum, and annual grasses (Avena, Briza). COLIN PATERSON-JONES 38 : LOWLAND FYNBOS ECOSYSTEMS
Limestone Fynbos, Groot Hagelkraal LOWLAND FYNBOS
Page 1: ECOSYSTEM GUIDELINES FOR ENVIRONMEN
Page 4 and 5: CHARL DE VILLIERS (EDITOR) Conserva
Page 6 and 7: CONTENTS 7 : 8 : 10 : 14 : 22 : 24
Page 8 and 9: “Environmental Assessment provide
Page 10 and 11: PREFACE Charl de Villiers These gui
Page 12 and 13: INTRODUCTION Susie Brownlie Purpose
Page 14 and 15: The drafting process, which was co-
Page 16 and 17: INCLUDING BIODIVERSITY CONSIDERATIO
Page 18 and 19: UNEP's voluntary guidelines on biod
Page 20 and 21: Breede River valley: CAPE and SKEP
Page 22 and 23: STEP 4: WHEN SIGNIFICANT IMPACTS AR
Page 24 and 25: A NOTE ON FIRE All fynbos types req
Page 26 and 27: COASTAL ESTUARIES COASTAL ECOSYSTEM
Page 28 and 29: COASTAL non-linear manner over wide
Page 30 and 31: COASTAL SANDY BEACHES & DUNE SYSTEM
Page 32 and 33: COASTAL What are the “bottom line
Page 34 and 35: COASTAL INCORPORATING WEST AND SOUT
Page 36 and 37: COASTAL Strandveld is also increasi
Page 38 and 39: What are the critical things to mai
Page 42 and 43: LOWLAND FYNBOS Veld clearance for r
Page 44 and 45: NICK HELME LOWLAND FYNBOS Leipoldtv
Page 46 and 47: MIDLAND & MOUNTAIN INCORPORATING AL
Page 48 and 49: MIDLAND & MOUNTAIN Altered fire reg
Page 50 and 51: MIDLAND & MOUNTAIN What are the cri
Page 52 and 53: MIDLAND & MOUNTAIN will move in fro
Page 54 and 55: RENOSTERVELD INCORPORATING COAST &
Page 56 and 57: RENOSTERVELD Urban expansion is a p
Page 58 and 59: RENOSTERVELD What, if any, reliable
Page 60 and 61: SUCCULENT KAROO INCORPORATING VYGIE
Page 62 and 63: SUCCULENT KAROO Quarrying for grani
Page 64 and 65: MAINLAND THICKET INCORPORATING THIC
Page 66 and 67: MAINLAND THICKET appear to recover
Page 68 and 69: MAINLAND THICKET What are the criti
Page 70 and 71: FRESHWATER FRESHWATER ECOSYSTEMS: W
Page 72 and 73: FRESHWATER What are the key issues,
Page 74 and 75: FRESHWATER exotic garden escapees i
Page 76 and 77: FRESHWATER INCORPORATING MINOR DRAI
Page 78 and 79: FRESHWATER Introduction to the syst
Page 80 and 81: SCEPS SPATIAL COMPONENTS OF ECOLOGI
Page 82 and 83: JAN VLOK SCEPS Quartz patches can s
Page 84 and 85: SCEPS those characterised by mosaic
Page 86 and 87: TABLE 4: EXAMPLES OF SPATIAL COMPON
Page 88 and 89: SCEPS ecosystems (e.g. Granite Fynb
Page 90 and 91:
REFERENCES & RESOURCES There is a w
Page 92 and 93:
APPENDIX 1 SOUTH AFRICAN VEGETATION
Page 94 and 95:
APPENDIX 2 RECOMMENDED TERMS OF REF
Page 96:
SALDANHA CAPE TOWN VANRHYNSDORP CER
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Ecosystem Guidelines for Environmental Assessment

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