1. Identification of the Network

2. Representative of biodiversity
2001/2002 a project aimed at identifying a representative conservation network initiated by the Environmental Management, CCT.
Representative of biodiversity
Scientifically rigorous (Systematic Conservation Prioritization principles)
Approach used similar to that used for the C.A.P.E. and SKEP projects
Established Conservation Targets using vegetation types and species.
Vegetation types identified and used as the primary biodiversity layer. Low 2000
Vegetation layer was based on the combined use of geology, rainfall and landscape form.
Floral data complemented this from the Protea Atlas and Species and Sites data base (Coastec)
During 2001/2002 a project aimed at identifying a representative conservation network was initiated Department of the City Cape Town. The project used the Systematic Conservation Planning approach to identify remnants of land within the City of Cape Town that would need to be conserved to ensure the protection of a representative sample of the areas biodiversity. This same approach was also used during the C.A.P.E. project, and has also subsequently been applied in the Succulent Karoo (SKEP) and Subtropical Thicket (STEP).
The identification of these areas was based on a set of conservation targets aimed at setting benchmarks for the conservation of vegetation types, floral species and a selected set of ecological processes. The setting of the conservation targets was done through a consultative process, which engaged key stakeholders involved in conservation within the City of Cape Town. The vegetation map developed by Barrie Low (Low, 2000) was used as the primary biodiversity layer (surrogate for habitat) for this study, with floral species distributional data from the Protea Atlas and the Species and Sites database used to supplement this.

3. Dune Thicket-Sandplain Fynbos Transition
West Coast
Renosterveld
Mountains
Msh
Mountain
Fynbos
Wsh
Koppies
Mshk
Recent
Inland Wq
Shales
Mountains Mg
Granites
Koppies
Mgk Wq
Precipitation<700 mm p.a.
Precipitation>700 mm p.a. Mq
Recent
Inland
Sandstones Ms
Dune
Thicket
Calcareous
Substrates
Acid
Sands
Sand Plain
Fynbos
Older
Inland Si Dc
Sand
Recent
Inland Sq
Limestone Dl
Marine Sm
Dune Thicket-Sandplain Fynbos Transition DS

4. Mountain Fynbos on granite on granite koppies on Shale
on on Shale >80mm Rainfall
on Sandstone
non-marine derived acid sands .

5. Sand Plain Fynbos on inland, non- marine-derived (older) acid sands
on marine-derived acid sands
non-marine- derived recent acid sands

6. Dune Thicket on calcareous sand on limestone
transition with dune thicket

7. Renosterveld on granite on shale inland, non-marine-derived
clay/loam sandy loam

8. Nineteen corridors were identified, along with 18 nodes
An initial set of 886 remnants were identified from high resolution imagery
This study identified a set of 261 remnants (32 262ha) – C-Plan analysis
This complemented an existing protected areas representing about ha
Corridors were then identified, which linked the following significant areas; Zandvlei, Macassar, Gordons Bay, Cape Point, Noordhoek Wetlands, West Coast, Mamre and Paardeberg
Ecological gradients are conserved, and to account for the predicted impacts of global climate change
Nineteen corridors were identified, along with 18 nodes
Nodes were originally seen as areas where the corridors intersect but has been re-interpreted as remnants or groups of remnants (“biodiversity hubs”)
This study identified a set of 261 remnants (32 262ha) from an initial set of 886. These selected remnants are in addition to the existing protected areas representing about ha. A set of corridors were then identified, which linked the following significant areas; Zandvlei, Macassar, Gordons Bay, Cape Point, Noordhoek Wetlands, West Coast, Mamre and Paardeberg. These corridors were identified to ensure that ecological gradients are conserved, and to account for the predicted impacts of global climate change. Effectively, these corridors optimise routes containing natural vegetation. Nineteen corridors were identified, along with 18 nodes. The nodes are originally seen as areas where the corridors intersect, and potentially represent critical “biodiversity intersections”. However, the nodes were not necessarily represented by large contiguous remnant areas. Stakeholders have subsequently understood the concept of nodes to be a term that best describes large remnants or groups of remnants (“biodiversity hubs”) meeting a significant proportion of conservation targets and providing a range of conservation-related uses. It is this concept that the CCT wishes to explore further with stakeholders.

9. All Natural Habitat Remnants Identified
886 Sites

10. Existing Reserves and Floral Core Sites

11. Candidate Sites
738 Sites

12. 261 Sites identified 221 sites selected from the vegetation types
5 sites selected from Protea Atlas data
35 Sites selected from Coastec SaS database
261 Sites identified

13. Need a starting POINT Need a target LINE Use a Bi-directional Pathway
Least Resistance pathway based on Cost Surface models which represent biodiversity compatibility
Need a starting POINT
Need a target LINE
Use a Bi-directional Pathway

14. All sites selected by the Biodiversity analysis and within the Major Corridors = 86 sites

15. Critical Vegetation Types
Initial prioritisation of the selected remnants was based on remnant size and the conservation of three critical vegetation types
Secondary prioritisation on whether the remnants were located in nodes or corridors
71 sites identified that were larger than 10ha
97 sites identified conserving at least one of the three critical vegetation types
69 sites identified to include remaining remnants greater than 10ha
25 sites left over from the selected set of 261 sites
86 selected sites in corridors
Critical Vegetation Types
Sand plain fynbos on inland
Older non-marine derived acid sands,
West coast renosterveld on shale west coast renosterveld on granite
An initial prioritisation of the selected remnants was based on remnant size and the conservation of three critical vegetation types, and secondarily on whether the remnants were located in nodes or corridors. These three types (sand plain fynbos on inland older non-marine derived acid sands, west coast renosterveld on shale and west coast renosterveld on granite) were listed as critical because the extant area was smaller than the area required for representative protection as described by the conservation targets.
Level 1 sites (71 sites identified) were those larger than 10ha area conserving any of the three critical vegetation types (plus the existing protected areas, Core Botanical Sites, wetlands and estuaries).
Level 2 sites (97 sites identified) were those conserving at least one of the three critical vegetation types, but irrespective of size.
Level 3 sites (69 sites identified) were those remaining remnants greater than 10ha.
Level 4 sites (25 sites identified) were the remaining remnants from the selected set of 261 not falling into the previous three levels.
The remaining unselected remnants (474) were grouped into level 5.