Description: Sub-Quaternary Catchments (SQ4) are used as planning units. These are the standard unit of analysis and monitoring for freshwater ecosystems in South Africa with a host of biodiversity and environmental data attached to these units.Many approaches were experimented with for determining a Marxan cost for catchments. On their own the DWS river PES and ES_EI data do not provide enough range in values to differentiate between SQ4 sufficiently. Approximately 60% of catchments are equal in terms of PES and ES_EI, and combinations of thereof, which meant that cost added little value to Marxan being able to discriminate sites that were equal in terms of contribution to targets.Marxan Analysis Notes:No BLM value was used in the final Marxan analysis. Initial testing indicated that even very low BLM values produced over clumping in the final selection of catchments.Initial analyses indicated that FEPAs do a very poor job at achieving conservation targets for fish species. When just using targets for fish species and locking in all FEPAs (n=384) Marxan selects an additrional 131 PUs (total n=515). When unconstrained by FEPAs Marxan selects only 315 sites. Therefore, in the final analysis only free flowing, fish sanctuary and flagship catchments were locked in as mandatory sites.The final Marxan selection contains 754 out of 1911 SQ4 planning units. This represents 44% of the Eastern Cape area.The final selection of sites achieves all biodiversity feature targets The critical biodiversity map development followed a logical workflow. The first component of the workflowestablished input data which consisted of Baseline Datasets, Protected Areas, Biodiversity Features and Biodiversity Conditions. The baseline datasets included: Area of Interest, Aerial Imagery, Digital Elevation Model, Cliffs, Relative Coastline Visibility, and Integrated Land Cover (derived from DEA GTI 2013/2014)Protected Areas and Conservation Areas Input layers mapped formal and de facto protected and conservation areas in the Eastern Cape.Spatial Biodiversity Framework input layers provided a simplified representation of the Living Landscape concept embodied in the Critical Biodiversity Areas (CBA) Map. Its purpose is to distil the complexity and key living landscape design elements of this map (Core biodiversity conservation landscapes and ecological corridors) into a conceptual mapthat can be more easily visualised by stakeholders, and be incorporated into provincial and national scale multi-sectoral planning tools.The 2ndprocess step of the workflowestablished the CBA MAP Criteria of which guidance was drawn from national guideline documents and bioregional plans from the North West Province and Limpopo.The 3rdProcess stepincluded Output 1: Derived Data Layers. Integration of indicators into a single cost score for each pixel* was done, using expert-derived, relative-importance ratings for each indicator. Two weighting scenarios were considered. Results were used to generate a ‘biodiversity vulnerability surface’ for the Eastern Cape, and as a cost input into the MARXAN analysis for the selection of least-cost priority biodiversity areas. The same data set, but with indicator weightings adjusted to be relevant for each taxon, was also used to calculate mean species vulnerability ratings, as well as to identify vulnerability hotspots within the distribution ranges of a number of Eastern Cape red data species. The derived data layers included:Protected and Conservation AreasPlanning Units (Terrestrial & Freshwater)Biodiversity featuresIntegrated 2014 Land CoverBiodiversity VulnerabilityIntegrated Other PlansTerrestrial Biodiversity FeaturesThis section provides a summary of the biodiversity features inputs to the Eastern Cape Biodiversity Conservation Plan that were used in the MARXAN analysis to develop the CBA map. In total, biodiversity feature information coverage of the Eastern Cape is extremely sparse. Of the 231 975 planning units used in the Marxan analysis, only 1720 (0.74%) have point locality information; and, 178 494 (77%) have polygon feature information other than the South African Vegetation Map (e.g. expert mapped areas). Only the South Africa vegetation map covers the entire province, and therefore 23% of planning units have one biodiversity feature in the analysis. An analysis of the Marxan feature x planning unit table shows that 34% of PUs contain information for 3 or less features. It is essential that for future iterations of the conservation plan that data density is increased to help make more informed decisions as to what constitute CBA areas. It is recognised that field observations will never adequately sample the entire province. Therefore, it is imperative that the available point locality data is used in species distribution models to help expand the density of biodiversity data use in planning.The 4thProcess of the workflowprovided Output 2: headline statistics which included:Ecosystem StatusLevels of ProtectionThe 5thstep in the workflowutilised Marxan Analysis. Terrestrial and Freshwater process (Analysis) included the biodiversity features plus targets, cost (vulnerability + opportunity) plus mandatory sites defined in other plans. Using the CBA Criteria, the 6th workflow step, derived analysis for the estuary, freshwater and terrestrial areas.The 7th process combined the CBA Map Criteria Analysis and the Marxan Analysis to compile the CBA Map input layers.The final process was the creation of a CBA Map.Input information has been incorporated into the final CBA map via four possible routes:Areas selected through the MARXAN analysis aimed to select enough sites to achieve representation targets for vegetation types, species of conservation concern and expert mapped areas important for biodiversity.Areas already identified as CBAs in existing plans and incorporated as is into the EC plan include:Estuary – All estuaries except those mapped by this project.Fresh water – NFEPA fish sanctuaries, Flagship Rivers and free flowing rivers.Terrestrial – none. CBAs in existing plan were integrated in to the Marxan cost layer.Entire mapped extent of features considered as being important for biodiversity pattern or process.Inputs used to inform the Marxan cost layer. These features do not appear in the final CBA map.They are use only to manipulate the cost layer to increase or decrease the likelihood of Marxanselecting a site to achieve any given target.
Service Item Id: 48b93cf90d7749789194e33894f49c14
Copyright Text: Hawley & Desmet. P. 2020. Eastern Cape Biodiversity and Conservation Plan, Freshwater CBA [shape file] version 5.2020. Eastern Cape South Africa: The Eastern Cape Department of Economic Development, Environment Affairs and Tourism.