The Critical Biodiversity Areas (CBA) map for the Garden Route Initiative (GRI) aims to guide sustainable development by providing a synthesis of biodiversity information to decision makers. It serves as the common reference for all multi-sectoral planning procedures, advising which areas can be lost to development, and which areas of critical biodiversity value and their support zones should be protected against any impacts. As part of the GRI and C.A.P.E. fine scale biodiversity planning, a systematic biodiversity assessment of the GRI was undertaken, and a critical biodiversity area (CBA) map was produced. This biodiversity assessment is used to inform Spatial Development Frameworks (SDFs), Biodiversity Sector plans, Environmental Management Frameworks (EMFs), Strategic Environmental Assessments (SEAs) and the Environmental Impact Assessment (EIA) process. This biodiversity assessment, through the development of a CBA map, is aimed at assisting biodiversity and land use managers and decision makers in this demanding task. This report summarizes the results of the biodiversity assessment conducted.

The CBA map indicates areas of land as well as aquatic features which must be safeguarded in their natural state if biodiversity is to persist and ecosystems are to continue functioning. Land in this category is referred to as a Critical Biodiversity Area. CBAs incorporate: (i) areas that need to be safeguarded in order to meet national biodiversity thresholds (ii) areas required to ensure the continued existence and functioning of species and ecosystems, including the delivery of ecosystem services; and/or (iii) important locations for biodiversity features or rare species.

Ecological Support Areas (ESAs) are supporting zones required to prevent the degradation of Critical Biodiversity Areas and Protected Areas. An ESA may be an ecological process area that connects and therefore sustains Critical Biodiversity Areas or a terrestrial feature, e.g. the riparian habitat surrounding and supporting aquatic Critical Biodiversity Areas.
Those areas of natural vegetation identified on the map as Other Natural Areas are sufficiently extensive at this stage that they may withstand some loss through conversion of their natural state, and undergo development. It is important to note that in the future, such areas will be increasingly converted or impacted, and it is possible that they will eventually be reclassified as Critical Biodiversity Areas. Therefore, in all decision making, the precautionary principle needs to be applied.

Biodiversity Overview

Biogeographically, the GRI falls entirely within the Southeast Phytogeographical Centre of the Cape Floristic Region (CFR) (Goldblatt and Manning, 2000), and perhaps more interestingly, contains the greatest extent of Afromontane forest in the CFR.

The GRI can conveniently be divided into three broad habitat types:

• The higher altitude Table Mountain Sandstone areas support the fynbos vegetation group, which contains the greatest number of taxa and highest levels of endemism
• The mid to low altitude coastal plateau, where in the east may form coastal cliffs.
• A narrow northern strip of Renosterveld, nestled in the Langkloof Valley.

Biodiversity data

• A fine-scale vegetation map was developed for the planning domain by Jan Vlok and Doug Euston Brown (See Vlok, J.H.J., Euston-Brown D.I.W. & Wolf, T. (2008). A vegetation map for the Garden Route Initiative for more details). The vegetation of the GRI was classified and mapped at a scale of 1:50 000.
• Additionally, where fine scale maps existed from neighbouring areas, these were incorporated. The breakdown of habitat unit contributions are as follows:

Fine Scale Vegmap	CR	EN	VU	LT	Total
Garden Route Vegetation	13 (+3)	14 (+2)	11 (+3)	30 (+6)	68 (+14)
Little Karoo Vegetation	5	2	7	8	22
Riversdale Vegetation	3	2	1	3	9
Total Unique Habitats	21	18	19	41	99

Numbers in brackets are GRI habitat units shared with the Little Karoo and Riversdale Fine scale vegetation maps

• Special species data such as distribution of endangered species (e.g. CREW), and special habitats know to have high biodiversity (intact Renosterveld) were included in the analysis.
• Expert-mapped information was collected, comprising important complimentary information to the habitat map.
• Nationally listed threatened ecosystems (under NEMBA) were incorporated.
• Other protected habitat types (Wetlands, Forests) not protected by NEMA were also incorporated.

Land cover data/Transformation

• A detailed new land cover layer was developed for the project. This was based on detailed aerial photograph interpretation undertaken at approximately 1:5 000 scale of colour aerial photographs obtained from DWAF (captured in 2000-2003), and updated with both SPOT5 satellite imagery (2005) and transformation data captured during aerial surveys (2008).
• At the district level, 48.1% is still natural vegetation, 11.9% is degraded, 19.8% is transformed by cultivation and 13.2% is afforested. Heavy Alien Degradation occupies 2.7%, while Alien transformed land forms 1.6%. 2.7% is transformed by urban and infrastructure (urban, roads and dams).

Ecosystem status and threats

• Agriculture and afforestation are likely to be the principal drivers of biodiversity loss in the district, especially in the mid and low altitude areas, at present about 51.9% of the area of the district’s ecosystems are transformed or degraded.
• Currently, of the 99 vegetation types described in the study, 22 are Critically Endangered, 18 are Endangered, 19 are classified as Vulnerable, while the remaining 41 are Least Threatened.

Protected area network

• The protected area (PA) network is not fully representative of the biodiversity in the GRI. At present, protected areas cover 27.4% of the GRI (formal and informal), however a large part of this comprises in mountain fynbos. 19 Vegetation units are not represented in a protected area.

Critical biodiversity areas

• The biodiversity assessment for the Overberg District Municipality is designed to identify an efficient set of Critical Biodiversity Areas (and Ecological Support Areas) that meet the targets for the underlying biodiversity features in as small an area as possible and in areas with least conflict with other activities. Of fundamental importance is that these areas are identified in a configuration that deliberately facilitates the functioning of ecological processes (both currently and in the face of climate change) which are required to ensure that the biodiversity features persist in the long term.
• A critical biodiversity area (CBA) map has been developed for the district.
• This CBA map is intended to act as the biodiversity sector’s input into multi-sectoral plans and assessments (e.g. SDF, EMF EIA, IDP, etc.).
• The CBA map product is aligned with national standards for bioregional plans in terms of terminology and methods.
• Land use guidelines have been developed for each CBA category and aligned with land use categories commonly used in SDFs.