Riviersonderend Mountains (100927)
South Africa, Africa
Site overview
KBA status: confirmed
Global KBA criteria: A1a, A1b, A1d, A1e, A2, B1, B2, B3a, B3b, B4, E
Year of last assessment: 2024
National site name: Riviersonderend Mountains
Central coordinates: Latitude: -34.0275, Longitude: 19.6433
System: terrestrial, freshwater
Elevation (m): 174 to 1484
Area of KBA (km2): 838.79386
Protected area coverage (%): 84.26
KBA classification: Global
Legacy site: No
Site details
Site description: Riviersonderend Mountains is a terrestrial site with substantial protection, found in the Western Cape, South Africa. Centred on an east west mountain chain where steep north-facing slopes, highly dissected in a few place and with extensive gentle lower slopes. Vegetation is an open, tall, proteoid-leaved evergreen shrubland with a dense moderately tall, ericoid-leaved shrubland as understorey. This is mainly asteraceous fynbos on the western and lower slopes, but extensive proteoid and restioid fynbos dominate the middle slopes. Ericaceous fynbos is restricted to the highest peaks. The deep sand habitat of the northern plateau, which runs along the length of the mountain, is a distinctive feature associated with many endemic species. Also includes steep to gentle southern slopes, with extensive cliffs in places. Vegetation a moderately tall, dense ericoid-leaved shrubland with open emergent proteoids. Ericaceous and restioid fynbos most common, with proteoid fynbos found mainly on lower slopes.
Rationale for qualifying as KBA: This site qualifies as a Key Biodiversity Area of international significance that meets the thresholds for 3 criteria described in the Global Standard for the Identification of KBAs. Based on current available information, 120 species meet one or more KBA criteria for this site. The KBA trigger species at this site include amphibians, birds, butterflies, fish, and plants. The site meets criterion A1 due to the presence of significant proportions of the global populations of 48 threatened species. Effectively the entire global populations of 6 Endangered and 7 Critically Endangered species are within the site. The site regularly holds 65 individual geographically restricted species, therefore meeting criterion B1. Assemblages of co-occurring range-restricted species in the Apiales, Asparagales, Asterales, Bruniales, Caryophyllales, Ericales, Fabales, Geraniales, Malvales, Myrtales, Proteales, Rosales, and Sapindales taxonomic groups regularly present within the site meet criterion B2. Co-occurring species endemic to the Fynbos shrubland terrestrial ecoregion and Fynbos terrestrial bioregion present at the site meet criterion B3. A quantitative analysis of irreplaceability indicates that the site is 100% irreplaceable for the global persistence of 54 species, therefore meeting criterion E. The site holds significant proportions of the global extent of 3 threatened ecosystems (meeting criterion A2) and 1 geographically restricted ecosystem (meeting criterion B4).
Additional biodiversity: 270 other potential trigger species meet minimum population parameter thresholds for the site, but presence and/or minimum reproductive units required to meet KBA criteria cannot be confirmed with available data.
Manageability of the site: This site is managed primarily by a protected area management authority, with part of the site managed by a regional conservation authority responsible for enforcing statutory regulations on landuse change in Critical Biodiversity Areas and threatened ecosystems.
Delineation rationale: Mountain protected area and immediately adjacent patches of intact threatened lowland fynbos categorised as Critical Biodiversity Area.
Habitats
Summary of habitats in KBA: Shrubland (94%)
Threats
| Threat level 1 | Threat level 2 | Threat level 3 | Timing |
|---|---|---|---|
| Agriculture & aquaculture | Wood & pulp plantations | Scale Unknown/Unrecorded | Ongoing |
| Agriculture & aquaculture | Annual & perennial non-timber crops | Scale Unknown/Unrecorded | Ongoing |
Additional information
Contributors: Gavin Masterson (Fathom Data), Warrick Stewart (Resilience Environmental Advice), Anisha Dayaram (South African National Biodiversity Institute), Maphale Monyeki (South African National Biodiversity Institute), Sediqa Khatieb (South African National Biodiversity Institute), Craig Hilton-Taylor (IUCN)