About 7.5 percent of the country is covered by the lush Karoo, which also includes the desert (approximately 83 000 km2). This biome includes Namaqualand and the Richtersveld, two dry regions in the western section of South Africa. Summertime conditions in the area are quite dry, with frequent highs of over 40°C.
Succulent biome: what is it?
The text that follows is an excerpt from Low & Rebelo’s (1996) study on the succulent karoo biome. The Greater Cape Floristic Region includes the Succulent Karoo Biome.
It is not a subtype of “a Karoo Biome,” but rather is on par with the other biomes in South Africa. Most of the biome is located to the west and south of the escarpment, and to the north of the Cape Fold Belt, and consists of a flat to slightly undulating plain with some hills and “broken” veld. Although it rarely rises above 800 meters, in the east it occasionally does. There are numerous geological units in the area. The soils of the Nama Karoo and Succulent Karoo Biomes are similar; they are both lime-rich, poorly formed soils on rock. The Gouritz River is located in the biome’s southeast. The Olifants and Doring Rivers are the main drainage systems in the west.
The Succulent Karoo Biome is largely characterized by the occurrence of extremely dry summers and little winter precipitation. The annual rainfall ranges from 20 to 290 mm. The erosive force of the rains is far lower than that of the summer rainfall biomes since they are caused by cyclones rather than thunderstorms. Summertime highs of more than 40C are typical. Near the seaside, fog is typical. Frost is not common. Berg Winds can be suffocating and hot throughout the year.
Dwarf, succulent bushes, particularly the Vygies (Mesembryanthemaceae) and Stonecrops (Crassulaceae), predominate in the vegetation. In the spring, annuals—mostly Daisies Asteraceae—floralize in profusion, frequently on degraded or fallow terrain. Except in a few sandy places, grasses are uncommon and are of the C3 variety. For such a large desert region, the number of plant species—mostly succulents—is extremely high and unmatched elsewhere in the world.
Information on the fauna of the Succulent Karoo is scarce. Heuweltjies, raised mounds of calcium-rich soil that are assumed to have been made by termites, are significant in the region. These frequently sustain unique plant communities.
Due to a shortage of water, the area has limited potential for agriculture. Because there are few grasses, grazing is restricted, and the low carrying capacity necessitates heavy supplemental feeding. Due to approximately 200 years of grazing, the biome has lost a significant amount of soil due to sheet erosion. In the Little Karoo in the biome’s south, ostrich farming is done with a lot of additional feeding. Wine grapes, fruit, and other commodities are grown in locations adjacent to the Fynbos Biome using the Fynbos water catchments. Major tourist attractions include the coastline landscape and the springtime huge flower displays. In the north especially, mining is significant.
The Succulent Karoo Biome has less than 0.5 percent of its area legitimately protected. The biome is home to many kinds of rare and Red Data Book plants. Due to its enormous species diversity and distinctive worldwide position, the biome urgently needs conservation attention. Fortunately, there aren’t many invasive foreign plants; the only one that poses a significant threat to the southern coastal areas is Rooikrans Acacia cyclops. The legal requirements for the revegetation of these places are insufficient for the near-desert conditions, and strip mining for diamonds is devastating in the northern coastal districts.
Disturbed location with spring blooms and Galenia africana plants near Springbok, Namaqualand.
Succulents with leaves and stems can be seen in Richtersveld National Park’s Helskloof in the Northern Cape.
The southern Succulent Karoo Biome has Tylecodon paniculatum and Euphorbia mauritanica.
What kind of biome is the Succulent Karoo?
The Succulent Karoo biome generally has a mild climate with a significant coastal impact. The majority of the area has winter rainfall, with year-round precipitation occurring in the eastern Little Karoo. The biome’s mean annual precipitation ranges from 100 to 200 mm for the majority of plant units. In certain places, such as those near the Namib Desert, the rainfall is less than 100 mm. The Robertson Karoo, which experiences about 300 mm of precipitation on average annually, is the biome’s wettest region.
The Succulent Karoo biome has an average yearly temperature of 16.8 C. Frost is very uncommon in the low-lying coastal areas, such as the Knersvlakte. However, frost is rather commonplace at higher elevations further inland, such as the Roggeveld Karoo, occuring on average about 60 days per year.
The Succulent Karoo Biome spans a huge region and is distinguished by its extremely intricate geology. The Bokkeveld group of the Cape supergroup’s shale geology accounts for the majority of the region’s geology. The Richtersveld Terrane, the Namaqua-Natal Metamorphic Belt, and the Gariep Metamorphic Belt make up the region’s northernmost portion of its geology.
Flora & Wildlife
There are over 6 350 species of vascular plants in the Succulent Karoo, of which nearly 2 440 (or 40%) are unique to the biome, meaning they cannot be found anywhere else on earth. The Succulent Karoo is home to a large number of plant species that are prominent habitat specialists and occupy very narrow habitat niches. The “halfmens” of the Richtersveld (Pachypodium namaquanum), which can reach heights of 4 meters, are one of the most well-known plant species from the Succulent Karoo.
More than 225 bird species, 75 mammal species, and more than 90 reptile species can be found in the Succulent Karoo. Due to the area’s aridity, amphibians are considerably underrepresented. The Barlow’s Lark is the only endemic bird, and the De Winton’s Golden Mole and Namaqua Dune Mole Rat are the only endemic animals. With more than 70 different species of scorpion present, invertebrate diversity is likewise very great.
The Poaching Problem
Sadly, illicit collection of succulents for the horticulture sector frequently targets the species that have made the Succulent Karoo famous. Without a permit, it is against the law in South Africa to take plants like these out of the wild, and the penalties for getting caught can be severe. Please always make sure that the plants you buy for your garden are from reliable growers who don’t illegally take plants from the wild. The Veld & Flora issue from September 2020 has more information on this.
Above: The Succulent Karoo of Namaqualand is already seeing widespread death of perennial plants, trees, and succulents due to more intense drought conditions brought on by a changing climate. Zo Chapman Poulsen is pictured.
Impacts of the Climate Crisis
The costs of the effects of the global climate crisis on the biodiversity and flora of the Succulent Karoo ecosystem are still being calculated. Temperatures are expected to rise throughout southern Africa, and the region will likely face longer and more severe droughts as well as increased aridity.
The biodiversity of this hotspot is already beginning to suffer greatly as a result of these changes. Succulents, perennial shrubs, and trees all died in large numbers as a result of the catastrophic drought the area has endured over the past few years, according to scientists. How these developments will affect the region moving ahead is yet uncertain. The March 2020 issue of Veld & Flora takes a closer look by Nick Helme and Ute Schmiedel.
Conservation & Management
As custodians of the Succulent Karoo, landowners must take special care to ensure that management and land use, such as livestock grazing, are in line with preserving the biodiversity of this extraordinary and one-of-a-kind region of South Africa. Life in this extraordinary semiarid landscape always takes place on the edge. The book Karoo Veld: Ecology and Management has further in-depth details about sustainable veld use and management for landowners.
Between Calvinia and Sutherland, along the R354, is lush Karoo vegetation. Zo Chapman Poulsen is pictured.
Collaboration in the Succulent Karoo
Ismail Ebrahim (CREW) and Rupert Koopman (BotSoc) oversaw a Bioblitz in the Vrolijkheid Nature Reserve during the most recent McGregor Magic Online Festival. Here you may see Ismail’s film of the occasion and read Rupert’s report of the Bioblitz’s preliminary findings.
The Karoo biome is what?
The Nama Karoo, which covers more than 260 000 km2 or roughly 20.5 percent of South Africa, is the third-largest biome there. It covers a sizable portion of the country’s central plateau towards the west. It is a semi-desert that gets some summertime rain.
What distinguishes the Succulent Karoo?
Flora. One-third of the estimated 10,000 species of succulent plants are found in the Succulent Karoo, which boasts the world’s richest succulent plant flora. Its succulent plants make up 40% of the species. There are about 630 species of geophytes in the area, which is incredibly rich in them.
The Succulent Karoo is where?
To maintain openness, information access, and to promote harmonization of Tentative Lists at regional and thematic levels, the World Heritage Centre publishes the Tentative Lists of States Parties on its website or in working documents.
Each Tentative List’s content is the sole responsibility of the corresponding State Party. The World Heritage Committee, the World Heritage Centre, or the Secretariat of UNESCO have not expressed any opinions regarding the boundaries or legal status of any country, territory, city, or other geographic area as a result of the publication of the Tentative Lists.
Property names are provided in the language that the State Party has supplied them in.
The Succulent Karoo biome is the only arid hotspot in the world and is a globally recognized hotspot for biodiversity. The 116 000 km2 biome stretches from South Africa’s southwest through its northern regions and into southern Namibia. The biome is home to 6 356 plant species, 936 (17%) of which are Red Data Book-listed and 40% of which are indigenous. Along with its floral variety, there are currently known 431 bird species, 68 mammal species, 27 amphibian species, 29 percent of which are endemic, 121 reptile species, 20 percent of which are endemic, and 27 amphibian species.
The Succulent Karoo’s diverse habitat types, which result from the area’s rough mountains, semi-arid shrublands, and coastal dunes, are what contribute to the region’s abundant biodiversity. The Succulent Karoo is known for its extraordinarily diverse and abundant indigenous vegetation. Due to extreme climate variations and significant environmental variability, an arid-adapted biota underwent enormous speciation, which is responsible for its biodiversity. Long-term relative stability of the environment has made it easier for the evolution’s byproducts to persist. High compositional change in communities with a diversity of species along environmental and geographic gradients is the cause of the high regional plant richness. Numerous species are restricted-range specialists in harsh habitats, primarily connected to soil type. Succulents, particularly members of the Mesembryanthemaceae family, and bulbs exhibit the highest levels of local endemism (i.e., the confinement of species to relatively narrow ranges of less than 50 km2). For certain taxa of invertebrates, similar patterns of compositional change over gradients have been seen.
Land ownership: The Protected Areas that will be considered for inclusion in the proposed transnational serial nomination are all legally protected and managed by SANParks, the Western Cape Nature Conservation Board, or the Northern Cape Department of Agriculture, Land Reform, Environment and Conservation in South Africa. In Namibia, the Protected Areas will be managed by the Ministry of Environment and Tourism.
Management framework: This potential transnational, serial, natural world heritage site does not yet have a coordinated management organization. The newly established “Joint Management Committee” for the CFRPA WHS could, however, be enlarged to include the State Party and extra management authorities. This would make it easier for these two globally recognized biodiversity hotspots to work together and integrate into the wider landscape. Not duplicating management structures would offer the added benefit of maximizing resources.
Budgetary considerations: The three entities indicated in point 1 above are responsible for funding the protected areas that could eventually make up the World Heritage Property.
Site readiness: All potential sites either have have current management plans in place or are working to update them. All necessary management structures are present.
Justification of Outstanding Universal Value
The Succulent Karoo biome is the only dry hotspot in the world and a recognized hotspot for biodiversity. The Succulent Karoo is known for its extraordinarily rich and diversified flora, which is particularly abundant in endemic succulents and bulbs.
Criteria (ix): There are important ongoing ecological and biological processes in the evolution and development of this terrestrial ecosystem because of the relatively little landscape modification and the size and placement of the protected areas.
The Succulent Karoo biome is the most biodiverse arid region in the world and contains the most significant and important natural habitat for the in-situ conservation of biological diversity, with 6 356 plant species living there, 40% of which are endemic and 936 (17%) of which are listed in the Red Data Book.
Statements of authenticity and/or integrity
An ecological profile was created using the findings of the Critical Ecosystem Partnership Fund-funded Succulent Karoo Ecosystem Planning (SKEP) process, which identified nine priority sites for conservation within the Succulent Karoo Hotspot. Within each of these nine priority zones, certain areas are being identified and targeted for increased conservation status through the SKEP process. But there are already a lot of legally protected national and provincial protected areas in many of the priority locations. These protected areas are often large enough to satisfy criterion (ix) and are situated in places that maximize biodiversity, so fulfilling criterion (x). The demands of development do not endanger them since they are properly controlled. Fragmentation is not a significant issue because less than 5% of the Succulent Karoo Biome has undergone irreversible transformation. Small stock have overused a number of locations beyond the protected regions, but this is generally still reversible and is being rectified. The Succulent Karoo’s mining impacts are typically confined and governed by EIA laws and regulations. The SKEP process will examine the contribution of these protected areas and determine whether or not they are properly situated and configured to achieve the conservation goals that have been established for the “pattern and process” protection of biodiversity. The current legally protected areas are expected to be assessed for their ability to contribute to a transnational serial nomination for the Succulent Karoo Protected Areas (SKPA) World Heritage Site and submitted as phase 1. These new protected areas will be assessed after the SKEP process of land identification and acquisition is complete, and those that qualify will be submitted as an extension nomination (phase 2).
Comparison with other similar properties
The nearby CFRPA WHS is the only other such serial nomination for a full, internationally recognized biodiversity hotspot. The addition of the SKPA would frequently be mutually beneficial because there are significant areas of “overlap” between these two contiguous hotspots, where transition from one to the other can happen over relatively short distances.
The Succulent Karoo, the most ecologically diversified dry region in the world, has been highlighted by the IUCN as a very clear gap on the World Heritage list.