| Scientific Name | Warburgia salutaris (G.Bertol.) Chiov. | Higher Classification | Dicotyledons | Family | CANELLACEAE | Synonyms | Chibaca salutaris Bertol.f., Warburgia breyeri Pott | Common Names | Amazwecehlabayo (z), Fever Tree (e), Isibaha (z), Isibhaha (z), Koorsboom (a), Manakha (v), Molaka (ss), Mulanga (v), Peperbasboom (a), Peperblaarboom (a), Pepper-bark (e), Pepper-bark Tree (e), Pepper-leaf (e), Pepper-root (e), Shibaha (ts), Sterkbos (a) |
National Status | Status and Criteria | Vulnerable C2a(i) | Assessment Date | 2022/10/18 | Assessor(s) | Y. Harvey-Brown, N.N. Mhlongo, D. Raimondo, V.L. Williams, J. Botha, M. Hofmeyr & L. Swemmer | Justification | This species has a population size estimated to be between 4638 and 5566 plants. The largest recorded subpopulation within its South African range consists of 952 plants. While it is possible that larger unrecorded subpopulations may exist, they are unlikely to have more than 1000 mature individuals. A conservation model developed and implemented in the Kruger National Park to reduce the threat of overharvesting on wild subpopulations for the traditional medicine trade by supplying traditional healers with cultivated plants to grow has been highly successful, and this model is being expanded to other areas within this species' range. This conservation intervention has reduced the rate of decline in the population and resulted in a genuine improvement in the species' status. It therefore qualifies as Vulnerable under criterion C. |
Distribution | Endemism | Not endemic to South Africa | Provincial distribution | KwaZulu-Natal, Limpopo, Mpumalanga | Range | This species has a scattered distribution in southern Africa where it is recorded from eastern South Africa (KwaZulu-Natal, Limpopo and Mpumalanga provinces), Eswatini, Mozambique (Maputo Province) and Zimbabwe (Mutema Highlands). |
Habitat and Ecology | Major system | Terrestrial | Major habitats | Maputaland Pallid Sandy Bushveld, Zululand Lowveld, Kaalrug Mountain Bushveld, Ohrigstad Mountain Bushveld, Poung Dolomite Mountain Bushveld, Soutpansberg Mountain Bushveld, Ironwood Dry Forest, Sand Forest, Northern Coastal Forest, Scarp Forest, Northern Mistbelt Forest, Northern Afrotemperate Forest, Lowveld Riverine Forest | Description | It is a small tree species that occurs in evergreen montane forest including wooded ravines and evergreen forest along the coast (Maroyi 2013) and bushveld (Senkoro et al. 2019). From data gathered in KwaZulu-Natal in South Africa in the early 2000s, there was very little seed set in the known subpopulations and no seedlings were reported. All new trees that were observed reproduce vegetatively. |
Threats | The major direct threat to the species is the exploitation of its bark, stem, and roots for use in traditional medicinal practices, which is driven by local subsistence uses and high commercial demand in urban areas (Senkoro et al. 2019). Although the tree can tolerate a certain degree of harvesting through the production of coppice shoots and regrowing stripped bark, excessive and unsustainable harvesting can cause the death of the tree. Unsustainable use and heavy exploitation of the species were first reported by Gerstner in 1938: "There are all over the country only poor coppices, every year cut right down to the bottom, used all over, and sold by Native herbalists as one of the most famous expectorants". In 1946, 40-50 bags of bark were sometimes railed in a single day from Hluhluwe to Durban (Gerstner 1946).
Cunningham (1988) recorded the conservation status of the species in KwaZulu-Natal as 'endangered' and reported that at least 315 bags of bark were traded annually between 54 herb traders in the region. The species was ranked 13th in terms of prevalence in the KwaZulu-Natal markets and was usually ranked first or second by the herb traders and herbalists as becoming scarce as far back as the 1980s (Cunningham 1988). 85-90% of herbalists and traders interviewed in the study considered the species scarce (Cunningham, 1988). Shops and street traders in the Johannesburg region, where 66% of muthi shops sold the bark in 1994, also considered the bark to be popular and very scarce (Williams et al. 2007). It was also sold by 22% of the street traders in the Faraday market in 2001, and the number of bags estimated to have been purchased was 76 (Williams et al. 2007). Williams et al. (2007) noted that the mean thickness of the bark sold in the Johannesburg markets decreased significantly between 1994 and 2001, indicating that increasingly smaller trees were being debarked by harvesters as the larger, more mature trees became unavailable (Williams et al. 2007). The species was also popular in the Mpumalanga markets (Botha et al. 2001).
In the early 2000s, bark stripping was recorded in three subpopulations in KwaZulu-Natal. In a 2020 survey of Phinda Reserve, no dead individuals were observed, but historical damage (7.56% of individuals) and recent damage (1.2% of individuals) were observed from bark harvesting. In the Mpumalanga province, Ehlanzeni District, two subpopulations recorded recent bark harvesting in 2020, and five recorded harvesting dating from more than 10 years ago. All communities of W. salutaris occurring on the western Soutpansberg, Limpopo, showed some signs of historic bark poaching. One community was observed to have been heavily poached and is under threat of extinction. Quite a few communities also showed signs of coppicing due to hominin felling. One community was found to consist of only coppicing trees. A survey conducted in 2006 at the Punda Maria area in Kruger National Park found that debarking was recorded on 56.7% of all plants surveyed, and 13.7% were completely dead as a result of ring barking (Zambatis 2006).
The demand for the species was so high that the bark started being imported into South Africa from Eswatini and Mozambique (Williams et al. 2008). Dludlu et al. (2017) estimated that 38% of individuals surveyed in Eswatini were ring-barked and 7% were felled and ring-barked. In Mozambique, 181 out of 182 respondents in Maputo Province, Southern Mozambique, reported using the tree for medicinal purposes, with the bark being the far most preferred part of the tree (92.2% of households). Active bark harvesting was recorded in the Futi Corridor, a protected area of southern Mozambique (Senkoro et al. 2019)
Due to the high levels of unsustainable harvesting for medicinal purposes, the species has been locally extinct in Zimbabwe since the 1990s (Maroyi 2011). The species is also known to be locally extinct in Kwangwenya, KwaZulu-Natal, and is suspected to have been harvested to extinction in several other localities in the province.
There has been some habitat loss due to agricultural activities, expansion of human habitation, and logging for firewood and timber. A few communities in the Limpopo province have been negatively affected due to road construction (Hahn 2021). Subpopulations of this species in Mozambique are threatened by fire from slash-and-burn agriculture (Senkoro et al. 2020). Fire and browsing were also noted as threats to the species in KwaZulu Natal. Elephant impact in the Kruger National Park was recorded on 20.0% of the individuals inspected and buffalo on 3.3%; however, very little fatal damage by herbivores was noted (Zambatis 2006). Animals rubbing up against trees, causing bark damage, and harvesting the tree for its timber were also noted in the Ehlanzeni District, Mpumalanga (Raimondo et al., 2021). Secondary termite and fungi damage was occasionally observed on trees that had been debarked by poachers in Limpopo. Seed from the False Bay subpopulation, KwaZulu-Natal, has been observed to be highly parasitized. |
Population | Warburgia salutaris often coppices from roots and from slender stems that fall over naturally, forming characteristic coppice subpopulations. In these coppice subpopulations, large clusters of plants are found in close proximity to each other. Population estimates collected throughout its range have used different methodologies to determine what constitutes an "individual" and may overestimate the true population size due to the high number of genetically identical coppice stems.
In Ehlanzeni District, Mpumalanga, eight subpopulations of W. salutaris were surveyed in 2020. During the field surveys, 1,116 trees were counted, of which 289 had a harvestable stem diameter of 8 cm or more. During the field survey work, it was not possible to count every tree at some of the larger subpopulations, and in extrapolating the actual counts to the full subpopulation extent (area of occupancy), it was estimated that there are about 2,044 W. salutaris trees within Ehlanzeni District, of which ca. 529 trees have a stem diameter ? 8 cm (Raimondo et al. 2021).
In the Soutpansberg area of Limpopo, the trees were planted hundreds of years ago as a hedge around homesteads by a cultural group that lived there before the Vendas, along with the coral and marula trees. Field work was conducted in western Soutpansberg in 2020, where 902 trees were recorded in 30 communities (Hahn 2021). About six communities of W. salutaris are known for the area around Punda Maria in the Kruger National Park. In Kruger National Park, two subpopulations have been identified with approximately 234 individuals.Â
In 2004, 11 subpopulations were known in the KwaZulu-Natal province. The subpopulation at False Bay consisted of 998 stems, Itala Game Reserve had 54 stems, and Hluhluwe Game Reserve had 382 stems (KZN Nature Conservation Service 2004). Phinda Reserve is the largest natural subpopulation in the province; 21 localities are known across the reserve, with 952 individuals recorded during survey work conducted in November 2020.
Dludlu et al. (2017) recorded 18 subpopulations in Eswatini, of which 14 had not been recorded previously, comprised of 700 mature and 764 juvenile W. salutaris trees. Its presence in small, isolated subpopulations represents a severely fragmented population. The subpopulation with the largest number of mature individuals recorded was 155.
In Mozambique, it is currently restricted to fragmented patches in the Lebombo Mountains, Tembe River, and Futi Corridor (Senkoro et al. 2020). In southern Mozambique, there are 6-14 localities in Maputo Province. Forty-eight individuals were sampled by Senkoro et al. (2020), and high genetic diversity was found between the three surveyed areas.
It is known historically from eastern Zimbabwe (Mutema Highlands), but it is now believed to be extinct in the wild in Zimbabwe (Maroyi 2008). The species is also thought to have gone extinct at many localities in the KwaZulu-Natal province (Cunningham, 1988). It is highly likely that subpopulations have also been lost in Limpopo. Botha et al. (2004) were unable to relocate the species in a protected area in Limpopo, despite an intensive search with an experienced ranger who was familiar with its previous location.
Based on the above surveys and research studies, the total population ranges from 4638 to 566 mature individuals. The population has a decreasing trend; however, rates of decline have slowed. Between 1980 and 2010, rates of decline were high; however, a successful conservation intervention involving the distribution of in excess of 20 000 tree samplings to traditional healers in and around Kruger National Park and more recently also in the Ehlanzeni district of Mpumalanga and northern KwaZulu Natal has led to in excess of 10 000 plants being grown successfully in home gardens. This has reduced pressure on wild populations, so while there is still decline taking place, it is at a much lower rate.
| Population trend | Decreasing |
Conservation | It is conserved in Itala Game Reserve, Hluhluwe-Umfolozi Park, False Bay Park, Tembe Elephant Park, Kakaza Nature Reserve and Maputaland Coastal Forest Reserve. |
Notes | Taxonomic Note:
W. salutaris is differentiated from Warburgia ugandensis Sprague, which occurs in East and Central Africa on the basis of differences in numbers of ovules, placentation and fruit size (Hollmann and Van der Schijff 1996, Verdcourt 1956, 1990).
This species is an important medicinal plant in southern Africa where it is used to treat a variety of ailments including coughs, colds and malaria. Its bark and leaves have antimicrobial properties and are sold in local markets and as over-the-counter products from pharmacies (Kotina et al. 2014). The distinctive peppery aroma of its leaves has resulted in its use as a condiment for food dishes and beverages (Senkoro et al. 2019). Its leaves are browsed by Black Rhino, hippos and antelope (Mbambezeli 2004, Nichols 2005). Timber harvesting from this species has also been observed (Raimondo et al. 2021). Timber is also collected for firewood.
Conservation:
To address uncertainty over population estimates it is recommended that a population survey methodology is developed that can be shared and used by stakeholders to ensure that the data being collected is consistent and comparable in the future.
South Africa
It is formally protected under South African legislation in the revised National Forests Act (2012) and the National Environmental Management Biodiversity Act (2004). It is assessed as Endangered in South Africa (Williams et al. 2008).
Mpumalanga: In Ehlanzeni District seven subpopulations are protected (two privately and five by the state) (Raimondo et al. 2021).
Limpopo: In recognition that subpopulations within Kruger National Park were severely threatened, particularly from illegal harvesting, the Warburgia salutaris Conservation Programme was initiated in 2008. The main aim of the programme was to promote the sustainable use of the species by providing alternative sources of material to wild trees. Experts from the Agricultural Research Council and South African National Biodiversity Institute were enlisted to improve the germination of species and enabled mass propagation of W. salutaris saplings at Skukuza Indigenous Nursery. With sponsorship from SAPPI, over 30,000 saplings have been distributed to traditional healers on the western boundary of Kruger. Since the beginning of the programme, over 2,500 local community members have been engaged either directly or indirectly. Survival rates of distributed saplings have found to be high (50-95%) and all participants surveyed were found to no longer buy W. salutaris material at local markets. This conservation model has proved so successful that it has been expanded to KwaZulu-Natal and at a smaller scale in Eswatini and Zimbabwe.
KwaZulu-Natal: It is found in the following protected areas: Itala Game Reserve, Huhluwe Umfolozi Park, False Bay Park, Tembe Elephant Park, Makaza Nature Reserve, Phinda Game Reserve, Maputaland Coastal Forest Reserve. W. salutaris is protected in KwaZulu-Natal under section 61 of the KwaZulu-Natal Conservation Management Amendment Act 5 of 1999. A recovery plan for the species was developed in 2004 for its distribution in KwaZulu-Natal however due to limitations in funding and capacity it was not able to be implemented (KZN Nature Conservation Service 2004).
Eswatini: Dludlu et al. (2017) recorded that three localities of the species were in protected areas and seven were in unprotected areas worthy of protection. The protected areas are Malolotja Nature Reserve, Mhlumeni Protected Area and Mlawula Nature Reserve. Three of the largest subpopulations, Ngudzeni, Sitsatsaweni and Bulunga (containing 351, 230 and 250 individuals respectively) were not found in protected areas. It is recommended that these areas become protected. It is listed as Endangered B2ab (iii,v) (Dludlu et al. 2017). It has been listed as Endangered in Eswatini (Dludlu et al. 2016).
Mozambique: It is assessed as Vulnerable in Mozambique (Izidine and Bandeira 2002). It is found in Futi Corridor in Southern Mozambique which is a protected area, however illegal harvesting is known to take place there (Senkoro et al. 2019). More survey work needs to be undertaken in Mozambique to get a more accurate estimate of the population size. |
Assessment History |
Taxon assessed |
Status and Criteria |
Citation/Red List version | Warburgia salutaris (G.Bertol.) Chiov. | EN A2acd | Raimondo et al. (2009) | Warburgia salutaris (G.Bertol.) Chiov. | EN | Scott-Shaw (1999) | Warburgia salutaris (G.Bertol.) Chiov. | Vulnerable | Hilton-Taylor (1996) | Warburgia salutaris (G.Bertol.) Chiov. | Vulnerable | Hall et al. (1980) | |
Bibliography | Aboyade, O.M., Syger, G., Gibson, D. and Hughes, G. 2014. Sutherlandia frutescens: The Meeting of Science and Traditional Knowledge. Journal of alternative and complementary medicine 20:71-76.
Boon, R. 2010. Pooley's Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.
Botes, P.J.J. 2020. Botanical Assessment. Gariep Housing Project: Proposed formalization and development of 135 new erven on plot 113, Gariped settlement. !Kheis Local Municipality, Northern Cape Province. PB Consult Environmental Management Services, Bredasdorp.
Ekotrust. 2020. Botanical survey: Turksvydam project, Upington.
Hall, A.V., De Winter, M., De Winter, B. and Van Oosterhout, S.A.M. 1980. Threatened plants of southern Africa. South African National Scienctific Programmes Report 45. CSIR, Pretoria.
Hilton-Taylor, C. 1996. Red data list of southern African plants. Strelitzia 4. South African National Botanical Institute, Pretoria.
Hilton-Taylor, C. 1998. Assessment of Southern African Trees for WCMC.
Loffler, L. and Loffler, P. 2005. Swaziland Tree Atlas, including selected shrubs and climbers. Southern African Botanical Diversity Network Report 35:1-196. SABONET, Pretoria.
Mannetti, L. 2011. Understanding plant resource use by the Khamani Bushmen of the southern Kalahari. M.Sc dissertation, University of Stellenbosch, Stellenbosch.
Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.
Williams, V.L., Witkowski, E.T.F. and Balkwill, K. 2007. Relationship between bark thickness and diameter at breast height for six tree species used medicinally in South Africa. South African Journal of Botany 73(3):449-465.
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Citation | Harvey-Brown, Y., Mhlongo, N.N., Raimondo, D., Williams, V.L., Botha, J., Hofmeyr, M. & Swemmer, L. 2022. Warburgia salutaris (G.Bertol.) Chiov. National Assessment: Red List of South African Plants version . Accessed on 2025/04/22 |
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