Vivienne L. Williams

Unraveling the commercial market for medicinal plants and plant parts on the Witwatersrand, South Africa.

To unravel the market for commercial medicinal plants on the Witwatersrand in South Africa, a semiquantitative approach was taken. A stratified random sample of 50 herb-traders was surveyed, and an inventory of all plants and parts sold was compiled. Research participants were questioned on the scarcity and popularity of the plants traded, as well as suppliers and origins. The rarefaction method established that the sample size was adequate. The diversity of the sample was determined using ecological indices of diversity, and found to be comparatively high. In addition, Spearman rank correlations, chi-squared and Fisher’s exact probability tests were used to assess the probability of certain taxa being used. At least 46% of the taxa traded showed a higher than expected probability of being utilized, and taxa tended to be harvested from the largest families proximate to the markets. About 511 species are traded in the region, and there is a low dominance in the use of species. Ethnic and floristic diversity are influential in deciding the trading patterns that have emerged.RésuméPour découvrir le marché commercial des plantes médicinales et des parties de plantes, nous avons utilisé une approche semiquantitative. Un échantillon pris au hasard, de 50 commerces basé sur une connaissance corporative de ce monde spécifique, et un inventaire de toutes les variétes de plantes offertes à la vente dans ces échopes a été effectuée. Les participants, furent questionnés sur la rareté et la popularité des plantes à l’étalage, ainsi que sur l’origine et les fournisseurs de ces mêmes plantes. La méthode basée sur la raréfaction indiqua que la taille de l’échantillonage était adéquat. La diversité des échantillons fut déterminé en utilisant les indices écologiques, de diversité et se révéla, en comparaison, important. De plus, la corrélation linéaire de Spearman, le test x2, et les tests de probabilité éxacte de Fisher furent utilisés pout évaluer la probabilité de certaine taxa utilisée. Au moins 46% de la taxa vendue, montre une probabilité supérieure à la moyenne d’être utilisée, et la taxa tend a être récoltée parmi les familles de plantes situées dans la vicinité des lieux de vente. 511 espéces sont à la vente dans la région, et il n’y a pas de dominance particulière sur certaines especes. La présence de plusieurs groupes ethniques et la diversité végétale influence les habitudes commerciales qui constituent la base de l’étude.

Application of diversity indices to appraise plant availability in the traditional medicinal markets of Johannesburg, South Africa

The lack of scientific rigour in analysing ethnobotanical surveys has prompted researchers to investigate ways of quantitatively describing their data, including the use of ecological diversity indices. There are numerous indices and measures available to describe sample diversity. Twenty-two measures of species richness, diversity and evenness were reviewed using six sets of ethnomedicinal data derived from 50 formal muti shop traders (of different ethnicities) and 100 informal street traders of traditional medicine in Johannesburg, South Africa, and a seventh data set from traders on the western boundary of the Kruger National Park, South Africa. The diversity measures were coupled with species accumulation curves to construct cumulative diversity curves used to determine the minimum viable sample size on which a diversity index should be based, and to better understand the differences in the relative diversities of the samples. Distinct differences in the relative abundance and diversity of plants sold by street traders and shop traders were evident. Species diversity and evenness was found to be higher in shops, thus resulting in a lower dominance in the sale of certain plant species compared to the street traders. A survey of an informal market should include no less than 35 research participants compared to no less than 20 for the muti shops. The use of selected indices of species richness (Margalefs), diversity (Shannon, Simpsons, Fishers alpha, Hills numbers) and evenness are recommended as a means of describing patterns exhibited within ethnobotanical data.

Animals Traded for Traditional Medicine at the Faraday Market in South Africa: Species Diversity and Conservation Implications

In South Africa, animals and plants are commonly used as traditional medicine for both the healing of ailments and for symbolic purposes such as improving relationships and attaining good fortune. The aim of this study was twofold: to quantify the species richness and diversity of traded animal species and to assess the trade in species of conservation concern. We surveyed the Faraday traditional medicine market in Johannesburg and conducted 45 interviews with 32 traders during 23 visits. We identified 147 vertebrates representing about 9% of the total number of vertebrates in South Africa and about 63% of the total number of documented species (excluding domestic animals) traded in all South African traditional medicine markets. The vertebrates included 60 mammal species, 33 reptiles, 53 birds and one amphibian. Overall, species diversity in the Faraday market was moderately high and highest for mammals and birds, respectively. Evenness values indicated that relatively few species were dominant. Mammal body parts and bones were the most commonly sold items (n = 453, excluding porcupine quills and pangolin scales), followed by reptiles (n = 394, excluding osteoderms), birds (n = 193, excluding feathers and ostrich eggs), and amphibians (n = 6). Most (87.5%) species traded were of Least Concern using IUCN criteria, although 17 species were of conservation concern. However, a higher than expected proportion of traders (62.5%) were selling listed species, which is a matter for concern and should be monitored in the future.

Phylogeography of the Afromontane Prunus africana reveals a former migration corridor between East and West African highlands

Scattered populations of the same tree species in montane forests through Africa have led to speculations on the origins of distributions. Here, we inferred the colonization history of the Afromontane tree Prunus africana using seven chloroplast DNA loci to study 582 individuals from 32 populations sampled in a range‐wide survey from across Africa, revealing 22 haplotypes. The predominant haplotype, HT1a, occurred in 13 populations of eastern and southern Africa, while a second common haplotype, HT1m, occurred in populations of western Uganda and western Africa. The high differentiation observed between populations in East Africa was unexpected, with stands in western Uganda belonging with the western African lineage. High genetic differentiation among populations revealed using ordered alleles (NST = 0.840) compared with unordered alleles (GST = 0.735), indicated a clear phylogeographic pattern. Bayesian coalescence modelling suggested that ‘east’ and ‘west’ African types likely split early during southward migration of the species, while further more recent splitting events occurred among populations in the East of the continent. The high genetic similarity found between western Uganda and west African populations indicates that a former Afromontane migration corridor may have existed through Equatorial Africa.

The use of incidence-based species richness estimators, species accumulation curves and similarity measures to appraise ethnobotanical inventories from South Africa

The incorporation of suitable quantitative methods into ethnobotanical studies enhances the value of the research and the interpretation of the results. Prediction of sample species richness and the use of species accumulation functions have been addressed little in applied ethnobotany. In this paper, incidence-based species richness estimators, species accumulation curves and similarity measures are used to compare and predict species richness, evaluate sampling effort and compare the similarity of species inventories for ethnobotanical data sets derived from the trade in traditional medicine in Johannesburg and Mpumalanga, South Africa. EstimateS was used to compute estimators of species richness (e.g. Jackknife), rarefaction curves, species accumulation curves and complimentarity. Results showed that while the Michaelis–Menten Means estimator appeared to be the best estimator because the curve approached a horizontal asymptote, it was not able to accurately predict species richness for one of the data sets when two of its subsamples were individually tested. Instead, the first-order Jackknife estimator best approximated the known richness.

Divergent pattern of nuclear genetic diversity across the range of the Afromontane Prunus africana mirrors variable climate of African highlands

BACKGROUND AND AIMS Afromontane forest ecosystems share a high similarity of plant and animal biodiversity, although they occur mainly on isolated mountain massifs throughout the continent. This resemblance has long provoked questions on former wider distribution of Afromontane forests. In this study Prunus africana (one of the character trees of Afromontane forests) is used as a model for understanding the biogeography of this vegetation zone. METHODS Thirty natural populations from nine African countries covering a large part of Afromontane regions were analysed using six nuclear microsatellites. Standard population genetic analysis as well as Bayesian and maximum likelihood models were used to infer genetic diversity, population differentiation, barriers to gene flow, and recent and all migration among populations. KEY RESULTS Prunus africana exhibits strong divergence among five main Afromontane regions: West Africa, East Africa west of the Eastern Rift Valley (ERV), East Africa east of the ERV, southern Africa and Madagascar. The strongest divergence was evident between Madagascar and continental Africa. Populations from West Africa showed high similarity with East African populations west of the ERV, whereas populations east of the ERV are closely related to populations of southern Africa, respectively. CONCLUSIONS The observed patterns indicate divergent population history across the continent most likely associated to Pleistocene changes in climatic conditions. The high genetic similarity between populations of West Africa with population of East Africa west of the ERV is in agreement with faunistic and floristic patterns and provides further evidence for a historical migration route. Contrasting estimates of recent and historical gene flow indicate a shift of the main barrier to gene flow from the Lake Victoria basin to the ERV, highlighting the dynamic environmental and evolutionary history of the region.

Quantifying the Trade in Cycads (Encephalartos Species) in the Traditional Medicine Markets of Johannesburg and Durban, South Africa1

Quantifying the Trade in Cycads (EncephalartosSpecies) in the Traditional Medicine Markets of Johannesburg and Durban, South Africa. Cycads have been used for traditional purposes for centuries, mainly as a source of starch during droughts and famines. In South Africa, Encephalartos species are traded for traditional medicine (TM) in local TM markets. The 2009 IUCN Red Data assessment for South African flora lists 78% of the 37 indigenous Encephalartos species as “Threatened”, with three species already “Extinct in the Wild” (EW). South African cycads face an extinction crisis, primarily due to collecting for the horticultural trade. The trade in Encephalartos for TM also has a significant impact on several species, and is largely understudied. In this paper, the trade in Encephalartos for TM was quantified in South Africa’s two largest TM markets, Faraday in Johannesburg and Warwick in Durban. Harvesting of South African Encephalartos for TM involves the removal of bark strips and/or whole stem sections. Encephalartos species were sold at 26% and 13% of the stalls at Faraday and Warwick, respectively, with an estimated 9.0 metric tons traded at Warwick in 2009. Stem samples purchased in the markets were assigned to stem diameter size classes using a size class chart, and regression analysis was used to validate the allocations. Most harvesting was from sub-adult and adult cycads, and it appears that bark strips are removed from large arborescent plants, whereas smaller individuals and subterranean-stemmed species are harvested by removing the entire plant. There is generally a positive relationship between stem diameter and leaf base length as well as stem diameter and pith radius. The former can be used as a predictor of stem diameter size class for market samples that prove difficult to assign to diameter classes using the chart. Overall, this is the first study to quantify the trade in Encephalartos for TM in South Africa with reference to the size classes of the plants traded.

Birds of a Feather: Quantitative Assessments of the Diversity and Levels of Threat to Birds Used in African Traditional Medicine

This chapter reviews the richness of bird use for traditional medicines across Africa. At least 354 species from 205 genera, 70 families, and 25 orders are used for traditional medicine in 25 African countries. Most birds are in the order Passeriformes (108 species used and 82 species traded), with the starlings (Sturnidae) the most commonly used family of passerines (nine species). Of all the bird families in trade, the Accipitridae had the most number of recorded genera (26 genera; 37 species; including kites, hawks, eagles, vultures), followed by the Ardeidae (11 genera; 15 species; including herons and egrets). The Bucerotidae (hornbills), Cuculidae (cuckoos) and Strigidae (owls) were the next most specious families in trade. The Ostrich was the most widely used bird species (11 African countries), although it was only recorded as sold in markets of four countries. Barn owls were the most widely sold. Using a widely accepted method for grouping species according to commonness or rarity, we show that 24% of traded bird species are very common and locally abundant in several habitats over a large geographic area. Ten percent of traded species are, however, rare, occurring in low numbers in specific habitats over a small geographic area. The order with the highest proportion of rare species was the Bucerotiformes (hornbills). Excluding non-breeding Palearctic (PAL) migrants, based on the 2011 IUCN Red List, 12 traded bird species are Threatened (three Endangered; nine Vulnerable) and eight are Near Threatened.

Risks to Birds Traded for African Traditional Medicine: A Quantitative Assessment

Few regional or continent-wide assessments of bird use for traditional medicine have been attempted anywhere in the world. Africa has the highest known diversity of bird species used for this purpose. This study assesses the vulnerability of 354 bird species used for traditional medicine in 25 African countries, from 205 genera, 70 families, and 25 orders. The orders most represented were Passeriformes (107 species), Falconiformes (45 species), and Coraciiformes (24 species), and the families Accipitridae (37 species), Ardeidae (15 species), and Bucerotidae (12 species). The Barn owl (Tyto alba) was the most widely sold species (seven countries). The similarity of avifaunal orders traded is high (analogous to “morphospecies”, and using Sørensens index), which suggests opportunities for a common understanding of cultural factors driving demand. The highest similarity was between bird orders sold in markets of Benin vs. Burkina Faso (90%), but even bird orders sold in two geographically separated countries (Benin vs. South Africa and Nigeria vs. South Africa) were 87% and 81% similar, respectively. Rabinowitzs “7 forms of rarity” model, used to group species according to commonness or rarity, indicated that 24% of traded bird species are very common, locally abundant in several habitats, and occur over a large geographical area, but 10% are rare, occur in low numbers in specific habitats, and over a small geographical area. The order with the highest proportion of rare species was the Musophagiformes. An analysis of species mass (as a proxy for size) indicated that large and/or conspicuous species tend to be targeted by harvesters for the traditional medicine trade. Furthermore, based on cluster analyses for species groups of similar risk, vultures, hornbills, and other large avifauna, such as bustards, are most threatened by selective harvesting and should be prioritised for conservation action.

The trade and marketing of traditional medicines in southern and central Malawi

ABSTRACT Malawi is one of the world’s 48 least developed countries and the population are alleged to be mostly reliant on traditional medicines. Approximately 90% of Malawians are forced by circumstances of low income to depend on the natural resource base for a living and to trade-off long-term sustainable resource use for short-term consumption of stocks. A study on the trade and marketing of traditional plant medicines in the southern and central regions of Malawi was conducted to characterise the stakeholders of the regional medicinal plant trade and to identify species that are harvested and sold both locally and internationally. Thirty traders and six border post officials were interviewed in eight Malawian districts that border with the neighbouring countries of Zambia and Mozambique. Men were the predominant traders of traditional medicine in the markets, and 90% of the respondents reported that they derived more than 50% of their households’ income from selling medicinal plants. Approximately 123 plant species were recorded during the survey and, based on frequencies, the most common species sold were: Cassia abbreviata (77% of traders), Cissus cornifolia and Aristolochia hockii (47% each), Zanha africana (37%), and Afzelia quanzensis, Combretum zeyheri and Dicoma amoena (30% each). Sixty-eight percent of the identified species were sold for roots, and 44% for bark. It also emerged that at least 26 species (24%) were being exported to southern Africa, including Mondia whitei (an Endangered species in South Africa), and that at least 73% of the respondents had sold plants to South Africa. Unregulated activities with respect to the domestic and international trade are compromising the sustainability of harvesting and consequently, the provision of sufficient ethnomedicinal plant resources in the long term. It would appear that one of the biggest interventions required in Malawi is to improve the ambiguous position allegedly held by the Malawian government towards traditional medicine in order to align policies with conservation needs to effect realistic and sustainable resource management strategies.