A WWF International Discussion Paper Prunus Africana Alternatives to the Unsustainable Exploitation of Wild Stocks in Africa and Madagascar Anthony B. Cunningham

• A WWF International Discussion Paper
  Prunus Africana
  Alternatives to the Unsustainable Exploitation of Wild Stocks in Africa and Madagascar
  Anthony B. Cunningham
  
  For further information, please contact:
  Clement Patient
  WWF International
  Avenue du Mont Blanc, 1196 Gland, Switzerland
  tel: + 44 22 364 9533
  fax: + 44 22 364 5829
  E-mail:cpatient@wwfnet.org
  
  Alan Hamilton
  E-mail:ahamilton@wwfnet.org
  Prunus Africana bark
  Alternatives to the Unsustainable Exploitation of Wild Stocks
  
  Introduction
  
  This paper takes the Prunus africana bark trade as an example to describe the path towards workable solutions in medicinal plants conservation. Although this case study only deals with Prunus africana, several issues raised are relevant to the exploitation of other medicinal species which are in trade. These issues are:
  
  1. the complexity of the medicinal plants trade from harvesters to final product;
  2. the reluctance of industry to invest in "green production" despite the benefits of doing so;
  3. underestimation of sustainable yields from wild populations;
  4. inappropriate local tenure systems;
  5. low prices to local harvesters which act as disincentives for growing medicinal plants or trees to relieve harvesting pressure on wild stocks.
  
  Although these factors complicate monitoring and resource management, the path towards workable solutions is more one of politics and people management than one based uniquely on natural resource management. As demand grows, cultivation of slower growing species such as Prunus africana can be a viable proposition. However, industry is often reluctant to commit resources to cultivation on a significant scale when wild stocks are still available. Resource mining is preferred to resource management despite the availability of information on volumes and products traded, on the economics of tree production, on genotypic variation within species, for developing on farm cultivation.
  
  Three changes are considered important for shifting from unsustainable wild harvest of Prunus africana to agroforestry or plantation scale production. These are:
  
  1. the application of "non-detriment" finding by CITES authorities with regard to export and import permits; ( in fact a ban on export and import of wild stocks);
  2. wider awareness amongst the European and North American public and the herbal products industry of the need for, and benefits of certified or sustainable sourcing; and
  3. the will to invest in the future and implement cultivation on a commercial scale.
  
  Trade in Prunus Africana
  
  Prunus africana is a tree species restricted to montane forests of Africa and Madagascar. To local people, Prunus africana is a multiple use species, used primarily for its bark (traditional medicines) and hard timber (building poles, fuelwood, axe handles). Internationally, Prunus africana bark extracts are used medicinally to treat prostate gland hypertrophy and benign prostatic hyperplasia (BPH).
  
  Trade in Prunus africana products takes place in several forms. Between 3 200 and 4 900 tons of bark are exploited annually for export, either as dried bark or bark extract. All of this is taken from wild populations from mountains forests in Cameroon (supplying 70% of world trade) and Madagascar (18% of world trade) and to a lesser extent from Zaire, Equatorial Guinea (the island Bioko) and Kenya. Bark extracts are also exported and used to produce herbal preparations in brand-name capsules.
  
  Twenty different European companies produce and sell herbal preparations containing Prunus africana extract. Several sell Prunus africana products under licensing agreement with Groupe Fournier (France) or Indena Spa. /Inverni della Beffa (Italy). In the USA, marketing of Prunus africana extract mixed with other ingredients (such as the fruit extract Saw Palmetto, Serenoa repens and pumpkin seeds, Cucurbita pepo), takes place by mail order and through the Internet. The retail cost of Prunus africana herbal preparations is high and the over-the-counter retail value of the trade is an estimated US$220 million/yr.
  
  In the 1970's and early 1980's, most bark was dried in source countries of Africa and Madagascar before export for processing in Europe. Since then, there has been a major shift in the two major exporting countries (Cameroon and Madagascar) away from export of unprocessed dried bark to export of locally produced bark extract. These two countries export some 14.6 tons of extract annually to France and Italy. Bark extract yields are 5kg of extract per ton of air-dry bark (or two tons of fresh bark). By contrast, yields of bark extract from black wattle (Acacia mearnsii), which is commercially cultivated for tannin, are 330kg per ton of wet bark. The low yields of Prunus africana bark extract are compensated for by its high value. In late 1996, its price was FrF4934 per kg (US$966/kg) compared to FrF1643 per kg (US$321) for Serenoa repens extract.
  
  Environmental effects
  
  Trade in Prunus africana bark is a significant source of foreign exchange for Cameroon and Madagascar. However, it has had a devastating effect on the wild populations of this unique resource. Distribution is limited to Afromontane forest "islands" which are generally above 1500 - 2000m altitude. The size of these "islands" has been greatly reduced by agricultural clearing, the major threat to Afromontane forests. It is these remaining Afromontane forests that are the current focus of Prunus africana bark exploitation.
  
  Although sustainable bark harvest is theoretically possible, tree or tree-crown die-off is common while felling to strip bark is frequent in Madagascar. Bark exploitation to meet the highest volumes of export demand even takes place inside "protected" forests and national parks. In Cameroon, commercial harvesting of bark has affected the habitat of three most important forests for bird conservation. (Mount Oku, Mount Cameroon and Mount Kupe). Cultivation in plantations or agroforestry systems within Africa is therefore the way forward to meet demand. However, international awareness of the destructive effects of this trade on wild populations should be further raised in order to promote a shift from wild populations harvesting to cultivated sources. This should take place before there is more extensive marketing of herbal extracts from Prunus africana in North America, which is considered to be the major potential market for Prunus africana herbal products in the future.
  
  Environmental sourcing
  
  The international trade in wild collected plant material to supply a thriving trade in dietary supplements and herbal products has grown rapidly over the past two decades. To increase market shares, companies are keen to produce quality products that are safe and effective. However, companies based in North America and Europe need to take the lead in developing a system of "environmental accounting" so that quality of herbal products and dietary supplements also encompass sustainable harvest and production. At present, there is not sufficient pressure on companies for developing methods of environmental sourcing. It is well recognised that far too many large companies (the main importer) leave issues such as origin of raw material and cultivation methods to local exporters and harvesters, and are therefore unaware of the destructive effects of their products on certain wild plant populations and habitats. Continuation of this practice will ultimately lead to the loss of the supply source for industry as habitat is damaged or selectively depleted of species. Local people will also lose out as their local self-sufficiency is eroded through overexploitation of popular plant species which they use as effective medicine.
  
  One way of achieving "environmental sourcing" is to give particular attention to slower growing, habitat specific medicinal plant species used in international trade. A growing number of these have been listed by CITES due to conservation concerns about overexploitation. Examples include American ginseng (Panax quinquefolius), Goldenseal (Hydrastis canadensis), African cherry (Prunus africana), jatamansi (Nardostchys jatamansi) and kukti (Picrorhiza kurrooa)
  
  Legislation and Resource Management
  
  All source countries (Uganda, Kenya, Madagascar, Zaire and Cameroon) are signatories to CITES. It is a requirement of CITES legislation that a Management Authority is established which would be responsible for national CITES control, administration and licences. This is not always the case.
  
  Prunus africana harvesting in Cameroon and Madagascar is allowed under permit systems issued by the national Departments of Forestry. The systems of exploitation that have been implemented are very different.
  
  In Madagascar, trees are routinely felled and stripped of their bark. Bark harvesters are supposed to leave 2 trees/ha undamaged as a source of seedlings in the future. These are supposed to be chosen by staff of the Forest Department. No felling is allowed within 10 m of a watercourse. Permits are issued for a duration of two years, and no limit is placed on the quantity of bark each person may collect.
  
  In Cameroon, sustainable bark harvesting was attempted between 1972 and 1987, when the company "Plantecam Medicam" had a monopoly on bark exploitation. This was carried out by trained teams of harvesters who removed opposing quarters of the trunk bark up to the first branch rather than girdling the trees. The intention was to return after 4-5 years to remove the undamaged trunk bark and after another 4-5 years, the regrowth. Although crown die-back occurred in some trees and bark regrowth was poor on trees located in open, dry sites, this practice had the advantage to reduce tree die-off due to bark damage. A real effort was made by Plantecam to ensure that all the bark harvesters employed were shown the collecting procedure of removing bark "quarters" from opposing sides of the tree trunk. Workers caught removing all bark from the trees also faced dismissal.
  
  Despite the commendable efforts of Plantecam at sustainable bark harvesting, there are many cases where this has not been achieved, particularly in north-west Cameroon. This is because the loss of monopoly control of Prunus Africana exploitation by Plantecam resulted in an opportunistic scramble for wild stocks by licensed entrepreneurs. In addition, the felling and/or complete stripping of Prunus africana trees by some bark harvesters has significantly reduced wild stocks. Concern about the effects of this over-harvesting resulted in recommendations leading to the partial ban on bark extraction in 1991. Cunningham and Mbenkum (1993) have shown that the ban may have had the opposite effect, as during 1991, over 3898 metric tons of bark, over twice the annual average, were processed.
  
  Concerning exploitation fees, all Special Permit holders in Cameroon, including Plantecam, pay a "Regeneration Tax" (2% of the value of the raw material) and a "Transformation Tax" to the Forestry Department. These are supposed to cover forest regeneration costs. These taxes have not been particularly effective in meeting their goals, and enrichment planting and regeneration schemes are limited. A similar regeneration tax system has been proposed for Madagascar.
  
  What Needs to be Done
  
  Meeting demand from cultivated sources
  
  To provide an alternative supply source and improve self-sufficiency of traditional medical practitioners, Prunus africana plants would need to be produced cheaply and in large quantity. In addition, bark prices and bark extract from "on farm" cultivation would have to be high enough to provide the necessary incentives for sustainable harvesting. In all cases where cultivation has taken place, (in Europe, Asia or Africa), plants have been grown for profit or for a high level of resource returns (eg: multiple use species for fruits, and medicinal properties). Relatively low Prunus africana bark prices, coupled with farmer's uncertainty concerning guaranteed entry to foreign markets, are disincentives which hamper cultivation. If small farmers are to become involved in Prunus africana cultivation, there needs to be a guaranteed market for the bark they produce at a price that makes production profitable.
  
  From an horticultural point of view, meeting commercial and domestic demands of the bark can be achieved relatively easily. The total volume of medicinal plant material is relatively small compared to food or timber products; therefore commercial demands can be met from relatively a small cultivated area. For example, the total Australian domestic demand of 200 - 300 tonnes of Aloe vera gel is met by 10-15 ha of Aloe barbadensis plantation. It is also estimated that 70 ha would be required to meet the regional demand of 300, 000 bulbs /yr of Scilla natalensis (Liliaceae), which is used in traditional medicine in KwaZulu/Natal, South Africa.
  
  In good growing conditions, bark production rates of Prunus africana are similar to Acacia mearnsii plantations, which produce 28 tons/bark/yr from 12 yr old stands with a mean density of 1 363 trees/ha. Before manufacture of the capsules, the bark extract of Prunus africana is standardised to contain 13% phytosterols. Twelve year old trees have about 50% of the phytosterol content, so twice the current tonnage would presumably be required. This suggests that the total annual world demand of 3200 - 4900 tonnes of Prunus africana bark could be produced from a total plantation area of 2743 - 4200 ha or a 12 year rotation of a total of 230 - 350 ha of trees felled and totally stripped of bark each year. Based on studies of Prunus africana bark production rates and prices, this can be an economic proposition
  
  Cultivation by small farmers
  
  As a relatively fast growing indigenous tree, Prunus africana also has great potential for reafforestation and agroforestry systems in deforested areas around forest remnants in Cameroon, Madagascar, Kenya, Uganda and Zaire. Several recent reports have drawn attention to conservation problems in these countries and suggested cultivation as a possible solution in order to take harvesting pressure off wild stocks. In Kenya, it is estimated that that there are 153 ha of Prunus africana plantations, nearly half of which are over 40 years old.
  
  The commercial importance of Prunus africana in north-west Cameroon has been an important stimulus for rural farmers to start growing this tree from seed, and some farmers in this area started planting as early as 1977. Most cultivation has however taken place since 1990 with support from local and international non-governmental organisations.
  
  An investigation, conducted by the author, on bark production and growth rates in Cameroon, found a statistically significant correlation between bark thickness, diameter at breast height (dbh) and tree height. This suggests that Prunus africana showed rapid growth. Trees with the fastest growth rates reached 14m high and 37cm dbh in 18yr. The study also compared the economics of cultivating Prunus africana and Eucalyptus camaldulensis (a popular introduced species in montane Africa), and showed that while Eucalyptus camaldulensis cultivation is 30% more profitable than Prunus africana production, there are reasons (such as the negative effects of Eucalyptus on crop yields) why farmers might rather invest in Prunus africana than in Eucalyptus trees. The 3500 farmers already planting Prunus africana in northwest Cameroon are evidence of this. To encourage further cultivation, steps need to be taken within exporting countries and internationally for the legal recognition of legitimate growers. If it is economically viable, small holder farmers should therefore play a greater role in Prunus africana cultivation, including agroforestry systems.
  
  Large scale cultivation
  
  Cultivation by small farmers is nowhere near the scale of planting required to reduce harvesting pressure on overexploited wild stocks. Herbal products companies with a high stake in Prunus africana should take direct responsibility for large scale cultivation. As argued in this paper, large scale cultivation to meet demand can be economically viable. Five options are suggested for cultivation on a large scale:
  
  1. cultivation done directly by the company, as Schwabe does with Gingko biloba in France. Similarly, the German company Boehringer Ingelheim in Australia produces about 40% of its requirements of Duboisia for production of scopalamine;
  
  2. research and cultivation through production contracts with selected farmers who then market their product to the company involved. An African example is the cultivation of Xysmalobium undulatum (Asclepiaceae), for a German and an Australian company.
  
  3. cultivation (and possibly on-farm research) by farmers who do not have access to a guaranteed market. This can be a high risk strategy (rather than a shared risk as in (2) above). A good example of this is the initial boom and bust experienced by Aloe vera (Aloe barbadensis) production in Australia during the mid-1980's when the market collapsed for many growers when prices plunged.
  
  4. research and cultivation by the State. Research that is publicly funded by the State can play an important role. A good example is the development of improved genetic material of Duboisia for plantation production of scopalamine in Australia. Large state owned plantations of timber trees provide a good example, although this option is unlikely for slower growing species. National governments, particularly in developing countries, are also reluctant to embark on such ventures.
  
  5. A combination of several of the above. If some of the different approaches are to be implemented, contracts between providers and buyer companies would have to be developed to get around the secretive approach which herbal product companies often take. Without this, production and marketing become fragmented and there is little co-operation between producers and industry.
  
  Lessons learned
  
  Traded internationally and harvested from the wild, Prunus africana is hardly a "minor forest product". Between 3200 - 4900 tonnes of bark are exploited annually for export to Europe. This represents the largest volume of any African medicinal plant in international trade. Neither the uncontrolled harvesting of wild Prunus africana populations, nor tree cultivation as one alternative to wild harvest are easy problems to resolve.
  
  Five lessons which have wide policy implications for plants in trade are put forward. Taking them into consideration could lead to a better balance between medicinal bark harvesting, forest conservation and local economic development.
  
  * Although sustainable harvest from wild populations was planned, this has unfortunately not occurred for a number of reasons.
  
  Local people have lost local self-sufficiency in an important traditional medicine; the Cameroon and Madagascar Forest Departments are concerned about the loss of foreign earnings; and international conservation organisations are worried about the effects on forest structure and biodiversity. Government regulations in Cameroon for a partial ban on harvest; for encouraging tree cultivation by the export company; or in Madagascar, the retention of two trees/hectare for seed production, have not been effective. Ironically, the loss of monopoly harvest-control by Plantecam in Cameroon and the partial ban on export, in fact led to a higher level of destructive harvest and volume of bark harvested than ever before.
  
  * A certain degree of control on the production and marketing of Prunus africana appears to be necessary to stop disorderly exploitation.
  
  Monopoly control on bark harvest in Cameroon had benefits for sustainable resource extraction, limiting tree felling or death from total debarking until 1978, when bark harvesting licences were granted to 50 Cameroonian entrepreneurs. Monopoly control on bark exports also had disadvantages for bark prices paid to harvesters, and consequently, reduced the incentive to cultivate trees. In 1994, illegal bark exploitation, fuelled by the higher price offered by an Italian company to three Cameroonian entrepreneurs resulted in extensive damage to Prunus africana trees on Mt Cameroon.
  
  * Overexploitation of wild Prunus africana populations has serious implication for conservation and cultivation.
  
  The location of isolated Prunus africana populations on montane "islands" dotted over virtually the entire length of sub-Saharan Africa and a few isolated mountains in Madagascar has probably been a key factor in genotypic and chemical differences between populations. Chemical analysis has shown, for example, that it is possible to distinguish between the bark extracts from different localities in Africa and Madagascar. These differences offer wider scope for selection of plant characteristics for the purposes of domestication and genetic improvement. It is also a point of concern that already isolated populations on montane islands are becoming further isolated due to the destruction of almost all large, reproductively mature trees from intervening "islands". The worst affected are also the most unusual - the Madagascan Prunus africana populations.
  
  * There is a need to change national forestry policy which prevents farmers selling Prunus africana bark.
  
  The rationale behind this regulation was to reduce uncontrolled exploitation of what was considered a national natural resource. However, it is a further disincentive for on-farm cultivation under rising scarcity of large Prunus africana trees.
  
  * It is encouraging to see that despite the lack of support from government, coupled with the disincentives of low bark prices and weak property rights, at least 3 500 small-scale farmers are already planting Prunus africana in agroforestry systems in north-west Cameroon.
  
  As a relatively fast growing indigenous tree, Prunus africana has great potential for reafforestation and agroforestry systems in deforested areas around forest remnants.
  
  References
  
  Cunningham, A B and F T Mbenkum. 1993. Sustainability of harvesting Prunus africana bark in Cameroon : a medicinal plant in international trade. People and Plants Working Paper 2. Paris, UNESCO.
  
  Cunningham, A B; E Ayuk, S Franzel, B Duguma and C Asanga. in press. An economic evaluation of medicinal tree cultivation : Prunus africana in Cameroon. Working Paper no. 6, WWF/UNESCO/Kew People and Plants Initiative.
  
  Cunningham, M, A B Cunningham and U Schippmann. 1997. Trade in Prunus africana and the implementation of CITES. Bundesamt fur Naturshutz, Germany.
  
  Davis, S D, V H Heywood and A C Hamilton. 1994. Centres of plant diversity : a guide and strategy for their conservation. IUCN Publications Unit, Cambridge, UK.
  
  Ewusi, B N, T Tanyi Charles, J Nyambi and J Acworth. 1996. Bark extraction : current situation and sustainable cropping of Prunus africana on Mount Cameroon. Unpublished paper, Mount Cameroon Project, Limbe, Cameroon.

  Reply

  Delete

Reply to this message...