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The Importance of Community Involvement in Conservation

Number 23 - December 2001

J.S. Ewane





Among the numerous things that are regularly exported from Cameroon to neighbouring Nigeria are food stuffs. Among these food items is a local vegetable called eru. Three days every week, the patient observer in Limbe can count as many as 45-50 eru buses on their way to Idenau. These are sixteen-seater buses, (with all the seats removed) filled, from bottom to top, with the green vegetable. About the same quantity is tied onto the top of the bus. Each bus transports between 1-2 tonnes fresh weight of eru per trip, bringing the total quantity to 90-100 tonnes per week. This is only what goes out through the port of Idenau. Other outlets of eru to Nigeria are Ekondo-Titi (by boat) and Mamfe (by road). Eru also leaves Cameroon through its southern and eastern borders to Gabon and the Republic of Central Africa.

All this is for export to Nigeria and further on to Europe and the USA. The eru trade is flourishing and there are all indications that it is going to stay this way, so long as the vegetable is available in the forest. But just as erosion moves top soil from one place to another, so do eru harvesters extract this vegetable from the wild to local and foreign markets. The consequence of such removal on eru populations in the wild is obvious. This threat has been signalled by different interested quarters for different reasons and with different degrees of intervention.

The Limbe Botanic Garden (LBG) is one of these institutions which is interested in the conservation of this species. Its intervention has been in the areas of research and the involvement of local people in the cultivation of eru. The rationale of this is that if people grow eru in their gardens, or on their farms, or on an even larger scale (plantations), pressure on the wild populations of the species will reduce.

Eru is a plant of the Gnetaceae family. It has two varieties and both occur in Cameroon: Gnetum africanum and Gnetum buchholzianum. It is native to West and Central Africa where it is variously called eru or kok in Cameroon, koko in the Republic of Central Africa, ntoumou in Gabon and afang or okasi in Nigeria.

Eru is a climbing rainforest vine which grows well in forest gaps and in fallow farms. Though it can survive in volcanic, sandy and even clayey soils, it cannot grow in marshy areas. The plant needs shade to grow well; direct sunlight will scorch its leaves. In the wild, the support of stronger stems and branches is imperative for the climbing eru vines.

Eru: the Young Vine and Mature Leaves and Stem

Eru is a very important plant, and in Cameroon, the recognition of its different qualities keeps spreading everyday. It is one of the commonest vegetables eaten in Cameroon today. Its protein content is high and can greatly reduce malnutrition in areas where meat (or other sources of protein) is scarce.

In the South West Province of Cameroon, eru was previously associated with a particular tribe (the Banyangs) as it was their staple meal. But in recent years, almost all ethnic groupings, especially those from the South West and North West Provinces have learnt to cook and eat eru in the Banyang fashion. Its popularity has spread to attain national dimensions. There are few parties at which this dish is not served. There is hardly a restaurant that does not have eru on its menu.

Mobile eru restaurants have provided employment for thousands of men and women who in turn support numerous households. In almost all traditional feasts or parties today, eru is sure to be one of the main dishes whether the people celebrating are Banyangs or not. The social, cultural and economic value of eru cannot be overstated.

Cultivated Eru growing in CameroonEru also has medicinal qualities; it can be used in the treatment of enlarged spleens, sore throats and nausea. It can also be used as an antidote to poison, especially arrow poison common with the Pygmy. The leaves, used as dressing can accelerate the maturation of furuncles and the stem can be taken as a tisane to ease childbirth.

The most significant change in the fortunes of eru is the recognition of its economic value. Trade in this vegetable has become very big business. In Cameroon, local consumption, common as it is, is insignificant compared to the quantity that is exported, first to Nigeria and then to Europe and the USA.

The economic value of the vegetable is very high, increasing progressively as it goes further from the source (Bokwe and Ngatum, 1994). In Cameroon, a kilogram of eru costs CFA 400F (about 40p) in the market. When it is exported to Nigeria, the price rises to CFA 4.000 F (about £4.00), in the UK and Europe to CFA 8.000 F (about £8.00) and in the USA up to CFA 30.000 F (about £30.00).

It is this economic use of eru that presents the greatest threat to the future of the species. In the quest for rapid financial benefit, people harvest enormous quantities. The issue here is that there is no tradition, amongst the people in Cameroon and other parts of West and Central Africa, to cultivate this plant. It is not like banana or cocoa which is widely cultivated. So of all the eru that is harvested and eaten, nothing goes back in the form of planting to replace the harvested stock. It is important for conservation measures (such as increasing available stock or creating gene banks) to be taken now because if things continue at this rate, the existing stocks of the plant may be wiped out.

Added to this issue of quantities harvested, is the way in which the harvesting is done. Because the plant is a climber, the choicest leaves are often high up in the canopy, entwined with the leaves and branches of the trees which give it support. The harvester usually stands on the ground to pull on the vines. More that half the leaves (the part of the plant which is eaten) remain at the tree tops and only a small fraction comes down to the harvester; there is a lot of waste. So, if a harvester brings out two bus loads of eru from the forest, they have left about three bus loads to dry up in the forest. If the harvester wants to collect all the leaves, then they have to cut down the supporting tree, and this tendency has been on the increase. Sometimes the eru plants are simply uprooted – another unsustainable harvesting method.

The facts stated above are the findings of a study carried out by LBG where the uncertain future of the species provoked research. The Garden’s 'Conservation Through Cultivation' programme is centred around a number of plant species that have been identified to be threatened and which have economic or socio-cultural value (Prunus africana, Gnetum africanum, Rattan spp for the moment). These are plants whose wild populations are threatened for different reasons (mainly economic) and which local people do not traditionally cultivate.

The applied research goal of the programme is to identify appropriate cultivation methods for these species and encourage local farmers to grow them. It is hoped that this will deviate pressure from wild populations. This programme constitutes a major contribution on the part of the Limbe Botanic Garden to the goal of the Mount Cameroon Project (MCP) which is to maintain the biological diversity of Mount Cameroon.

Community Involvement

LBG contribution to MCP’s conservation goal necessitated a solid outreach programme. The people needed to be informed of research findings and be involved actively in the implementation of their recommendations. This has been the case with the Eru Project.

Public Awareness

The findings and results of the 'Conservation Through Cultivation' (CTC) programme have been brought to the knowledge of the public both at the local and national level. At trade fairs and exhibitions in the South West Province and at a national level, live samples of eru, rattans and Prunus africana have been displayed. General information, the conservation status and the research going on in the garden about these species is provided for visitors at the LBG stand.

Local and national radio have also been used to inform the public on the CTC Programme and the possibility of cultivating plants like eru. In the garden, an information panel has been set up for the eru trial plot for visitors to consult. There is a CTC poster at the Visitor Centre explaining the process and potential in cultivating Prunus, rattans and eru.

The public also benefit from the eru manual that was used at a training workshop organised by the garden. It will be updated with information, to be contributed by farmers, and published.

The garden set up two strategically located eru trial plots and one gene bank within its premises. The two plots illustrate different soil types and financial implications in cultivating eru with regard to the kind of material used to provide shade for the plant. Adequate interpretation has been provided by the Education Unit. For all people who come to the Limbe Botanic Garden, and who know eru, it is a great old myth that has been broken – its domestication.

The Eru Manual

For the benefit of some institutions and those farmers who can read, the Limbe Botanic Garden has produced the Eru Manual. The technical information received from the Conservation Through Cultivation Unit was transformed into an illustrated manual, easy enough to be used by anyone who can read. It provides all information and advice needed by anyone who wants to begin an eru farm. The manual was designed in such a way that the farmers can contribute to its evaluation and review.

Farmer Training

In addition to the displays in the garden and the manual, community participation was encouraged by a free training workshop on the cultivation of eru. The workshop was held at the Garden’s Visitor Centre and it lasted 6 working days (12 to 19 July 1999). It involved farmers from the Bimbia-Bonadikombo area, one of the Mount Cameroon Project’s field divisions, where the eru farm extension scheme is limited to for now.

The training was both theory and practice. The practical part took the participants through the different steps involved in the cultivation of eru. Participants had the opportunity of visiting and even planting the crop on farms in the Bimbia-Bonadikombo farmland area. The entire workshop was facilitated by staff of the Mount Cameroon Project; technical information was provided by the Conservation Through Cultivation Unit. The participants went through the following necessary activities: preparing plant material, selecting the right site, digging the hole, planting, staking, taking care of the plant and harvesting.

During the practical part of the workshop, three eru farms were set up in the Bimbia Bonadikombo area. For the farmers who participated at the workshop, they each had to construct their own propagators in their villages and carry on with the propagation of their own eru cuttings. After this, they will plant on their farms. At the end of the workshop, participants agreed on roles and responsibilities for joint monitoring with feedback and consultation happening every month.

The Next Step

After this workshop and considering the results that the first trial will give, the Eru Programme will extend to train other farmers in the Mount Cameroon Project area, the South West Province and, hopefully, other parts of Cameroon. This will depend largely on the availability of funds for this activity. Already the programme has caught the attention of the Minister of the Environment and Forestry and he has requested the Limbe Botanic Garden to set up a demonstration farm in a village in the Centre Province, about 500km from Limbe. This might be the beginning of the spread of the Limbe Botanic Garden Eru project to other parts of the country.

Some Lessons Learnt


LBG studies and experience indicate that it is profitable to grow eru on one’s farm. Not only does it provide easy access to the vegetable and eliminates the difficulties of going far into the forest for it, but it also presents impressive economic benefit. For an eru farm of 100 square metres, yielding a average of one kilogram per plant with each plant harvested three times a year, the following estimates were made for the benefit of workshop participants:

  • Total expenditure for the different items (plant material, digging of holes and planting, staking, weeding and harvesting) will be CFA 70.000 F.
  • Selling at CFA 400 F per kilogram, the farm will give 300kg x 400 F = CFA 120.000 F.
  • Income from water leaf (a complementary vegetable which can be planted with eru in mixed cropping) will be CFA 60.000 F.
  • The net benefit in the first year will be 120.000 F + 60.000F – 70.000 F = 110.000 F.
  • In the second year, the expenditure will drop to CFA 20.000 F and the net profit will be 180.000 F – 20.000 F = 160.000 F.

The Ideal Situation

To get participants for the farmer training workshop, LBG staff conducted a farm survey of the Bimbia-Bonadikombo forest area. On one of the farms, a woman, Rose Teke, was practising in-situ cultivation of Eru. When the forested area was transformed into farmland, she came across some eru plants which she left to grow, in their natural habitat. She nurtured them and spread the seed some of which actually germinated and grew. Though it takes approximately nine months for the seed of Eru to germinate, this presents the ideal situation; unfortunately, cases like hers are rare.

The farm is about three hectares large, one third of which is estimated to be eru. She harvests the vegetable from her farm but she has never kept any records of what she harvests or how much income she gets. With the training she received at the workshop, she can easily increase the quantity of eru on her farm and monitor the income.

Eru and Agro-Forestry

The cultivation of eru, both in-situ and ex-situ, promotes agro-forestry. Because the plant needs shade to grow well, farmers are likely to either leave trees standing on their farms or plant new ones to provide the shade. They will also benefit by providing live stakes for the vines because they will not need to change them every season. All these are environmentally positive practices.


It is certain that the Limbe Botanic Garden has done a lot of research on eru and has arrived at some impressive conclusions. But there are still some information gaps in the domestication of eru which can be filled by farmers, especially with regard to the results to be obtained on the farms away from the garden. For this and for the sake of its extension programme, LBG needs to maintain a strong link with the farmers who are involved in the cultivation of the crop.

LBG has been involved in institutional partnerships which has been important in the eru extension programme. The garden has had to work with staff from the Cameroon Ministry of Agriculture for support in extension, and socio-economists from a local World Bank (GEF) surveys unit to provide a grounding to the on-farm extension support.

Implications for LBG

The Limbe Botanic Garden until recently, has been research dominated with little experience in extension work. The field work is done by the Mount Cameroon Project staff who are not part of the Limbe Botanic Garden, though the work they do might be a direct result of Limbe Botanic Garden research. Garden staff have not been involved in extension work with local farmers. The Eru Project is the first instance where the Limbe Botanic Garden staff have been directly involved with extension activities. This has necessitated the shift of staff from MCP to LBG. The need has now been identified to recruit an agricultural extension worker.

The role of the Garden’s Education Unit has also broadened to support the effective delivery/communication of extension messages to local farmers. The target audience of the unit has now increased to include the people whom the 'Conservation through Cultivation' programme is trying to reach. The unit, working closely with the agricultural extension worker, will design appropriate methods to communicate messages to farmers. This will include visual aids like posters and illustrated manuals (the current eru manual being the first), workshops and even documentaries on video.

The role of education and communication is very important at this point because, though a good number of people have heard of, or shown interest in, the cultivation of eru, many local people still consider it a vegetable that can only be got from the forest; not grown on farms. Environmental education should not end with simple information or sensitisation but should go on to provide the learner with skills necessary to take positive action for the environment. The Eru Project is doing just this.

The fact that LBG is getting directly involved in extension work will greatly improve its status with regard to the conservation work going on in the Mount Cameroon Region. The Mission of the Garden is to provide facilities and services for long term collaborative research, education and training in support of the biodiversity conservation in the Mount Cameroon Region and beyond. The Eru Project is a step towards the fulfilment of this mission.

In addition to playing the conservation role, the garden will be actively involved in providing direct tangible benefits to farmer livelihoods and alleviating poverty beyond the Garden walls. If the Eru Project becomes fully operational and is accepted by the people, it will be contributing to the economic growth of the area. Considering the high economic value and the ever-increasing demand for the vegetable, local farmers would better their livelihoods if they engaged in eru cultivation and trade.

L’importance de l’Implication des Communautés Locales Pour la Conservation


Eru (Gnetum africanum et Gnetum buchholzianum) est l’un des légumes le plus communément consommé au Cameroun. Il est riche en protéines et est prescrit comme médicament dans toute une série de troubles: pour la gorge, les nausées et comme antidote dans les cas d’empoisonnement par flèches. Cependant l’Eru est sérieusement menacé en raison de sa sur-exploitation. De grandes quantités sont exportées chaque semaine au Nigeria voisin et transitent de là vers l’Europe et les USA. Le jardin botanique de Limbe s’intéresse à la conservation de cette espèce et a été largement impliqué dans des programmes de recherche et a incité les communautés locales à cultiver l’Eru. Cet article détaille l’importance de l’espèce, les menaces qui pèsent sur elle et explique comment le jardin botanique de Limbe contribue à sa conservation, ceci grâce expositions et foires, l’utilisation de la radio locale et nationale, la mise en place de cultures d’essai, la formation des fermiers à la culture de l’Eru et la mise au point d’un manuel sur l’Eru.

Es Importante Involucrar a la Comunidad en la Conservacion


El eru (Gnetum africanum y Gnetum buchholzianum) es la hortaliza mas comida hoy en el Camerun. Es una importante fuente de proteinas y se utiliza medicinalmente para una gran gama de dolencias, incluyendo el dolor de garganta, las nauseas, y como antidoto al veneno de las flechas. Pero aun asi el eru esta en peligro por razon de su sobre-explotacion. Grandes cantidades son exportadas semanalmente a la vecina Nigeria y de este pais a Europa y a los Estados Unidos. El Jardin Botanico de Limbe se interesa en la conservacion de esta especie y se ha dedicado energeticamente a la investigacion y a involucrar a la poblacion local en el cultivo del eru. Este articulo detalla la importancia del eru y los peligros que le afrontan, y explica como el Jardin Botanico de Limbe contribuye a su conservacion. Entre otras cosas se celebran exposiciones y ferias para fomentar el conocimiento publico, se hace uso de las emisoras de radio locales y nacionales, se establecen zonas piloto para cultivar el eru para el interes de los visitantes, se desarolla la ensenanza a los granjeros sobre su cultivo y se esta preparando un manual del eru.