Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The prolific orphan trees in the Cameroon forests

29.04.2003


The Ntumu (the Beti-Fang), live in the equatorial forest in southern Cameroon, in the north of Gabon and of Equatorial Guinea. They practice a semi-nomadic slash-and-burn form of agriculture. Their farming is highly diversified, mainly of food crops (such as cassava, plantain banana, sweet potato, yam and taro) but they also produce cash crops (cacao, groundnuts). When they clear a plot (1 ha on average), the Ntumu systematically spare certain trees, generally about 15 whatever cutting methods or implements they use: chainsaw or axe. Thus, contrary to what is often stated, selective felling is conducted not because the workforce is insufficient or for lack of time. Nor is determined by the hardness of the timber or the exhausting nature of the task. On the contrary, it is a deliberate traditional practice which requires a sophisticated knowledge of the environment and the different types of forest trees. It demands a long learning period.



Why do the Ntumu spare these trees, “orphans of the forest”, as they call them? Investigation of the species preserved reveals that they have a high social, cultural, agronomic and even ecological value in the long term. They are varieties that can provide food or medicinal resources (fruit and seeds), firewood or construction timber or represent prized hunting grounds. Some species, such as the kapok tree also contribute to the habitat’s fertility; their presence improves food production thanks to the humus generated by falling leaves, flowers and fruit as well as the shade they offer for crops. The three species – Ceiba pentandia, Triplochiton scleroxylon and Terminalia superba – which most particularly play this fertilizing role have a high cultural value and hence together represent a third of all protected trees left in the fields.

The orphan trees have, other than their immediate utility in the Ntumu’s subsistence economy, a driving role in forest regeneration when the fields return to fallow. These trees constitute highly attractive sites for seed-dispersing animals (birds, bats, monkeys) which use them to perch or as shelter against predators and sometimes find abundant food in them. In addition, under their crown, the seed density and diversity (over 100 different species1 have been recorded) are clearly higher than for those observed where no such trees remain. Most of these seeds belong to ligneous species (97% as against 60% in open fields)2. The trees isolated in the fields also create a microclimate which favours, or even accelerates, regrowth of forest species. They supply an input of nutrients (leaves, fruit, animal excreta) and increased soil humidity thanks to the shade under the crown. This shade encourages long-life forest tree species. In contrast, in some areas of the open plots, more short-life heliophile pioneer species are found. These species, most often herbaceous, are sometimes invasive. Forest regrowth thus develops more rapidly and intensively under the orphan trees: they act as the nuclei of regeneration which, when they coalesce will contribute to the rapid reconstitution of the forest cover.


At the level of agricultural regime, this ancestral practice favours the maintenance of a forest cover and contributes to the continuation of slash-and-burn agricultural systems. At the landscape level, the farmers have over the centuries, by systematically selecting certain species as they clear forest, oriented the specific diversity of the Cameroon forest towards a greater proportion of useful species, which can become highly valued. This long-term strategy of forest management thus represents one of the many agricultural approaches in which environmental factors are taken into account that forest-dwelling peoples in the tropics have developed.

Marie-Lise Sabrie | alfa
Further information:
http://www.ird.fr

More articles from Ecology, The Environment and Conservation:

nachricht Preservation of floodplains is flood protection
27.09.2017 | Technische Universität München

nachricht Conservationists are sounding the alarm: parrots much more threatened than assumed
15.09.2017 | Justus-Liebig-Universität Gießen

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>