Silviculture

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transport du bois sur l'Amazone
Silviculture, or “cultivation of the forest”, involves exploiting the potential of the raw materials (wood, other non-ligneous products) and services (shelter, reservoir of biodiversity) provided by forests. It includes the exploitation of natural forests, which represent 93% of the surface area of world forests, and plantations.

In 2000, 35% of woodland areas were used to produce timber. The surface area of productive plantations increased by 25 million hectares between 2000 and 2005. Each year, the demand for products made from wood increases by 2.7% and the forest surface area shrinks by 0.2% (7.9 million hectares). The felling of primary forests has led to their disappearance, as in Western Europe, or to their decline in the tropical countries of Africa, Latin America and Asia. The silvicultural sector as a whole provided employment to about 13 million people in 2000. Closely dependent on the human societies that practise it, silviculture has been regarded in recent years by the UN’s Food and Agriculture Organisation as a potentially effective means of fighting against poverty, given that poverty is the main cause of deforestation in sub-Saharan Africa.

Practices

There are three types of practice in forest management and timber production:

– An intensive system involving uniform high forest and short-rotation coppice: planting and clear cutting, systematic monocultures of fast-growing tree species, possibly some clonal or genetically modified varieties, use of fertilisers and pesticides. 54% of the trees planted are conifers (of which 32% are pines) and 32% are deciduous (of which eucalyptus makes up 8% and acacia 5%). It is managed on a profit basis, the aim being to ensure that yield objectives are met and the dimensions of the timber produced are controlled. This system is to be found in every country.

– A system of illegal harvesting and felling of forests without any management whatsoever, practised essentially in tropical regions.

– A system that recognizes the multiple functions of the forest, corresponding to non-uniform high forest. It is a holistic management system that combines biodiversity, ecological balances, landscape, utilitarian and leisure use by humans, and timber production. It has existed in Western and Central Europe for over a hundred years, depending on the country, and is now spreading throughout the world under the label of Sustainable Management.

The economy of wood

The market for wood and forest products was worth 327 billion dollars in 2007 with a production of 3,832 million m3 that breaks down into 1,644 million m3 of roundwood, 422 million m3 of sawn timber and 1,766 million m3 of energy wood. In 2005, 54% of the total surface area of productive plantations were in Asia, 75% of which were in China (54 million hectares), and 24% in Europe, of which 36% in Russia (11.9 million hectares). Europe continues to be the world’s largest importer with 47% of world trade in 2004 and Russia the largest exporter of industrial roundwood with 35% of world trade. The main actors in the industry are the companies that utilize roundwood (sawmills) and energy wood (in Europe) and the companies that manufacture paper and boards, along with traders in tropical timber (worldwide), although this trade has been going downhill since the introduction of strict regulations. The energy wood industry is currently booming in response to the demand for substitutes for fossil fuels. In developing countries, wood is the main, if not the only, source of energy for heating and cooking; in Africa, it covers 90% of these needs.

Pressure on the forests

The intensive management of forest, and in particular the gradual dominance of softwoods GLOSSARY in forests in industrialized countries, has many consequences: the depletion of forest ecosystems with a drop in biodiversity, the growing uniformity of landscapes, the depletion or acidification of the soil, the exhaustion of water resources, vulnerability to fires, and an increased sensitivity to diseases and parasites. This is for example the case of eucalyptus plantations in Latin America, which use large quantities of water, or of the replacement of endemic species of tree by highly productive exotic species: forests of conifers from Oregon and Washington states, Sequoia sempervirens from California or Podocarpaceae from New Zealand. An additional aspect of this trend are strategies for mass agrofuel production, as in Malaysia where the development of oil palm plantations is to blame for 87% of the country’s deforestation over the last 30 years.

As for illegal harvesting, it is partly responsible for deforestation, and has caused many social and ecological, as well as economic imbalances. Some poor exporting countries try to make the most of their resources by overexploiting them, but this practice is detrimental in the short, medium or long term.

The fight against poverty

There are an increasing number of studies that show the value of small-scale silviculture practised by local communities, both from a social and an environmental point of view. Many of the products provided by silviculture (food, fuel, remedies and fibres, crop cultivation and animal rearing under the forest canopy) contribute to food security in areas where the potential for agriculture is low, to household income and to some national economies. From an environmental perspective, it has been noted that this type of small-scale silviculture plays a very important role in safeguarding biodiversity, which can also make a contribution to people’s subsistence by providing a balanced variety of foodstuffs. Bad forest management in poor regions can cause economic, ecological and even health disasters. This is because silviculture is associated with emerging infectious diseases such as HIV, yellow fever or Lyme’s disease. Variations in forest cover (deforestation, fragmentation) as well as human mobility are the main factors identified as potentially responsible for the emergence of diseases in human populations.

In 1989, professionals from the timber industry founded the association Pro Silva Europe in Slovenia and it has since expanded to several forested regions of Europe. Pro Silva France was founded in 1990. The objective of its members, who are foresters from different backgrounds (owners, professionals, friends of the forest…) is to “promote silvicultural practice that respects the natural processes of forest ecosystems while also being economically viable.”

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