7. What are the protective effects of forests?
- 7.1 How much of the forest area has been set aside for protective purposes?
- 7.2 How much forest is planted for protective purposes?
Apart from providing wood and other products, forests and trees outside forests play a protective role, for instance in ecosystem conservation, in maintaining clean water, and in reducing the risks of impacts of floods, avalanches, erosion and drought. Many countries have identified and given special status to protective forest areas.
Protective functions can be local or global and include:
- Influence on climate.
- Protection from wind erosion.
- Coastal protection.
- Protection from avalanches.
- Air-pollution filters.
- Protecting water resources.
Though information available on areas that have protective purposes is somewhat limited, the information presented here is a start and shows the importance of the protective functions of forests.
7.1 How much of the forest area has been set aside for protective purposes?
In 2005, the total area of forests designated as having protection as their primary function was, close to 10% of total forest area (3.5 million km2) [Table 6.2]. Asia has the highest proportion of forests with a primary function of protection, followed by South America and Europe.
The reported figures for Western and Central Africa are quite low. This may be explained by the fact that only a few countries in those regions have adequate data. In North and Central America and in Oceania a relatively small proportion of forests has been designated as having protection as primary function, because protective forest areas in USA, Canada and Australia tend to be classified as having multiple purposes, and not as being primarily protective.
In 2005, all forest areas with protection as primary or secondary function represented about a third of total forest area (11.9 million km2) [Table 6.3].
According to available data, there has been an overall increase in the area of forests with protection as their primary function, from 8% in 1990 to 9% in 2005, as well as in the area of forests with protection as one of their designated functions from 61% in 1990 to 65% in 2005. More...
7.2 How much forest is planted for protective purposes?
Recognizing the important protective role of forests, many countries have planted substantial areas of forests and trees for this purpose, for example to stabilize sand dunes or provide windbreaks. Protective forest plantations may be subject to some harvesting of wood, or other products, but their main objective is protection.
In 2005, the global area of protective forest plantations was 301 000 km2 (a little less than 1% of global forest area). The ten countries with the largest area of protective forest plantations accounted for 85% of the global protective forest plantation area
The global area of protective forest plantations increased on average by 4050 km2 per year between 1990 and 2000 and 3300 km2 per year between 2000 and 2005. Such plantations represent a small, but increasing proportion of total forest area, 0.63% in 1990, 0.75% in 2000, and 0.82% in 2005. In addition to the establishment of new protective forest plantations, this trend also reflects the reclassification of existing areas (e.g. in Japan). More...