2. Land Use Theory & Deforestation
The theory of land use
The driving force in the dynamic of land uses has been the economic gain (profit) that has been obtained from each alternative. Land uses, which can produce economic profit or other benefits to land owners (be they private or public) have been allocated more land at the cost of less productive or less intensive land uses. Basically, the same principle works for forested land uses. If the intensity of recreational use or tourism grows sufficiently then forested land would be re-allocated from wood production to recreational purposes.
Throughout history, the competition between forested and agricultural has been particularly intense. If the soil of forests was found to be good enough for sustainable agricultural production, being able to produce more economic benefits, then it was only logical to change the land use. However, in many cases, the shift from forested land use to agricultural land use has not resulted in sustainable agricultural production (i.e, on the steep slopes of mountainous tropical forest areas). In some instances, this shift has been the result of excessive agricultural subsidies or tax exempts (i.e., clearing forests for cattle production). Further, in other cases, it has caused biodiversity or other ecological losses.
In almost all countries the state and the regional/local authorities are engaged in long term broad land use planning. Detailed local planning procedures also exist in order to promote balanced changes in land use and then to appropriately guide the spatial organization of different activities. However, very seldom has spatial planning helped in maintaining forest cover.
Early Deforestation and the Mediterranean Region
There exist only rough estimates of the extent of forests before the evolution of the humankind. Generally speaking forests were the principal life form on earth. Grasses started to develop and gain area from trees over 20 million years ago. The spread of these grasses instigated the evolution of our ancestors and became the main reason for the descent of our arboreal ancestors the apes from trees. These great apes and hominids separated about 5 million years ago and the Australopithecus walked on two feet (Westoby 1989).
In the last two to three million years, the earth's climate has fluctuated considerably, and there have been successive ice ages. During each ice age, the temperate forests shrank back, only to spread again towards the poles as the ice receeded (Westoby 1989).
Up until the development of early civilizations, forests covered about half of the earth's surface. The impact of human development in the Mediterranean is explored in the following animation.
Deforestation is mainly due to the conversion of forests to agricultural land, and it continues at an alarmingly high rate of about 13 million hectares per year. South America suffered the largest net loss of forests from 2000 to 2005 - about 4.3 million hectares per year - followed by Africa, which lost 4.0 million hectares annually.
At the same time, forest planting, landscape restoration and the natural expansion of forests have significantly reduced the net loss of forest area. Large scale reforestation has been reported in China and other forest areas continue to expand in Europe, although at slower scale than before.
The net change in forested land during the period 2000 to 2005 is estimated at -7.3 million hectares per year, down from -8.9 million hectares per year in the period between 1990-2000 (FAO 2005). Although the global forest situation is still alarming, at least the recorded net losses seem to be slowing down.