Page 41 - Soil Degradation, Conservation and Remediation

26 1 Soil Resources and Soil Degradation

Fig. 1.3 Deforestation and soil degradation. One can hardly imagine that this was once a dense
tropical forest (Photo courtesy of Mr. Dilip Kumar)

impact has been enormous. Deforestation is expanding and accelerating into the
remaining areas of undisturbed forest, and the quality of the remaining forests is
declining. Until quite recently, most of the deforestation occurred in Europe, North
Africa, and the Middle East. By the beginning of this century, these regions had
been mostly converted from the original cover. Now, deforestation in these regions
has stabilized, and regrowth is occurring in some places, although the resulting
secondary forests are of a different character. In the last few decades, the vast major-
ity of deforestation has occurred in the tropics – and the pace still accelerates. The
removal of tropical forests in Latin America is proceeding at about 2 % per year. In
Africa, the pace is about 0.8 % per year and in Asia it is 2 % per year. According to
the FAO analysis, deforestation was concentrated in the developing world, which
lost nearly 200 million hectares between 1980 and 1995 (FAO 2000 ). Five tropical
countries with the greatest total area of deforestation are Indonesia, Sudan,
Myanmar, and the Democratic Republic of Congo. This loss is partially counterbal-
anced by reforestation efforts, new forest plantations, and the gradual regrowth and
expansion of forested area in developed countries. However, the remaining natural
forests are also highly degraded if not deforested. Measuring the extent and rate of

deforestation is not as simple as it might at first appear (Singh et al. 2001 ). The fi rst

challenge is to define what is meant by a “forested area.” In other words, what
density of tree cover is required for an area to be considered a forest? The “continu-

ous fields” tree cover map prepared by the Global Land Cover Facility (DeFries
et al. 2000 ) shows that far from being homogenous, land areas can vary from 10 to
2
100 % forest cover and still be considered forests. Today, only 28 million km is in
so- called closed forests of 40 % canopy cover or above (Singh et al. 2001 ).