3.2. Some differing views about the geography of change
The loss in tropical forests is subject to debate.
FAO calculates a net loss of tropical forests of 123,000 km²
per year. WRI gives a higher estimate of 160,000 km² per year.
Emily Mathews of the WRI bases some calculations on the FAO FRA
2000 report to reach the conclusion that the average rate of loss
in tropical forest area is 0.87% per year for the period 1990-2000.
3.2.1. Much of the variation in global forest cover estimates
has to do with the inclusion or exclusion of planted forests, both
in temperate and tropical areas. Do planted forests have the same
ecological function as natural forests? In fact, plantations are
often planted with single species, and treated with herbicides,
pesticides and fertilizers. Silvicultural measures are frequently
used and the understory is suppressed to maximize the yield. This
plantation scenario often takes place where old-growth forests have
been logged. More...
3.2.2. Estimates of forest loss have varied considerably. During the 1970s
and 1980s, over-pessimistic estimates of forest losses varied from
2.3% to a high estimate of 4.8% annually. In the 1970s, deforestation
was highlighted as one of the most dramatic and urgent environmental
issues. Current figures proposed range from 316,000 km² a year
(Grist Magazine) to almost zero (Bjørn Lomborg). With a few
exceptions, most reliable estimates of deforestation now converge
around a figure for a net annual global loss of forest of an order
of magnitude of between 0.5% and 0.9% (120,000 km² to 160,000 km²
each year). In temperate areas, the area of forestland seems to
be stable or even increasing with an expansion of plantations and
reforestation, although there continues to be a loss of natural
forest. In the tropics, there continues to be significant loss of
forest which is not compensated for by reforestation or natural