|
The decline in tropical forest area, particularly rain forest,
has drawn much attention. While it is clear that significant
decreases have taken place, it is difficult to pin down exact
numbers due to variation in definitions and methods used to
measure the extent of forests. In its 2000 analysis of forest
ecosystems, WRI estimates that global forest cover has been
reduced by 20 percent since pre-agricultural times, and possibly
as much as 50 . The decline in tropical rain forest cover
is recent. When a longer time perspective is considered, tropical
rain forest is actually in a phase of spreading after a significant
contraction during Pleistocene cool and dry periods (Ice Ages).
Forest area has increased slightly since 1980 in industrial
countries, but has declined by c. 9.1% in developing countries,
with highest loss in Africa (10.5%)
Global deforestation trends 1980-1995. Source: WRI
PAGE report
| Region |
% per year (1980-1995) |
Km2 per year (1990-1995) |
| Europe |
4.1
|
|
| Temperate and Boreal North America |
2.6
|
|
| Australia, New Zealand, Japan |
1.0
|
|
| Total Developed World |
2.7
|
|
| |
|
|
| Developing Asia and Oceania |
-6.4
|
-41,700
|
| Africa |
-10.5
|
-37,500
|
| Latin America, Caribbean |
-9.7
|
-58,100
|
| Total Developing World |
-9.1
|
-137,300
|
The FAO estimated the resulting annual global forest loss
at 9.4 million hectares per year in the 1990s, a slight decrease
compared with the 1980s. The rate of change is not equally
distributed over the world: decreasing forest cover is the
rule in West Africa, East Africa, Central America and Mexico,
and South-east Asia, while increase in forest cover is reported
from Europe, China and Vietnam. Tropical deforestation probably
exceeds 13 million ha a year.
It is much more difficult to estimate the area of forest that
has been degraded. Though this degradation does not necessarily
cause the loss of forest cover, it is frequently the first
step in a chain of events that can lead to permanent deforestation.
If WRI's frontier forest concept is used to define non-degraded
forests, then only 8%, 6% and 46% of all remaining forest
can be considered not degraded, in Africa, Asia and South
America, respectively. Logging is cited as the main threat
to the world's remaining frontier forests.
|
TBI sources
 click
on the book for more information
Jepma, C.J. (1995) Tropical deforestation. A socio-economic
approach.
|
Causes of deforestation
Many factors, proximate and ultimate, contribute to deforestation.
Causes vary from place to place and from time to time, and include
agricultural and urban expansion, degradation due to logging,
shifting cultivation or fire (overview list in ). In most cases,
economic forces, governance failure and ethical failure are
the ultimate drivers of changes in forest cover. Non-existing
markets for forest-based values, timber concession policies,
perverse and trade-distorting subsidies, inadequate tenure arrangements,
gender inequity and corruption all contribute to forest loss.
Many of these problems find their basis outside forests, but
have a direct influence on human activities in forests. The
World Commission on Forests and Sustainable Development (WCFSD)
provides a good summary of these failures and how they affect
deforestation.
|
CIFOR
intro
to deforestation
World Commission on Forests and Sustainable Development
Summary
report
|
