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Results of a new study by the UN Food and Agriculture Organization (FAO) of the world’s forest resources conducted using satellite imagery, which provides updated information on the extent and rate of global forest losses. The figures are based on the most comprehensive use yet of high-resolution satellite data to provide a sample of forests worldwide.
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Global area in forest land use continues to decline...
YearSource
Remote Sensing Global Forest Resource Assessment
In millions of hectares
1990 3 767 4 168
2000 3 694 4 061
...but not as much as previously thought
• FAO Forest Resources Assessment estimated a loss of 107 million ha from 1990 to 2005
• This survey detected a change of 73 million ha for the same period
• A difference of 32%
Nearly 80% of the world’s forests are in the tropics and boreal zones
Gross gain
Gross loss
Net change
Net change was positive in each climatic zone except the tropics
Boreal Temperate Subtropical Tropical World90-00 00-05 90-00 00-05 90-00 00-05 90-00 00-05 90-00 00-05
10 000
-10 000
thou
sand
s he
ctar
es (‘
000)
Global forest area by region
Area in forest land use by region
Region
Source
Remote Sensing Global Forest Resource Assessment
In millions of hectares
1990
2005 1990
2005
Africa 518 492 749 691
Asia 497 516 576 584
Europe (including Russia) 1 080 1 071 989 1 001
North and Central America 736 723 708 705
Oceania 117 115 199 197
South America 857 804 946 882
Most forest conversion to other land uses was in South America and Africa
Gross gain
Gross loss
Net change
Africa Asia Europe N. America Oceania90-00 00-05 90-00 00-05 90-00 00-05 90-00 00-05 90-00 00-05
thou
sand
s he
ctar
es (‘
000)
4 000
-4 000
S. America90-00 00-05
How did we obtain these findings?
Landsat imagery was classified from sample sites – classified, reviewed
and analyzed
> 13,000 sites worldwide
~10,000 with tree cover
A systematic 1 degree grid...
Land cover changes
Gain in trees (green)
Loss (red stripes) Shrubs (young trees?)
2000
1990
Change
=
Forest or Non-forest Processing
Review and revision by 200 national experts....
Conclusions
• Net conversion of forest land is substantially lower than previously estimated
• The conversion of forest land into other land uses continues most actively in the tropics...
• ... but is also occurring in Europe, North America/Central America and Africa
• The methods used in this survey can be used a means of improving estimates of forest land use change at national, regional and global scales
