METHODOLOGICAL DESCRIPTION (a) Underlying Definitions and Concepts: Definitions are available from the Forest
Resources Assessments of the Food and Agricultural Organization of the United
Nations (FAO). Forest area is defined as lands with a tree crown cover equal to or
more than 10% of the area; plantation as the artificial establishment of forests by
planting or seeding; and natural forests as natural and/or semi-natural established
forests. The comparisons of forest area over time using reference years allows the
calculation of change in absolute values and as a percentage of the total rate of
deforestation (TRD). The rate of deforestation attributed to the use of wood as fuel
(RD fw ) is determined by using the ratio of the average annual fuelwood production
(FWP) to the annual total forest fellings(TFF).
(b) Measuring Methods: The measurement methods for forest area can be contained
in national forest inventories and obtained by remote sensing, by sampling ground or
cadastral surveys, or through a combination of these methods.
The forest area is calculated as the sum of plantations and natural forest areas with
tree crown cover of at least 10%. This calculation is made at given reference years as
follows:
The total rate of deforestation (TRD) is the compound annual rate in percent from year
P to year N:
(
)
⎟
⎟
⎟
⎠
⎞
⎜
⎜
⎜
⎝
⎛
⎟
⎠
⎞
⎜
⎝
⎛
−
=
⎟⎠
⎞
⎜⎝
⎛
−P N P N area Forest area Forest TRD 1
1
100
.
Then, the rate of deforestation attributed to fuelwood (RD fw ) is
⎟
⎠
⎞
⎜
⎝
⎛
=
TFF FWP TRD RD fw ,
where
FWP is annual fuelwood production and TFF is annual total forest fellings.