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3.4.1. Identification of ARD Activities
Regarding the determination of the area of ARD land, there are fundamentally
two sources of information available: reports of activities (in countries where
such reports exist) and monitoring of forest/non-forest change.
The activity reporting approach assumes that a well-defined set of human activities
will determine ARD land and that information about these activities will be
reliably reported and compiled. In some countries, for example, conversion of
forest requires some form of legal permission. Because afforestation and reforestation
activities require investments, it should be possible to create incentives for
reporting of activities that would benefit the national carbon balance. An activity
reporting approach is best if the ARD activities are well defined and are limited
to changes to and from forest (e.g., the Land Use scenario) rather than changes
within forest classes. An activity reporting approach cannot meet the data requirements
for scenarios that include a transition from one forest class to another (e.g.,
the Degradation/Aggradation scenario).
Several techniques are available for monitoring forest/non-forest change. The
simplest method is to identify the total area considered forest in 1990 and
at the end of the commitment period. This information might be collected through
independent samples at two points in time. A net increase in forest area represents
an excess of afforestation and reforestation over deforestation; a net decline
represents the reverse. This technique does not follow the fate of individual
forest stands. Thus, it allows deforestation to the extent that it is compensated
by afforestation and reforestation. A zero net change in forest area can be
achieved by deforesting and afforesting the same amount of area. Because the
two activities would be expected to contain very different carbon stocks per
hectare, however, the zero net change in area would not result in a zero net
change in carbon stocks. Therefore, an alternative technique that avoids this
problem would be to identify specifically which areas were afforested, reforested,
or deforested during the time period.
ARD activities can be monitored in a variety of ways. The two predominant methods
are field sampling and remote sensing. These techniques are described in more
detail in Section 2.4; both involve sampling the land
(with either field plots or aerial/ orbital images) at multiple points in time
and subsequently identifying locations (or sample plots) where land-use or land-cover
changes indicate that ARD activities have occurred. ARD activities could be
identified by an assessment of forest extent in 1990 and in 2012; those areas
that change from forest to non-forest or from non-forest to forest during this
interval could be deemed to have undergone an ARD event. An assessment conducted
only at the endpoints of this interval, however, may miss many ARD events that
could result in changes in carbon stocks. For example, a 1990 forest that is
deforested in 1991, only to be reforested in 2010, is in forest condition at
both interval endpoints, yet it may be counted as ARD land.
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