Most of the definitions collected by Lund (1999) characterize deforestation
as the long-term or permanent removal of forest cover and conversion to a non-forested
land use. For example, deforestation is the "permanent removal of forest cover
and withdrawal of land from forest use, whether deliberately or circumstantially."
Similarly, the IPCC Guidelines emphasize the conversion of forests (to pasture,
cropland, or other managed uses): "Conversion of forests is also referred to
as 'deforestation,' and it is frequently accompanied by burning."
It is important to note that a common forestry definition of reforestation
is not the antonym (mirror) to the common definition of deforestation. In forestry
practice, reforestation commonly refers to any act involving reestablishment
of trees regardless of whether it follows harvesting or a long period of deforestation,
but harvesting is not equated with deforestation. For example: "Clear-cutting
(even with stump removal), if shortly followed by reforestation, is not deforesting"
(FAO, cited in Lund, 1999).
Nevertheless, many of the issues that arise with regard to certain definitions
of reforestation also apply in defining deforestation. The period of changed
land use required for reestablishment of trees to be treated as reforestation
must be compatible with the period of changed land use that describes deforestation.
Including a waiting period in the definition of deforestation (e.g., "the act
of removing forest cover and not beginning to regenerate forest within X years")
introduces accounting needs that can extend beyond a specific commitment period.
For example, areas cleared of forest during the first commitment period would
not be confirmed as deforested for some years after the clearing, which may
extend beyond 2012.
Many definitions of deforestation include natural (non-anthropogenic) events
such as landslides, volcanism, and so forth. Where these events are unambiguously
not direct results of human activities, the Protocol and Decision 9/CP.4 are
clear: If they do not meet the "direct human-induced LULUCF activities" requirement,
they would not be included as deforestation under Article 3.3.
Not all natural events are so easily partitioned, however. In particular, several
difficult definitional issues arise where significant forest losses occur as
a result of fire (and, in some cases, landslides). Forest fires can be the result
of natural events (notably lightning) or the direct (or indirect) result of
human activities, including prescribed burning (and their escape), accidental
fires, and arson. Even if the cause of the fire can be unambiguously attributed
to prescribed burning, arson, or escape from deliberate fires (including camp
fires and cigarettes), the act may or may not be deforestation in the sense
defined above. In many-but not all-instances, forest cover loss is followed
by natural (or aided) regeneration of new forest. To the extent that the regrowth
is complete, the net release of carbon to the atmosphere may be completely recovered
over time by the new forest. There is, however, an asymmetry in the rates (Kurz
et al., 1995): The net release of carbon to the atmosphere is rapid, whereas
the recapture takes decades or more. From a scientific perspective, however,
asymmetrical accounting of changes in carbon stock over time arises if only
one of the paired activities (forest loss and regrowth) is accounted as deforestation
or reforestation, respectively.
Given that distinguishing between natural and anthropogenic factors that influence
the vulnerability of the land to disturbance will be difficult, a key question
for policymakers is whether the accounting should include only direct human
activities (reforestation) or both the human activities and the event (fire)
that makes the opportunity for reforestation possible.
In some cases, there are definitional and carbon accounting issues concerning
drawing a clear boundary between natural phenomena and human-induced activities,
when, for example, significant forest losses occur as a result of fires or disturbances
such as pest outbreaks. In cases involving lands under Article 3.3 or 3.4 where
fires or pest outbreaks occur in a forest, a question is whether accounting
should, inter alia: (i) count neither the loss nor subsequent uptake of carbon
(which reflects the actual net change in carbon stocks on those lands and exchange
of carbon with the atmosphere in the long term, but creates problems in continuing
to account for the area burnt/defoliated as lands under Article 3.3 or 3.4);
(ii) count both the loss and subsequent uptake of carbon (which reflects the
actual net change in carbon stocks on those lands and exchange of carbon with
the atmosphere, but creates an initial carbon debit for the Party concerned);
(iii) count only the loss of carbon (which would overestimate the actual losses
of carbon stocks, not represent the exchanges of carbon with the atmosphere,
and create future accounting problems), or (iv) count only the subsequent uptake
(which would fail to reflect the actual changes in carbon stock and would not
represent the exchanges of carbon with the atmosphere, and would provide carbon
credits for the Party concerned).
In cases involving lands that do not fall under Articles 3.3 or 3.4, where
fires or pest outbreaks trigger land-use change, the consequences are similar
to deforestation. If similar vegetation cover is allowed to regenerate, such
disturbances may not lead to a long-term change in carbon stocks.
Will forest protection practices (such as fire management systems that seek
to prevent wildfires or ameliorate the damage they cause through suppression
efforts) be rewarded (in a Protocol sense)? Will Parties be penalized (under
the Protocol) for failing to manage wildfires? These issues remain to be resolved
through negotiation by the Parties.
A further complication is the fact that fires in many ecosystems do not result
in complete tree mortality, even though there are significant changes in the
carbon balance of the affected areas. Individual trees and small patches of
trees and understory can survive. In some forest types (e.g., eucalypt and some
pine forests), even the most intense fires do not cause significant mortality
of mature trees. Significant quantities of carbon may be released, but most
trunks and large branches survive and regrow full canopies within a few years.
Although measurement of these changes under the stock change method as recommended
by Article 3.3 is possible, in practice the areas of forest meeting the deforestation
requirement of Article 3.3 would be contentious and difficult to assess.
A less difficult situation arises when land-use change takes place subsequent
to or as a result of fire. In many parts of the world, major forest fires (whether
ignited by humans or naturally caused) are taken as the cue for land-use change
to agricultural or pastoral uses. In these cases, the combination of fire and
land-use change should be accounted as deforestation in a comprehensive and
symmetric accounting system.
For several reasons, accounting procedures that always treat changes in carbon
stocks that are attributable to fire as debits may be inconsistent with long-term
objectives of increasing carbon stocks. First, fire has been used in some ecosystems
as a forest management tool for enhancing forest growth over the long term,
even though it might result in some carbon reductions over the short term (for
example, during a commitment period). Second, fire is a natural part of many
forest ecosystems, and management to eliminate fire can be futile or counterproductive.
Natural or prescribed ground fires in such ecosystems may result in preservation
of carbon stocks at the landscape scale by creating firebreaks-thus reducing
the likelihood of widespread, intense fires.
In the long term and over large areas, there is a balance between carbon loss
resulting from fires and carbon sequestered in regrowth, providing there is
no change in the fire regime. This balance underlies the recommendation in the
IPCC Guidelines to treat wildfires as carbon-neutral. Although this approach
is pragmatic, there is some evidence that fire regimes are changing in parts
of the world (e.g., Kurz and Apps, 1999). In some cases, these changes may be
a result of deliberate human manipulation; in others, it is an indirect consequence
of human actions-possibly including climate change. Moreover, because of asymmetry
in the rates and timing of carbon loss from fire and its re-accumulation through
regrowth, the complete balance is not achieved if fire regimes vary in response
to changes in El Niño patterns or rapid climate change.