change (see also Chap. 10, Vol. 1). Through a literature review, we identified the
main threats that forests and savannas are experiencing in central Africa. Additionally, we extracted spatial information on land allocated for biodiversity conservation
(i.e., protected areas) and to economic exploitation, specifically logging concessions.
We used protected area maps
8 for the six countries of central Africa mentioned (Sect.
9.2.1) and data from the World Resources Institute to produce a map of the areas
under logging concessions and identified as having forest restoration opportunities.
9.2.2.4 Prediction of Future Vegetation Change
We estimated the area of current forest and savanna that may be impacted by future
rainfall and agricultural activity (Sect. 9.3.3). In particular, we used the projected
annual rainfall and cropland area for 2070 in central Africa derived from the two
most contrasted scenarios of future global change: the Representative Concentration
Pathways (RCP) 2.6 and 8.5. These RCPs represent different trajectories for greenhouse gases (GHG) concentrations and radiative forcing for the year 2100 (Van
Vuuren et al. 2011). RCPs contain different assumptions about socioeconomic
trajectories (e.g., demography, economy, land use).
RCP 8.5 is the most pessimistic scenario (Van Vuuren et al. 2011). In this
scenario, radiative forcing and GHG concentration continue to increase at the current
rate, while cropland and pasture land also expand significantly due to large population increase (Hurtt et al. 2011). Conversely, RCP 2.6 represents the most optimistic
scenario in terms of GHG emissions, as they are expected to eventually decline due
to declining fossil fuel consumption and aggressive climate policies implemented to
reduce climate change. A crucial element of RCP 2.6 is the use of bioenergy, and
carbon capture and storage technologies, which are expected to result in negative
emissions (see Chap. 2, Vol. 1). However, the extensive bioenergy expansion is
expected to cause a large increase in the cropland dedicated to biofuel production
(Hurtt et al. 2011).
Future climate projections for the year 2070 (average 2061–2080) were taken
from all general circulation models (GCM) for the two RCPs, which are available
downscaled and calibrated against Worldclim 1.4 as baseline climate (Hijmans et al.
2009), using relative change for rainfall. Future land use projections for cropland
area for the year 2070 are averaged between 2061 and 2080 for the two RCPs, in
order to be consistent with the climate data.
We compared areas that are currently forests and savannas, and that will be
impacted by future changes in annual rainfall (>100 mm year
À1
) and by changes in
the fraction of pixels affected by cropland (>0.25). This analysis is conducted for
forests that are currently under logging concession and for forests/savannas areas that
are currently protected areas. The rationale is that protected areas can potentially buffer
against climate and/or land use change (Loarie et al. 2009; Aleman et al. 2016).
8 For more information refer to: https://www.protectedplanet.net (accessed August 2017).
9 Long-Term Vegetation Change in Central Africa: The Need for an Integrated. . .
291
main threats that forests and savannas are experiencing in central Africa. Additionally, we extracted spatial information on land allocated for biodiversity conservation
(i.e., protected areas) and to economic exploitation, specifically logging concessions.
We used protected area maps
8 for the six countries of central Africa mentioned (Sect.
9.2.1) and data from the World Resources Institute to produce a map of the areas
under logging concessions and identified as having forest restoration opportunities.
9.2.2.4 Prediction of Future Vegetation Change
We estimated the area of current forest and savanna that may be impacted by future
rainfall and agricultural activity (Sect. 9.3.3). In particular, we used the projected
annual rainfall and cropland area for 2070 in central Africa derived from the two
most contrasted scenarios of future global change: the Representative Concentration
Pathways (RCP) 2.6 and 8.5. These RCPs represent different trajectories for greenhouse gases (GHG) concentrations and radiative forcing for the year 2100 (Van
Vuuren et al. 2011). RCPs contain different assumptions about socioeconomic
trajectories (e.g., demography, economy, land use).
RCP 8.5 is the most pessimistic scenario (Van Vuuren et al. 2011). In this
scenario, radiative forcing and GHG concentration continue to increase at the current
rate, while cropland and pasture land also expand significantly due to large population increase (Hurtt et al. 2011). Conversely, RCP 2.6 represents the most optimistic
scenario in terms of GHG emissions, as they are expected to eventually decline due
to declining fossil fuel consumption and aggressive climate policies implemented to
reduce climate change. A crucial element of RCP 2.6 is the use of bioenergy, and
carbon capture and storage technologies, which are expected to result in negative
emissions (see Chap. 2, Vol. 1). However, the extensive bioenergy expansion is
expected to cause a large increase in the cropland dedicated to biofuel production
(Hurtt et al. 2011).
Future climate projections for the year 2070 (average 2061–2080) were taken
from all general circulation models (GCM) for the two RCPs, which are available
downscaled and calibrated against Worldclim 1.4 as baseline climate (Hijmans et al.
2009), using relative change for rainfall. Future land use projections for cropland
area for the year 2070 are averaged between 2061 and 2080 for the two RCPs, in
order to be consistent with the climate data.
We compared areas that are currently forests and savannas, and that will be
impacted by future changes in annual rainfall (>100 mm year
À1
) and by changes in
the fraction of pixels affected by cropland (>0.25). This analysis is conducted for
forests that are currently under logging concession and for forests/savannas areas that
are currently protected areas. The rationale is that protected areas can potentially buffer
against climate and/or land use change (Loarie et al. 2009; Aleman et al. 2016).
8 For more information refer to: https://www.protectedplanet.net (accessed August 2017).
9 Long-Term Vegetation Change in Central Africa: The Need for an Integrated. . .
291