Chapter 9
Long-Term Vegetation Change in Central
Africa: The Need for an Integrated
Management Framework for Forests
and Savannas
Julie C. Aleman and Adeline Fayolle
9.1 Introduction
Tree-dominated forests and grass-dominated savannas represent the two main tropical biomes covering the overwhelming majority of sub-Saharan Africa (SSA)
(White 1983). Forests and savannas have a different, even antagonistic, ecological
functioning (Staver et al. 2011a), but they both provide critical services to local
populations (see Chaps. 7 and 10, Vol. 1; Chaps. 5 and 6, Vol. 2). Tropical forests
are dominated by trees, forming closed canopies and complex vertical structures, and
contain in their understory C3 grasses that are more adapted to humidity and shadow.
Such forests are encountered in areas of high annual rainfall and limited seasonality
(Malhi et al. 2009), and are very sensitive to disturbances. In contrast, trees and C4
grasses in tropical savannas coexist, are more adapted to aridity, are shade intolerant,
and are found in areas that are drier and have higher seasonality (Ratnam et al. 2011).
Savannas rely on frequent disturbances due to fires and/or mega-herbivores that
maintain an open canopy and species diversity (Bond et al. 2005; Sankaran et al.
2005; Staver and Bond 2014).
The occurrence of tropical forests and savannas is, however, not rigidly determined by climatic conditions. Recent analyses of remotely sensed tree cover at the
global (Hirota et al. 2011; Staver et al. 2011b) and at the regional (Favier et al. 2012)
scales, supported by theoretical work (Staver et al. 2011a; Staver and Levin 2012),
J. C. Aleman (*)
Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
Department of Geography, University of Montréal, Montreal, QC, Canada
A. Fayolle
Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
e-mail: Adeline.Fayolle@uliege.be
© Springer Nature Singapore Pte Ltd. 2020
A. Gasparatos et al. (eds.), Sustainability Challenges in Sub-Saharan Africa I,
Science for Sustainable Societies, https://doi.org/10.1007/978-981-15-4458-3_9
281
Long-Term Vegetation Change in Central
Africa: The Need for an Integrated
Management Framework for Forests
and Savannas
Julie C. Aleman and Adeline Fayolle
9.1 Introduction
Tree-dominated forests and grass-dominated savannas represent the two main tropical biomes covering the overwhelming majority of sub-Saharan Africa (SSA)
(White 1983). Forests and savannas have a different, even antagonistic, ecological
functioning (Staver et al. 2011a), but they both provide critical services to local
populations (see Chaps. 7 and 10, Vol. 1; Chaps. 5 and 6, Vol. 2). Tropical forests
are dominated by trees, forming closed canopies and complex vertical structures, and
contain in their understory C3 grasses that are more adapted to humidity and shadow.
Such forests are encountered in areas of high annual rainfall and limited seasonality
(Malhi et al. 2009), and are very sensitive to disturbances. In contrast, trees and C4
grasses in tropical savannas coexist, are more adapted to aridity, are shade intolerant,
and are found in areas that are drier and have higher seasonality (Ratnam et al. 2011).
Savannas rely on frequent disturbances due to fires and/or mega-herbivores that
maintain an open canopy and species diversity (Bond et al. 2005; Sankaran et al.
2005; Staver and Bond 2014).
The occurrence of tropical forests and savannas is, however, not rigidly determined by climatic conditions. Recent analyses of remotely sensed tree cover at the
global (Hirota et al. 2011; Staver et al. 2011b) and at the regional (Favier et al. 2012)
scales, supported by theoretical work (Staver et al. 2011a; Staver and Levin 2012),
J. C. Aleman (*)
Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
Department of Geography, University of Montréal, Montreal, QC, Canada
A. Fayolle
Gembloux Agro-Bio Tech, University of Liège, Gembloux, Belgium
e-mail: Adeline.Fayolle@uliege.be
© Springer Nature Singapore Pte Ltd. 2020
A. Gasparatos et al. (eds.), Sustainability Challenges in Sub-Saharan Africa I,
Science for Sustainable Societies, https://doi.org/10.1007/978-981-15-4458-3_9
281