Adi Mama (2013). Anthropization of landscapes in Benin: dynamics, fragmentation and agricultural development. Interfaculty School of Bioengineers, Department of Landscape Ecology and Plant Production Systems, Faculty of Science, Free University of Brussels, Belgium, 198 pages.
Promotors: Prof. DE CANNIERE Charles (Bruxelles), Prof. BOGAERT Jan (Belgique), et Prof. SINSIN Brice (Bénin).
Abstract: To understand better the anthropization of the landscape in Benin, the dynamics of the land use was estimated in soudanian zone (North-Benin), soudano-Guinean (Centre-Benin) and guinean (south-Benin) from three Landscape satellite images (MSS 1972, TM 1986, and ETM+ 2006), supported by field visits. These three zones reflect well enough the environmental and human context of the intertropical zone. The main objective of the present dissertation was to quantify the landscape dynamics due to the anthropization of the landscapes of forests-savannahs from the remote sensing, geographical information system and from landscape ecology.
Our results showed that the ecological balance of the forests-savannahs underwent important disturbances. Slash-and-burn agriculture, logging for timber, the carbonization, urbanization, vegetation fire and three plantations have been identified as the main driving strengths of these dynamics.
The landscape metric’s, whish were historically constituted by forests-savannas was substituted by a mosaic of savannah, fields-fallows, grounds nudes-urban area and plantations. The use of remote sensing data was able to distinguish four big spatial transformation processes of the land cover classes. So, between 1972 and 2006, the dominant processes in the landscape were the deforestation, the savanization, the agricultural development marked by the creation followed by the enlargement of the spots of field-fallows. The quantification of the anthropogical disturbances of the indications of the spatial structure calculated for every land cover classes on the basis of the density, of the average area, of the dominance, of the shape index and the fractal dimension index of the spots of the classes allowed detecting a global fragmentation process and the anthropization of the landscapes.
The temporal dynamics of the structure and composition of the forests-savannahs landscape in the three climatic zones area of Benin showed an anthropization illustrated especially by the forest-savannahs fragmentation, the data simulation by means of Markov chains of the first degree tendency showed that while fields-fallows, three plantations and nudes-urban area will extend, forests-savannahs shall know a strong decrease. After all, our study highlighted that every three zones were highly dynamics. These anthropogenic transformations are dangerously going to compromise the future of these landscapes on which depends the survival of the local populations.
Our approach allows putting the natural bases of a rational preservation policy and management of landscapes by the establishment of thresholds of fragments necessary for the conservation of the biodiversity.
Keywords: Anthropization, landscape ecology, remote sensing, geographical information system, the process spatial transformation, landscapes metrics, dynamics, fragmentation, Benin.