Problématique des plantes envahissantes au sud du Togo (Afrique de l'Ouest) : apport de l'analyse systémique paysagère et de la télédétection

Abstract

The issue of invasive plants in Togo (West Africa): contribution of landscape systemic analysis and remote sensing. Description of the subject. Invasive plants are a major threat to natural habitats, agriculture and health worldwide. Certain land uses are known to promote plant invasions. Despite the occurrence of rapid land-use mutations, particularly around protected areas in Togo, the diversity and abundance of invasive plants in relation to land use are poorly documented. This prospective study, through systemic analysis and remote sensing, proposed to investigate the land uses and diversity of dominant invasive plants in and around the Togodo Protected Area in southeastern Togo. Objectives. The objectives of this study were: to map the land use of the study area, to identify both the main landscape elements in and around the Togodo Protected Area and their driving forces of change, and to inventory the diversity of dominant invasive plants within these different landscape elements. Method. The following were created: a map of land use via an object-oriented approach, a typology of landscape elements through systemic analyses, and an inventory of dominant invasive plants following transects. Results. Agricultural practices were found to be the main driving forces behind the land use on the site. Thirty species of invasive plants were identified, and fallows were the areas most dominated by invasive plants. Conclusions. Systemic landscape analyses and remote sensing are operational tools that can provide a better understanding of the issue of invasive plants within the anthropogenic ecosystems of the savannahs and dry forests of West Africa.

Keywords

• Chromolaena odorata
• Panicum maximum
• Spilanthes costata
• landscape dynamics
• land cover mapping
• Dahomey Gap