Dynamique de la mangrove et perceptions locales dans le Département d’Oussouye (Basse-Casamance, Sénégal) entre 1972 et 2018

Abstract

Mangrove dynamics and local perception in the Department of Oussouye (Basse-Casamance, Senegal) between 1972 and 2018. In Lower-Casamance, the mangrove is a particular ecosystem that is home to many resources and remains the seat of the main rural activities. In the Oussouye area, this mangrove has experienced a significant decline during the 1970s and 1980s. The study of its spatio-temporal dynamics, using geomatics tools coupled with field surveys, made it possible to apprehend its decline between 1972 and 1994 of -42 %; and its positive evolution of +22.44 % between 1994-2018. The factors behind the decline during the 1970s and 1980s were mainly the rainfall deficit, with the consequences of salinization and acidification of the land, and the weakness of natural regeneration. The study also showed that anthropogenic actions such as cutting wood for various reasons and stilt roots have long harmed mangrove ecosystems. The recovery observed in recent decades is to be seen in the context of the return of rainfall to a better situation and the awareness of the populations of the strategic and important role of the mangrove.

Keywords

• mangrove
• dynamics
• management
• mapping
• lower-casamance
• senegal