Laurence Tubiana, Raphaël Billé and Romain Pirard wrote the september issue's editorial of The West African Protected Areas Newsletter, dealing with the notion of ecosystemic service.

This issue also includes an abridged version of Questioning the theory of Payments for Ecosystem Services (PES) in light of emerging experience and plausible developments, an article written by Raphaël Billé, Romain Pirard and Thomas Sembrés (World Bank), and published in June 2010 within the Analyses IDDRI's collection.

>> Read n°34 online