The Panafrican Agency of the Great Green Wall (GGW), in collaboration with FAO and IRD, has devoted this Special Edition No.2 of the Echoes of the Great Green Wall to the state of progress in key areas and concrete scientific, technological and innovative contributions in support of implementations and deliveries.  The research and innovations that are studied and developed as solutions and knowledge to support effective and efficient approaches and technical itineraries offer options for scaling them up and disseminating successes and achievements. Through 30 articles, this issue highlights how the science of complex systems in land restoration can help up to understand and possibly correct the failures of interventions, which we have all observed and experienced in various projects and programmes, and how we build on the successes.

Structured in three related themes, biophysical research is presented through the (i) planning of large-scale restoration of degraded lands; the (ii) deployment of large-scale land restoration techniques and approaches; and the (iii) monitoring and evaluation of large scale restoration of GGW. The three other themes deal with socio-economic aspects including (iv) food and therapeutic uses of local plants and their impacts on food security, health and nutrition of communities; the (v) benefits, goods and ecosystems services from large-scale land and ecosystem restoration; including mammals and migratory birds and lastly the (vi) governance and management of village lands and landscapes in Great Green Wall areas of interest.