**6.3 The landscape history of the Sahelian savannas during the last 100 years. Guidimouni – a key locality for the Sahelian savannas**

In addition to the historical descriptions (see above), we also dispose on physical archives,which describe the landscape evolution during the last 100 years. They come from southeast Niger. The dune depression of Guidimouni in southeastern Niger has been described several times in the last 200 years [20, 72]. Moreover, it was possible to core the upper part of the lake sediments [76].
