Fig. 1
From: Human transformations of the Wadden Sea ecosystem through time: a synthesis
Human influence on the landscape in the Ijsselmeer region (former Zuiderzee) in the Netherlands A.D. 850–1993 by building dikes, draining lakes and lowering groundwater tables: a gives the degree of habitat ‘naturalness’, and b shows the composition of major landscape types. Percentage area estimates were derived from paleographic maps (adapted from van Eerden 1997)