“De Brabantse Biesbosch” is probably the first doctor’s thesis ever presented in the Netherlands in the form of a trilogy. This ambitious aspect of the work is not merely accidental; it is also a symbolic reflection of the huge amount of methodically synthesized documentation and interpretation which is brought together in these three volumes. The area which forms the subject of this study is a large fresh-water delta with a tidal difference of ca. 2 m, which is unique in temperate Europe, and therefore of considerable scientific interest. As yet, the study of this kind of biotope has been largely neglected, both ecologically and pedologically, in Europe and also elsewhere. The main cause of this neglect may be that these biotopes are very difficult of access, which disfavours an ecological study so detailed as modern science demands. This gap in our knowledge has been filled up in an outstanding way by the present study; this was carried out in the years 1948-1955, but several years of orientating research had preceded it.