Could we assert that Congo was a 'Belgian Java'? Historical arguments confirm it since, right from the start, the Belgian colonial system borrowed practices from the Dutch colonial model, so as to acquire natural resources at little cost and use them as a tool for promoting metropolitan economy. Environmental knowledge regarding Congo, benefiting from the progress of scientists commissionned by the State or not, boosted its exploitation. This contributed to land structuring but revealed the danger of its excesses as well. Experimental and scientific transfers between colonial Belgium and The Netherlands, their questioning about biodiversity protection, within the international context, stimulated ecological consciousness.