The 1991 exhibition showed the development of the screw propeller and presented Ressel as both an inventor and forester. His forestry suggestions were not often appreciated by authorities, although he contributed greatly to providing wood for dockyards, and had a rational approach to forest management.
A series of droughts and poor harvests in the first decades of the 19th century induced Emperor Franz I to abolish reserves of private woods and to allow the export of wood. Wood traders benefited considerably from this measure, and the French and English navies bought large quantities of good wood from Friuli and Istria. The devastation of forest areas contributed to a change of climate and subsequent bad harvests.
Ressel carried out a reforestation programme and suggested a purchase reserve. He developed a procedure for conservation of wood to be used in shipbuilding, and insisted that more iron parts should be used instead of wood. His reforestation programme did not only consider the technical side of the problem. He believed that the local administrations should take responsibility for reducing poverty and that a promotional campaign was needed to convince farmers of the necessity of reforestation and its positive effect on the harvests. He insisted that the penalty for stealing wood should not be too high, and that grazing should be allowed in the forests. If peasants were able to find wood for fire and construction of houses, there would have been less theft of the high quality wood that was intended for shipbuilding.
Ressel's programmes were an early stage of modern regional planning, taking into consideration the complex economic interrelations. Considering the prospective growth of the Austrian navy, the measures he introduced into forestry helped preserve the precious forests in a way that would satisfy even today's standards.
