Interdisciplinarity is currently high on the agenda of scientists and science policy makers alike. Forestry science is thereby often seen as a successful attempt to overcome the limits of disciplinary approaches, or even as an inherently interdisciplinary science. The paper discusses the underlying assumptions of such claims and confronts them with new concepts from the sociology of scientific knowledge, such as ,,epistemic cultures" and ,,transdisciplinarity". Firstly, the notion of discipline which is basic to a clear understanding of interdisciplinarity is reconstructed along the lines of its institutional, methodological and historic dimensions. It is concluded that while forestry sience shows the features of a discipline according to broadly accepted criteria, the convergence of the different dimensions is much less clear than in other scientific fields. Secondly, tendencies inherent in scientific development combined with recent changes in the demand for education and research may lead to further differentiation and the need for alliances with other scientific partners outside the traditional field. Such trends are currently being reinforced by developments that can be summarised with the term ,,transdisciplinarity". ,,Transdisciplinarity" is now commonly used to denote a combination of three factors: problem oriented research, strong links with the fields of application throughout the different phases of the research process, and a growing degree of social accountability of scientific institutions, programs and scientists. The last aspect, social accountability of sciences, is shortly discussed in its implications, highlighting the need to open the forestry sciences to broader social discourse and raise the ability to form new alliances with actors such as environmental organisations and the media. To sum up, forestry sciences are likely to be faced with contradictory developments in the future: On the one hand a further differentiation and drifting apart of its subdisciplines seems inevitable and a growing theoretical integration rather unlikely. On the other hand the overall picture of the development of the scientific field suggests that the importance of disciplines in controlling and directing scientific development is declining and disciplinary coherence becomes less important. At the same time, the ability of science to enter into a broader dialogue with extra-scientific actors about social development might turn into a decisive factor for the further development of forestry sciences.
