New research relating to Mediterranean grazing land management issues, e.g. fire hazard control, biodiversity conservation, vibrant rural areas, etc. addresses the role that livestock farming systems can play. Established technical knowledge about livestock farming cannot contribute to these issues because it relies on standardised animal feeding techniques, focusing on cultivable forage areas and distribution of feed. These have led to the decline of the herders’ knowledge of grazing management and of herding practices. Thus original research works were needed. The works have been carried out by an interdisciplinary team of researchers in animal sciences, ecology and social sciences, from an INRA laboratory in Avignon (France) The research focuses on how the herders interact with ecosystems and landscapes through the management of their flocks, and investigations deal with the question of ‘how can one steer grazing for animal production and environment maintenance?’ (i.e. control scrub development, maintain biodiversity and promote the habitat of particular populations of plants and animals in need of protection). The paper presents the chronicle of this research over twenty years. It asks how the problematic evolved as a result of the accumulated scientific knowledge and the shift in societal questioning in relation to the rise of environmental concerns and the changes in rural and residential issues. Field observations, surveys and inquiries, public policies analysis, farm monitoring and systems modelling were used, combined or successively, in the course of five different research stages The authors lead up to an analysis of the different epistemological standpoints of disciplines and types of actual action representing a transdisciplinary approach. This approach is founded on a distributed view of knowledge, articulating different forms of scientific knowledge – according to the set of involved disciplines – and lay person knowledge and know-how in order to produce relevant categories and rules of action.