After a period of sharp conflicts with representatives of forest, hunting and agricultural interests, the French administration decided in 2000 that management objective projects were to be finalised in each of the future 1.200 Special Areas of Conservation designated according to the EU Habitats Directive. The aim of these projects is to define locally which activities should be developed by rural customers to achieve the habitats conservation objectives. The projects are worked out by state appointed local institutions (municipalities, environmental associations, forest agencies…) which have a wide autonomy in the organisation of the procedure. A postal survey has been conducted among these institutions to identify the actors and scientific abilities which were chosen and the kind of knowledge produced in the process of planning the adjustment of economic and recreational practices to the objectives of nature conservation. The paper presents the results of this survey (360 questionnaires). Beyond empirical data, it emphasises the fact that new expert skills appear, particularly among local municipalities, which ability is more to combine previously distinct areas of knowledge and know-how than to produce new scientific and technical conservation outcomes. However, the institutional framework in which these new forms of expertise emerge make it precarious, as no particular professional status has been institutionalised, nor any centre of capitalisation of these experiences has been set up