French forests are "in crisis" (Ateliers ReGeFor 2020, 2023). Yet their area has been steadily increasing since the mid-19th century and the beginning of the 2nd phase of the forestry transition. But forests are currently suffering new changes, visible and worrying: dieback is on the increase. Fears are all the more pressing given the erosion of biodiversity and the proliferation of invasive exotic species, etc. Forests are affected by global change and undergoing profound transformations. Climate-change-induced actions aimed at adaptation or mitigation are reinforcing the trend: planting of species better adapted to new and future climatic conditions; use of forests for ecological transition (use of wood for energy or construction). Expectations of forests are therefore numerous and often contradictory. They offer local and renewable resources. They are thus being exploited more and more, and some people are denouncing an "industrialization" of the forest, pointing the finger at so-called clear-cutting and mechanized logging. These questions about forests and their future are particularly perceptible in the Compiègne forest, a 14,500-hectare state-owned forest. The Compiègne forest is ancient (attested as early as the 6th century: Horen et al., 2017), but is also partly the result of 18th and 19th century plantations (Buridant, 2008), including coniferous trees. Today it is particularly affected by dieback (up to 30%) and is being invaded by an exotic species - Prunus serotina - which may have been introduced before Napoleon III, for aesthetic reasons (Javelle et al., 2006). This species is little known to the general public, but it can be appreciated, so much so that "some people even attack ONF agents they see cutting Prunus serotina" (ibid., transl.). These reactions are, in fact, widespread in this peri-urban forest: ONF staff report great difficulty in harvesting, and strong social mobilization against clear-cutting, sometimes leading to violent action against operators (FiBois testimony). Our research thus consists of semi-directive interviews with forestry stakeholders and nature protection associations, aimed at gaining a better understanding of the situation, in particular these conflicts, and the underlying issues. Ultimately, however, our interest is in the way the forest is perceived by users and local residents, in its present, future and past dynamics. The challenge here is to go beyond the expected and/or "politically correct" answers. We will therefore present the methods we have implemented, some of which have already been tried and tested on the issue of forest plantations. In this case, we favor semi-directive interviews with support material (photos, etc.). Above all, the use of participatory cartography and photo elicitation interviews enables us to place the respondent in a position of knowledge, thereby gaining his/her trust and facilitating communication.