Abridged English Version The study of the karstification of the low limestone plateaus of eastern France highlights karsts under the forest of the covered karst type or of the litho-stratigraphic contact karst type at the limit of the extension of the geological cover. The knowledge of the spatial distribution of the exokarst detected thanks to the field inventories is difficult in private forests because of the difficulties of access of these spaces. This is the case of the Montagne de Reims, whose plateau is composed of a complex assemblage of 33% state and communal forests and 66% private forests. It is a space with strong heritage issues (Regional Natural Park (PNR), Forest of Exception®, Biological Reserves, UNESCO inscription). During the winter of 2017-2018 a LiDAR campaign was conducted for the ONF and the PNR Montagne de Reims (fig. 1). The product of this campaign is a high resolution DTM. It allows the detection of natural and anthropic morphologies in this forest context with heavy historical legacies (archaeological structures, geomaterials extraction, polemological landscapes). The semi-automatic processing of the LiDAR image via standardized treatments such as local model relief, multidirectional shading and the creation and sorting of isolines allowed the detection of 10,000 closed depressions. These depressions were processed using a multi-criteria approach under GIS based on morphological, environmental and bibliographic indices, allowing the discrimination of more than 750 karst depressions (fig. 5). The first observations of the exokarst showed a distribution of shapes along a narrow and discontinuous border (fig. 8). On the front of the coast, up-dip, where it occupies mainly structural flats while on the reverse, it is inscribed in valleys where the dynamics of infiltration (at the head of the talweg) and withdrawal (on the slopes) dominate (fig. 9). Various studies on the relationship between exokarst and valley incision, on the role of variations in the thickness of the Tertiary cover and on the close links between exokarst and land movements have been carried out in order to explain this spatial distribution (fig. 11). This has shown that the spatial organization of the karst belt of the Montagne de Reims presents a double discontinuity, both regional and local. On a regional scale, the morphostructural framework, although obviously uniform, hides strong lateral variations of facies inherited from the depositional conditions of the Paleocene. Karstification is limited to the existence of Microcodium calcarenites in the Thanetian formation. The latter, karstifiable and present mainly on the eastern terminus of the Montagne de Reims, form an exokarst feeding karstic systems that concentrate the flows towards the chalk karst. The thickness of the geological cover, which increases with the dip, also limits the karstification of the calcarenites and the chalk towards the west. On a local scale, the karst is related to the talweg network with an obvious north-south opposition. The northern slope of the Montagne de Reims, corresponding to the front of the Ile-de-France coast, is less karstified than the southern slope. The latter is cut by a well hierarchical and incised hydrographic network giving it a multiplicity of outcrops of calcarenites, local base levels, strong hydraulic gradients and a partitioning of the space. This multiplies the potential for the installation of restricted, but more numerous, karstic systems in the calcarenites, which favors the concentration of flows towards the chalk endokarst. Finally, locally, the karstic border is interrupted by numerous land movements on the southern slope (fig. 12).