In 2022, a collective made up of Ecofirst, CWEPSS and MaSePaS, was entrusted by the Service Public de Wallonie (Département de la Nature et des Forêts and DEMNA) with an exciting if quite complex mission: to propose a methodology for assessing the conservation status of Natura 2000 habitat 8310, i.e. natural caves not exploited by tourism.

Beyond the strict protection of vulnerable and priority species (Annex II of the Habitats Directive), it is now generally accepted that the protection of biodiversity also (and above all) requires the sustainable management and protection of their habitats, and therefore of the living conditions of these same species and communities. The aim of this work is to provide the SPW with a protocol which, based on a series of field observations and the compilation of existing biological data, will enable the most objective and coherent assessment possible of the good (or bad) state of the underground environment in Wallonia. The proposed approach integrates the “abiotic” characteristics of the environment (physico-chemical conditions, microclimate), biological data (lists of species present, rarity and population dynamics) as well as the threats (notably linked to anthropogenic activities) to this environment and the biodiversity it contains.

This document summarizes the bibliographical research carried out as part of the project. It includes a summary of practices for assessing this habitat in neighboring countries, a chapter on habitat description, a section on abiotic parameter measurements, a section on the assessment of living beings in underground sites and, finally, an assessment of threats and protection measures.