Existing measures for preventing and mitigating light and noise pollution impacts on terrestrial biodiversity and ecosystem services. PLAN-B project Deliverable 5.1

•Artificial light at night (ALAN) and anthropogenic noise are increasingly recognised as important environmental pressures on terrestrial biodiversity and ecosystem services (TBES). This deliverable (D5.1) provides a structured review of existing measures for preventing and mitigating the impacts of light pollution and noise pollution (LNP) on TBES. The review is based on published scientific literature, PLAN-B evidence-mapping outputs, selected legal and policy instruments, technical guidance, reference documents and supporting implementation input from Communities of Practice (CoP). •The review groups existing mitigation measures into five practical families: regulatory, planning, technological, environmental and social measures. Regulatory measures create formal requirements, policy conditions and governance opportunities for mitigation. Planning measures identify where exposure should be avoided, reduced or spatially controlled, for example, through the protection of dark corridors, quiet areas, ecological networks and sensitive habitat edges. Technological measures reduce or modify emissions at source or along the exposure pathway, including through shielding, adaptive dimming, spectral control, low-noise surfaces, quieter equipment and sensor-based operation. Environmental measures provide species/taxon-specific protection through habitat buffers, screening vegetation, earth berms, refuges and restoration-oriented actions. Social measures, including awareness, citizen science, stewardship, codes of practice and stakeholder engagement, support acceptance, compliance, reporting and long-term maintenance. •A key finding is that evidence is generally stronger for exposure reduction than for documented biodiversity recovery or ecosystem-service improvement. The implementation of a measure does not automatically demonstrate ecological effectiveness. A measure is ecologically relevant when it reduces the exposure pathway that matters for sensitive species, organism groups, habitats, ecological processes or ecosystem-service functions, at the right place, time and spatial scale. Where feasible, this should be validated through taxon-specific monitoring, implementation checks and ecological response indicators. •The review also shows that light and noise pollution are still frequently overlooked or addressed inconsistently, despite the fact that both pressures often occur simultaneously within the same habitats, ecological corridors, protected area boundaries, transport networks, and recreational landscapes. Future mitigation efforts should ensure that both forms of pollution are systematically considered in planning and management processes. In addition, where feasible, opportunities for integrated mitigation should be explored. Where light and noise pollution affect the same receptors or exposure pathways, combined mitigation measures may offer a more effective approach than addressing each pressure separately. •The review concludes that mitigation should start from the ecological problem, not from the measure itself. The key question is what pressure affects which species, habitat or ecological function, and where this exposure occurs. Future work should develop practical tools for measuring light and noise from the point of view of species and habitats, improve monitoring, and support combined light-noise mitigation where both pressures occur together. Biodiversity-sensitive mitigation should also become part of planning, procurement, permitting, protected-area management and long-term maintenance.