Glossary of Key Terms

This glossary provides definitions for key terms used throughout the Biodiversity & Infrastructure Handbook, supporting consistent understanding across disciplines such as ecology, engineering, transport planning and policy.

Definitions are based on legal texts, reference documents and expert agreement, and cover essential concepts related to wildlife and traffic, habitat fragmentation, ecological connectivity, mitigation measures, monitoring, green infrastructure and nature-based solutions. The glossary helps practitioners interpret technical guidance and supports clear communication between stakeholders involved in infrastructure projects.

If you are new to transport ecology or working in a multi-disciplinary team, the glossary can serve as a quick reference before exploring detailed handbook chapters. Terms will continue to evolve as the handbook is updated through expert collaboration and user feedback.

Last update: October 2023 – How to cite

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There are currently 13 names in this directory beginning with the letter L.
Land cover
Combination of landuse and vegetation cover.
Land unit 
The smallest functional element of the landscape.
Land use planning
Activity aimed at predetermining the future spatial usage of land and water by society. Synonym: ‘Spatial planning’.
Landform
Natural feature on the surface of the earth.
Landscape
The total spatial and visual entity of human living space integrating the geological, biological and human-made environment. It is an heterogeneous land area composed of a cluster of interacting ecosystems that create a specific, recognisable pattern. According to the European Landscape Convention, a landscape is perceived differently by local people or visitors, and evolves through time as a result of being acted upon by natural forces and humans.
Landscape diversity
The variation and richness of landscapes in a region.
Landscape element 
Each of the relatively homogeneous units, or spatial elements, recognised at the scale of a landscape mosaic.
Landscape overpass
Large structure over transport infrastructure to provide continuity of habitats from both sides. Due to their width, a diversity of habitat types (e.g. vegetation or soil types, stone rows or piles, ponds, etc.) could be included. Combined with perimeter fencing that funnels the animals to the structure and with light/noise screens to reduce disturbance by traffic when required. The main difference to wildlife overpasses is their width and possibilities for vegetation cover and diversity of habitats being created which facilitate better ecosystem connection. Landscape overpasses can also be constructed over cut-and-cover or excavated tunnels. Synonyms: ‘Ecoduct’; 'Green bridge'. See also ‘Wildlife overpass’.
Landscape underpass
See 'Adapted viaduct'.
Landscaping
To modify the original landscape by altering the topography and/or plant cover. This may include building earthworks to form new landscape structures.
Level crossing
A place designated for large mammals to cross a road at the same level than traffic combining fences to guide fauna to an open section equipped whith Animal Detection Systems which detect the fauna and trigger driver warnings'. Synonym 'At Grade Passage'.
Like-for-like
Conservation (through the biodiversity offset) of the same type of biodiversity as that affected by the project. Sometimes referred to as in-kind. Several biodiversity offset policies are based on a principle either of ‘like-for-like’ or of ‘like-for-like or better’. ‘Like-for-like’ requires conservation (through the biodiversity offset) of the same type of biodiversity as that affected by the project. This is sometimes modified to ‘like-for-like or better’, in which the offset conserves components of biodiversity that are a higher conservation priority (for example because they are more irreplaceable and vulnerable) than those affected by the development project for which the offset is envisaged. This is also known as ‘trading up’.
Linear transport infrastructure
Road, railway or navigable inland waterway. Powerlines and pipelines are also included as they are designed for the transport of materials.