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 10 names in this directory beginning with the letter H.
Habitat
The type of site (vegetation, soils, etc.) where an organism or population naturally occurs - including a mosaic of components required for the survival of a species.
Habitat attrition
Habitat destruction due to progressive damage, loss or decline in quality.
Habitat fragmentation 
Dissection and reduction of the habitat area available to a given species - caused directly by habitat loss (e.g. land-take) or indirectly by habitat isolation (e.g. by barriers preventing movement between neighbouring habitat patches).
Habitat translocation
The relocation of a habitat from one place to another usually to avoid destruction of the habitat by infrastructure development.
Habitats related to Transport Infrastructures (HTI)
Green areas associated with transport infrastructure and usually managed by transport authorities and stakeholders. These areas include verges, resting sites, water retention ponds and other drainage elements, as well as fauna passages. These areas are inhabited by many animals, plants and other organisms which find refuge, food or other resources and can potentially have either negative or positive effects on natural ecosystems and landscape surrounding the infrastructure.
Hard shoulder
See 'Shoulder'.
Hedgerow
A close row of woody species (bushes or trees) serving as a boundary feature between open areas (often used in combination with or as an alternative to a fence).
Herbicide
A chemical application which kills weeds.
Highway
Major road, usually with two or more lanes in each direction. See also ‘Road’.
Hotspot (AVC hotspot/Roadkill hotspot)
See ‘Cluster’.