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

All | # A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
There are currently 13 names in this directory beginning with the letter G.
Game
Animals hunted for sport and food.
Game fencing
Fencing specifically for game species such as wild boar and deer. See also ‘Fencing’.
Gene flow
The transfer of alleles or genes from one population to another.
Genetic diversity
The level of variability of genetic data within a sample or population, commonly measured through metrics such as heterozygosity and allelic richness.
Geographic Information System
A conceptualised framework that provides the ability to capture and analyse spatial and geographic data. GIS applications (or GIS app) are computer-based tools that allow the user to create interactive queries (user-created searches), store and edit spatial and non-spatial data, analyse spatial information output, and visually share the results of these operations by presenting them as maps.
Good practice
A methodology, process or technique that represents an effective way of achieving a specific objective, one that has been proven to work well and produce expected results, and is therefore recommended as a model or as a useful example. See also ‘Best Practice’.
Gradient
The (rate of) change of a parameter between one area or region and another.
Green bridge
See 'Landscape overpass'.
Green Infrastructure (GI)
A strategically planned network of natural and semi-natural areas with other environmental features designed and managed to deliver a wide range of ecosystem services. It incorporates green spaces (or blue if aquatic ecosystems are concerned) and other physical features in terrestrial (including coastal) and marine areas. It is also defined as ‘an interconnected network of protected land and water that supports native species, maintains natural ecological processes, sustains air and water resources and contributes to the health and quality of life for communities and people’.
Grey infrastructure
Engineered assets that aim to provide one or multiple services required by society, such as road, railways, urban areas, resource extraction, and other infrastructure.
Guard-rail
See 'Safety fence'.
Guide fencing
Fencing built to lead wild animals to a dedicated crossing point. See also ‘Fencing’ and ‘Amphibian fencing’.
Gutter
Paved channel designed to carry runoff from the edge of infrastructure into the drainage system.