Glossary

A constructed mound of earth, usually along a road or railway, to provide a visual screen or absorb sound. See also ‘Berm’.

See ‘Landscape overpass’.

Items of the infrastructure that have an ecological value. It includes wildlife mitigation measures preventing impacts on wildlife and enhancing traffic safety such as fencing, wildlife passages, screens, adapted illumination and wildlife traffic signs. Drainage systems, road verges and other green areas associated with the infrastructure, managed in a way that supports wildlife conservation are also included.

Parameter of landscape function that describes the processes by which sub-populations or organisms are interconnected into a functional demographic unit. More generally, the Convention on Migratory Species defines it as the unimpeded movement of species and the flow of natural processes that sustain life on Earth which means it can also encompass other processes such as flow of water or nutrients. Synonym: ‘Connectivity’.

A geographically defined area which allows species to move between landscapes, ecosystems and habitats, natural or modified, and is intended to ensure the maintenance of biodiversity and ecological and evolutionary processes. Synonym: ‘Corridor’.

In the context of biodiversity offsets, the term is synonymous with the concept of ‘like-for-like’ and refers to areas with highly comparable biodiversity components. This similarity can be observed in terms of species diversity, functional diversity and composition, ecological integrity or condition, landscape context (e.g., connectivity, landscape position, adjacent land uses or condition, patch size, etc.), and ecosystem services (including people’s use and cultural values).

A system of core habitats (protected areas, other conservation areas, and non managed intact natural areas), connected by ecological corridors, specifically designed, implemented and managed to ensure that ecological connectivity is maintained and enhanced where it is present, or restored where it has been lost. See 'Ecological connectivity'.

Habitats that attract wildlife but pose hidden risks to the survival of animals. For example, attractive herbaceous vegetation near roads and railroads can increase road mortality risk for foraging animals.

Dynamic complex of plant, animal and micro-organism communities and their non-living environment, interacting as a functional unit.

Involves the ecological and evolutionary processes, including gene flow, disturbance, pollination and nutrient cycling.

Benefits provided to society by ecosystems. They are usually classified as provisioning (for example the production of food and water), regulation or maintenance (such as the control of climate, nutrient cycles…), and cultural, which includes the non-material characteristics of ecosystems that affect the physical and mental states of people.

Transitional zone between two habitats.

Distinct area with a recognisable set of characteristics relating to the soil, vegetation or water conditions. The ecotope represents the smallest land unit that makes up the landscape mosaic. See also 'Biotope'.

The portion of an ecosystem near its perimeter, where influences of the surroundings prevent the development of interior environmental conditions.

See 'Impact'.

Strip of land both sides of an infrastructure where landscape conditions are modified by the effects of the infrastructure. The distance over which disturbances affect nature depends on topography, wind direction, vegetation, and the type of agent. The width of the affected zone is likely a magnitude larger than the physical width of the infrastructure itself. Synonym: 'Road effect zone'.

Metrics for quantifying the effective number of meshes per square kilometre, that is the density of the meshes. The effective mesh density value rises when fragmentation increases. See also ‘Effective mesh size’.

Metrics for quantifying the degree of landscape fragmentation, based on the probability that two randomly located points (or animals) in an area are connected and are not separated by a barrier (e.g. roads, urban area). The smaller the effective mesh size, the more fragmented the landscape. See also ‘Effective mesh density’.

The number of interbreeding adults in a population (smaller than the total population because it excludes juveniles, non?reproductive and post?reproductive individuals).

Artificial bank (made of packed earth or gravel) such as a mound or dike, constructed above the natural ground surface in a linear form and designed to carry a roadway or railway across a lower lying area.

A network of areas of special conservation interest (ASCIs), which is to be established in the territory of the contracting parties and observer States to the Bern Convention, including, among others, central and east European countries and the EU Member States. For EU Member States, Emerald network sites are those of the Natura 2000 network. See also 'Natura 2000 Network'.

A species confined to a particular region and thought to have originated there.

Procedure that ensures that the environmental implications of transport infrastructure development are taken into account before the decisions are made. Environmental assessment can be undertaken for public plans or programmes ('Strategic Environmental Assessment', SEA) or for individual projects, such as a motorway, an airport or a channel ('Environmental Impact Assessment' EIA).

A process, applied mainly at project level, to improve decision making and to ensure that development options under consideration are environmental and socially sound and sustainable. EIA identifies, predicts and evaluates foreseeable impacts, both beneficial and adverse, of public and private development activities, alternatives and mitigating measures, and aims to eliminate or minimise negative impacts and optimise positive impacts. A subset of tools has emerged from EIA, including social impact assessment, cumulative effects assessment, environmental health impact assessment, risk assessment, biodiversity impact assessment and SEA. See also 'Strategic Environmental Assessment'.

Measure installed to prevent animals from becoming trapped by fences along infrastructure, e.g. badger gate, or built in the edge of a canal to enable animals to exit, e.g. escape-ramps. Synonym: ‘Fauna exit’.

A process that critically assesses, test and measure the design, implementation and results of a plan or project, in relation to its objectives. It can be conducted both qualitatively and quantitatively, to determine the difference between actual and desired outcome. In transport ecology, the aim is to check whether a project and the mitigation measures applied have met their objectives in terms of reduction of and compensation for impacts.