Skip Content


Apropriate Assessment
This is an assessment carried out under Regulation 48 of the Habitats Regulations.

A group of species found in the same location.

See mitigation.

Baseline Conditions
The conditions that would pertain in the absence of the proposed project at the time that the project would be constructed/operated/decommissioned.  The definition of these baseline conditions should be informed by changes arising from other causes (e.g. other consented developments).

The biological diversity of the earth’s living resources.  The total range of variability among systems and organisms at the following levels of organisation: bioregional, landscape, ecosystem, habitat, communities, species, populations, individuals, genes and the structural and functional relationships within and between these different levels.

The physical habitat with its biological communities.

Carrying Capacity
The maximum number of organisms or amount of biomass that can be supported in a given area.

Measures taken to make up for the loss of, or permanent damage to, biological resources through the provision of replacement areas.  Any replacement area should be similar to or, with appropriate management, have the ability to reproduce the ecological functions and conditions of those biological resources that have been lost or damaged.

Competent Authority
An organisation or individual who is responsible for determining an application for a consent for a project.  In the context of the Habitats Regulations, ‘competent authority’ has a wider meaning, which includes any Minister, government department, public or statutory undertaker, public body of any description or person holding a public office.

A measure of the functional availability of the habitats needed for a particular species to move through a given area.  Examples include movements of migratory fish from feeding grounds to spawning grounds or linking areas of appropriate habitat needed by some slow colonising species if they are to spread.

Conservation Status
For habitats, the elements of Conservation Status that relate to extent, structure, function, and typical species are used to provide guidance on attributes and targets. For species, the elements of population dynamics, range, habitat extent and quality are important.
Important elements which define Favourable Conservation Status which need to be reflected in the assessment of feature condition, are the 'long-term maintenance' and 'foreseeable future' criteria incorporated in Articles 1e and 1i of the Habitats Directive. For a feature to be assessed as being in favourable condition, the ecological circumstances need to be such that there is a reasonable expectation that the feature will be maintained in that condition (i.e. not deteriorate) in the long- term.

Cumulative Impact
Impacts caused either by a number of separate developments in the same area or those caused by increasing the size of arrays of marine renewable units or other developments.

Ecological Feature
Living systems or entities that exist because of specific limiting factors such as the soils and nutrients, availability of water, climate, etc.

Ecological Resource
Goods and services that come from the natural environment, such as fish, timber ores and water.

Ecological Services
Ecological functions that support and protect the human activities of production and consumption or affect overall wellbeing in some way.

Ecological Systems or Ecosystems
A dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.  Systems in which species evolve

These guidelines use the word impact rather than effect when referring to how ecological resources might be affected by a project.

The genuine enhancement of the natural heritage interest of a site or area because the project includes improved management or new habitats or features, which are better than the prospective management, or the habitats or features present there now. There is, therefore, a net or new benefit to the natural heritage.

Environmental Action Plan (EAP)
In these Guidelines EAP has been used to denote Environmental Management Plans and Environmental Design Management systems.

Environmental Impact Assessment (EIA)
This is an assessment carried out under the EIA Regulations.

EIA Regulations
The UK statutory instruments that are designed to meet the requirements of Council Directive 85/337/EEC on the Assessment of the effects of certain public and private projects on the environment, as amended by Council Directive 97/11/EC.

The degree of sensitivity of habitats, communities and species to environmental change.  It requires a consideration of intrinsic and extrinsic factors.

The breaking up of a habitat, ecosystem or biotope into smaller parcels with a consequent impairment of functioning.

A place in which a particular plant or animal lives.  Often used in the wider sense referring to major assemblages of plants and animals found together.

The way in which an ecological resource/receptor is affected by a project (see effect).

The coherence of a site’s ecological structure and function across its whole area that enables it to sustain the habitat, complex of habitats and/or levels of populations of the species for which it was classified.

Local Sites
‘Non-statutory’ sites of nature conservation value that have been designated ‘locally’ (i.e. excluding SSSIs, ASSIs, SPAs, SACs, and Ramsar Sites).  Local Nature Reserves are included as they are a designation made by the Local Authority not statutory country conservation agencies.  These are often called Wildlife Sites, Sites of Importance for Nature Conservation or other similar names.

Measures taken to avoid or reduce negative impacts.  Measures may include:  locating the development and its working areas and access routes away from areas of high ecological interest, or timing works to avoid sensitive periods.  See also compensation (which is separate from mitigation).

An interconnected system of corridors.

Net Ecological Gain
The point at which the quality and quantity of habitats or species improves compared to their original condition. i.e. improvements over and above those required for mitigation/compensation.

A collection of individuals (plants or animals), all of the same species and in a defined geographical area.

Precautionary Principle
In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.

In these guidelines ‘project’ is used to refer to any development project(s)/scheme or other land use change for which it may be appropriate to undertake an EcIA.

A measure of relative abundance.

Any ecological or other defined feature (e.g. human beings) that is sensitive to or has the potential to be affected by an impact.

Process by which plant and animal communities revert to their pre–perturbation state.

See mitigation.

The creation of a habitat that is an acceptable replacement for the habitat which has been lost.

Any ecological or other environmental component affected by an impact.

The active re-establishment of a damaged or degraded system or habitat to a close approximation of its pre-degraded condition.

The level or geographic context for evaluation.

Schedule 1
Development that falls within a relevant description in Schedule 1 to the EIA Regulations always requires EIA.

Schedule 2
Development of a type listed in Schedule 2 to the EIA Regulations requires EIA if it is development likely to have significant effects on the environment by virtue of factors such as its size, nature or location.

Determination of the extent of an assessment (of an EcIA or full EIA).

Determination of whether or not an EIA is necessary.

An area of land assessed for its scientific value in terms of biodiversity, landscape and geological features

Those affected by or interested in the project/development.

UK Governing Body Websites
The websites of the Department of Communities and Local Government, Scottish Government and Northern Ireland Environment Agency.

Zone of Influence
The areas/resources that may be affected by the biophysical changes caused by activities associated with a project.