Understand the foundations

This set of definitions explain some of the key terms used throughout UKGBC’s work about nature and biodiversity net gain.

Biodiversity refers to the variety of life. The UN Convention on Biological Diversity provides the following definition: ’Biological diversity’ means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and of ecosystems.”

Biodiversity is vital for humans because so much of what we require comes from nature – such as fuel, food, medicines. There are estimated to be 8.7 million species (give or take 1.3 million and excluding bacteria) on Earth (source: UNEP)

Definition Source: IEMA, Biodiversity and Natural Capital Buzzword Guide

The balance of species in an ecosystem depends on the natural features of the environment such as the nutrient status, climatic conditions, water and light, as well as the relationship with other organisms including predators and agents of disease. ‘An ecosystem is a dynamic complex of plant, animal and micro-organism communities and the non-living environment interacting as a functional unit.’ (UK Millennium Ecosystem Assessment, 2005)

Definition Source: IEMA, Biodiversity and Natural Capital Buzzword Guide

“The contributions of ecosystems to the benefits that are used in economic and other human activity.” Examples include, food and timber provision, climate regulation (carbon storage and sequestration, urban cooling), water purification and flow regulation, flood protection, recreation, tourism, and physical and mental health.

Read more about nature as a service.

Definition Source: IEMA, Biodiversity and Natural Capital Buzzword Guide

‘A high-level goal and concept describing a future state of nature (e.g., biodiversity, ecosystem services and natural capital) which is greater than the current state.’

Definition Source: IEMA, Biodiversity and Natural Capital Buzzword Guide

A habitat is the area and resources used by a living organism or assemblage of animals and plants.

Definition Source: Biodiversity Net Gain for local authorities, Local Government Association

Biodiversity Net Gain is development that leaves biodiversity in a better state than before. It is also an approach where developers work with local governments, wildlife groups, land owners and other stakeholders in order to support their priorities for nature conservation. Note: the approach is becoming established in England. Other UK nations are considering similar approaches. Measures to deliver net gain increase the quantity and/ or quality of natural capital and can therefore also deliver gains in ecosystem services.

Definition Adapted from: IEMA, Biodiversity and Natural Capital Buzzword Guide

Biodiversity Net Gain statuary legislation under the UK Environment Act, requires all new development to produce a quantified positive habitat change by a minimum of 10% from the pre-development biodiversity value through the use of the DEFRA metric. This applies to all to all development where planning permission is granted; achieved either onsite, or offsite through the use of statutory credits.

Environmental net gain is an approach to development that leaves both biodiversity and the environment in a measurably better state than prior to development – as measured by biodiversity measures, ecosystem services and environmental metrics.

‘Biodiversity net gain initiatives can be accomplished either on-site or off-site (depending on the feasibility of the site after applying the mitigation hierarchy). On-site biodiversity net gain projects are those within the red line boundary and/or the planning boundary i.e. the immediate surroundings of the development. In contrast, off-site biodiversity net gain interventions include all habitat projects outside of the development’s boundary, regardless of ownership. These interventions may take the form of statutory credits, the establishment of a habitat bank, or the procurement of biodiversity credits from a private or independent entity.’

Getting more technical

These definitions are relevant to the process of implementing biodiversity net gain on development sites in line with the upcoming UK legislation.

Local Nature Recovery Strategies are a forthcoming, England-wide system of spatial strategies required through the Environment Act. They are intended to identify key priorities and map proposals for specific actions to drive nature’s recovery, and wider environmental benefits, in a local area – underpinning the national Nature Recovery Network.

Biodiversity offsets are conservation activities that are designed to give biodiversity benefits to compensate for losses – ensuring that when a development damages nature (and this damage cannot be avoided or mitigated) new nature sites will be created. Following the planning system Mitigation Hierarchy, offsetting is to be considered a last resort option after all onsite Biodiversity Net Gain (BNG) measures have been explored.

Definition Source: DEFRA and Natural England

Statutory biodiversity credits will be sold by the UK Government to developers as a last resort, where developers can demonstrate as part of the net gain plan that they are unable to achieve net gain on-site, off-site on other landholdings or by purchasing biodiversity units on the market.

Definition Source: DEFRA Consultation

Additionality is a crucial aspect of post-development assessment that demands a demonstrable enhancement in biodiversity, in accordance with the Defra Metric compared to the original state. Beyond direct BNG enhancement, wider species and habitat interventions are weighted differently towards overall additionality (i.e. nutrient neutrality). ‘To qualify as genuinely additional, at least 10% of the total post-development biodiversity score (110% or more) must come from measures that go beyond addressing the effects on protected species or protected sites.’

Definition Source: DEFRA, via the Planning Advisory Service

Stacking is when various overlapping ecosystem services produced on a given piece of land are measured and separately ‘packaged’ into a range of different credit types or units of trade that together form a stack. The components of the stack can then be sold individually to different buyers and separate payments received for each set of services.

Definition Source: Forest Trends

Bundling is when a suite of ecosystem services produced on a piece of land is sold as a single package (typically as a single unit of trade or credit) to the same buyer. There is one payment for an aggregated set of overlapping services. The extent to which the range of services making up the bundle are explicitly identified and measured varies significantly.

Definition Source: Forest Trends

‘a parcel of land, usually 10 hectares or larger in size (even up to 100ha) that is leased from and managed by the landowner with support from an expert ecologist. Through a robust land management plan and contractual arrangement, the land is developed into biodiversity-rich habitat that has guaranteed long-term (30+ years) of funding for its management.’

Definition Source: Environment Bank

Biodiversity gains and losses of a development will be measured in ‘biodiversity units’, using the biodiversity metric 4.0. The metric uses habitats as a proxy for biodiversity and calculates units by taking account of the type, extent and condition of habitats. Landowners can enhance existing or create new habitat on their land: they can work out the biodiversity gain of this activity using the metric, and then sell those biodiversity units to developers.

An expanding, increasingly connected, network of wildlife rich habitats supporting species recovery, alongside wider benefits such as carbon capture, water quality improvements, natural flood risk management and recreation. It includes the existing network of protected sites and other wildlife rich habitats as well as landscape or catchment scale recovery areas where there is coordinated action for species and habitats.

Definition Source: National Planning Policy Framework

Natural Capital accounting creates a consistent, standardised, and repeatable system for documenting information about natural capital and the ecosystem services it provides, regardless of whether those services have a market value. By doing so, it enables the measurement, valuation, monitoring, and communication of the condition of natural assets in a particular area, consolidating physical and financial data on the asset and its service flows. This process can be undertaken at various levels, such as national, regional, local, or organisational.

Definition Adapted From: DEFRA

Wildlife specific definitions

These definitions relate to wildlife in the UK, and methods of increasing biodiversity through wider habitat connectedness and urban greening.

Any site which would be included within the definition at regulation 8 of the Conservation of Habitats and Species Regulations 2017 for the purpose of those regulations, including candidate Special Areas of Conservation, Sites of Community Importance, Special Areas of Conservation, Special Protection Areas and any relevant Marine Sites.

Definition Source: National Planning Policy Framework

Habitats which would be technically very difficult (or take a very significant time) to restore, recreate or replace once destroyed, taking into account their age, uniqueness, species diversity or rarity. They include ancient woodland, ancient and veteran trees, blanket bog, limestone pavement, sand dunes, salt marsh and lowland fen.

Natural capital refers to the valuable physical assets of natural resources, such as forests, soils, mineral deposits, and rivers, that are utilized to provide goods and services. These assets are the foundation for ecosystem services, which are vital for meeting the basic needs of humans. In essence, natural capital represents the global stock of natural assets that support the essential ecosystem services that sustain human well-being.

Areas of habitat connecting wildlife populations

A habitat corridor can be defined as a network of designated sites which connect spaces which serve as pathways or stepping stones for wildlife, intended to facilitate the movement of individual species essential for maintaining biodiversity.

Definition Adapted From: DEFRA

Unconnected areas of semi-natural habitat close to habitat corridors, allowing more mobile species to move through the landscapes.

Green infrastructure can embrace a range of spaces and assets that provide environmental and wider benefits. It can, for example, include parks, playing fields, other areas of open space, woodland, allotments, private gardens, sustainable drainage features, green roofs and walls, street trees and ‘blue infrastructure’ such as streams, ponds, canals and other water bodies.

Learn more about Green Infrastructure and its value in our report the Value of Nature Based Solutions.

A tool that evaluates and quantifies the amount and quality of urban greening that a scheme provides to inform decisions about appropriate levels of greening in new developments

Habitats of Principal Importance included in the England Biodiversity List published by the Secretary of State under section 41 of the Natural Environment and Rural Communities Act 2006.

European protected species (EPS) have full protection under The Conservation of Habitats and Species Regulations 2017. It’s an offence to deliberately capture, injure or kill, or deliberately disturb EPS. It may be possible to use licensing policy 4 which allows, in certain circumstances, for reduced survey work and worst-case scenario compensation to be proposed.

Additional Biodiversity Net Gain resources