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Biodiversity Intactness Index

Key indicator facts

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Last update

2018

Coverage

Global

Availability

Data freely available

Partners

Nhm logo

Natural History Museum

Contact point

Andy Purvis - andy.purvis@nhm.ac.uk

Indicator description

The Biodiversity Intactness Index (BII) indicates the average abundance of a large, taxonomically, and ecologically diverse set of naturally-occurring species in a terrestrial area, relative to a baseline with minimal human impacts. BII was first proposed by Scholes & Biggs (2005). BII estimates the status of local terrestrial biodiversity; average BII is meaningful at any spatial scale, making it easy to estimate status and trends within any desired region (e.g. UN subregion, country or biome).

BII was first estimated globally by Newbold et al. (2016) as part of the PREDICTS project (www.predicts.org.uk) by combining models of overall abundance with models of abundance-based compositional similarity and global fine-scale (1km) estimates of land use and other pressures. The modelling framework has now been refined, especially for compositional similarity, improving the ability to detect human impacts on assemblage composition. This approach to BII estimation is discussed in detail by Purvis et al. (2018).

Because BII is estimated based on statistical models of how local biodiversity responds to land use and related pressures, it can be projected for any past or future date for which estimates of pressures are available. As a result, BII can report not only on current status and recent trends (using observed data on pressures), but also on the longer history of biodiversity change; and it can be used for policy screening of scenarios.

Related Aichi Targets

Primary target

12

Target 12:

By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

Secondary targets

Target 14:

By 2020, ecosystems that provide essential services, including services related to water, and contribute to health, livelihoods and well-being, are restored and safeguarded, taking into account the needs of women, indigenous and local communities, and the poor and vulnerable.

Primary target

12

Target 12:

By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

14
12

Related SDGs

E sdg goals icons individual rgb 15

GOAL 15 - Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss.

Target 15.1| Relevant indicator

By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements.

E sdg goals icons individual rgb 15

GOAL 15 - Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss.

E sdg goals icons individual rgb 15

Other related MEAs and processes

Indicator icon

IPBES Regional Assessment Chapters

Chapter 3| Relevant indicator

Status, trends and future dynamics of biodiversity and ecosystems underpinning nature’s benefits to people

Indicator icon

IPBES Regional Assessment Chapters

Indicator icon

Themes

Bip species
Bip terrestrial

Partners

Nhm logo

Key indicator facts

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Last update

2018

Coverage

Global

Availability

Data freely available

Indicator description

The Biodiversity Intactness Index (BII) indicates the average abundance of a large, taxonomically, and ecologically diverse set of naturally-occurring species in a terrestrial area, relative to a baseline with minimal human impacts. BII was first proposed by Scholes & Biggs (2005). BII estimates the status of local terrestrial biodiversity; average BII is meaningful at any spatial scale, making it easy to estimate status and trends within any desired region (e.g. UN subregion, country or biome).

BII was first estimated globally by Newbold et al. (2016) as part of the PREDICTS project (www.predicts.org.uk) by combining models of overall abundance with models of abundance-based compositional similarity and global fine-scale (1km) estimates of land use and other pressures. The modelling framework has now been refined, especially for compositional similarity, improving the ability to detect human impacts on assemblage composition. This approach to BII estimation is discussed in detail by Purvis et al. (2018).

Because BII is estimated based on statistical models of how local biodiversity responds to land use and related pressures, it can be projected for any past or future date for which estimates of pressures are available. As a result, BII can report not only on current status and recent trends (using observed data on pressures), but also on the longer history of biodiversity change; and it can be used for policy screening of scenarios.

Contact point

Andy Purvis - andy.purvis@nhm.ac.uk

Graphs / Diagrams

Figure. Global Biodiversity Intactness Index (BII) since 1970, and Tropical Forest BII since 2000.

The Biodiversity Intactness Index results can also be viewed and explored on the BIP Dashboard, which includes downloadable graphs of trends.

Current storyline

BII is on a scale from 100% (for pristine assemblages) to 0% (wholly destroyed or replaced assemblages). The Planetary Boundaries framework (Steffen et al. 2015) proposes a safe limit of 90% for BII, arguing that levels below that may risk large-scale disruption of the provision of ecosystem services. Negative trends in BII indicate declining intactness; positive trends are possible in principle (e.g. through land abandonment or, agricultural de-intensification). Globally, the average BII of terrestrial ecosystems is estimated to have fallen from 81.6% in 1970 to 78.6% in 2014. (These estimates are lower than the previously-published estimate – 81.4% in 2005 – mainly because of the more sensitive modelling of compositional similarity.) In tropical forest biomes, BII has fallen from 60.3% in 2000 to 58.4% in 2012, i.e., a loss of 1.9% of originally-present BII in only 12 years. This steeper decline could reflect greater pressure on tropical forests, greater sensitivity of the biomes’ biota, or differences in the land-use products used in making projections; analyses are underway to produce comparable and consistent annual BII estimates within each biome.

Indicator relationship to Aichi Targets 12 and 14

Target 12 - By 2020 the extinction of known threatened species has been prevented and their conservation status, particularly of those most in decline, has been improved and sustained.

- BII relates to this target by reporting on average trends across a wide basket of species.

Target 14 - By 2020, ecosystems that provide essential services, including services related to water, and contribute to health, livelihoods and well -being, are restored and safeguarded, taking into account the needs of women, indigenous and local communities, and the poor and vulnerable

- BII relates to this target because – in all terrestrial ecosystems – sustainable delivery of many ecosystem services depends on retention of adequate biodiversity.

Data and methodology

Coverage: Global/Sub-global/Regional/National

Scale: Global data - can be disaggregated to any region of interest.

Time series available: 1900-2010 (global); 2000-2014 (tropical forest)

Next planned update: 2018. The tropical forest BII analysis will be repeated for all biomes using similarly high-resolution pressure data. A range of possible alternative compositional similarity measures is being considered, in order to make BII more sensitive to observed compositional change. Estimates will continue to be updated as additional years of pressure data become available.

Possible disaggregations: The same analytical approach can be used on geographical, ecological or taxonomic subsets of the underlying database.

Metadata used: Provenance of pressure data used to drive the projections.

Methodology: BII is estimated by combining models of overall abundance with models of abundance-based compositional similarity and global fine-scale (1km) estimates of land use and other pressures. Models depend on an underlying database that has collated matched biodiversity surveys of multiple sites facing different human pressures around the world, and which has been published (Hudson et al. 2017). For full methodological details on how BII is estimated, see Purvis et al. (2018).

National use of indicator

Producing this indicator nationally: National estimates of BII are easy to produce from the global models. Countries with many underlying biodiversity data sets in the PREDICTS database may support country-specific statistical models (e.g., Colombia: Echeverria-Londono et al. 2016) but this requires additional research effort. Likewise, projections may be able to use country-specific pressure data, but this requires additional research effort.

Use of the global method and data at the national level: The high-resolution map of modelled BII for the year 2005 can be downloaded and is free to use. BII can be estimated for any region of interest as an average across all cells within the region; for large-scale analyses, we recommend weighting cells by their net primary production (such that more ecologically active cells receive more weight than e.g. deserts). The global values shown in the figure are based on coarse-scale pressure data, hampering interpretation of country-level status and trends. Country-level summaries of the tropical forest BII trends will be published soon and are available now on request. The global analysis will shortly be repeated using high-resolution pressure data for all biomes, at which point country-level summaries will be made available.

The approach can be applied to biodiversity data collected from a single country (e.g., Colombia: Echeverria-Londono et al. 2016), provided enough data can be assembled to support statistical modelling.

Examples of national use: The 2016 UK State of Nature report mapped BII within the UK and compared the UK with all other countries, using a global statistical model. Newbold et al. (2015) related projected national trends in related measures to national Human Development Index scores under four future scenarios. Echeverria-Londono et al. (2016) estimated statistical models using data from a single country (Colombia) and made projections of a closely-related measure within the same framework.

Availability of global data for national use: freely available for non-commercial use.

Global map of BII at 1km resolution: http://data.nhm.ac.uk/dataset/global-map-of-the-biodiversity-intactness-index-from-newbold-et-al-2016-science

Underpinning biodiversity data: http://data.nhm.ac.uk/dataset/the-2016-release-of-the-predicts-database

Further resources

Key indicator facts

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Indicator type

State

Applicable for national use

Yes (find out more)

Indicator classification

Operational and included in the CBD's list of indicators

Last update

2018

Coverage

Global

Availability

Data freely available

Partners

Nhm logo

Natural History Museum

Contact point

Andy Purvis - andy.purvis@nhm.ac.uk