Areas of particular importance for biodiversity

Summary Global Guidelines Technical and interactive resources

Biodiversity is not distributed evenly on the planet. The best areas for biodiversity conservation for Protected and Conserved Areas (PCAs) must be prioritised to be effective and efficient.

Representation is a useful concept in selecting PCAs. Representation means including viable populations of the full variety of biodiversity of different biological realms (freshwater, marine and terrestrial through all the ecoregions) and biological scales (ecosystems, species and within-species variation) within a system of PCAs. Identifying areas of particular importance for biodiversity can be considered at different scales – from Global Biodiversity Hotspots to Key Biodiversity Areas to regional, national or subnational identification systems.

Although national-level planning is essential, it is also important to develop this in the context of the global significance of a species’ population at a site, to avoid spending effort conserving globally abundant species that may be rare in a particular country because they are at the edge of their range. Conservation biologists also advise building some functional redundancy into the PCA system to ensure that omissions are minimized and there is some insurance against loss of critical sites. In some cases, locally rare species common elsewhere may have cultural or spiritual significance that means they also deserve special attention.

Why 30% might not be enough and what that means right now

Given the current bias in the type of ecosystem represented in protected areas, achieving representation by any measure (ecoregions, bioregions, ecosystems or species) will require more than 30% area-based conservation. This is true for biodiversity and ecosystem services conservation as a whole: analysis suggests that almost 80% of remaining natural vegetation is needed to meet the full range of issues identified in four United Nations’ resolutions (UNCCD, UNFCCC, CBD and the Sustainable Development Goals).

This means that PCA efforts, which may expand in future with a larger target, need to focus on the most urgent needs now. It is also important to understand what can effectively be conserved in the wider landscape and seascape; this is context-specific and depends largely on the extent to which area-based conservation is integrated into the rest of the landscape and seascape.


Approximately a dozen different issues must be considered when prioritizing future sites (figure below): all are important and should not be traded off against each other. Many tools exist to help these processes, from software planning packages to bottom-up planning approaches. There are also many critical input datasets – for example, the World Database on Key Biodiversity Areas (KBAs) provides large quantities of information that can help identify sites of global importance to biodiversity for protection.

Enabling factors and challenges

Multiple studies report beneficial effects of protected areas on species abundance and diversity for all types of protected areas. Yet at present, many species are missed by the global protected area system, and others are not covered in sufficient numbers to ensure survival. Similarly, many ecosystems and important sites, including KBAs, are not or are inadequately included. Indeed, KBAs have not been comprehensively identified in many countries across all taxonomic groups and this should be a national priority.

An analysis from 2010–2019 of over 12,000 threatened species (e.g., Vulnerable, Endangered or Critically Endangered on the IUCN Red List) found 87.6% had some portion of their geographic range protected. But only 2% had gained protection in the last decade suggesting slow progress towards representation. Also, biodiversity in protected areas is affected by wider environmental and climate changes. Research in German protected areas found a 76% decline in flying insect biomass over 27 years, with agricultural intensification the likely cause. Lack of insect food is a major driver behind a 55% decline in European farm birds since 1980. And climate change can not only make species go extinct due to inability to adapt, but also change their distribution. Many times, species will have nowhere to go because their future, habitable environment is not itself protected. So protected areas must also take into account future habitat under climate change wherever possible.

Guidelines for using A Global Standard for the Identification of Key Biodiversity Areas: Version 1.2

This resource provides an overview of the steps for identifying and delineating Key Biodiversity Areas (KBAs), which are defined as sites that contribute significantly to the global persistence of biodiversity. There are eleven criteria grouped into the following five overarching criteria for KBAs that address all levels of biodiversity, including genetic, species, and ecosystem diversity. These are:

  1. Threatened biodiversity;
  2. Geographically restricted biodiversity;
  3. Ecological integrity;
  4. Biologically processes, and
  5. Very high irreplaceability, which are coupled with quantitative percentage thresholds. A site only needs to meet one criterion or sub-criterion to qualify as a KBA.

The publication contains ten main sections: 1. Introduction; 2. Identifying Key Biodiversity Areas using species-based criteria (A1, B1-3, D1-3); 3. Assessment parameters for species-based criteria; 4. Identifying Key Biodiversity Areas using ecosystem-based criteria; 5. Identifying Key Biodiversity Areas based on ecological integrity (Criterion C); 6. Identifying Key Biodiversity Areas based on quantitative analysis of irreplaceability (Criterion E); 7. Delineation procedures; 8. Stakeholder consultation and involvement; 9. Data availability, quality and uncertainty, and 10. Reassessment. The document also contains ten appendices that provide more insight into the terms used, the threshold percentages, additional tools and resources, and more.

Overall, the aim of this resource is to ensure that KBA identification is based on consistent, scientifically rigorous, and practical methods. It details how the KBA criteria, thresholds, and delineation procedures should be implemented in an objective, transparent, and replicable way.

Key Take Aways:

  1. Key Biodiversity Areas (KBAs) are defined as sites that contribute significantly to the global persistence of biodiversity.
  2. There are five main criteria for KBAs that address all levels of biodiversity, including genetic, species, and ecosystem diversity: A. Threatened biodiversity; B. Geographically restricted biodiversity; C. Ecological integrity; D. Biologically processes, and E. Very high irreplaceability, which are coupled with quantitative percentage thresholds.
  3. To be identified as a KBA, a site only needs to meet the requirements for one criterion or sub-criterion. However, it is recommended that all sites are evaluated against as many KBA criteria, taxonomic groups, and ecosystem types as possible based on the available data. Assessing sites against multiple criteria and for various elements of biodiversity will enhance the reliability of KBA identification, making it less vulnerable to changes in the status of particular species, groups, or ecosystem types.