This general term relates to regions around the world that either have globally important levels of biodiversity and endemism, considered to be under threat in some cases, or include representative examples of important ecosystems. It differs from the more formal definition used by Conservation International (see below). The following include the designations covered by this website but this is not an exhaustive list and will be continually updated as further information becomes available. For local biodiversity hotspots go to individual bioprovince webpages.

Global 200 Sites (WWF)

These comprise a series of ecoregions (see below) identified by the World Wide Fund for Nature (World Wildlife Fund) as the most biologically distinct parts of the planet and therefore prioritised for conservation.

Ecoregions (WWF)

Designating ecoregions was the first comparative analysis of biodiversity to cover every major habitat type on the planet. Not all of them therefore can be classed as biodiversity hotspots. They cover relatively largeareas of land or water containing characteristic and geographically distinct assemblages of natural communities and species, and are described by WWF as: (a) sharing a large majority of their species and ecological dynamics, (b) sharing similar environmental conditions, and (c) interacting ecologically in ways that are critical for their long-term persistence. Altogether 825 terrestrial ecoregions across the globe have been identified, and a set of 426 freshwater ecoregions has just been completed. WWF has recently launched an analogous global framework of 229 coast and shelf marine ecoregions in collaboration with The Nature Conservancy.

Natural World Hertage Sites (UNESCO)

The United Nations Educational, Scientific and Cultural Organization (UNESCO) criteria for designating natural as opposed to cultural World Heritage sites is that they should contain:

Superlative natural phenomena or areas of exceptional natural beauty and aesthetic importance

Outstanding examples of major stages of earth's history, including the record of life, significant on-going geological processes in the development of landforms, or significant geomorphic or physiographic features

Outstanding examples representing significant on-going ecological and biological processes in the evolution and development of terrestrial, fresh water, coastal and marine ecosystems and communities of plants and animals

The most important and significant natural habitats for in-situ conservation of biological diversity, including those containing threatened species of outstanding universal value from the point of view of science or conservation

Centres of Plant Diversity (IUCN/WWF) [No appropriate website available as yet]

Initated by International Union for the Conservation of Nature (IUCN) and WWF the objective here was to identify which areas of the world, if conserved, would safeguard the greatest number of plant species. The selection criteria are that each site must have one or both of the following characteristics: (1) be evidently species-rich, even though the number of species might not be accurately known, and (2) known to contain a large number of endemic species. Other factors considered were: the importance of genepools of plants valuable or potentially valuable to humans; the diversity of habitats; the significance of species adapted to special edaphic conditions; and the degree of threat to large-scale devastation. 

Endemic Bird Areas (Birdlife International)

Devised by Birdlife International, Endemic Bird Areas (EBAs) are regions of the world supporting two or more restricted-range species (secondary EBAs support one or more restricted-range species), and are regarded as critical regions for bird conservation.

Biosphere Reserves (UNESCO)

A designation developed by UNESCO in an attempt to create an international network of protected areas encompassing examples of all the Earth's major vegetation and physiographic types. They were primarily created to promote and demonstrate a balanced relationship between humans and the biosphere. In line with this requirement each reserve should have:

A core conervation area or areas devoted to long-term protection, and managed in accordence the with conservation objectives of the biosphere reserve and be of sufficient size to meet these objectives

A buffer zone or zones clearly identified and surrounding or contiguous with the core area or areas where only activities compatible with the conservation objectives are allowed

An outer transition area where sustainable resource management practices are promoted and developed

Biodiversity Hotspots (Conservation International)

For a region to qualify as a Conservation International Biodiversity Hotspot, they have set two strict criteria. The area must contain at least 1500 species of vascular plants (> 0.5 percent of the world’s total) as endemics, and it has to have lost at least 70 percent of its original habitat. These areas are guaranteed to lose species if they are not properly conserved. All hotspots contain at least one Global 200 Ecoregion and all but three contain at least one Endemic Bird Area. 60 percent of Global 200 terrestrial Ecoregions and 78 percent of EBAs overlap with hotspots.

Wildernes Areas (Conservation International)

To qualify these must constitute a distinct biogeographic unit or a series of units within a single biome and have minimum areas of 10,000 km² or 1 million ha. They are therefore larger than any existing protected-areas.

Their original natural vegetation should be at least 70% intact—meaning that no more than 30% has been destroyed or significantly degraded by human activities. In this respect they are the opposite of Biodiversity Hotspots. They should also still maintain intact faunal assemblages of large mammals and birds, especially large, wide-ranging predators.

Finally their human population density should be no more than about 5 inhabitants per km² for the region as a whole once urban areas have been subtracted.

They comprise the tropical humid forest of Amazonia, Congo and New Guinea, the tropical dry forests and grasslands of the Chaco, Miombo-Mopane and Australian savannas, the mixed mountain, temperate rain, and temperate needleleaf forests of the Rocky Mountains, Pacific Northwest , Magellanic areas and the Tasmanian World Heritage Wildlife Area, the northern boreal forests, the wetlands of the Llanos, Pantanal, Bañados del Este and Sundarbans, the warm and cold-winter deserts of North America, Patagonia, Sahara, Kalahari-Namib, Arabia, Central Asia and Australia, and the Arctic and Antarctic tundra.  However, five of these: Amazonia, the Congo forests, New Guinea, the Miombo-Mopane woodlands of Southern Africa and the North American desert complex of northern Mexico and the southwestern US are classed as High-Biodiversity Wilderness Areas.

The Alliance for Zero Extinction (AZE) Sites

The AZE is a joint initiative of biodiversity conservation organizations from around the world aiming to prevent extinctions by identifying and safeguarding key sites, each one of which is the last remaining refuge of one or more Endangered or Critically Endangered species.

AZE sites must meet all three of the following criteria to qualify:

Contain at least one Endangered (EN) or Critically Endangered (CR) species, as listed on the IUCN Red List [Endangerment Criterion].

Be the sole area where an EN or CR species occurs or contains the overwhelmingly significant known resident population of the EN or CR species, or contains the overwhelmingly significant known population for one life history segment (e.g. breeding or wintering) of the EN or CR species [Irreplaceability Criterion].

Have a definable boundary within which the character of habitats, biological communities, and/or management issues have more in common with each other than they do with those in adjacent areas [Discreteness Criterion].

Key Biodiversity Areas (IUCN)

Key Biodiversity Areas build on the 25 years experience gained through the BirdLife International partnership in identifying, safeguarding and monitoring Important Bird Areas (see below). This methodology has now been applied to other taxa, resulting in the development of Important Plant Areas (see below), Important Amphibian Areas, Important Mammal Areas, Prime Butterfly Areas and Prime Dragonfly Areas.

They are regarded as places of international importance for biodiversity conservation, and aim to provide universal standards for selecting sites of global significance for conservation through the application of quantitative criteria that can be applied across all biogeographic regions and taxonomic groups. They should eventually form a systematic network of sites aimed at protecting potentially threatened species within all taxanomic groups. It is advocated that four criteria are used in the selection process. Each site should support one or a combination of Threatened species, Restricted-range species with small global ranges, Congregatory species, which concentrate in large numbers at a particular site during some stage in their life cycle, and Biome-restricted assemblages (sets of species confined to a particular habitat type or biome).

Important Bird Areas (Birdlife International)

Important Bird Areas (IBAs) are areas recognized as being globally important habitat for the conservation of bird populations. There are currently about 10,000 IBAs worldwide and are an integral part of the Key Biodiversity Area approach to site-based conservation (see above). In summary for a site to be designated as an IBA, it must satisfy at least one of the following rating criteria:

It must hold a population categorized by the IUCN Red List as Critically Endangered, Endangered or Vulnerable (globally threatened species).

It must form one of a set of sites selected to ensure that all restricted-range species of an Endemic Bird Area or Secondary Area are present in significant numbers in at least one site and preferably more (restricted-range species).

It must forms one of a set selected to ensure adequate representation of all species restricted to a given biome (biome-restricted species).

It regularly supports 1% of the individuals in a population of one species or subspecies of waterbird (Article 6 of the Ramsar Convention)

It includes seabird species not covered by Delaney and Scott (2002) 'Waterbird Population Estimates' Third Edition, Wetlands International, Wagenigen, The Netherlands. Quantitative data are taken from a variety of published and unpublished sources.

It regularly supports 20,000 or more waterbirds (Article 5 of the Ramsar Convention).

The population at the site is thought to exceed thresholds set for migratory species at bottleneck sites.

Important Plant Areas (Plantlife International & IUCN)

Important Plant Areas (IPAs) are defined as natural or semi-natural sites exhibiting exceptional botanical richness and/or supporting outstanding assemblages of rare, threatened and/or endemic plant species and/or vegetation of high botanic value. These are regarded as an integral part of the Key Biodiversity Area approach to site-based conservation (see above), and identified according to three specific criteria:

Criterion A (Threatened Species) - the site most holds significant populations of one or more species that are of global or regional conservation concern.

Criterion B (Botanical Richness) - the site must have an exceptionally rich flora in a regional context in relation to its biogeographic zone.

Criterion C (Threatened Habitat) - the site is an outstanding example of a habitat or vegetation type of global or regional plant conservation and botanical importance.

Natura 2000 Network (European Commission)

This is an ecological network of protected areas in the territory of the European Union. The so-called Birds Directive (1979) and the Habitats Directive (1992) provided the legal basis for each Member State to compile a list of the best wildlife areas containing the habitats and species listed in the directives. After European Commission approval, sites identified under the Birds Directive were designated as Special Protection Areas (SPAs) while Habitat Directive sites were designated Special Areas of Conservation (SACs), which together make up the Natura 2000 network. This is now the largest coherent network of protected areas in the world with some 26,000 protected sites covering an area of about 850,000 km2, representing approximately 18% of total EU terrestrial area.

Ramsar Convention

The Convention on Wetlands (Ramsar, Iran, 1971), known as the 'Ramsar Convention', is an intergovernmental treaty that embodies the commitments of its member states to maintain the ecological character of their Wetlands of International Importance. The Convention uses a broad definition of wetlands covering lakes, rivers, swamps, marshes, wet grasslands, peatlands, oases, estuaries, deltas and tidal flats, near-shore marine areas, mangroves and coral reefs, as well as human-made sites such as fish ponds, rice paddies, reservoirs, and salt pans. A number of sites have World Heritage status. The criteria used to indentify wetlands of international importance are as follows:

Group A. Sites containing representative, rare or unique wetland types

Criterion 1: A wetland should be considered internationally important if it contains a representative, rare, or unique example of a natural or near-natural wetland type found within the appropriate biogeographic region.

Group B. Sites of international importance for conserving biological diversity

Criteria based on species and ecological communities

Criterion 2: A wetland should be considered internationally important if it supports vulnerable, endangered, or critically endangered species or threatened ecological communities.

Criterion 3: A wetland should be considered internationally important if it supports populations of plant and/or animal species important for maintaining the biological diversity of a particular biogeographic region.

Criterion 4: A wetland should be considered internationally important if it supports plant and/or animal species at a critical stage in their life cycles, or provides refuge during adverse conditions.

Specific criteria based on waterbirds

Criterion 5: A wetland should be considered internationally important if it regularly supports 20,000 or more waterbirds.

Criterion 6: A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of waterbird.

Specific criteria based on fish

Criterion 7: A wetland should be considered internationally important if it supports a significant proportion of indigenous fish subspecies, species or families, life-history stages, species interactions and/or populations that are representative of wetland benefits and/or values and thereby contributes to global biological diversity.

Criterion 8: A wetland should be considered internationally important if it is an important source of food for fishes, spawning ground, nursery and/or migration path on which fish stocks, either within the wetland or elsewhere, depend.

Specific criteria based on other taxa

Criterion 9: A wetland should be considered internationally important if it regularly supports 1% of the individuals in a population of one species or subspecies of wetland-dependent non-avian animal species.