A biodiversity hotspot is a biogeographic region with significant levels of biodiversity that is threatened by human habitation. [1] [2] Norman Myers wrote about the concept in two articles in The Environmentalist in 1988 [3] and 1990, [4] after which the concept was revised following thorough analysis by Myers and others into "Hotspots: Earth's Biologically Richest and Most Endangered Terrestrial Ecoregions" [5] and a paper published in the journal Nature, both in 2000. [6]
To qualify as a biodiversity hotspot on Myers' 2000 edition of the hotspot map, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (more than 0.5% of the world's total) as endemics, and it has to have lost at least 70% of its primary vegetation. [6] Globally, 36 zones qualify under this definition. [7] These sites support nearly 60% of the world's plant, bird, mammal, reptile, and amphibian species, with a high share of those species as endemics. Some of these hotspots support up to 15,000 endemic plant species, and some have lost up to 95% of their natural habitat. [7]
Biodiversity hotspots host their diverse ecosystems on just 2.4% of the planet's surface. [2] Ten hotspots were originally identified by Myer; [1] the current 36 used to cover more than 15.7% of all the land but have lost around 85% of their area. [8] This loss of habitat is why approximately 60% of the world's terrestrial life lives on only 2.4% of the land surface area. Caribbean Islands like Haiti and Jamaica are facing serious pressures on the populations of endemic plants and vertebrates as a result of rapid deforestation. Other areas include the Tropical Andes, Philippines, Mesoamerica, and Sundaland, which, under the current levels at which deforestation is occurring, will likely lose most of their plant and vertebrate species. [9]
Only a small percentage of the total land area within biodiversity hotspots is now protected. Several international organizations are working to conserve biodiversity hotspots.
Most biodiversity exists within the tropics; likewise, most hotspots are tropical. [15] Of the 36 biodiversity hotspots, 15 are classified as old, climatically-buffered, infertile landscapes (OCBILs). [16] These areas have been historically isolated from interactions with other climate zones, but recent human interaction and encroachment have put these historically safe hotspots at risk. OCBILs have mainly been threatened by the relocation of indigenous groups and military actions, as the infertile ground has previously dissuaded human populations. [17] The conservation of OCBILs within biodiversity hotspots has started to garner attention because current theories believe these sites provide not only high levels of biodiversity, but they have relatively stable lineages and the potential for high levels of speciation in the future. Because these sites are relatively stable, they can be classified as refugia. [18]
North and Central America
The Caribbean
Southeast Asia and Asia-Pacific
The high profile of the biodiversity hotspots approach has resulted in some criticism. Papers such as Kareiva & Marvier (2003) [21] have pointed out that biodiversity hotspots (and many other priority region sets) do not address the concept of cost, [22] and do not consider phylogenetic diversity. [23]
An ecoregion is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterise an ecoregion tends to be distinct from that of other ecoregions. In theory, biodiversity or conservation ecoregions are relatively large areas of land or water where the probability of encountering different species and communities at any given point remains relatively constant, within an acceptable range of variation . Ecoregions are also known as "ecozones", although that term may also refer to biogeographic realms.
The Western Ghats, also known as the Sahyadri, is a mountain range that stretches 1,600 km (990 mi) along the western coast of the Indian peninsula. Covering an area of 160,000 km2 (62,000 sq mi), it traverses the states of Gujarat, Maharashtra, Goa, Karnataka, Kerala, and Tamil Nadu. The range forms an almost continuous chain of mountains along the western edge of the Deccan Plateau, from the Tapti River to Swamithoppe in Kanyakumari district at the southern tip of the Indian peninsula. The Western Ghats meet with the Eastern Ghats at Nilgiris before continuing south.
Conservation biology is the study of the conservation of nature and of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and the erosion of biotic interactions. It is an interdisciplinary subject drawing on natural and social sciences, and the practice of natural resource management.
The Atlantic Forest is a South American forest that extends along the Atlantic coast of Brazil from Rio Grande do Norte state in the northeast to Rio Grande do Sul state in the south and inland as far as Paraguay and the Misiones Province of Argentina, where the region is known as Selva Misionera.
Wallacea is a biogeographical designation for a group of mainly Indonesian islands separated by deep-water straits from the Asian and Australian continental shelves. Wallacea includes Sulawesi, the largest island in the group, as well as Lombok, Sumbawa, Flores, Sumba, Timor, Halmahera, Buru, Seram, and many smaller islands. The islands of Wallacea lie between the Sunda Shelf to the west, and the Sahul Shelf including Australia and New Guinea to the south and east. The total land area of Wallacea is 347,000 km2 (134,000 sq mi).
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be endemic to that particular part of the world. An endemic species can also be referred to as an endemism or, in scientific literature, as an endemite. Similarly many species found in the Western ghats of India are examples of endemism.
Habitat destruction occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved to elsewhere or are dead, leading to a decrease in biodiversity and species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide.
Southwest Australia is a biogeographic region in Western Australia. It includes the Mediterranean-climate area of southwestern Australia, which is home to a diverse and distinctive flora and fauna.
The Cerrado is a vast ecoregion of tropical savanna in eastern Brazil, being present in the states of Goiás, Mato Grosso do Sul, Mato Grosso, Tocantins, Maranhão, Piauí, Bahia, Minas Gerais, São Paulo, Paraná and the Federal District. The core areas of the Cerrado biome are the Brazilian highlands – the Planalto. The main habitat types of the Cerrado consist of forest savanna, wooded savanna, park savanna and gramineous-woody savanna. The Cerrado also includes savanna wetlands and gallery forests.
The Meghalaya subtropical forests is an ecoregion of Northeast India. The ecoregion covers an area of 41,700 square kilometers (16,100 sq mi), and despite its name, comprise not only the state of Meghalaya, but also parts of southern Assam, and a tiny bit of Nagaland around Dimapur and adjacent Bangladesh. It also contains many other habitats than subtropical forests, but the montane subtropical forests found in Meghalaya is an important biome, and was once much more widespread in the region, and for these reasons chosen as the most suitable name. The scientific designation is IM0126.
The Lower Guinean forests also known as the Lower Guinean-Congolian forests, are a region of coastal tropical moist broadleaf forest in West Africa, extending along the eastern coast of the Gulf of Guinea from eastern Benin through Nigeria and Cameroon.
The Guinean forest-savanna, also known as the Guinean forest-savanna transition, is a distinctive ecological region located in West Africa. It stretches across several countries including Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo, Benin, Nigeria, and Cameroon. This region is characterized by a unique blend of forested areas and savannas, creating a diverse and dynamic landscape.
The Tropical Andes is northern of the three climate-delineated parts of the Andes, the others being the Dry Andes and the Wet Andes. The Tropical Andes' area spans 1,542,644 km2 (595,618 sq mi).
The campo rupestre is a discontinuous montane subtropical ecoregion occurring across three different biomes in Brazil: Cerrado, Atlantic Forest and Caatinga. Originally, campo rupestre was used to characterize the montane vegetation of the Espinhaço Range, but recently this term has been broadly applied by the scientific community to define high altitudinal fire-prone areas dominated by grasslands and rocky outcrops.
Cristina Goettsch Mittermeier is a Mexican photographer, conservationist, biologist, and author.
Lee Hannah is a conservation ecologist and a Senior Researcher in Climate Change Biology at Conservation International. Hannah is one of many authors who published an article predicting that between 15% and 37% of species are at risk of extinction due to climate change caused by human greenhouse gas emissions.
The Timor and Wetar deciduous forests is a tropical dry forest ecoregion in Indonesia and East Timor. The ecoregion includes the islands of Timor, Wetar, Rote, Savu, and adjacent smaller islands.
Biogeographic classification of India is the division of India according to biogeographic characteristics. Biogeography is the study of the distribution of species (biology), organisms, and ecosystems in geographic space and through geological time. India has a rich heritage of natural diversity. India ranks fourth in Asia and tenth in the world amongst the top 17 mega-diverse countries in the world. India harbours nearly 11% of the world's floral diversity comprising over 17500 documented flowering plants, 6200 endemic species, 7500 medicinal plants and 246 globally threatened species in only 2.4% of world's land area. India is also home to four biodiversity hotspots—Andaman & Nicobar Islands, Eastern Himalaya, Indo-Burma region, and the Western Ghats. Hence the importance of biogeographical study of India's natural heritage.
Keo Seima Wildlife Sanctuary is a 2,926.9 km2 (1,130.1 sq mi) protected area of mixed seasonal tropical forest in eastern Cambodia, located in Mondulkiri and Kratié provinces. The area was first established as Seima Biodiversity Conservation Area in 2002, later becoming Seima Protection Forest in 2009, finally becoming Keo Seima Wildlife Sanctuary in 2016. The site is of national, regional, and global importance for a range of biodiversity, with more than 950 species recorded within the protected area. It is also the ancestral and contemporary home of a large number of the Bunong ethnic group.
The Biodiversity of South Africa is the variety of living organisms within the boundaries of South Africa and its exclusive economic zone. South Africa is a region of high biodiversity in the terrestrial and marine realms. The country is ranked sixth out of the world's seventeen megadiverse countries, and is rated among the top 10 for plant species diversity and third for marine endemism.