The Caucasus, Madagascar and Caribbean Islands: Biodiversity Hotspots

Biodiversity Hotspots The Caucasus: The Caucasus hotspot, historically interpreted as the area of land between the Black and Caspian seas, covers a total area of 580,000 km. Located at a biological crossroads, species from Central and Northern Europe, Central Asia, the Middle East and North Africa mingles here with endemics found nowhere else. One of the most biologically rich regions on Earth, the Caucasus is among the planet’s 25 most diverse and endangered hotspots. The Caucasus is one of WWF’s Global 200 ‘ecoregions’ identified as globally outstanding for biodiversity.
The Caucasus has also been named a large herbivore hotspot by WWF’s Large Herbivore Initiative. Eleven species of large herbivores, as well as five large carnivores, are found over a relatively small area to be endemic. The 2002 IUCN Red List identifies 50 species of globally threatened animals and one plant in the Caucasus. Among the IUCN species, 18 have restricted ranges or are endemics. The Caucasus Mountains harbor a wealth of highly sought after medical and decorative plants, as well as a vast endemism of plant communities. [pic]
Spanning the borders of six countries, the Caucasus hotspot is a globally significant center of cultural diversity, where a multitude of ethnic groups, languages and religions intermingle over a relatively small area. Close cooperation across borders will be required for conservation of unique and threatened ecosystems, while helping to foster peace and understanding in an ethnically diverse region with a history of contrasting political and religious views. The Caucasus is a hotspot of plant and animal species diversity and endemism important for the conservation of biodiversity on a global scale.

High levels of landscape diversity in the Caucasus are largely the result of altitude variability in the region. The unique geology and terrain, consisting of three major mountain chains separated by valleys and plains, permit a variety of different microclimate, soil and vegetative conditions. Climatic conditions are very diverse, with precipitation ranging from more than 4,000 mm per year in the southwestern Caucasus to less than 200 mm a year in deserts in the eastern Caucasus. These wide ranges of climatic conditions are a key factor that makes this area such a biologically important area.
The Caribbean islands: [pic] The Caribbean Islands Biodiversity Hotspot is exceptionally important for global biodiversity conservation, due to high levels of species endemism and threat. The Caribbean is home to approximately 11,000 plants species, of which 72% are endemic to the region. The vertebrates are also characterized by extremely high levels of endemism: 100% of 189 amphibian species, 95% of 520 reptile species, 74% of 69 mammal species and 26% of 564 species birds are unique to the Caribbean Islands.
In terms of endemism at the genus (biological classification of living organisms) ranking level, it ranks third among the world’s 34 Biodiversity Hotspots with 205 plants and 65 vertebrate genera endemic to the islands. Species restricted to the Caribbean Islands Biodiversity Hotspot represent 2. 6% of the world’s 300,000 plants species and 3. 5% of the world’s 27,298 vertebrate species). The high level of biological diversity in the Caribbean is due to several factors. During the early Cretaceous (120 to 140 million years b. ), a chain of volcanic islands (called Proto-Antilles) began to emerge along the eastern edge of the Caribbean Plate in the Pacific Ocean. The plate drifted eastward serving as a stepping-stone route exchange of terrestrial organisms between two previously separated regions. By the Eocene era (58 million years a. c), the core of the Greater Antilles achieved their present positions. The Lesser Antilles are the active remnants of an ancient volcanic chain, and are younger than the Greater Antilles.
Several islands have particularly rugged and mountainous landscapes separated by large stretches of sea, which resulted in the isolation of populations. The Caribbean has suffered from high levels of habitat loss since the arrival of Europeans in the 1490s. This destruction has reduced the hotspot’s original estimated 229,549km2 of natural vegetation to just 22,955km2(or just 10%). The loss of native habitat combined with other threat factors, such as introduced (alien invasive) species, has resulted in severe and widespread degradation of the Caribbean’s unique biodiversity.
Currently, 755 plants and vertebrate species are at risk of extinction, making the region one of the biodiversity hotspots holding the most globally threatened species. Madagascar: [pic] Madagascar is an island off the coast of Africa which is known to have some of the world’s most interesting animals. It has a land area of 600,461 km?. About 80 percent of the species found in Madagascar live nowhere else on the planet. Madagascar is the forth largest island in the world and broke away from the mainland about 160 million years ago. Therefore, the hotspot is a living example of species evolution in isolation.
Despite close proximity to Africa, the islands do not share any of the typical animal groups of nearby Africa, making Madagascar home to a vast variety of endemic species. The island contains 5% of animal and plant species on Earth, with 80% endemic to the island. Madagascar is thought to have 11,600 endemic species of plant, 57 threatened endemic birds and 51 threatened endemic mammals. 18,482km of the island is protected land. Western areas of the island consist of dry savannah with deserts found in central regions. The eastern side of Madagascar facing the Indian Ocean is tropical rainforest with a high level of rainfall.
The island is also host to several high mountain ecosystems. These biomes each support contrasting species, portraying the contrasting ecoregions in Madagascar. Madagascar and the surrounding islands have a total of eight plant families, four bird families, and five primate families that live nowhere else on Earth. Madagascar has more than 50 lemur species which are commonly associated with the island and are the focal point for conservation. The carnivorous fossa is another example of an endemic species as well as six Baobab species (huge trees with wide stumps).
There are so many species endemic to Madagascar that some ecologists have called it “the eighth continent”. Many of these species, such as the fossa, are now considered to be an endangered species, with only about 2,500 mature fossa individuals in existence. Tenrecs, a family of small omnivorous mammals, primarily find their home on Madagascar, with 30 species found only there, and just 3 on the African mainland. There are numerous other species endemic to Madagascar, including 14 unique rodents, 15 species of bat, various chameleons and geckos, over a hundred birds, and hundreds of beetles and other insects.
Conservation efforts must proceed aggressively to preserve this unique Madagascar fauna. Specific locations in Madagascar which are renowned for high biodiversity are situated on the eastern coast which is mainly tropical rainforest. These areas have year-round warmth and receive a lot of rainfall. Interestingly, the soils in the rainforest are poor because most of the biomes nutrients are locked up in the vegetation. In terms of flagship species in Madagascar, Baobabs are considered to be flagship trees for landscape conservation in western Madagascar, unique and individual features to the island landscape.
Madagascar has seven of the world’s eight Baobab tree species, six of them endemic to the island. Another endemic flagship plant to the island is the traveler’s tree or palm, pollinated by the island’s flagship vertebrate species, the lemurs. The tomato frog is a flagship amphibian of Madagascar, found only in a small corner of northeastern Madagascar. Threats to biodiversity Of the 10,000 plants native to Madagascar, 90% are found nowhere else in the world. Madagascar’s varied fauna and flora are endangered by human activity, as a third of its native vegetation has disappeared since the 1970s, and only 18% remains intact.
However, there are several national parks which have been established to help protect many of the endemic species. Extensive deforestation has taken place in parts of the country, reducing certain forest habitat and applying pressure to some endangered species. Madagascar has a population growth rate of approximately 3%, therefore, with a growing population, more of the islands endemic species become at risk due to the increase in human activity and development.