As threats to biodiversity continue to mount, areas of the world that exemplify tremendous biodiversity but face massive negative impacts from various forces find themselves on a poignant list – the biodiversity hotspots.

How do we decide which areas are priorities for conservation? In 1988, British ecologist Norman Myers developed the concept of biodiversity hotspots to address the dilemma of identifying areas most important for preserving Species. Many areas of global significance face tremendous pressure from logging, agriculture, hunting, and climate change, among others. The hotspots strategy emphasizes risks of species extinction, since species loss is irreversible. The strategy also emphasizes species endemism. Since these species can only be found in specific areas, the loss of such areas would be considered “irreplaceable”.

Myers developed the hotspots concept with Conservation International (CI), which adopted the strategy in 1989. CI designated hotspots as regions that must support at least 1,500 plant species found nowhere else in the world, and they must have lost at least 70 percent of its original habitat. The organization employs a dual conservation strategy that always prioritizes endemic-rich areas and high risk areas, while preemptively protecting equally unique places that are not yet under extreme threat.

CI has identified of 34 biodiversity hotspots all over the world. These regions hold especially high numbers of endemic species, yet their combined area of remaining habitat covers only 2.3 percent of the Earth's land surface. Each hotspot faces extreme threats and has already lost at least 70 percent of its original natural vegetation. Over 50 percent of the world’s plant species and 42 percent of all terrestrial vertebrate species are endemic to these areas. Four of these hotspots are in Southeast Asia: Indo-Burma, the Philippines, Sundaland and Wallacea.

ASEAN hotspots are getting hotter

Scientists have long lauded the wealth of biodiversity found in Southeast Asia, also known as the Association of Southeast Asian Nations (ASEAN) region. Occupying a mere three percent of the world’s surface, the region is home to 20 percent of all known plant, animal and marine species. The ASEAN region includes three mega-diverse countries - Indonesia, Malaysia and the Philippines; several bio-geographical units - Malesia, Wallacea, Sundaland, Indo-Burma, and the Central Indo-Pacific; and numerous centers of concentration of restricted-range bird, plant and insect species. It also has one-third or 284,000 square kilometers of all coral reefs. Many of the region’s species are also biologically diverse from the rest of the world due to the unique geological history of Southeast Asia.

However, various drivers of biodiversity loss continue to undermine the ASEAN region’s natural environment. Out of 64,800 species found in the region, 1,312 are endangered due to deforestation; wildlife hunting for food, pets, and medicine; climate change; pollution; population growth; and other causes. Destruction of habitats will result in long-term impacts on ecosystem services, as well as lead to the extinction of valuable species. Biodiversity hotspots in Southeast Asia include the following:

Indo-Burma

The Indo-Burma hotspot encompasses 2,373,000 km² of tropical Asia. It contains the Lower Mekong catchment, and begins in eastern Bangladesh and then extends across north-eastern India, to encompass nearly all of Myanmar, part of southern and western Yunnan Province in China, all of the Lao People’s Democratic Republic, Cambodia and Vietnam, the vast majority of Thailand, and a small part of Peninsular Malaysia. The hotspot also covers the coastal lowlands of southern China, and several offshore islands.

Some of the features of biodiversity richness in Indo-Burma include:

• Around 13,500 vascular plant species, of which about 7,000 (52 percent) are endemic.
• Over 1,260 bird species, more than 60 of which are endemic.
• 430 mammal species, of which more than 70 species and seven genera are endemic.
• 520 reptile species, of which 12 genera and over 200 species are endemic.
• Highest diversity of freshwater turtles in the world with 53 species, representing one-fifth of the world's species.
• More than 280 amphibian species, over 150 of which are endemic.
• More than 1,260 documented freshwater fish species, or about 10 percent of the world’s freshwater fishes. More than 560 of these species are endemic.

Philippines

The Philippines holds the distinction as the only country in ASEAN identified as a biodiversity hotspot. Geological movements, tropical weather and once extensive forest cover of the country have conspired to develop high species diversity in some groups of organisms and a very high level of endemism. There are five major and at least five minor centers of endemism, from Luzon (with at least 31 endemic mammal species) to tiny Camiguin Island (at least two endemic mammal species). The Philippines has among the highest rates of discovery in the world with 16 new species of mammals discovered in the last 10 years.

Some features of the Philippines’ rich biodiversity include:

• 9,250 vascular plant species, at least one-third of which are endemic.
• More than 150 species of palms, around two-thirds of these are endemic.
• 1,000 species of orchids, with 70 percent endemic.
• Over 530 bird species, about 185 of these are endemic (35 percent) and over 60 are threatened.
• At least 165 mammal species, with over 100 endemic species (61 percent), one of the highest levels of mammal endemism in any hotspot.
• 235 species of reptiles, some 160 of which are endemic (68 percent).
• Nearly 90 amphibian species, almost 85 percent of which are endemic.
• More than 280 inland fish, including nine endemic genera and more than 65 endemic species, many of which are confined to single lakes.
• 21,000 recorded insect species, 70 percent of which are endemic.

Sundaland

The Sundaland hotspot covers the western half of the Indo-Malayan archipelago, and is dominated by Borneo and Sumatra. It is bordered by three hotspots: Indo-Burma on the northwest, Wallacea on the east, and the Philippines on the northeast.

Samples of Sundaland’s unique and threatened biodiversity include:

• About 25,000 species of vascular plants, 15,000 (60 percent) of which are endemic.
• About 3,000 species of trees in Borneo, including more than 265 species of dipterocarps, 155 of which are endemic. Borneo also has more than 2,000 species of orchids.
• Approximately 770 bird species, nearly 150 are endemic. Borneo supports nearly 30 endemic species.
• More than 380 mammal species, over 170 are endemic. Borneo has the most endemic mammal species of any island in the hotspot, with over 25 species.
• Over 450 species of reptiles, roughly 250 of which are endemic, including 24 genera.
• More than 240 species of amphibians, nearly 200 of which are endemic.
• About 1,000 known species of fish, about 200 species of which have only been discovered in the last decade. Borneo has about 430 species, more than 160 of which are endemic.

Wallacea

Wallacea encompasses the central islands of Indonesia east of Java, Bali, and Borneo, and west of the province of New Guinea, and the whole of Timor Leste. The hotspot occupies a total land area of 338,494 km² including the large island of Sulawesi, the Moluccas, and the Lesser Sundas.

Some features of the rich biodiversity of Wallacea include:

• An estimated 10,000 species of vascular plants, with roughly 1,500 endemic species (15 percent) and at least 12 endemic genera. There are about 500 endemic species on Sulawesi, 120 on the Lesser Sudas and 300 on the Moluccas.
• About 650 regularly occurring bird species, of which roughly 265 (40 percent) are endemic. There are also 29 endemic genera.
• Sulawesi has the largest number of fauna, with 356 species, including 96 endemics.
• More than 220 mammal species, with around 125 endemics.
• The island of Sulawesi has at least seven species of endemic macaques and at least five species of endemic tarsiers.
• More than 220 species of reptiles, nearly 100 of which are endemic.
• Nearly 50 amphibian species; more than 30 of these are endemic.
• More than 300 freshwater fish species, about 75 of which are endemic. Sulawesi alone has nearly 70 known fish species, about three-quarters of which are endemic.

These four hotspots cut across a wide area of the ASEAN region, and stress the significance of the region’s rich biodiversity, as well as the rapid rate of biodiversity loss caused by wide-ranging threats. According to Executive Director Rodrigo U. Fuentes of the ASEAN Centre for Biodiversity (ACB), these biodiversity hotspots underline the need for a regional approach to biodiversity conservation to protect a common resource base.

“The ASEAN environment is a shared heritage, and all Member States must work together to ensure greater success in reducing biodiversity loss and thus maximizing its benefits to the people of the region,” said Fuentes.

References: Conservation International (http://www.conservation.org/) and National Geographic News (news.nationalgrographic.com)