The environment of Sri Lanka exhibits a remarkable biodiversity. [1]
Sri Lanka is considered to be the richest country in Asia in terms of species concentration [2] and is one of the world's biodiversity hotspots. [3]
Sri Lanka was once part of the southern supercontinent Gondwana, which also included South America, Africa, India and Antarctica. Gondwana began to break up 140 million years ago. The tectonic plate on which Sri Lanka was located, the Indian plate, collided with the Eurasian plate creating the Himalayas.
Sri Lanka was originally part of the Deccan land mass, contiguous with Madagascar. The Loris, found only in Sri Lanka and South India, is related to the Lemurs of Madagascar. The connection to India led to a commonality of species, e.g. freshwater fish, the now extinct Sri Lankan Gaur (Bibos sinhaleyus) and the Sri Lankan Lion (Panthera leo sinhaleyus). [5]
The island was connected, off and on at least 17 times in the past 700,000 years, to India.
Sri Lanka's biological richness has exceptional levels of endemism. [7] 43% [8] of indigenous vertebrates animals of Sri Lanka are endemic (excluding marine forms).
Today, 25% of the 3,000 angiosperms of Sri Lanka are endemic [9] (angiosperms are approximately 80% of all living green plants [10] ).
According to the U.N. FAO, 28.8% of Sri Lanka was forested in 2010 (about 1,86 million hectares). In 1995, it was 1.94 million hectares or 32.2% [11] of the land area that was classified as dense forests while the balance 0.47 million hectares or 7% the land area classified as open forests. [12]
9.0% (167,000 hectares [13] ) of Sri Lanka's forests are classified as primary forest (the most biodiverse and carbon-dense form of forest).
Sri Lanka's forests contain 61 million metric tons of carbon in living forest biomass (in 2010 [14] ).
The southwest portion of the island, where the influence of the moisture-bearing southwest monsoon is strongest, is home to the Sri Lanka lowland rain forests. At higher elevations they make the transition to the Sri Lanka montane rain forests. Both these tropical moist forest ecoregions bear strong affinities to those of India's Western Ghats.
The northern and eastern portions of the island are considerably drier, lying in the rain shadow of the central highlands. The Sri Lanka dry-zone dry evergreen forests are a tropical dry broadleaf forest ecoregion, which, like the neighbouring East Deccan dry evergreen forests of India's Coromandel Coast, is characterised by evergreen trees, rather than the dry-season deciduous trees that predominate in most other tropical dry broadleaf forests.
These forests have been largely cleared for agriculture, timber or grazing, and many of the dry evergreen forests have been degraded to thorn scrub, savanna, or thickets. Several preserves have been established to protect some of Sri Lanka's remaining natural areas. The island has three biosphere reserves, Hurulu (established 1977), Sinharaja (established 1978), and Kanneliya-Dediyagala-Nakiyadeniya (KDN) (established 2004).
The coastal estuaries are home to mangrove habitats, e.g. the Maduganga river.
Offshore are found habitats associated with coral reefs, e.g. the Bar Reef. Also of note are the pearl banks of Mannar, which are also home to Chank, sea cucumbers and sea grasses.
Sri Lanka is a party to: Biodiversity, Climate Change, Desertification, Endangered Species, Environmental Modification, Hazardous Wastes, Law of the Sea, Nuclear Test Ban, Ozone Layer Protection, Ship Pollution, Wetlands.
It has signed, but not ratified: Marine Life Conservation
Environmental concerns include deforestation; soil erosion; wildlife populations threatened by poaching and urbanization; coastal degradation from mining activities and increased pollution; freshwater resources being polluted by industrial wastes and sewage runoff; waste disposal; air pollution in Colombo
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, with half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute.
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds in situ. It does not include land that is predominantly under agricultural or urban use." Using this definition, Global Forest Resources Assessment 2020 found that forests covered 4.06 billion hectares, or approximately 31 percent of the world's land area in 2020.
Rainforests are forests characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforests can be generally classified as tropical rainforests or temperate rainforests, but other types have been described.
The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive several hundred centimeters of rain per year, they have long dry seasons that last several months and vary with geographic location. These seasonal droughts have great impact on all living things in the forest.
Sinharaja Forest Reserve is a forest reserve and a biodiversity hotspot in Sri Lanka. It is of international significance and has been designated a Biosphere Reserve and World Heritage Site by UNESCO.
Tropical rainforests are rainforests that occur in areas of tropical rainforest climate in which there is no dry season – all months have an average precipitation of at least 60 mm – and may also be referred to as lowland equatorial evergreen rainforest. True rainforests are typically found between 10 degrees north and south of the equator ; they are a sub-set of the tropical forest biome that occurs roughly within the 28-degree latitudes. Within the World Wildlife Fund's biome classification, tropical rainforests are a type of tropical moist broadleaf forest that also includes the more extensive seasonal tropical forests.
The Sri Lanka dry-zone dry evergreen forests are a tropical dry broadleaf forest ecoregion of the island of Sri Lanka.
The environment of Indonesia consists of 17,508 islands scattered over both sides of the equator. Indonesia's size, tropical climate, and archipelagic geography, support the world's second highest level of biodiversity after Brazil.
Environmental issues in Brazil include deforestation, illegal wildlife trade, illegal poaching, air, land degradation, and water pollution caused by mining activities, wetland degradation, pesticide use and severe oil spills, among others. As the home to approximately 13% of all known species, Brazil has one of the most diverse collections of flora and fauna on the planet. Impacts from agriculture and industrialization in the country threaten this biodiversity.
Forest, agriculture, and the collection of wood for fuel are cited as the leading causes of deforestation in the West African country of Nigeria. They are also the causes of deforestation in other parts of Nigeria like South East.
Deforestation is one of the most serious environmental issues in Sri Lanka. Sri Lanka's current forest cover as of 2017 was 29.7%. In the 1920s, the island had a 49 percent forest cover but by 2005 this had fallen by approximately 26 percent. Between 1990 and 2000, Sri Lanka lost an average of 26,800 ha of forests per year. This amounts to an average annual deforestation rate of 1.14%. Between 2000 and 2005 the rate accelerated to 1.43% per annum. However, with a long history of policy and laws towards environmental protection, deforestation rates of primary cover have decreased 35% since the end of the 1990s thanks to a strong history of conservation measures. The problem of deforestation in Sri Lanka is not as significant in the southern mountainous regions as it is in northern and lowland southern Sri Lanka, largely due to the nature of environmental protection.
Malaysia faces several environmental issues. Malaysia's environment possesses megadiverse biological diversity, with globally significant endemism and biodiversity, but is threatened by several issues. Deforestation is a major issue in the country that has led to many species becoming threatened with extinction. As a major economic sector, palm oil production has had a substantial environmental impact. Air pollution is also a major issue, with the country one of the most affected countries by seasonal Southeast Asian haze. The country is also affected by climate change.
Rates and causes of deforestation vary from region to region around the world. In 2009, two-thirds of the world's forests were located in just 10 countries: Russia, Brazil, Canada, the United States, China, Australia, The Democratic Republic of the Congo, Indonesia, India, and Peru.
The environment of Malaysia is the biotas and geologies that constitute the natural environment of Malaysia. Malaysia's ecology is megadiverse, with a biodiverse range of flora and fauna found in various ecoregions throughout the country. Tropical rainforests encompass between 59% and 70% of Malaysia's total land area, of which 11.6% is pristine. Malaysia has the world's fifth largest mangrove area, which totals over a half a million hectares.
Deforestation in Indonesia involves the long-term loss of forests and foliage across much of the country; it has had massive environmental and social impacts. Indonesia is home to some of the most biologically diverse forests in the world and ranks third in number of species behind Brazil and the Democratic Republic of Congo.
Forest degradation is a process in which the biological wealth of a forest area is permanently diminished by some factor or by a combination of factors. "This does not involve a reduction of the forest area, but rather a quality decrease in its condition. "The forest is still there, but with fewer trees, or less species of trees, plants or animals, or some of them affected by plagues. This degradation makes the forest less valuable and may lead to deforestation. Forest degradation is a type of the more general issue of land degradation. Deforestation and forest degradation continue to take place at alarming rates, which contributes significantly to the ongoing loss of biodiversity.
Deforestation in Borneo has taken place on an industrial scale since the 1960s. Borneo, the third largest island in the world, divided between Indonesia, Malaysia and Brunei, was once covered by dense tropical and subtropical rainforests.
Environmental issues in Sri Lanka include large-scale logging of forests and degradation of mangroves, coral reefs and soil. Air pollution and water pollution are challenges for Sri Lanka since both cause negative health impacts. Overfishing and insufficient waste management, especially in rural areas, leads to environmental pollution. Sri Lanka is also vulnerable to climate change impacts such as extreme weather events and sea level rise.
Situated in the South Caucasus Region bordered by the Black Sea to the West, the Russian Federation to the North, Azerbaijan to the East, Turkey to the Southwest, and Armenia to the South, Georgia is a small country supplied with profitable natural resources, heavenly scenes, copious water assets, rich living spaces, and ecosystems that are of local and worldwide significance.
Sri Lanka exhibits a remarkable biological diversity and is considered to be the richest country in Asia in terms of species concentration.
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