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 Queensland tropical rain forests ecoregion covers a portion of the coast of Queensland in northeastern Australia and belongs to the Australasian realm. The forest contains the world's best living record of the major stages in the evolutionary history of the world's land plants, including most of the world's relict species of plants from the ancient supercontinent of Gondwana. The history of the evolution of marsupials and songbirds is also well represented.
The Aravalli West Thorn Scrub Forests, formerly known as Northwestern thorn scrub forests, is a xeric shrubland ecoregion of Pakistan and Northern India, stretching along the border lowlands and hills between the two countries. Once covered in deciduous forest, this ecoregion has been degraded through agriculture and the extraction of timber so that it currently has a scanty covering of thorny scrub dominated by such trees as Acacia senegal, Acacia leucophloea and Prosopis cineraria. Where the soils are particularly saline, there are patches of semi-desert. A number of mammals are found in this habitat, including about four hundred species of bird. Some small areas are protected but the collection of firewood and the conversion of the land to subsistence farming continues.
The Western Guinean lowland forests ecoregion is a tropical moist broadleaf forest ecoregion of West Africa. It is centered on Liberia, with portions in surrounding countries. It is the westernmost tropical rainforest in Africa, and has high levels of species endemism, with over 200 species of endemic plants.
The Western Congolian swamp forests are an ecoregion of the Republic of the Congo, Democratic Republic of the Congo and adjoining Central African Republic. Together with the adjacent Eastern Congolian swamp forests, it forms one of the largest continuous areas of freshwater swamp forest in the world. It is a flooded forest with a high canopy, dense undergrowth and has a muddy floor. It has not been disturbed very much by outside influences and so remains largely pristine as getting through this forest is called "almost impossible".
The Northeastern Brazil restingas are an ecoregion of northeastern Brazil. Restingas are coastal forests which form along coastal sand dunes in Brazil. The soils are typically sandy, acidic, and nutrient-poor, and are characterized by medium-sized trees and shrubs adapted to local conditions. Restingas have aspects of mangroves, caatingas, wetlands, and moist forests, often forming along wind-driven sand dunes. The Northeast Brazil restingas are the most northerly of the forest type in Brazil.
The South Saharan steppe and woodlands, also known as the South Sahara desert, is a deserts and xeric shrublands ecoregion of northern Africa. This band is a transitional region between the Sahara's very arid center to the north, and the wetter Sahelian Acacia savanna ecoregion to the south. In pre-modern times, the grasslands were grazed by migratory gazelles and other ungulates after the rainfalls. More recently, over-grazing by domestic livestock have degraded the territory. Despite the name of the ecoregion, there are few 'woodlands' in the area; those that exist are generally acacia and shrubs along rivers and in wadis.
The Dinaric Mountains mixed forests are a terrestrial ecoregion of the temperate broadleaf and mixed forests biome in Southeastern Europe, according to both the WWF and Digital Map of European Ecological Regions by the European Environment Agency. It also is in the Palearctic realm.
The Belizean Coast mangroves ecoregion covers the brackish and salt-water habitats along the Caribbean Sea coast of Belize, and of Amatique Bay in Guatemala; small parts in the border with Mexico are also present on this ecoregion. The mangroves are partially protected from the open sea by the Belize Barrier Reef, and this ecoregion is distinct from the reef-based Belizean Reef mangroves ecoregion offshore. There is a large population of the vulnerable West Indian manatee in the area. It covers an area of around 2850 km2.
The Northwestern Congolian lowland forests is a tropical moist broadleaf forest ecoregion that spans Cameroon, Gabon, the Republic of Congo, the Central African Republic and a minuscule part of the Democratic Republic of the Congo. It forms part of the larger Congolian rainforests region in Central Africa. The region is noteworthy for very high levels of species richness and endemism. It is home to a core population of the critically endangered Western lowland gorilla. There are also large populations of forest elephants.
The East European forest steppe ecoregion is a patchwork of broadleaf forest stands and grasslands (steppe) that stretches 2,100 km across eastern Europe from the Ural Mountains in Ural, through Povolzhye, Central Russia to the middle of Ukraine. There are isolated areas of similar character off the western end in eastern Romania, Moldova, and Bulgaria.
The Kazakh forest steppe ecoregion is a long thin strip of transition zone between the forested taiga of Siberian Russia, and the Kazakh steppe to the south. The ecoregion stretches over 2,000 km from the southern Ural mountains in the west to the foothills of Altai mountains in the east, yet averages only 200 km from south to north across its length. Because the region is farther inland than European forest steppe, and some 300 to 500 km farther north, the climate is more continental and with less precipitation the tree cover more sparse. The ecoregion is in the Temperate grasslands, savannas, and shrublands biome, and the Palearctic realm, with a Humid Continental climate. It covers 420,614 km2 (162,400 sq mi).
The Caspian lowland desert ecoregion covers the north and southeast coasts of the Caspian Sea, including the deltas of the Volga River and Ural River in the northern region. While the region gets relatively low amounts of precipitation, wildlife is supported by the river estuaries and the sea itself. The wetlands are an internationally important area for bird nesting and migratory resting. The ecoregion is in the Palearctic realm, and the deserts and xeric shrublands biome. It has an area of 267,300 square kilometres (103,200 sq mi).
The Manchurian mixed forests ecoregion covers the forested hills surrounding the river plains of northern China, Russia, North Korea, and South Korea. The ecoregion supports a number of rare species due to the relative isolation, the diversity of habitat, with mixed forests of deciduous Mongolian oak and conifers of Korean pine. Because mountains rise above the region on three sides, with plains and wetlands below, the area supports high biodiversity as a transition zone.
The South Taiwan monsoon rain forests ecoregion covers the southern tip of Taiwan, 200 km east of the mainland. The area is one of high biodiversity, due to its location between temperate and subtropical zones, its monsoon exposure, and its high altitude variation.
The Afghan Mountains semi-desert ecoregion covers three disconnected interior valleys in the north of the mountains of Afghanistan. These valleys are arid, and covered mostly in thorny shrubs. Overgrazing by livestock has put pressure on the grasses and the wild animals dependent on them.
The Central American Atlantic moist forests ecoregion covers the lowland coastal forests of Honduras, southeast Guatemala, and the eastern forests of Nicaragua. Half of the ecoregion is closed-canopy tropical broadleaf evergreen forest, with tree heights reaching 50 meters. This ecoregion has the largest single fragment of natural forest in Central America, with a size of 14,629 square kilometres (5,648 sq mi). The total area is 89,979 square kilometres (34,741 sq mi).
The Miskito pine forests ecoregion covers lowland pine forests and savanna along much of the Mosquito Coast in northeastern Nicaragua and southeastern Honduras. Pines are adapted to grow in the poor soil, relative to the surrounding moist forest, and repeated burning have left one species – the Caribbean pine – dominant. Although the ecoregion receives high levels of rain, the hard soils, repeated burning, and exposure to hurricanes have left expanses of 'pine savanna' and seasonal wetlands. The area is thinly settled by humans and there is little crop agriculture.
The Baluchistan xeric woodlands ecoregion covers the middle elevations of a series of mountain ranges of western Pakistan and northeastern Afghanistan, reaching 1,200 kilometres (750 mi) from the Arabian Sea in the south to the Hindu Kush Mountains and the Himalayas in the north. The characteristic vegetation is xeric (dry) woodlands of shrubs and herbaceous cover. The region has rich biodiversity but relatively few endemic species.
The Belizean reef mangroves ecoregion covers the mangrove habitats along the islands and cayes of the Belize Barrier Reef. This ecoregion is distinct from the mainland Belizean Coast mangroves ecoregion, and may be considered a sub-unit of the overall Mesoamerican Gulf-Caribbean mangroves ecoregion.
