Biomes (main)

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Biomes


Biomes are the composite of all species within a large scale ecological community. In the natural environment, these assemblies have typically co-evolved, so that they have a natural arrangement in terms of their positioning to compete for sunlight, water and nutrient resources; in some cases these associations are symbiotic, but in most cases they are simply optimal spatial arrangements to take advantage of all the resources available in a given habitat. For example, there is typically a vertical tiering, where plants of differing light requirements can occupy canopy, mid-level or forest floor niches; the same theory applies even in a grassland, where the canopy is simply the tallest of the grasses or herbs.

In the case of water competition, depth of rooting and tolerance to arid soils are chief determinants for spatial arrangement; as far as nutrient competition, plants will compete to determine the most robust competitor for a given edaphic niche. While the outcome geometry for the plant palette usually appears random, there is a complex network of ecological theory at work that determines the layout of the assembled community. The same concept applies to aquatic communities as to terrestrial systems, with some plants having immersed roots and others, either macrophytes or phytoplankton, floating or immersed at varying levels suitable for their sunlight needs.

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Desertelephantsnwnamibia.jpg Namibian savanna woodlands Last Updated on 2015-09-07 13:29:18 WWF Terrestrial Ecoregions Collection The Namibian savanna woodlands ecoregion covers the Great Escarpment that delimits the interior of southern Africa from both the Kaokoveld Desert and Namib Desert. This broken and deeply dissected escarpment is an area of high endemism for plants, invertebrates, amphibians, reptiles, mammals and birds. The northern area of the ecoregion, the Kaoko escarpment, is an endemism "hotspot" (area of extremely high species richness and endemism). The Namibian savanna woodlands comprise a land area of approximately 87,100 square miles. This northern area is poorly protected and is under threat from poaching, off-road driving, and to a lesser extent from farming, and resultant habitat fragmentation; much of this destabilisation in the Angolan portion of the ecoregion stems from the Cuban mercenaries aided... More »
KodachromeIMGP1890.jpg Colorado Plateau shrublands Last Updated on 2015-09-05 12:10:49 WWF Terrestrial Ecoregions Collection The Colorado Plateau shrublands is epitomized by the Grand Canyon, an area that has been called the "land of color and canyons." The Plateau can be thought of as an elevated, northward-tilted saucer. It is characterized by its high elevation and arid to semi-arid climate. The Colorado Plateau has developed extensive topographic relief through the erosive action of high-gradient, swift-flowing rivers that have downcut and incised the plateau. Approximately 90 percent of the plateau is drained by the Colorado River and its tributaries, notably the lower catchmentCatchment is the entire area of a hydrological drainage basin. of the Green River, the San Juan River and Animas River. This ecoregion is classified within the Deserts and Xeric Shrublands biome, and is codified as WWF Ecoregion... More »
Botswanaaerialxeric.jpg Kalahari xeric savanna Last Updated on 2015-07-10 18:01:28 WWF Terrestrial Ecoregions Collection The Kalahari xeric savanna is an ecoregion in southern Africa characterized by a harsh climate, where temperatures may vary by 44°C from night to day, and rainfall is infrequent. Rain appears only during the austral summer on the reddish-brown Kalahari sands , pelting the savanna with violent, localized storms. Although this area is semi-arid, there is an impressive diversity of migratory birds and large mammals, both herbivorous and carnivorous; in fact, 550 different vertebrates have been observed in the Kalahari xeric savanna. This ecoregion is classified within the Deserts and Xeric Shrublands biome. A considerable fraction (approximately 18 percent) of the Kalahari xeric savanna is protected. Where lands are not protected, overgrazing has often severely degraded habitat. Fences are a significant... More »
5257365421 6f354b518a o.jpg Madagascar spiny thickets Last Updated on 2015-06-25 20:16:56 WWF Terrestrial Ecoregions Collection The Madagascar spiny thickets or spiny desert of southern Madagascar, also referred to as deciduous thicket, is a globally distinctive ecoregion. This ecoregion is part of the Deserts and Xeric Shrublands biome, within the Afrotropics Realm. While the island of Madagascar is notable for exceptional levels of endemic plants and animals, the spiny thicket is particularly distinctive with 95 percent of the plant species endemic to the ecoregion. Members of the endemic Didiereaceae family present dominate the thicket, which have similar xeric adaptations to New World cacti, such as small leaves and spines, but with the Madagascar spiny thickets displaying more woody rather than succulent characteristics. There are a total of 288 recorded vertebrate taxa in the Madagascar spiny thickets, including several endemic... More »
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