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.

  • Borneo montane rainforests Featured Article Borneo montane rainforests Borneo montane rainforests

    WWF Terrestrial Ecoregions Collection The Borneo montane rainforests can be likened to montane islands in a sea of lowland dipterocarp... More »

  • Ecoregions of Malaysia Featured Article Ecoregions of Malaysia Ecoregions of Malaysia

    The ecogegions of Malaysia include a number of distinct types of rainforests, all of which are sustained by the plentiful rainfall of this equatorial region of Southeast Asia. In... More »

  • Great Victoria Desert Featured Article Great Victoria Desert Great Victoria Desert

    WWF Terrestrial Ecoregions Collection A vast, sparsely populated region covered by dunefields and gibber plains, the Great Victoria Desert... More »

  • Declining grassland biodiversity Featured Article Declining grassland biodiversity Declining grassland biodiversity

    Declining grassland biodiversity is a major ecological issue, although it has received only a small fraction of the attention given to forests or wetlands, by... More »

  • Ecoregions of Chile Featured Article Ecoregions of Chile Ecoregions of Chile

    Chile has eight ecoregions that occur entirely or partly within its borders on the mainland and three ecorgions offshore: Sechura desert Atacama... More »

  • Magellanic subpolar forests Featured Article Magellanic subpolar forests Magellanic subpolar forests

    WWF Terrestrial Ecoregions Collection The Magellanic subpolar forests is an ecoregion dominated by trees of the genus Nothofagus; this... More »

  • Namibian savanna woodlands Featured Article Namibian savanna woodlands Namibian savanna woodlands

    WWF Terrestrial Ecoregions Collection The Namibian Savanna Woodlands ecoregion covers the Great Escarpment that delimits the interior of... More »

  • Belizean pine forests Featured Article Belizean pine forests Belizean pine forests

    WWF Terrestrial Ecoregions Collection The Belizean pine forests on Central America's northwestern Caribbean Sea coast represent various... More »

Recently Updated
Sierra Nevada forests Last Updated on 2015-01-24 12:04:06 WWF Terrestrial Ecoregions Collection The Sierra Nevada forests are the forested areas of the Sierra Nevada Mountains, which run northwest to southwest and are approximately 650 kilometers long and 80 km wide. The range achieves its greatest height towards the south, with a number of peaks reaching heights of over 4000 meters. Several large river valleys dissect the western slope with dramatic canyons. The eastern escarpment is much steeper than the western slope, in general.   The range supports a diverse set of natural communities with many endemic species and extraordinary habitats. A significant fraction of the land area in the Sierra Nevada Mountains is unforested, since elevations above the treeline do not support even conifer growth. This ecoregion is part of the Nearctic Realm. The Sierra Nevada forests ecoregion harbors one... More »
Snake-Columbia shrub steppe Last Updated on 2015-01-14 18:54:29 WWF Terrestrial Ecoregions Collection   The Snake-Columbia shrub steppe is a vast, mostly arid ecoregion. Its easternmost limit is the Continental Divide in eastern Idaho. From there, the ecoregion follows the arc of the Snake River Plain as far as Hell's Canyon. The ecoregion thence extends throughout southeastern Oregon, spreading along the Deschutes River catchmentCatchment is the entire area of a hydrological drainage basin. to the Columbia River. It also includes, following hydrographic lines, parts of northern Nevada and the extreme northeast of California. To the north, the ecoregion dominates the western portion of the Columbia Basin in Washington. The Snake-Columbia shrub steppe is within the Nearctic Realm. The ecoregion is largely in the rain shadow of the Cascade Mountains and thus receives little precipitation. Latitude... More »
Daugava River Last Updated on 2015-01-12 07:37:16 The Daugava River drains portions of the countries of Latvia, Belarus and Russia, prior to discharging to the Gulf of Riga. Also known as the West Dvina River, this watercourse is the fourth largest river discharging to the Baltic Sea catchment. This 1005 kilometer long river has suffered environmental damage from agricultural runoff and from hydroelectric dam construction, with major impacts dealt in the Soviet era of collective farming. In ancient history the Daugava estuary was a locus of prehistoric settlement, and later marked one of the eastern limits of the voyages of the Vikings. The lower Daugava valley (nearest the Gulf of Riga) was formed in relatively recent times, as glacial meltwater formed incision on the relatively level terrain near the Baltic Sea coast; these events occurred in the early Holocene, approximately 11,000 years before present. The relatively soft upper... More »
Etosha Pan halophytics Last Updated on 2014-12-26 13:11:38 WWF Terrestrial Ecoregions Collection The Etosha Pan Halophytics ecoregion is the relict landform of a prehistoric expansive, inland Pliocene lake. Today, the Etosha Pan is mostly an arid, saline desert. Typically, the intensively cracked, whitish clay is split into hexagonal salt-encrusted fragments, and wildlife is sustained only by scattered freshwater springs, which manifest as watering holes. These springs attract a diverse array of large mammals, especially during the dry season, making Etosha Pan a popular tourist destination. In unusually wet years, when the Ekuma, Oshigambo and Omuramba Ovambo Rivers receive sufficient rainfall, the pan is temporarily transformed into a shallow lake. When surface water is present, it can be classified as a hypersaline lake, due to the elevated salinity. The Etosha Pan halophytics is considered within the... More »
Angolan mopane woodlands Last Updated on 2014-12-25 13:37:21 WWF Terrestrial Ecoregions Collection The Angolan Mopane Woodlands are located in northern Namibia and  southern Angola, completely surrounding the Etosha Pan, which is considered a separate ecoregion. Mopane trees (Colophospermum mopane) dominate the vegetation, and are an essential resource for both the people and wildlife of the region. African Bush Elephants (Loxodonta africana) utilize almost every part of the mopane tree, and the region supports other large herbivores, including the critically   endangered   Black Rhinoceros (Diceros bicornis). Species richness in this ecoregion is high, especially in comparison with the arid deserts to the west. Conservation potential is high in Namibia, due to the vastness of the desolate Namib Desert and the presence of Etosha National Park, and increasing awareness of conservation... More »