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
Zambezian flooded grasslands Last Updated on 2015-04-08 23:59:46 WWF Terrestrial Ecoregions Collection Located within the miombo and mopane woodlands of the Central African Plateau, Zambezian flooded grasslands are an anomaly of productivity and abundance in a landscape characterized by nutrient deficient soil and associated vegetation. Unlike the surrounding woodlands that generally support animals only in rather low densities, the wetlands and floodplains of this ecoregion provide habitats to sizable faunal populations, since food and water are abundant throughout most of the year. Large populations of waterbirds gather during the rainy season, and numerous herd animals and  carnivores  frequent the landscape. However, in a climate of rapid population growth and increasing need for land and natural resources, this fragile ecoregion may face increasing threat. Several conservation measures are... More »
Kalahari acacia-baikiaea woodlands Last Updated on 2015-04-08 23:56:27 WWF Terrestrial Ecoregions Collection Semi-arid Kalahari acacia-baikiaea woodland stretches across the center of southern Africa, from northern Namibia through Botswana and just into the Tuli Block of South Africa. Surface water is scarce here, and droughts occur approximately once every seven years. As a result, the human population is relatively low, especially on the sandveld that covers most of the ecoregion. This woodland supports a rich and diverse fauna, including a variety of ungulates and a number of threatened large mammals such as White Rhinoceros (Ceratotherium simum), Black Rhinoceros (Diceros bicornis), African Painted Hunting Dog (Lycaon pictus), and African Elephant (Loxodonta africana). However, human populations are increasing and the growing cattle industry has far-reaching adverse effects on the environment and wildlife. The... More »
Madagascar mangroves Last Updated on 2015-04-08 23:48:19 WWF Terrestrial Ecoregions Collection Shielded from monsoon winds by the central mountains of Madagascar, Madagascar mangroves occupy a wide range of environmental and climatic conditions along the western coastline along the Indian Ocean. Although the ecoregion’s species richness is low, it is unusual in supporting certain endemic tree species. The mangroves also shelter highly diverse mollusk and crustacean communities, while capturing sediment that threatens coral reefs and seagrass beds. Birds, sea turtles, and dugongs all utilize mangroves, as do the Malagasy people. Rice farming, shrimp aquaculture and construction materials are all carried out within these mangroves. On Madagascar, mangroves are found primarily along the western coast. They occur in a wide range of environmental and climatic conditions, fostered by a low coastal... More »
Sierra Nevada forests Last Updated on 2015-01-29 19:20:06 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 of... 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 »