Biogeography

Biogeography is the study of the distribution of biological organisms. The scale of analysis ranges from very small micro-topography regimes to continental dimensions. Fundamental concepts in this field of study are the nature of barrier formation and response of species to their patterns of travel and migration; in particular, the presence of rivers, mountain ranges, deserts and other natural boundaries are examples of large scale barriers. Besides such major landform barriers there are soil, topographic and meteorological factors that influence the distribution of each species. In the case of smaller scale regimes that are applicable for some bacteria or limited range plant species, there are often very restricted niches; for example, certain bacteria extremophiles may be limited to such localized features as small geyser pools, and some rare plants may have a single extant colony defined specialized soils such as serpentine and narrow climatic zone. Inherent in the concept of biogeography are the processes of speciation, extinction, dispersal and migration.   

  • Douglas-fir Featured Article Douglas-fir Douglas-fir

    The Douglas-fir (scientific name: Pseudotsuga) is a genus of tree that includes ar least five species found in North America and Asia: Scientific... More »

  • Ocean acidification troubles Featured Article Ocean acidification troubles Ocean acidification troubles

    The seas in which corals and other calcifying species dwell are turning acidic, their pH slowly dropping as Earth's oceans acidify in response to increased carbon dioxide... More »

  • Big Bend National Park, United States Featured Article Big Bend National Park, United States Big Bend National Park, United States

    Big Bend National Park is one of the two National Parks located in the state of Texas, in the USA. Big Bend National Park is located in the Big Bend region along the border of... 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 »

  • Daugava River Featured Article Daugava River Daugava River

    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... More »

  • Mojave Desert Featured Article Mojave Desert Mojave Desert

    WWF Terrestrial Ecoregions Collection The Mojave Desert is the smallest of the four North American deserts. While the Mojave lies between the... More »

  • Cactus Featured Article Cactus Cactus

    Cactus is a family of plants that are specially adapted to survive arid conditions, most often having leaves reduced to spines, and succulent characteristics. The scientific... More »

  • Spinner dolphin Featured Article Spinner dolphin Spinner dolphin

    The Spinner dolphin (Stenella longirostris), a marine mammal in the family of oceanic dolphins,  gets its name from the spinning behavior it shows when it leaps out of... 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 »

Recently Updated
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 »
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 »