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.   

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    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 »

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    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
Madagascar dry deciduous forests Last Updated on 2015-05-28 20:11:13 WWF Terrestrial Ecoregions Collection The Madagascar dry deciduous forests of western Madagascar are some of the world’s most species rich and most distinctive tropical dry forests. They are characterized by very high local plant and animal endemism at the species, genera and family levels. A significant fraction of these dry forests have been previously cleared, and the remaining forests are fragmented and critically threatened by uncontrolled burning and cuttining for charcoal production, grazing and agriculture. Since human settlement of this region during the Holocene, an estimated 97 percent of the island’s dry deciduous western forests have been destroyed, and those remaining are extremely localized and fragmented. This ecoregion also contains spectacular limestone karst formations, known as tsingy, and their associated forests,... More »
Madagascar mangroves Last Updated on 2015-05-27 11:30:24 WWF Terrestrial Ecoregions Collection Shielded from monsoon winds by the Central Highlands of Madagascar, Madagascar mangroves occupy a wide range of environmental and climatic conditions, and chiefly occur at the western coastline along the Mozambique Channel of the Indian Ocean. Although the ecoregion’s species richness is low, it is noteworthy in supporting certain endemic tree species; for example, thre are only 163 vertebrate taxa found in the entire ecoregion. The Madagascar mangroves are within the Mangroves biome of the Afrotropic Realm. These mangroves also shelter highly diverse mollusk and crustacean communities, while capturing sediment that threatens coral reefs and seagrass beds. Dugongs, birds and sea turtles utilise mangroves, as do the native Malagasy people. Rice farming, shrimp aquaculture as well as stockpiling of... More »
Zambezian Baikiaea woodlands Last Updated on 2015-05-16 21:25:29 WWF Terrestrial Ecoregions Collection The Zambezian Baikiaea woodlands lie along a zone where deep Kalahari sands occur in a wide belt along the Angolan-Namibian border across to Zimbabwe, supporting dry deciduous forest dominated by Baikiaea plurijuga. The hot, semi-arid climate and nutrient-poor soils mean that this region is not suitable for farming, and thus it has retained some of its natural vegetation. Over 160 mammal species are found here, including ungulates and large predators. However, human settlements occur along the Kunene, Kwando and Zambezi rivers, and the valuable Baikiaea plurijuga is sought after for the timber trade. The instability promoted in Angola by Soviet financed Cuban troops, and hostilities between Angola and Namibia in the Caprivi Strip have contributed to the degradation of this ecoregion. This ecoregion is a... More »
Zambezian halophytics Last Updated on 2015-05-15 15:26:27 WWF Terrestrial Ecoregions Collection The Zambezian halophytics ecoregion includes two spatially disjunctive units in Southern Africa: The Makgadikgadi Pan complex in Botswana and a smaller hypersaline unit in southern inland Mozambique. One of the largest saltpans in the world, the Makgadikgadi Pan complex in Botswana stretches out over 12,000 square kilometres. The ecoregion is classified within the Flooded Grasslands and Savanna biome. Surrounded by the semi-arid Kalahari savannas, the pans experience a harsh climate, hot with little rain, and are normally a vast, glaring expanse of salt-saturated clay. These pans are sustained by freshwater from the Nata River, and more infrequently, from input from the Okavango Alluvial Fan by way of the Boteti River. Saline- and drought-tolerant plant species generally line the pan perimeters, with grasslands... More »
Kalahari acacia-baikiaea woodlands Last Updated on 2015-05-11 18:02:12 WWF Terrestrial Ecoregions Collection Semi-arid Kalahari acacia-baikiaea woodlands stretches across the center of southern Africa, from northern Namibia through Botswana and slightly into the Tuli Block of South Africa. Surface water is scarce, and droughts occur approximately once every seven years. Therefore, the human population is relatively low, particularly on the sandveld that covers most of the ecoregion. This Kalahari woodland supports a rich and diverse fauna, including a variety of ungulates and a number of threatened large mammalian taxa such as White Rhinoceros (Ceratotherium simum), Black Rhinoceros (Diceros bicornis), Painted Hunting Dog (Lycaon pictus), and African Elephant (Loxodonta africana). However, human populations are increasing, and the burgeoning cattle industry has far-reaching adverse effects on the natural environment and... More »