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, Estonia and Russia, prior to discharging to the Gulf of Riga. Also known as the West Dvina River, this... 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 »

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Mangrove ecology Last Updated on 2014-10-01 10:45:20 ​Mangrove ecology is the study of biotic interactions within mangrove swamp ecosystems. These habitats are significant not only for the biodiversity they represent, but also for the protection of coastal erosion, and for the provision of protected nursery areas for marine fauna.   Mangroves worldwide cover an approximate area of 240 000 square kilometers of sheltered coastlines in the tropics and subtropics. Mangroves stabilize coastal intertidal soils pereventing coastal erosion Four of the most common ecotypes include fringe, riverine, basin, and scrub forests. Mangroves are restricted to the intertidal zone. Mangroves in general have a great capacity to recover from major natural disturbances. Mangroves maintain water quality by trapping sediments and taking up excess... More »
Habitat fragmentation Last Updated on 2014-09-30 10:21:30 Habitat fragmentation involves alteration of habitat resulting in spatial separation of habitat units from a previous state of greater continuity. Figure 1. Aerial photograph of dry forest scrub in southern Zambia, fragmented by agricultural land conversion. 2008 This phenomenon occurs naturally on a geologic time-scale or in unusual and catastrophic events: however, since the Holocene era, humans have produced dramatic and swift transformation of landscapes throughout the world, resulting in a level of habitat fragmentation that has induced worldwide reduction in biodiversity and interuption of  sustainable yields of natural resources. Humans produce habitat fragmentation chiefly from agricultural land conversion, urbanization, pollution, deforestation and introduction of alien species; ironically, both human caused wildfires as well as the... More »
Species Last Updated on 2014-09-15 11:53:19 A species is a group of organisms capable of interbreeding and producing fertile offspring of both genders, and separated from other such groups with which interbreeding does not characteristically occur: however, for asexual organisms, a distinct species may be considered a collection of organisms which have very similar DNA or physical characteristics. Certain species are further subdivided into subspecies. The early Greeks and Romans had a well established set of taxonomic names for species of animals and plants, based upon the macroscopically observable characteristics of organisms, with Aristotle being the chief architect of this codification; even earlier, the Egyptians and Cretans developed basic symbols and names for species important in farming and culture. It was not until the year 1686 when English naturalist John Ray introduced the concept that species were... More »
Ecoregions of Canada Last Updated on 2014-09-06 20:21:29 Canada  has 50 ecoregions that occur entirely or partly within its borders as listed below and shown in the accompanying figure:     South Avalon-Burin oceanic barrens Eastern Canadian forests Newfoundland Highland forests New England-Acadian forests Gulf of St. Lawrence lowland forests Eastern Great Lakes lowland forests Southern Great Lakes forests Eastern forest-boreal transition Eastern Canadian Shield taiga Torngat Mountain tundra Low Arctic tundra Middle Arctic tundra High Arctic tundra Davis Highlands tundra Baffin coastal tundra Southern Hudson Bay taiga Central Canadian Shield forests Western Great Lakes forests Northern tall grasslands Midwestern Canadian Shield forests Northern Canadian Shield taiga Mid-Continental Canadian forests Canadian Aspen... More »
Climate change effects on birds Last Updated on 2014-09-06 19:35:56 Many birds species all over the world are highly sensitive to the effects of climate change. Scientists have found declines of up to 90 percent in some bird populations, as well as total and unprecedented reproductive failure in others, althought the role of any change in climate is typically not determined. Population declines generally have several associative causal factors including habitat loss, habitat fragmentation and pollution. Specific groups that are at high risk from climate change include migratory birds, mountain birds, island birds,   wetland   birds, Arctic birds, Antarctic birds and seabirds. Bird species that can move easily to new habitat are expected to continue to do well; however, bird species that thrive only in a narrow environmental range can be expected to decline, and to be outcompeted by invasive species. With a 0.8°C average... More »