Habitat

In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both physical and biological features. A species' habitat is those places where it can find food, shelter, protection and mates for reproduction.

The physical factors are for example soil, moisture, range of temperature, and light intensity as well as biotic factors such as the availability of food and the presence or absence of predators. Every organism has certain habitat needs for the conditions in which it will thrive, but some are tolerant of wide variations while others are very specific in their requirements. A habitat is not necessarily a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, and for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body.

Habitat types include polar, temperate, subtropical and tropical. The terrestrial vegetation type may be forest, steppe, grassland, semi-arid or desert. Fresh water habitats include marshes, streams, rivers, lakes, and ponds, and marine habitats include salt marshes, the coast, the intertidal zone, estuaries, reefs, bays, the open sea, the sea bed, deep water and submarine vents.

Habitats change over time. This may be due to a violent event such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents; or the change may be more gradual over millennia with alterations in the climate, as ice sheets and glaciers advance and retreat, and as different weather patterns bring changes of precipitation and solar radiation. Other changes come as a direct result of human activities; deforestation, the plowing of ancient grasslands, the diversion and damming of rivers, the draining of marshland and the dredging of the seabed. The introduction of alien species can have a devastating effect on native wildlife, through increased predation, through competition for resources or through the introduction of pests and diseases to which the native species have no immunity.

Rotjan - Enderbury Day 1 - 2nd half (62)
This coral reef in the Phoenix Islands Protected Area is a rich habitat for sea life.
Antarctic (js) 18
Few creatures make the ice shelves of Antarctica their habitat.
Ibex in the French Vanoise National Park
Ibex in alpine habitat

Definition and etymology

The word "habitat" has been in use since about 1755 and derives from the Latin habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the natural environment of an organism, the type of place in which it is natural for it to live and grow.[1][2] It is similar in meaning to a biotope; an area of uniform environmental conditions associated with a particular community of plants and animals.[3]

Environmental factors

The chief environmental factors affecting the distribution of living organisms are temperature, humidity, climate, soil type and light intensity, and the presence or absence of all the requirements that the organism needs to sustain it. Generally speaking, animal communities are reliant on specific types of plant communities.[4]

Some plants and animals are generalists, and their habitat requirements are met in a wide range of locations. The small white butterfly (Pieris rapae) for example is found on all the continents of the world apart from Antarctica. Its larvae feed on a wide range of Brassicas and various other plant species, and it thrives in any open location with diverse plant associations.[5] The large blue butterfly is much more specific in its requirements; it is found only in chalk grassland areas, its larvae feed on Thymus species and because of complex lifecycle requirements it inhabits only areas in which Myrmica ants live.[6]

Disturbance is important in the creation of biodiverse habitats. In the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Wildflower meadows are sometimes created by conservationists but most of the flowering plants used are either annuals or biennials and disappear after a few years in the absence of patches of bare ground on which their seedlings can grow.[7] Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created.[8] Similarly coastal habitats can become dominated by kelp until the seabed is disturbed by a storm and the algae swept away, or shifting sediment exposes new areas for colonisation. Another cause of disturbance is when an area may be overwhelmed by an invasive introduced species which is not kept under control by natural enemies in its new habitat.[9]

Types

Epiphytes (Dominica)
Rich rainforest habitat in Dominica

Terrestrial habitat types include forests, grasslands, wetlands and deserts. Within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils, altitudes and vegetation types. Many of these habitats grade into each other and each one has its own typical communities of plants and animals. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities and its efficiency as a coloniser.[10]

Danau Sentarum 2006
Wetland habitats in Borneo

Freshwater habitats include rivers, streams, lakes, ponds, marshes and bogs.[11] Although some organisms are found across most of these habitats, the majority have more specific requirements. The water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools, bayous and backwaters which provide a range of habitats. Similarly, aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marginal plants provide important habitat for both invertebrates and vertebrates, and submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution.[12]

Marine habitats include brackish water, estuaries, bays, the open sea, the intertidal zone, the sea bed, reefs and deep / shallow water zones.[11] Further variations include rock pools, sand banks, mudflats, brackish lagoons, sandy and pebbly beaches, and seagrass beds, all supporting their own flora and fauna. The benthic zone or seabed provides a home for both static organisms, anchored to the substrate, and for a large range of organisms crawling on or burrowing into the surface. Some creatures float among the waves on the surface of the water, or raft on floating debris, others swim at a range of depths, including organisms in the demersal zone close to the seabed, and myriads of organisms drift with the currents and form the plankton.[13]

Marsa Alam R18
Desert scene in Egypt

A desert is not the kind of habitat that favours the presence of amphibians, with their requirement for water to keep their skins moist and for the development of their young. Nevertheless, some frogs live in deserts, creating moist habitats underground and hibernating while conditions are adverse. Couch's spadefoot toad (Scaphiopus couchii) emerges from its burrow when a downpour occurs and lays its eggs in the transient pools that form; the tadpoles develop with great rapidity, sometimes in as little as nine days, undergo metamorphosis, and feed voraciously before digging a burrow of their own.[14]

Other organisms cope with the drying up of their aqueous habitat in other ways. Vernal pools are ephemeral ponds that form in the rainy season and dry up afterwards. They have their specially-adapted characteristic flora, mainly consisting of annuals, the seeds of which survive the drought, but also some uniquely adapted perennials.[15] Animals adapted to these extreme habitats also exist; fairy shrimps can lay "winter eggs" which are resistant to desiccation, sometimes being blown about with the dust, ending up in new depressions in the ground. These can survive in a dormant state for as long as fifteen years.[16] Some killifish behave in a similar way; their eggs hatch and the juvenile fish grow with great rapidity when the conditions are right, but the whole population of fish may end up as eggs in diapause in the dried up mud that was once a pond.[17]

Many animals and plants have taken up residence in urban environments. They tend to be adaptable generalists and use the town's features to make their homes. Rats and mice have followed man around the globe, pigeons, peregrines, sparrows, swallows and house martins use the buildings for nesting, bats use roof space for roosting, foxes visit the garbage bins and squirrels, coyotes, raccoons and skunks roam the streets. About 2,000 coyotes are thought to live in and around Chicago.[18] A survey of dwelling houses in northern European cities in the twentieth century found about 175 species of invertebrate inside them, including 53 species of beetle, 21 flies, 13 butterflies and moths, 13 mites, 9 lice, 7 bees, 5 wasps, 5 cockroaches, 5 spiders, 4 ants and a number of other groups.[19] In warmer climates, termites are serious pests in the urban habitat; 183 species are known to affect buildings and 83 species cause serious structural damage.[20]

Microhabitats

A microhabitat is the small-scale physical requirements of a particular organism or population. Every habitat includes large numbers of microhabitats with subtly different exposure to light, humidity, temperature, air movement, and other factors. The lichens that grow on the north face of a boulder are different to those that grow on the south face, from those on the level top and those that grow on the ground nearby; the lichens growing in the grooves and on the raised surfaces are different from those growing on the veins of quartz. Lurking among these miniature "forests" are the microfauna, each species of invertebrate with its own specific habitat requirements.[21]

There are numerous different microhabitats in a wood; coniferous forest, broad-leafed forest, open woodland, scattered trees, woodland verges, clearings and glades; tree trunk, branch, twig, bud, leaf, flower and fruit; rough bark, smooth bark, damaged bark, rotten wood, hollow, groove and hole; canopy, shrub layer, plant layer, leaf litter and soil; buttress root, stump, fallen log, stem base, grass tussock, fungus, fern and moss.[22] The greater the structural diversity in the wood, the greater the number of microhabitats that will be present. A range of tree species with individual specimens of varying sizes and ages, and a range of features such as streams, level areas, slopes, tracks, clearings and felled areas will provide suitable conditions for an enormous number of biodiverse plants and animals. For example, in Britain it has been estimated that various types of rotting wood are home to over 1700 species of invertebrate.[22]

For a parasitic organism, its habitat is the particular part of the outside or inside of its host on or in which it is adapted to live. The life cycle of some parasites involves several different host species, as well as free-living life stages, sometimes providing vastly different microhabitats.[23] One such organism is the trematode (flatworm) Microphallus turgidus, present in brackish water marshes in the southeastern United States. Its first intermediate host is a snail and the second, a glass shrimp. The final host is the waterfowl or mammal that consumes the shrimp.[24]

Extreme habitats

Cryptoendolith
An Antarctic rock split apart to show an endolithic lifeform showing as a green layer a few millimeters thick

Although the vast majority of life on Earth lives in mesophyllic (moderate) environments, a few organisms, most of them microbes, have managed to colonise extreme environments that are unsuitable for most higher life forms. There are bacteria, for example, living in Lake Whillans, half a mile below the ice of Antarctica; in the absence of sunlight, they must rely on organic material from elsewhere, perhaps decaying matter from glacier melt water or minerals from the underlying rock.[25] Other bacteria can be found in abundance in the Mariana Trench, the deepest place in the ocean and on Earth; marine snow drifts down from the surface layers of the sea and accumulates in this undersea valley, providing nourishment for an extensive community of bacteria.[26]

Other microbes live in habitats lacking in oxygen, and are dependent on chemical reactions other than photosynthesis. Boreholes drilled 300 m (1,000 ft) into the rocky seabed have found microbial communities apparently based on the products of reactions between water and the constituents of rocks. These communities have been little studied, but may be an important part of the global carbon cycle.[27] Rock in mines two miles deep also harbour microbes; these live on minute traces of hydrogen produced in slow oxidizing reactions inside the rock. These metabolic reactions allow life to exist in places with no oxygen or light, an environment that had previously been thought to be devoid of life.[28][29]

The intertidal zone and the photic zone in the oceans are relatively familiar habitats. However the vast bulk of the ocean is unhospitable to air-breathing humans, with scuba divers limited to the upper 50 m (160 ft) or so.[30] The lower limit for photosynthesis is 100 to 200 m (330 to 660 ft) and below that depth the prevailing conditions include total darkness, high pressure, little oxygen (in some places), scarce food resources and extreme cold. This habitat is very challenging to research, and as well as being little studied, it is vast, with 79% of the Earth's biosphere being at depths greater than 1,000 m (3,300 ft).[31] With no plant life, the animals in this zone are either detritivores, reliant on food drifting down from surface layers, or they are predators, feeding on each other. Some organisms are pelagic, swimming or drifting in mid-ocean, while others are benthic, living on or near the seabed. Their growth rates and metabolisms tend to be slow, their eyes may be very large to detect what little illumination there is, or they may be blind and rely on other sensory inputs. A number of deep sea creatures are bioluminescent; this serves a variety of functions including predation, protection and social recognition.[31] In general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure-resistant biomolecules and small organic molecules present in their cells known as piezolytes, which give the proteins the flexibility they need. There are also unsaturated fats in their membranes which prevent them from solidifying at low temperatures.[32]

Dense mass of anomuran crab Kiwa around deep-sea hydrothermal vent
Dense mass of white crabs at a hydrothermal vent, with stalked barnacles on right

Hydrothermal vents were first discovered in the ocean depths in 1977.[33] They result from seawater becoming heated after seeping through cracks to places where hot magma is close to the seabed. The under-water hot springs may gush forth at temperatures of over 340 °C (640 °F) and support unique communities of organisms in their immediate vicinity.[33] The basis for this teeming life is chemosynthesis, a process by which microbes convert such substances as hydrogen sulfide or ammonia into organic molecules.[34] These bacteria and Archaea are the primary producers in these ecosystems and support a diverse array of life. About 350 species of organism, dominated by molluscs, polychaete worms and crustaceans, had been discovered around hydrothermal vents by the end of the twentieth century, most of them being new to science and endemic to these habitats.[35]

Besides providing locomotion opportunities for winged animals and a conduit for the dispersal of pollen grains, spores and seeds, the atmosphere can be considered to be a habitat in its own right. There are metabolically active microbes present that actively reproduce and spend their whole existence airborne, with hundreds of thousands of individual organisms estimated to be present in a cubic meter of air. The airborne microbial community may be as diverse as that found in soil or other terrestrial environments, however these organisms are not evenly distributed, their densities varying spatially with altitude and environmental conditions. Aerobiology has been little studied, but there is evidence of nitrogen fixation in clouds, and less clear evidence of carbon cycling, both facilitated by microbial activity.[36]

There are other examples of extreme habitats where specially adapted lifeforms exist; tar pits teeming with microbial life;[37] naturally occurring crude oil pools inhabited by the larvae of the petroleum fly;[38] hot springs where the temperature may be as high as 71 °C (160 °F) and cyanobacteria create microbial mats;[39] cold seeps where the methane and hydrogen sulfide issue from the ocean floor and support microbes and higher animals such as mussels which form symbiotic associations with these anaerobic organisms;[40] salt pans harbour salt-tolerant microorganisms and also Wallemia ichthyophaga, a basidomycotous fungus;[41] ice sheets in Antarctica which support fungi Thelebolus spp.,[41] and snowfields on which algae grow.[42]

Habitat change

Mt st helens Johnston ridge 25 years later
Twenty five years after the devastating eruption at Mount St. Helens, United States, pioneer species have moved in.

Whether from natural processes or the activities of man, landscapes and their associated habitats change over time. There are the slow geomorphological changes associated with the geologic processes that cause tectonic uplift and subsidence, and the more rapid changes associated with earthquakes, landslides, storms, flooding, wildfires, coastal erosion, deforestation and changes in land use.[43] Then there are the changes in habitats brought on by alterations in farming practices, tourism, pollution, fragmentation and climate change.[44]

Loss of habitat is the single greatest threat to any species. If an island on which an endemic organism lives becomes uninhabitable for some reason, the species will become extinct. Any type of habitat surrounded by a different habitat is in a similar situation to an island. If a forest is divided into parts by logging, with strips of cleared land separating woodland blocks, and the distances between the remaining fragments exceeds the distance an individual animal is able to travel, that species becomes especially vulnerable. Small populations generally lack genetic diversity and may be threatened by increased predation, increased competition, disease and unexpected catastrophe.[44] At the edge of each forest fragment, increased light encourages secondary growth of fast-growing species and old growth trees are more vulnerable to logging as access is improved. The birds that nest in their crevices, the epiphytes that hang from their branches and the invertebrates in the leaf litter are all adversely affected and biodiversity is reduced.[44] Habitat fragmentation can be ameliorated to some extent by the provision of wildlife corridors connecting the fragments. These can be a river, ditch, strip of trees, hedgerow or even an underpass to a highway. Without the corridors, seeds cannot disperse and animals, especially small ones, cannot travel through the hostile territory, putting populations at greater risk of local extinction.[45]

Habitat disturbance can have long-lasting effects on the environment. Bromus tectorum is a vigorous grass from Europe which has been introduced to the United States where it has become invasive. It is highly adapted to fire, producing large amounts of flammable detritus and increasing the frequency and intensity of wildfires. In areas where it has become established, it has altered the local fire regimen to such an extant that native plants cannot survive the frequent fires, allowing it to become even more dominant.[46] A marine example is when sea urchin populations "explode" in coastal waters and destroy all the macroalgae present. What was previously a kelp forest becomes an urchin barren that may last for years and this can have a profound effect on the food chain. Removal of the sea urchins, by disease for example, can result in the seaweed returning, with an over-abundance of fast-growing kelp.[47]

Habitat protection

The protection of habitats is a necessary step in the maintenance of biodiversity because if habitat destruction occurs, the animals and plants reliant on that habitat suffer. Many countries have enacted legislation to protect their wildlife. This may take the form of the setting up of national parks, forest reserves and wildlife reserves, or it may restrict the activities of humans with the objective of benefiting wildlife. The laws may be designed to protect a particular species or group of species, or the legislation may prohibit such activities as the collecting of bird eggs, the hunting of animals or the removal of plants. A general law on the protection of habitats may be more difficult to implement than a site specific requirement. A concept introduced in the United States in 1973 involves protecting the critical habitat of endangered species, and a similar concept has been incorporated into some Australian legislation.[48]

International treaties may be necessary for such objectives as the setting up of marine reserves. Another international agreement, the Convention on the Conservation of Migratory Species of Wild Animals, protects animals that migrate across the globe and need protection in more than one country.[49] However, the protection of habitats needs to take into account the needs of the local residents for food, fuel and other resources. Even where legislation protects the environment, a lack of enforcement often prevents effective protection. Faced with food shortage, a farmer is likely to plough up a level patch of ground despite it being the last suitable habitat for an endangered species such as the San Quintin kangaroo rat, and even kill the animal as a pest.[50] In this regard, it is desirable to educate the community on the uniqueness of their flora and fauna and the benefits of ecotourism.[51]

Monotypic habitat

A monotypic habitat is one in which a single species of animal or plant is so dominant as to virtually exclude all other species. An example would be a sugarcane plantation; this is planted, burnt and harvested, with herbicides killing weeds and pesticides controlling invertebrates.[52] The monotypic habitat occurs in botanical and zoological contexts, and is a component of conservation biology. In restoration ecology of native plant communities or habitats, some invasive species create monotypic stands that replace and/or prevent other species, especially indigenous ones, from growing there. A dominant colonization can occur from retardant chemicals exuded, nutrient monopolization, or from lack of natural controls such as herbivores or climate, that keep them in balance with their native habitats. The yellow starthistle, Centaurea solstitialis, is a botanical monotypic-habitat example of this, currently dominating over 15,000,000 acres (61,000 km2) in California alone.[53] The non-native freshwater zebra mussel, Dreissena polymorpha, that colonizes areas of the Great Lakes and the Mississippi River watershed, is a zoological monotypic-habitat example; the predators that control it in its home-range in Russia are absent and it proliferates abundantly.[54] Even though its name may seem to imply simplicity as compared with polytypic habitats, the monotypic habitat can be complex. Aquatic habitats, such as exotic Hydrilla beds, support a similarly rich fauna of macroinvertebrates to a more varied habitat, but the creatures present may differ between the two, affecting small fish and other animals higher up the food chain.[55]

See also

Notes and references

  1. ^ "Habitat". Dictionary.com. Retrieved 16 May 2016.
  2. ^ "Habitat". Merriam-Webster Dictionary. Retrieved 4 June 2016.
  3. ^ "Biotope". Oxford Dictionaries. Retrieved 4 June 2016.
  4. ^ Everyman's Encyclopedia; Volume 4. J.M. Dent. 1967. p. 581. ASIN B0015GRC04.
  5. ^ Richards, O.W. (1940). "The biology of the small white butterfly (Pieris rapae), with special reference to the factors controlling its abundance". Journal of Animal Ecology. 9 (2): 243–288. doi:10.2307/1459. JSTOR 1459.
  6. ^ Spitzer, L.; Benes, J.; Dandova, J.; Jaskova, V.; Konvicka, M. (2009). "The Large Blue butterfly ("Phengaris [Maculinea] arion"), as a conservation umbrella on a landscape scale: The case of the Czech Carpathians". Ecological Indicators. 9 (6): 1056–1063. doi:10.1016/j.ecolind.2008.12.006.
  7. ^ Sutherland, William J.; Hill, David A. (1995). Managing Habitats for Conservation. Cambridge University Press. p. 6. ISBN 978-0-521-44776-8.
  8. ^ Richard J. Huggett (2004). Fundamentals of Biogeography. Psychology Press. p. 146. ISBN 978-0-415-32347-5.
  9. ^ "Invasive species". National Wildlife Federation. Retrieved 24 May 2016.
  10. ^ Breed, Michael D.; Moore, Janice (2011). Animal Behavior. Academic Press. p. 248. ISBN 978-0-08-091992-8.
  11. ^ a b "Habitats". BBC Nature. Retrieved 24 May 2016.
  12. ^ Cook, C.D.K.; Gut, B.J.; Rix, E.M.; Schneller, J. (1974). Water Plants of the World: A Manual for the Identification of the Genera of Freshwater Macrophytes. Springer Science & Business Media. p. 7. ISBN 978-90-6193-024-2.
  13. ^ Roff, John (2013). Marine Conservation Ecology. Routledge. p. 105. ISBN 978-1-136-53838-4.
  14. ^ "Couch's spadefoot (Scaphiopus couchi)". Arizona–Sonora Desert Museum. Retrieved 16 May 2016.
  15. ^ Witham, Carol W. (1998). Ecology, Conservation, and Management of Vernal Pool Ecosystems. California Native Plant Society. p. 1. ISBN 978-0-943460-37-6.
  16. ^ Green, Scott. "Fairy shrimp". The Vernal Pool Association. Archived from the original on 23 April 2016. Retrieved 17 May 2016.
  17. ^ Walker, Matt (21 May 2015). "The most extreme fish on Earth". BBC Earth. Retrieved 17 May 2016.
  18. ^ Read, Nicholas (2012). City Critters: Wildlife in the Urban Jungle. Orca Book Publishers. p. 2. ISBN 978-1-55469-394-8.
  19. ^ John G. Kelcey, John G. (2015). Vertebrates and Invertebrates of European Cities:Selected Non-Avian Fauna. Springer. p. 124. ISBN 978-1-4939-1698-6.
  20. ^ Abe, Y.; Bignell, David Edward; Higashi, T. (2014). Termites: Evolution, Sociality, Symbioses, Ecology. Springer. p. 437. ISBN 978-94-017-3223-9.
  21. ^ "Microhabitats". Australian National Botanic Gardens, Centre for Australian National Biodiversity Research (An Australian Government Initiative). Government of the Commonwealth of Australia. Retrieved 18 May 2016.
  22. ^ a b "Woodlands & Biodiversity". Offwell Woodland & Wildlife Trust. Retrieved 18 May 2016.
  23. ^ Lewis, E.E.; Campbell, J.F.; Sukhdeo, M.V.K. (2002). The Behavioural Ecology of Parasites. CABI. p. 183. ISBN 978-0-85199-754-4.
  24. ^ Pung, Oscar J.; Burger, Ashley R.; Walker, Michael F.; Barfield, Whitney L.; Lancaster, Micah H.; Jarrous, Christina E. (2009). "In vitro cultivation of Microphallus turgidus (Trematoda: Microphallidae) from metacercaria to ovigerous adult with continuation of the life cycle in the laboratory". Journal of Parasitology. 95 (4): 913–919. doi:10.1645/ge-1970.1. JSTOR 27735680.
  25. ^ Gorman, James (6 February 2013). "Bacteria Found Deep Under Antarctic Ice, Scientists Say". New York Times. Retrieved 18 May 2016.
  26. ^ Choi, Charles Q. (17 March 2013). "Microbes Thrive in Deepest Spot on Earth". LiveScience. Retrieved 18 May 2016.
  27. ^ Oskin, Becky (14 March 2013). "Intraterrestrials: Life Thrives in Ocean Floor". LiveScience. Retrieved 18 May 2016.
  28. ^ Schultz, Steven (13 December 1999). "Two miles underground". Princeton Weekly Bulletin. Archived from the original on 13 January 2016.
  29. ^ Chang, Kenneth (12 September 2016). "Visions of Life on Mars in Earth's Depths". New York Times. Retrieved 12 September 2016.
  30. ^ Cole, Bob (March 2008). "Appendix 6". The SAA BUhlmann DeeP-Stop System Handbook. Sub-Aqua Association. pp. vi–1. ISBN 978-0-9532904-8-2.
  31. ^ a b "The Deep Sea". MarineBio Conservation Society. 29 December 2011. Retrieved 19 May 2016.
  32. ^ "What does it take to live at the bottom of the ocean?". BBC Earth. 2016. Retrieved 19 May 2016.
  33. ^ a b "A hydrothermal vent forms when seawater meets hot magma". Ocean facts. National Ocean Service. 11 January 2013. Retrieved 20 May 2016.
  34. ^ "Hydrothermal Vent Creatures". Ocean Portal. Smithsonian National Museum of Natural History. Retrieved 20 May 2016.
  35. ^ Desbruyères, Daniel; Segonzac, Michel (1997). Handbook of Deep-sea Hydrothermal Vent Fauna. Editions Quae. p. 9. ISBN 978-2-905434-78-4.
  36. ^ Womack, Ann M.; Bohannan, Brendan J.M.; Green, Jessica L. (2010). "Biodiversity and biogeography of the atmosphere". Philosophical Transactions of the Royal Society B. 365 (1558): 3645–3653. doi:10.1098/rstb.2010.0283. PMC 2982008. PMID 20980313.
  37. ^ Schulze-Makuch, Dirk; Haque, Shirin; Resendes de Sousa Antonio, Marina; Ali, Denzil; Hosein, Riad; Song, Young C.; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M.; Guinan, Edward; Lehto, Harry J.; Hallam, Steven J. (2011). "Microbial Life in a Liquid Asphalt Desert". Astrobiology. 11 (3): 241–258. arXiv:1004.2047. Bibcode:2011AsBio..11..241S. doi:10.1089/ast.2010.0488. PMID 21480792.
  38. ^ "Petroleum fly". Grzimek's Animal Life Encyclopedia. Volume 3: Insects (2nd ed.). The Gale Group. 2004. p. 367. ISBN 978-0-7876-5779-6.
  39. ^ McGregor, G.B.; Rasmussen, J.P. (2008). "Cyanobacterial composition of microbial mats from an Australian thermal spring: a polyphasic evaluation". FEMS Microbiology Ecology. 63 (1): 23–35. doi:10.1111/j.1574-6941.2007.00405.x. PMID 18081588.
  40. ^ Hsing, Pen-Yuan (18 October 2010). "Gas-powered Circle of Life: Succession in a Deep-sea Ecosystem". Lophelia II 2010. NOAA. Retrieved 22 May 2016.
  41. ^ a b Gostincar, C.; Grube, M.; De Hoog, S.; Zalar, P.; Gunde-Cimerman, N. (2010). "Extremotolerance in fungi: Evolution on the edge". FEMS Microbiology Ecology. 71 (1): 2–11. doi:10.1111/j.1574-6941.2009.00794.x. PMID 19878320.
  42. ^ Takeuchi, Nozomu (2014). "Snow algae on Alaskan glaciers". Retrieved 22 May 2016.
  43. ^ Lindenmayer, David B.; Fischer, Joern (2013). Habitat Fragmentation and Landscape Change: An Ecological and Conservation Synthesis. Island Press. pp. 1–10. ISBN 978-1-59726-606-2.
  44. ^ a b c Miller, G. Tyler; Spoolman, Scott (2008). Living in the Environment: Principles, Connections, and Solutions. Cengage Learning. pp. 193–195. ISBN 978-0-495-55671-8.
  45. ^ Holland, Matthew D.; Hastings, Alan (2008). "Strong effect of dispersal network structure on ecological dynamics". Nature. 456 (7223): 792–794. Bibcode:2008Natur.456..792H. doi:10.1038/nature07395.
  46. ^ Brooks, M.L.; D'Antonio, C.M.; Richardson, D.M.; Grace, J.B.; Keeley, J.E.; DiTomaso, J.M.; Hobbs, R.J.; Pellant, M.; Pyke, D. (2004). "Effects of invasive alien plants on fire". BioScience. 54 (7): 677–688. doi:10.1641/0006-3568(2004)054[0677:EOIAPO]2.0.CO;2.
  47. ^ Lawrence, John M. (2013). Sea Urchins: Biology and Ecology. Academic Press. pp. 196–202. ISBN 978-0-12-397213-2.
  48. ^ de Klemm, Cyrille (1997). Comparative Analysis of the Effectiveness of Legislation for the Protection of Wild Flora in Europe. Council of Europe. pp. 65–70. ISBN 978-92-871-3429-5.
  49. ^ "Convention on the Conservation of Migratory Species of Wild Animals". UNEP/CMS Secretariat. Retrieved 7 July 2016.
  50. ^ Endangered Wildlife and Plants of the World. Marshall Cavendish. 2001. p. 750. ISBN 978-0-7614-7200-1.
  51. ^ Honey, Martha (2008). Ecotourism and Sustainable Development: Who Owns Paradise?. Island Press. p. 33. ISBN 978-1-59726-125-8.
  52. ^ Rio Guanajibo River Basin Flood Protection Project, Mayaguez, Hormigueros, San German: Environmental Impact Statement. 1994. p. 94.
  53. ^ "1970 distribution of yellow starthistle in the U.S." Yellow Starthistle Information. UCD. Archived from the original on 2006-12-31.
  54. ^ "Invasive Mussels". National Wildlife Federation. Retrieved 29 June 2016.
  55. ^ Theel, Heather J.; Dibble, Eric D.; Madsen, John D. (2008). "Differential influence of a monotypic and diverse native aquatic plant bed on a macroinvertebrate assemblage; an experimental implication of exotic plant induced habitat". Hydrobiologia. 600: 77–87. doi:10.1007/s10750-007-9177-z.

External links

  • The dictionary definition of habitat at Wiktionary
  • Media related to Habitats at Wikimedia Commons
Biome

A biome is a community of plants and animals that have common characteristics for the environment they exist in. They can be found over a range of continents. Biomes are distinct biological communities that have formed in response to a shared physical climate. "Biome" is a broader term than "habitat"; any biome can comprise a variety of habitats.

While a biome can cover large areas, a microbiome is a mix of organisms that coexist in a defined space on a much smaller scale. For example, the human microbiome is the collection of bacteria, viruses, and other microorganisms that are present on or in a human body.A 'biota' is the total collection of organisms of a geographic region or a time period, from local geographic scales and instantaneous temporal scales all the way up to whole-planet and whole-timescale spatiotemporal scales. The biotas of the Earth make up the biosphere.

Black panther

A black panther is the melanistic color variant of any big cat species. Black panthers in Asia and Africa are leopards (Panthera pardus), and those in the Americas are jaguars (Panthera onca).

Cantabrian capercaillie

The Cantabrian capercaillie (Tetrao urogallus cantabricus) is a subspecies of the western capercaillie in the grouse family Tetraonidae. It is one of two subspecies found in Spain.

Cougar

The cougar (Puma concolor), also commonly known by other names including catamount, mountain lion, panther, and puma, is a large felid of the subfamily Felinae native to the Americas.

Its range, from the Canadian Yukon to the southern Andes of South America, is the widest of any large wild terrestrial mammal in the Western Hemisphere. An adaptable, generalist species, the cougar is found in most American habitat types. It is the biggest cat in North America, and the second-heaviest cat in the New World after the jaguar. Secretive and largely solitary by nature, the cougar is properly considered both nocturnal and crepuscular, although daytime sightings do occur. The cougar is more closely related to smaller felines, including the domestic cat (subfamily Felinae), than to any species of subfamily Pantherinae, of which only the jaguar is native to the Americas.

The cougar is an ambush predator that pursues a wide variety of prey. Primary food sources are ungulates, particularly deer. It also hunts species as small as insects and rodents. This cat prefers habitats with dense underbrush and rocky areas for stalking, but can also live in open areas. The cougar is territorial and survives at low population densities. Individual territory sizes depend on terrain, vegetation, and abundance of prey. While large, it is not always the apex predator in its range, yielding prey it has killed to lone jaguars, American black bears, and grizzly bears, and to groups of gray wolves. It is reclusive and mostly avoids people. Fatal attacks on humans are rare, but have recently been increasing in North America as more people enter cougar territories.Intensive hunting following European colonization of the Americas and the ongoing human development of cougar habitat has caused populations to drop in most parts of its historical range. In particular, the North American cougar was extirpated in eastern North America in the beginning of the 20th century, except for the isolated Florida panther subpopulation. Transient males have been verified in Minnesota, Missouri, Iowa, Michigan, Indiana, and Illinois (where a cougar was shot in the city limits of Chicago), and in at least one instance, observed as far east as coastal Connecticut. Reports of eastern cougars (P. c. cougar) still surface, although it was declared extirpated in 2011.

Council on Tall Buildings and Urban Habitat

The Council on Tall Buildings and Urban Habitat (CTBUH) is an international body in the field of tall buildings and sustainable urban design. A non-profit organization based at the Monroe Building in the city of Chicago, Illinois, United States, the CTBUH announces the title of "The World's Tallest Building" and is widely considered to be an authority on the official height of tall buildings. Its stated mission is to study and report "on all aspects of the planning, design, and construction of tall buildings." The Council was founded at Lehigh University in 1969 by Lynn S. Beedle, where its office remained until October 2003 when it moved to the Illinois Institute of Technology in Chicago.

Endangered Species Act of 1973

The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) serves as the enacting legislation to carry out the provisions outlined in The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Designed to protect critically imperiled species from extinction as a "consequence of economic growth and development untempered by adequate concern and conservation", the ESA was signed into law by President Richard Nixon on December 28, 1973. The law requires federal agencies to consult with the Fish and Wildlife Service &/or the NOAA Fisheries Service to ensure their actions are not likely to jeopardize the continued existence of any listed species or result in the destruction or adverse modification of designated critical habitat of such species. The U.S. Supreme Court found that "the plain intent of Congress in enacting" the ESA "was to halt and reverse the trend toward species extinction, whatever the cost." The Act is administered by two federal agencies, the United States Fish and Wildlife Service (FWS) and the National Marine Fisheries Service (NMFS).

Endangered species

An endangered species is a species which has been categorized as very likely to become extinct. Endangered (EN), as categorized by the International Union for Conservation of Nature (IUCN) Red List, is the second most severe conservation status for wild populations in the IUCN's schema after Critically Endangered (CR).

In 2012, the IUCN Red List featured 3,079 animal and 2,655 plant species as endangered (EN) worldwide. The figures for 1998 were, respectively, 1,102 and 1,197.

Many nations have laws that protect conservation-reliant species: for example, forbidding hunting, restricting land development or creating protected areas. Population numbers, trends and species' conservation status can be found at the lists of organisms by population.

Endemism

Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species that is endemic is precinctive, which applies to species (and subspecific categories) that are restricted to a defined geographical area.

Habitat destruction

Habitat destruction is the process by which natural habitat becomes incapable of supporting its native species. In this process, the organisms that previously used the site are displaced or destroyed, reducing biodiversity. Habitat destruction by human activity is mainly for the purpose of harvesting natural resources for industrial production and urbanization. Clearing habitats for agriculture is the principal cause of habitat destruction. Other important causes of habitat destruction include mining, logging, trawling, and urban sprawl. Habitat destruction is currently ranked as the primary cause of species extinction worldwide. It is a process of natural environmental change that may be caused by habitat fragmentation, geological processes, climate change or by human activities such as the introduction of invasive species, ecosystem nutrient depletion, and other human activities.

The terms habitat loss and habitat reduction are also used in a wider sense, including loss of habitat from other factors, such as water and noise pollution.

Habitat for Humanity

Habitat for Humanity International (HFHI), generally referred to as Habitat for Humanity or simply Habitat, is an international, non-governmental, and nonprofit organization, which was founded in 1976 by Linda and Millard Fuller. Habitat has been devoted to building "simple, decent, and affordable" housing, a self-described "Christian housing ministry," and has addressed the issues of poverty housing all over the world. The international operational headquarters are located in Americus, Georgia, United States, with the administrative headquarters located in Atlanta. There are five area offices located around the world: United States and Canada; Africa and the Middle East (located in Pretoria, South Africa); Asia-Pacific (Manila, Philippines); Europe and Central Asia (Bratislava, Slovakia); and Latin America and the Caribbean (San Jose, Costa Rica).

Community-level Habitat offices act in partnership with and on behalf of Habitat for Humanity International. In the United States, these local offices are called Habitat affiliates; outside the United States, Habitat operations are managed by national offices. Each affiliate and national office is an independently run, nonprofit organization. Affiliates and national offices coordinate all aspects of Habitat home building in their local area, including fundraising, building site selection, partner family selection and support, house construction, and mortgage servicing.

The mission statement of Habitat for Humanity is "Seeking to put God's love into action, Habitat for Humanity brings people together to build homes, communities and hope". Homes are built using volunteer labor and Habitat makes no profit on the sales. In some locations outside the United States, Habitat for Humanity charges interest to protect against inflation. This policy has been in place since 1986. Habitat has helped more than 4 million people construct, rehabilitate or preserve more than 800,000 homes since its founding in 1976, making Habitat the largest not-for-profit builder in the world.

Habitat fragmentation

Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment

(suspected of being one of the major causes of speciation),and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species.

Heath

A heath () is a shrubland habitat found mainly on free-draining infertile, acidic soils and is characterised by open, low-growing woody vegetation. Moorland is generally related to high-ground heaths with—especially in Great Britain—a cooler and damper climate.

Heaths are widespread worldwide, but are fast disappearing and considered a rare habitat in Europe. They form extensive and highly diverse communities across Australia in humid and sub-humid areas where fire regimes with recurring burning are required for the maintenance of the heathlands. Even more diverse though less widespread heath communities occur in Southern Africa. Extensive heath communities can also be found in the California chaparral, New Caledonia, central Chile and along the shores of the Mediterranean Sea. In addition to these extensive heath areas, the vegetation type is also found in scattered locations across all continents, except Antarctica.

Jaguar

The jaguar (Panthera onca) is a wild cat species and the only extant member of the genus Panthera native to the Americas. The jaguar's present range extends from Southwestern United States and Mexico in North America, across much of Central America, and south to Paraguay and northern Argentina in South America. Though there are single cats now living within the Western United States, the species has largely been extirpated from the United States since the early 20th century. It is listed as Near Threatened on the IUCN Red List; and its numbers are declining. Threats include loss and fragmentation of habitat.

Overall, the jaguar is the largest native cat species of the New World and the third largest in the world. This spotted cat closely resembles the leopard, but is usually larger and sturdier. It ranges across a variety of forested and open terrains, but its preferred habitat is tropical and subtropical moist broadleaf forest, swamps and wooded regions. The jaguar enjoys swimming and is largely a solitary, opportunistic, stalk-and-ambush predator at the top of the food chain. As a keystone species it plays an important role in stabilizing ecosystems and regulating prey populations.

While international trade in jaguars or their body parts is prohibited, the cat is still frequently killed, particularly in conflicts with ranchers and farmers in South America. Although reduced, its range remains large. Given its historical distribution, the jaguar has featured prominently in the mythology of numerous indigenous American cultures, including those of the Maya and Aztec.

Key Habitat Site

A Key Habitat Site is a Canadian Wildlife Service designation for an area that supports at least 1% of the country's population of any migratory bird species, or subspecies, at any time. There may be overlap with areas designated as a migratory bird sanctuary or National Wildlife Area.

Quail

Quail is a collective name for several genera of mid-sized birds generally placed in the order Galliformes.

Old World quail are placed in the family Phasianidae, and New World quail are placed in the family Odontophoridae. The species of buttonquail are named for their superficial resemblance to quail, and form the family Turnicidae in the order Charadriiformes. The king quail, an Old World quail, often is sold in the pet trade, and within this trade is commonly, though mistakenly, referred to as a "button quail". Many of the common larger species are farm-raised for table food or egg consumption, and are hunted on game farms or in the wild, where they may be released to supplement the wild population, or extend into areas outside their natural range. In 2007, 40 million quail were produced in the U.S.The collective noun for a group of quail is a flock, covey, or bevy.

Riparian zone

A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by hydrophilic plants. Riparian zones are important in ecology, environmental resource management, and civil engineering because of their role in soil conservation, their habitat biodiversity, and the influence they have on fauna and aquatic ecosystems, including grasslands, woodlands, wetlands, or even non-vegetative areas. In some regions the terms riparian woodland, riparian forest, riparian buffer zone, riparian corridor and riparian strip are used to characterize a riparian zone. The word riparian is derived from Latin ripa, meaning river bank.

Sketch comedy

Sketch comedy comprises a series of short comedy scenes or vignettes, called "sketches", commonly between one and ten minutes long. Such sketches are performed by a group of comic actors or comedians, either on stage or through an audio or visual medium such as radio and television. Often sketches are first improvised by the actors and written down based on the outcome of these improv sessions; however, such improvisation is not necessarily involved in sketch comedy.

An individual comedy sketch is a brief scene or vignette of the type formerly used in vaudeville, and now used widely in comedy and variety shows, talk shows and some children's television series (such as Sesame Street). Warner Bros. Animation made two sketch comedy shows, including Mad and Right Now Kapow.

Sketch comedians routinely differentiate their product from a "skit", maintaining that a skit is a (single) dramatized joke (or "bit") while a sketch is a comedic exploration of a concept, character or situation.

United Nations Human Settlements Programme

The United Nations Human Settlements Programme (UN-Habitat) is the United Nations agency for human settlements and sustainable urban development. It was established in 1978 as an outcome of the First UN Conference on Human Settlements and Sustainable Urban Development (Habitat I) held in Vancouver, Canada, in 1976. UN-Habitat maintains its headquarters at the United Nations Office at Nairobi, Kenya. It is mandated by the United Nations General Assembly to promote socially and environmentally sustainable towns and cities with the goal of providing adequate shelter for all. It is a member of the United Nations Development Group. The mandate of UN-Habitat derives from the Habitat Agenda, adopted by the United Nations Conference on Human Settlements (Habitat II) in Istanbul, Turkey, in 1996. The twin goals of the Habitat Agenda are adequate shelter for all and the development of sustainable human settlements in an urbanizing world.

Since January 2018 the Executive Director is Maimunah Mohd Sharif, who had served as the Mayor of Penang Island prior to her appointment in UN-Habitat by the Secretary-General of the United Nations, António Guterres.

Vulnerable species

A vulnerable species is one which has been categorized by the International Union for Conservation of Nature as likely to become endangered unless the circumstances that are threatening its survival and reproduction improve.

Vulnerability is mainly caused by habitat loss or destruction of the species home. Vulnerable habitat or species are monitored and can become increasingly threatened. Some species listed as "vulnerable" may be common in captivity, an example being the military macaw.

There are currently 5196 animals and 6789 plants classified as vulnerable, compared with 1998 levels of 2815 and 3222, respectively. Practices such as Cryoconservation of animal genetic resources have been enforced in efforts to conserve vulnerable breeds of livestock specifically.

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