Columbian mammoth
The Columbian mammoth is an extinct species of mammoth that inhabited North America as far north as the northern United States and as far south as Costa Rica during the Pleistocene epoch. It was one of the last in a line of mammoth species, beginning with Mammuthus subplanifrons in the early Pliocene; the Columbian mammoth evolved from the steppe mammoth, which entered North America from Asia about 1.5 million years ago. The pygmy mammoths of the Channel Islands of California evolved from Columbian mammoths; the closest extant relative of the Columbian and other mammoths is the Asian elephant. Reaching 4 m at the shoulders and 10 tonnes in weight, the Columbian mammoth was one of the largest species of mammoth, it had long, curved tusks and four molars, which were replaced six times during the lifetime of an individual. It most used its tusks and trunk like modern elephants—for manipulating objects and foraging. Bones, hair and stomach contents have been discovered, but no preserved carcasses are known.
The Columbian mammoth preferred open areas, such as parkland landscapes, fed on sedge and other plants. It did not live in the Arctic regions of Canada; the ranges of the two species may have overlapped, genetic evidence suggests that they interbred. Several sites contain the skeletons of multiple Columbian mammoths, either because they died in incidents such as a drought, or because these locations were natural traps in which individuals accumulated over time. For a few thousand years prior to their extinction, Columbian mammoths coexisted in North America with Paleoamericans – the first humans to inhabit the Americas – who hunted them for food, used their bones for making tools, depicted them in ancient art. Columbian mammoth remains have been found in association with Clovis culture artifacts; the Columbian mammoth disappeared at the end of the Pleistocene around 11,500 years ago, most as a result of habitat loss caused by climate change, hunting by humans, or a combination of both. The Columbian mammoth was first scientifically described in 1857 by the naturalist Hugh Falconer, who named the species Elephas columbi after the explorer Christopher Columbus.
The animal was brought to Falconer's attention in 1846 by Charles Lyell, who sent him molar fragments found during the 1838 excavation of the Brunswick–Altamaha Canal in Georgia, in the southeastern United States. At the time, similar fossils from across North America were attributed to woolly mammoths. Falconer found that his specimens were distinct, confirming his conclusion by examining their internal structure and studying additional molars from Mexico. Although the scientists William Phipps Blake and Richard Owen believed that E. texianus was more appropriate for the species, Falconer rejected the name. More complete material that may be from the same quarry as Falconer's fragmentary holotype molar was reported in 2012, could help shed more light on that specimen, since doubts about its adequacy as a holotype have been raised. In the early 20th century, the taxonomy of extinct elephants became complicated. In 1942, the paleontologist Henry Fairfield Osborn's posthumous monograph on the Proboscidea was published, wherein he used various genus and subgenus names, proposed for extinct elephant species, such as Archidiskodon, Metarchidiskodon and Mammonteus.
Osborn retained names for many regional and intermediate subspecies or "varieties", created recombinations such as Parelephas columbi felicis and Archidiskodon imperator maibeni. The taxonomic situation was simplified by various researchers from the 1970s onwards: all species of mammoth were retained in the genus Mammuthus, many proposed differences between species were instead interpreted as intraspecific variation. In 2003, the paleontologist Larry Agenbroad reviewed opinions about North American mammoth taxonomy, concluded that several species had been declared junior synonyms, that M. columbi and M. exilis were the only species of mammoth endemic to the Americas. The idea that species such as M. imperator and M. jeffersoni were either more primitive or advanced stages in Columbian mammoth evolution was dismissed, they were regarded as synonyms. In spite of these conclusions, Agenbroad cautioned that American mammoth taxonomy is not yet resolved; the earliest known members of Proboscidea, the clade that contains the elephants, existed about 55 million years ago around the Tethys Sea area.
The closest living relatives of the Proboscidea are the hyraxes. The family Elephantidae existed six million years ago in Africa, includes the living elephants and the mammoths. Among many now extinct clades, the mastodon is only a distant relative, part of the distinct family Mammutidae, which diverged 25 million years before the mammoths evolved; the Asian elephant is the closest extant relative of the mammoths. The following cladogram shows the placement of the Columbian mammoth among other proboscideans, based on characteristics of the hyoid bone in the neck: Since many remains of each species of mammoth are known from several localities, it is possible to reconstruc
Coastal sage scrub
Coastal sage scrub known as coastal scrub, CSS, or soft chaparral, is a low scrubland plant community of the California coastal sage and chaparral subecoregion, found in coastal California and northwestern coastal Baja California. It is within the California chaparral and woodlands ecoregion, of the Mediterranean forests and scrub biome. Plant communityCoastal sage scrub is characterized by low-growing aromatic, drought-deciduous shrubs adapted to the semi-arid Mediterranean climate of the coastal lowlands; the community is sometimes called "soft chaparral" due to the predominance of soft, drought-deciduous leaves in contrast to the hard, waxy-cuticled leaves on sclerophyllous plants of California's chaparral communities. FloraCharacteristic shrubs and subshrubs include: California sagebrush Black sage White sage California buckwheat Coast brittle-bush Golden yarrow Larger shrubs include: Toyon Lemonade berry Herbaceous plants, in some locales and succulents, are part of the flora. Hesperoyucca whipplei, colloquially known as Chaparral Yucca, is commonplace throughout the climate zone.
The coastal sage scrub plant community is divided into three geographical subtypes — northern coastal scrub, southern coastal scrub, maritime succulent scrub. The coastal scrub communities are divided into three regions: Northern Coastal Scrub and Coastal Prairie, which lies in San Luis Obispo to Oregon. Coastal Sage scrub, which lies in San Diego to Monterey. Maritime Succulent Scrub, which can be found in the San Diego County to Baja California; the Northern Coastal Scrub consists of prairie, terraces with deep alluvial soils, scrub, found on steeper slopes and ravine areas. Evergreen shrubs and subshrubs, which are soft leaves, they are found in semi-open with multiple layers. Some examples of the plant species that can be found are Bush monkeyflower, Poison oak, Coffee berry, Golden yarrow. California sagebrush can be found in Coastal Sage Scrub community in Orange County; some other plant species that can be found is Giant coreopsis, Black sage, California buckwheat, White sage. Plant species that can be found in Maritime Succulent Scrub is Coast prickly pear, Coast barrel cactus, Cliff spurge, Bush rue, Dudleya spp.
Northern coastal scrub occurs along the Pacific Coast from the northern San Francisco Bay Area northwards to southern Oregon. It forms a landscape mosaic with the California coastal prairie plant community; the predominant plants are low evergreen herbs. Characteristic shrubs include coyote brush, yerba santa, coast silk-tassel and yellow bush lupine. Herbaceous species include western blue-eyed grass, Douglas iris, grasses. Southern coastal scrub is found along the maritime Central Coast region, the terraces and mountains with coastal climate influence in Southern California, its distribution extends from the southwestern San Francisco Bay Area in the north, through Big Sur, Vandenberg Air Force Base, the Oxnard Plain, the Los Angeles Basin, most of Orange County, parts of Riverside County, coastal San Diego County, the northwestern region of Baja California state in Mexico, including the areas around Tijuana and Ensenada. Southern CaliforniaThe metropolitan areas of Los Angeles, San Diego, Tijuana are located in the southern coastal scrublands, most of the scrublands have been lost to urbanization and agriculture.
The plants of this community prefer the mild maritime climates found along Southern California's coastline. World Wildlife Fund estimates that only 15 percent of the coastal sage scrublands remain undeveloped; some of the remaining southern coastal scrub in Los Angeles County can be found in dunes under the takeoff path at Los Angeles International Airport—LAX, in the coastal Santa Monica Mountains National Recreation Area, at the Robert J. Bernard Field Station at the Claremont Colleges. In San Diego County, the Camp Pendleton Marine Corps Base protects larger areas, the Marine Corps Air Station Miramar has vernal pools and the endemic mint Pogogyne abramsii. One of the largest remaining areas of inland coastal sage scrub is found in the Temescal Mountains of Riverside County. A number of rare and endangered species occur in southern coastal scrub habitats. For example, the California gnatcatcher is a threatened bird species endemic to the coastal sage scrublands. Other endemic fauna includes the El Segundo blue butterfly in the LAX dunes.
The endangered Torrey pine is the dominant tree at Torrey Pines State Reserve in San Diego, one of only two known stands of this pine species. Terrace California coastal prairie California coastal sage and chaparral ecoregion In: Mayer KE and Laudenslayer WF. A Guide to Wildlife Habitats of California. Sacramento, CA: California Department of Fish and Game. Schoenherr, Allan A.. A Natural History of California. Berkeley, CA: University of California Press. "California coastal sage scrub and chaparral". Terrest
Petroleum industry
The petroleum industry known as the oil industry or the oil patch, includes the global processes of exploration, refining and marketing of petroleum products. The largest volume products of the industry are fuel gasoline. Petroleum is the raw material for many chemical products, including pharmaceuticals, fertilizers, synthetic fragrances, plastics; the extreme monetary value of oil and its products has led to it being known as "black gold". The industry is divided into three major components: upstream and downstream. Petroleum is vital to many industries, is necessary for the maintenance of industrial civilization in its current configuration, making it a critical concern for many nations. Oil accounts for a large percentage of the world’s energy consumption, ranging from a low of 32% for Europe and Asia, to a high of 53% for the Middle East. Other geographic regions' consumption patterns are as follows: South and Central America and North America; the world consumes 30 billion barrels of oil per year, with developed nations being the largest consumers.
The United States consumed 25% of the oil produced in 2007. The production, distribution and retailing of petroleum taken as a whole represents the world's largest industry in terms of dollar value. Governments such as the United States government provide a heavy public subsidy to petroleum companies, with major tax breaks at every stage of oil exploration and extraction, including the costs of oil field leases and drilling equipment. In recent years, enhanced oil recovery techniques — most notably multi-stage drilling and hydraulic fracturing — have moved to the forefront of the industry as this new technology plays a crucial and controversial role in new methods of oil extraction. Petroleum is a occurring liquid found in rock formations, it consists of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds. It is accepted that oil is formed from the carbon rich remains of ancient plankton after exposure to heat and pressure in Earth's crust over hundreds of millions of years.
Over time, the decayed residue was covered by layers of mud and silt, sinking further down into Earth’s crust and preserved there between hot and pressured layers transforming into oil reservoirs. Petroleum in an unrefined state has been utilized by humans for over 5000 years. Oil in general has been used since early human history to keep fires ablaze and in warfare, its importance to the world economy however, evolved with whale oil being used for lighting in the 19th century and wood and coal used for heating and cooking well into the 20th century. Though the Industrial Revolution generated an increasing need for energy, this was met by coal, from other sources including whale oil. However, when it was discovered that kerosene could be extracted from crude oil and used as a lighting and heating fuel, the demand for petroleum increased and by the early twentieth century had become the most valuable commodity traded on world markets. Imperial Russia doubled its output by mid-century. After oil drilling began in what is now Azerbaijan in 1846 in Baku, two large pipelines were built in the Russian Empire: the 833 km long pipeline to transport oil from the Caspian to the Black Sea port of Batum, completed in 1906, the 162 km long pipeline to carry oil from Chechnya to the Caspian.
Batum is renamed to Batumi in 1936. At the turn of the 20th century, Imperial Russia's output of oil entirely from the Apsheron Peninsula, accounted for half of the world's production and dominated international markets. Nearly 200 small refineries operated in the suburbs of Baku by 1884; as a side effect of these early developments, the Apsheron Peninsula emerged as the world's "oldest legacy of oil pollution and environmental negligence". In 1846, Baku the first well drilled with percussion tools to a depth of 21 meters for oil exploration. In 1878, Ludvig Nobel and his Branobel company "revolutionized oil transport" by commissioning the first oil tanker and launching it on the Caspian Sea. Samuel Kier established America's first oil refinery in Pittsburgh on Seventh avenue near Grant Street, in 1853. One of the first modern oil refineries were built by Ignacy Łukasiewicz near Jasło, Poland in 1854–56; these were small, as demand for refined fuel was limited. The refined products were used in artificial asphalt, machine oil and lubricants, in addition to Łukasiewicz's kerosene lamp.
As kerosene lamps gained popularity, the refining industry grew in the area. The first commercial oil well in Canada became operational in 1858 at Ontario. Businessman James Miller Williams dug several wells between 1855 and 1858 before discovering a rich reserve of oil four metres below ground. Williams extracted 1.5 million litres of crude oil by 1860, refining much of it into kerosene lamp oil. Some historians challenge Canada’s claim to North America’s first oil field, arguing that Pennsylvania’s famous Drake Well was the continent’s first, but there is evidence to support Williams, not least of, that the Drake well did not come into production until August 28, 1859. The controversial point might be that Williams found oil above bedrock while Edwin Drake’s well located oil within a bedrock reservoir; the discovery at Oil Springs touched off an oil boom which brought hundreds of speculators and workers to the area. Canada's first gusher (fl
Mid-century modern
Mid-century modern is the design movement in interior, graphic design and urban development from 1933 to 1965. The term, employed as a style descriptor as early as the mid-1950s, was reaffirmed in 1983 by Cara Greenberg in the title of her book, Mid-Century Modern: Furniture of the 1950s, celebrating the style, now recognized by scholars and museums worldwide as a significant design movement; the Mid-Century modern movement in the U. S. was an American reflection of the International and Bauhaus movements, including the works of Gropius, Florence Knoll, Le Corbusier and Ludwig Mies van der Rohe. Although the American component was more organic in form and less formal than the International Style, it is more related to it than any other. Brazilian and Scandinavian architects were influential at this time, with a style characterized by clean simplicity and integration with nature. Like many of Wright's designs, Mid-Century architecture was employed in residential structures with the goal of bringing modernism into America's post-war suburbs.
This style emphasized creating structures with ample windows and open floor plans, with the intention of opening up interior spaces and bringing the outdoors in. Many Mid-century houses utilized then-groundbreaking post and beam architectural design that eliminated bulky support walls in favor of walls made of glass. Function was as important as form in Mid-Century designs, with an emphasis placed on targeting the needs of the average American family. In Europe the influence of Le Corbusier and the CIAM resulted in an architectural orthodoxy manifest across most parts of post-war Europe, challenged by the radical agendas of the architectural wings of the avant-garde Situationist International, COBRA, as well as Archigram in London. A critical but sympathetic reappraisal of the internationalist oeuvre, inspired by Scandinavian Moderns such as Alvar Aalto, Sigurd Lewerentz and Arne Jacobsen, the late work of Le Corbusier himself, was reinterpreted by groups such as Team X, including structuralist architects such as Aldo van Eyck, Ralph Erskine, Denys Lasdun, Jorn Utzon and the movement known in the United Kingdom as New Brutalism.
Pioneering builder and real estate developer Joseph Eichler was instrumental in bringing Mid-Century Modern architecture to subdivisions in the Los Angeles area and the San Francisco Bay region of California, select housing developments on the east coast. George Fred Keck, his brother Willam Keck, Henry P. Glass, Ludwig Mies van der Rohe, Edward Humrich created Mid-Century Modern residences in the Chicago area. Mies van der Rohe's Farnsworth House is difficult to heat or cool, while Keck and Keck were pioneers in the incorporation of passive solar features in their houses to compensate for their large glass windows; the city of Palm Springs, California is noted for its many examples of Mid-century modern architecture. Architects include: Welton Becket: Bullock's Palm Springs John Porter Clark: Welwood Murray Library. J. Robinson House. John Lautner: Desert Hot Springs Motel. John Black Lee: Specialized in residential houses. Lee House 1, Lee House 2 for which he won the Award of Merit from the American Institute of Architects, Day House, * System House, Rogers House, Ravello Frederick Monhoff: Palm Springs Biltmore Resort Richard Neutra: Grace Lewis Miller house.
M. Schindler: Paul and Betty Popenoe Cabin, Coachella. Home develope
Los Angeles County Museum of Art
The Los Angeles County Museum of Art is an art museum located on Wilshire Boulevard in the Miracle Mile vicinity of Los Angeles. LACMA is on Museum Row, adjacent to the La Brea Tar Pits. LACMA is the largest art museum in the western United States, it attracts nearly a million visitors annually. It holds more than 150,000 works spanning the history of art from ancient times to the present. In addition to art exhibits, the museum features concert series; the Los Angeles County Museum of Art was established as a museum in 1961. Prior to this, LACMA was part of the Los Angeles Museum of History and Art, founded in 1910 in Exposition Park near the University of Southern California. Howard F. Ahmanson, Sr. Anna Bing Arnold and Bart Lytton were the first principal patrons of the museum. Ahmanson made the lead donation of $2 million, convincing the museum board that sufficient funds could be raised to establish the new museum. In 1965 the museum moved to a new Wilshire Boulevard complex as an independent, art-focused institution, the largest new museum to be built in the United States after the National Gallery of Art.
The museum, built in a style similar to Lincoln Center and the Los Angeles Music Center, consisted of three buildings: the Ahmanson Building, the Bing Center, the Lytton Gallery. The board selected LA architect William Pereira over the directors' recommendation of Ludwig Mies van der Rohe for the buildings. According to a 1965 Los Angeles Times story, the total cost of the three buildings was $11.5 million. Construction began in 1963, was undertaken by the Del E. Webb Corporation. Construction was completed in early 1965. At the time, the Los Angeles Music Center and LACMA were concurrent large civic projects which vied for attention and donors in Los Angeles; when the museum opened, the buildings were surrounded by reflecting pools, but they were filled in and covered over when tar from the adjacent La Brea Tar Pits began seeping in. Money poured into LACMA during the boom years of the 1980s, a $209 million in private donations during director Earl Powell's tenure. To house its growing collections of modern and contemporary art and to provide more space for exhibitions, the museum hired the architectural firm of Hardy Holzman Pfeiffer Associates to design its $35.3-million, 115,000-square-foot Robert O. Anderson Building for 20th-century art, which opened in 1986.
In the far-reaching expansion, museum-goers henceforth entered through the new roofed central court, nearly an acre of space bounded by the museum's four buildings. The museum's Pavilion for Japanese Art, designed by maverick architect Bruce Goff, opened in 1988, as did the B. Gerald Cantor Sculpture Garden of Rodin bronzes. In 1999, the Hancock Park Improvement Project was complete, the LACMA-adjacent park was inaugurated with a free public celebration; the $10-million renovation replaced dead trees and bare earth with picnic facilities, viewing sites for the La Brea tar pits and a 150-seat red granite amphitheater designed by artist Jackie Ferrara. In 1994, LACMA purchased the adjacent former May Company department store building, an impressive example of streamline moderne architecture designed by Albert C. Martin Sr. LACMA West increased the museum's size by 30 percent when the building opened in 1998. In 2004 LACMA's Board of Trustees unanimously approved a plan for LACMA's transformation by architect Rem Koolhaas, who had proposed razing all the current buildings and constructing an new single, tent-topped structure, estimated to cost $200 million to $300 million.
Kohlhaas edged out French architect Jean Nouvel, who would have added a major building while renovating the older facilities. The list of candidates had narrowed to five in May 2001: Koolhaas, Steven Holl, Daniel Libeskind and Thom Mayne. However, the project soon stalled. In 2004 LACMA's Board of Trustees unanimously approved plans to transform the museum, led by architect Renzo Piano; the planned transformation consisted of three phases. Phase I started in 2004 and was completed in February 2008; the renovations required demolishing the parking structure on Ogden Avenue and with it LACMA-commissioned graffiti art by street artists Margaret Kilgallen and Barry McGee. The entry pavilion is a key point in architect Renzo Piano's plan to unify LACMA's sprawling confusing layout of buildings; the BP Grand Entrance and the adjacent Broad Contemporary Art Museum comprise the $191 million first phase of the three-part expansion and renovation campaign. BCAM is named for Edy Broad, who gave $60 million to LACMA's campaign.
BCAM opened on February 2008, adding 58,000 square feet of exhibition space to the museum. In 2010 the Lynda and Stewart Resnick Exhibition Pavilion opened to the public, providing the largest purpose-built lit, open-plan museum space in the world; the second phase was intended to turn the May building into new offices and galleries, designed by SPF Architects. As proposed, it would have had flexible gallery space, education space, administrative offices, a new restaurant, a gift shop and a bookstore, as well as study centers for the museum's departments of costume and textiles and prints and drawings, a roof sculpture garden with two works by James Turrell. However, construction of this phase was halted in November 2010. Phase two and three were never completed. In October 2011, LACMA entered into an agreement with the Academy of Motion Picture Arts and Sciences under which the Academ
Habitat
In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both biological features. A species' habitat is those places where it can find food, shelter and mates for reproduction; the physical factors are for example soil, range of temperature, 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 specific in their requirements. A habitat is not a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, 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 and tropical; the terrestrial vegetation type may be forest, grassland, semi-arid or desert. Fresh water habitats include marshes, rivers and ponds, marine habitats include salt marshes, the coast, the intertidal zone, reefs, 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. Other changes come as a direct result of human activities; 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. 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, it is similar in meaning to a biotope. The chief environmental factors affecting the distribution of living organisms are temperature, climate, soil type and light intensity, the presence or absence of all the requirements that the organism needs to sustain it. Speaking, animal communities are reliant on specific types of plant communities.
Some plants and animals are generalists, their habitat requirements are met in a wide range of locations. The small white butterfly 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, it thrives in any open location with diverse plant associations. The large blue butterfly is much more specific in its requirements. 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. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. 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, not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands and deserts. Within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils 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. Freshwater habitats include rivers, lakes, ponds and bogs. 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 and backwaters which provide a range of habitats.
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, submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. Marine habitats include brackish water, bays, the open sea, the intertidal zone, the sea bed and deep / shallow water zones. Further variations include rock pools, sand banks, brackish lagoons and pebbly beaches, seagrass beds, all supporting their own flora and fauna; the benth
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is 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, civil engineering because of their role in soil conservation, their habitat biodiversity, the influence they have on fauna and aquatic ecosystems, including grasslands, wetlands, or 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. Riparian zones may be natural or engineered for soil restoration; these zones are important natural biofilters, protecting aquatic environments from excessive sedimentation, polluted surface runoff and erosion. They supply shelter and food for many aquatic animals and shade that limits stream temperature change.
When riparian zones are damaged by construction, agriculture or silviculture, biological restoration can take place by human intervention in erosion control and revegetation. If the area adjacent to a watercourse has standing water or saturated soil for as long as a season, it is termed a wetland because of its hydric soil characteristics; because of their prominent role in supporting a diversity of species, riparian zones are the subject of national protection in a biodiversity action plan. These are known as a "Plant or Vegetation Waste Buffer". Research shows that riparian zones are instrumental in water quality improvement for both surface runoff and water flowing into streams through subsurface or groundwater flow. Riparian zones can play a role in lowering nitrate contamination in surface runoff, such as manure and other fertilizers from agricultural fields, that would otherwise damage ecosystems and human health; the attenuation of nitrate or denitrification of the nitrates from fertilizer in this buffer zone is important.
The use of wetland riparian zones shows a high rate of removal of nitrate entering a stream and thus has a place in agricultural management. Riparian zones dissipate stream energy; the meandering curves of a river, combined with vegetation and root systems, slow the flow of water, which reduces soil erosion and flood damage. Sediment is trapped, reducing suspended solids to create less turbid water, replenish soils, build stream banks. Pollutants are filtered from surface runoff; the riparian zones provide wildlife habitat, increased biodiversity, wildlife corridors, enabling aquatic and riparian organisms to move along river systems avoiding isolated communities. Riparian vegetation can provide forage for wildlife and livestock. Riparian zones are important for the fish that live within rivers, such as brook and charr. Impacts to riparian zones can affect fish, restoration is not always sufficient to recover fish populations, they provide native landscape irrigation by extending perennial flows of water.
Nutrients from terrestrial vegetation are transferred to aquatic food webs. The vegetation surrounding the stream helps to shade the water, mitigating water temperature changes; the vegetation contributes wood debris to streams, important to maintaining geomorphology. From a social aspect, riparian zones contribute to nearby property values through amenity and views, they improve enjoyment for footpaths and bikeways through supporting foreshoreway networks. Space is created for riparian sports such as fishing and launching for vessels and paddlecraft; the riparian zone acts as a sacrificial erosion buffer to absorb impacts of factors including climate change, increased runoff from urbanization and increased boat wake without damaging structures located behind a setback zone. The protection of riparian zones is a consideration in logging operations; the undisturbed soil, soil cover, vegetation provide shade, plant litter, woody material, reduce the delivery of soil eroded from the harvested area.
Factors such as soil types and root structures, climatic conditions and vegetative cover determine the effectiveness of riparian buffering. The assortment of riparian zone trees varies from those of wetlands and consists of plants that are either emergent aquatic plants, or herbs and shrubs that thrive in proximity to water. Herbaceous Perennial: Herbaceous Perennial: In western North America and the Pacific coast, the riparian vegetation includes: Riparian trees Riparian shrubs Other plants In Asia there are different types of riparian vegetation, but the interactions between hydrology and ecology are similar as occurs in other geographic areas. Typical riparian vegetation in Temperate New South Wales, Australia include: Typical riparian zone trees in Central Europe include: Land clearing followed by floods can erode a riverbank, taking valuable grasses and soils downstream, allowing the sun to bake the land dry. Natural Sequence Farming techniques have been used in the Upper Hunter Valley of New South Wales, Australia, in an attempt to restore eroded farms to optimum productivity.
The Natural Sequence Farming technique involves placing obstacles in the water's pathway to lessen the energy of a flood, help the water to deposit soil and seep into the flood zone. Another technique is to establish ecological succession by encouraging fast-growing plants such as "weeds" to grow; these may spread along the watercourse and cause enviro
