Alaska is a U. S. state located in the northwest extremity of North America. To the north are the Chukchi and Beaufort seas–the southern parts of the Arctic Ocean, the Pacific Ocean lies to the south and southwest. Alaska is the largest state in the United States by area, the 3rd least populous, approximately half of Alaskas residents live within the Anchorage metropolitan area. Alaskas economy is dominated by the fishing, natural gas, military bases and tourism are a significant part of the economy. The United States purchased Alaska from the Russian Empire on March 30,1867, the area went through several administrative changes before becoming organized as a territory on May 11,1912. It was admitted as the 49th state of the U. S. on January 3,1959, the name Alaska was introduced in the Russian colonial period when it was used to refer to the peninsula. It was derived from an Aleut, or Unangam idiom, which refers to the mainland of Alaska. Literally, it means object to which the action of the sea is directed, Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere.
Alaska is the only non-contiguous U. S. state on continental North America and it is technically part of the continental U. S. but is sometimes not included in colloquial use, Alaska is not part of the contiguous U. S. often called the Lower 48. The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system. Alaskas territorial waters touch Russias territorial waters in the Bering Strait, as the Russian Big Diomede Island, Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the area of the next three largest states, Texas and Montana. It is larger than the area of the 22 smallest U. S. states. Also referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States, as such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase.
The region is dominated by the Alexander Archipelago as well as the Tongass National Forest and it contains the state capital Juneau, the former capital Sitka, and Ketchikan, at one time Alaskas largest city. The Alaska Marine Highway provides a vital transportation link throughout the area. The Interior is the largest region of Alaska, much of it is uninhabited wilderness, Fairbanks is the only large city in the region
Composed of igneous rock resulting from its long volcanic history, the area is covered by a thin layer of soil. Human population is sparse, and industrial development is minimal, while mining is prevalent, the Canadian Shield is a physiographic division, consisting of five smaller, physiographic provinces, the Laurentian Upland, Kazan Region, Davis and James. The shield extends into the United States as the Adirondack Mountains, the Canadian Shield is U-shaped and is a subsection of the Laurentia craton signifying the area of greatest glacial impact creating the thin soils. The Canadian Shield is more than 3.96 billion years old, the Canadian Shield once had jagged peaks, higher than any of todays mountains, but millions of years of erosion have changed these mountains to rolling hills. The Canadian Shield was the first part of North America to be elevated above sea level and has remained almost wholly untouched by successive encroachments of the sea upon the continent. It is the Earths greatest area of exposed Archean rock, the metamorphic base rocks are mostly from the Precambrian Supereon, and have been repeatedly uplifted and eroded.
Today it consists largely of an area of low relief 300 to 610 m above sea level with a few monadnocks, during the Pleistocene Epoch, continental ice sheets depressed the land surface, scooped out thousands of lake basins, and carried away much of the regions soil. When the Greenland section is included, the Shield is approximately circular, bounded on the northeast by the northeast edge of Greenland and it covers much of Greenland, most of Quebec north of the St. In total, the area of the Shield covers approximately 8,000,000 km2. The underlying rock structure includes Hudson Bay, the Canadian Shield is among the oldest on earth, with regions dating from 2.5 to 4.2 billion years. The multitude of rivers and lakes in the region is caused by the watersheds of the area being so young. It has some of the oldest volcanoes on the planet and it has over 150 volcanic belts whose bedrock ranges from 600 to 1200 million years old. Each belt probably grew by the coalescence of accumulations erupted from numerous vents, many of Canadas major ore deposits are associated with Precambrian volcanoes.
The Sturgeon Lake Caldera in Kenora District, Ontario, is one of the worlds best preserved mineralized Neoarchean caldera complexes, the Canadian Shield contains the Mackenzie dike swarm, which is the largest dike swarm known on Earth. Mountains have deep roots and float on the denser mantle much like an iceberg at sea, as mountains erode, their roots rise and are eroded in turn. The rocks that now form the surface of the Shield were once far below the Earths surface, the high pressures and temperatures at those depths provided ideal conditions for mineralization. Although these mountains are now eroded, many large mountains still exist in Canadas far north called the Arctic Cordillera. This is a vast deeply dissected mountain range, stretching from northernmost Ellesmere Island to the northernmost tip of Labrador, the ranges highest peak is Nunavuts Barbeau Peak at 2,616 metres above sea level
Hawaii is the 50th and most recent state to have joined the United States of America, having received statehood on August 21,1959. Hawaii is the only U. S. state located in Oceania and it is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean. Hawaii is the only U. S. state not located in the Americas, the state encompasses nearly the entire volcanic Hawaiian archipelago, which comprises hundreds of islands spread over 1,500 miles. At the southeastern end of the archipelago, the eight main islands are—in order from northwest to southeast, Niʻihau, Kauaʻi, Oʻahu, Molokaʻi, Lānaʻi, Kahoʻolawe and the Island of Hawaiʻi. The last is the largest island in the group, it is called the Big Island or Hawaiʻi Island to avoid confusion with the state or archipelago. The archipelago is physiographically and ethnologically part of the Polynesian subregion of Oceania, Hawaii has over a million permanent residents, along with many visitors and U. S. military personnel.
Its capital is Honolulu on the island of Oʻahu, Hawaii is the 8th-smallest and the 11th-least populous, but the 13th-most densely populated of the fifty U. S. states. It is the state with an Asian plurality. The states coastline is about 750 miles long, the fourth longest in the U. S. after the coastlines of Alaska, the state of Hawaii derives its name from the name of its largest island, Hawaiʻi. A common Hawaiian explanation of the name of Hawaiʻi is that was named for Hawaiʻiloa and he is said to have discovered the islands when they were first settled. The Hawaiian language word Hawaiʻi is very similar to Proto-Polynesian *Sawaiki, cognates of Hawaiʻi are found in other Polynesian languages, including Māori and Samoan. According to linguists Pukui and Elbert, lsewhere in Polynesia, Hawaiʻi or a cognate is the name of the underworld or of the home, but in Hawaii. A somewhat divisive political issue arose in 1978 when the Constitution of the State of Hawaii added Hawaiian as an official state language.
The title of the constitution is The Constitution of the State of Hawaii. Article XV, Section 1 of the Constitution uses The State of Hawaii, diacritics were not used because the document, drafted in 1949, predates the use of the okina and the kahakō in modern Hawaiian orthography. The exact spelling of the name in the Hawaiian language is Hawaiʻi. In the Hawaii Admission Act that granted Hawaiian statehood, the government recognized Hawaii as the official state name. Official government publications and office titles, and the Seal of Hawaii use the spelling with no symbols for glottal stops or vowel length
A national park is a park in use for conservation purposes. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns, although individual nations designate their own national parks differently, there is a common idea, the conservation of wild nature for posterity and as a symbol of national pride. An international organization, the International Union for Conservation of Nature, although Yellowstone was not officially termed a national park in its establishing law, it was always termed such in practice and is widely held to be the first and oldest national park in the world. The first area to use national park in its legislation was the USs Mackinac Island. Australias Royal National Park, established in 1879, was the third official national park. In 1895 ownership of Mackinac Island was transferred to the State of Michigan as a state park, as a result, Australias Royal National Park is by some considerations the second oldest national park now in existence.
The largest national park in the meeting the IUCN definition is the Northeast Greenland National Park. According to the IUCN,6,555 national parks worldwide met its criteria in 2006, IUCN is still discussing the parameters of defining a national park. National parks are almost always open to visitors, in 1971, these criteria were further expanded upon leading to more clear and defined benchmarks to evaluate a national park. In 1810, the English poet William Wordsworth described the Lake District as a sort of property, in which every man has a right and interest who has an eye to perceive. It was known as Hot Springs Reservation, but no authority was established. Federal control of the area was not clearly established until 1877, John Muir is today referred to as the Father of the National Parks due to his work in Yosemite. He published two articles in The Century Magazine, which formed the base for the subsequent legislation. President Abraham Lincoln signed an Act of Congress on July 1,1864, ceding the Yosemite Valley, according to this bill, private ownership of the land in this area was no longer possible.
The state of California was designated to manage the park for use, resort. Leases were permitted for up to ten years and the proceeds were to be used for conservation, a public discussion followed this first legislation of its kind and there was a heated debate over whether the government had the right to create parks. The perceived mismanagement of Yosemite by the Californian state was the reason why Yellowstone at its establishment six years was put under national control, in 1872, Yellowstone National Park was established as the United States first national park, being the worlds first national park. In some European countries, national protection and nature reserves already existed, such as Drachenfels, Yellowstone was part of a federally governed territory
World War II
World War II, known as the Second World War, was a global war that lasted from 1939 to 1945, although related conflicts began earlier. It involved the vast majority of the worlds countries—including all of the great powers—eventually forming two opposing alliances, the Allies and the Axis. It was the most widespread war in history, and directly involved more than 100 million people from over 30 countries. Marked by mass deaths of civilians, including the Holocaust and the bombing of industrial and population centres. These made World War II the deadliest conflict in human history, from late 1939 to early 1941, in a series of campaigns and treaties, Germany conquered or controlled much of continental Europe, and formed the Axis alliance with Italy and Japan. Under the Molotov–Ribbentrop Pact of August 1939, Germany and the Soviet Union partitioned and annexed territories of their European neighbours, Finland and the Baltic states. In December 1941, Japan attacked the United States and European colonies in the Pacific Ocean, and quickly conquered much of the Western Pacific.
The Axis advance halted in 1942 when Japan lost the critical Battle of Midway, near Hawaii, in 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained all of its territorial losses and invaded Germany and its allies. During 1944 and 1945 the Japanese suffered major reverses in mainland Asia in South Central China and Burma, while the Allies crippled the Japanese Navy, thus ended the war in Asia, cementing the total victory of the Allies. World War II altered the political alignment and social structure of the world, the United Nations was established to foster international co-operation and prevent future conflicts. The victorious great powers—the United States, the Soviet Union, the United Kingdom, the Soviet Union and the United States emerged as rival superpowers, setting the stage for the Cold War, which lasted for the next 46 years. Meanwhile, the influence of European great powers waned, while the decolonisation of Asia, most countries whose industries had been damaged moved towards economic recovery.
Political integration, especially in Europe, emerged as an effort to end pre-war enmities, the start of the war in Europe is generally held to be 1 September 1939, beginning with the German invasion of Poland and France declared war on Germany two days later. The dates for the beginning of war in the Pacific include the start of the Second Sino-Japanese War on 7 July 1937, or even the Japanese invasion of Manchuria on 19 September 1931. Others follow the British historian A. J. P. Taylor, who held that the Sino-Japanese War and war in Europe and its colonies occurred simultaneously and this article uses the conventional dating. Other starting dates sometimes used for World War II include the Italian invasion of Abyssinia on 3 October 1935. The British historian Antony Beevor views the beginning of World War II as the Battles of Khalkhin Gol fought between Japan and the forces of Mongolia and the Soviet Union from May to September 1939, the exact date of the wars end is not universally agreed upon.
It was generally accepted at the time that the war ended with the armistice of 14 August 1945, rather than the formal surrender of Japan
Bureau of Land Management
President Harry S. Truman created the BLM in 1946 by combining two existing agencies, the General Land Office and the Grazing Service. Most BLM public lands are located in these 12 western states, Arizona, Colorado, Montana, New Mexico, Utah and Wyoming. The mission of the BLM is to sustain the health, originally BLM holdings were described as land nobody wanted because homesteaders had passed them by. All the same, ranchers hold nearly 18,000 permits, the agency manages 221 wilderness areas,23 national monuments and some 636 other protected areas as part of the National Landscape Conservation System totaling about 30 million acres. There are more than 63,000 oil and gas wells on BLM public lands, total energy leases generated approximately $5.4 billion in 2013, an amount divided among the Treasury, the states, and Native American groups. The BLMs roots go back to the Land Ordinance of 1785 and these laws provided for the survey and settlement of the lands that the original 13 colonies ceded to the federal government after the American Revolution.
As additional lands were acquired by the United States from Spain and other countries, the United States Congress directed that they be explored, during the Revolutionary War, military bounty land was promised to soldiers who fought for the colonies. After the war, the Treaty of Paris of 1783, signed by the United States, France, in the 1780s, other states relinquished their own claims to land in modern-day Ohio. By this time, the United States needed revenue to function, Land was sold so that the government would have money to survive. In order to sell the land, surveys needed to be conducted, the Land Ordinance of 1785 instructed a geographer to oversee this work as undertaken by a group of surveyors. The first years of surveying were completed by trial and error, once the territory of Ohio had been surveyed, in 1812, Congress established the General Land Office as part of the Department of the Treasury to oversee the disposition of these federal lands. By the early 1800s, promised bounty land claims were finally fulfilled, over the years, other bounty land and homestead laws were enacted to dispose of federal land.
Several different types of patents existed and these include cash entry, homestead, military warrants, mineral certificates, private land claims, state selections, town sites, and town lots. A system of land offices spread throughout the territories, patenting land that was surveyed via the corresponding Office of the Surveyor General of a particular territory. This pattern gradually spread across the entire United States, the laws that spurred this system with the exception of the General Mining Law of 1872 and the Desert Land Act of 1877 have since been repealed or superseded. The Mineral Leasing Act of 1920 allowed leasing and production of selected commodities, such as coal, gas, the Taylor Grazing Act of 1934 established the United States Grazing Service to manage the public rangelands by establishment of advisory boards that set grazing fees. The Oregon and California Revested Lands Sustained Yield Management Act of 1937, commonly referred as the O&C Act, in 1946, the Grazing Service was merged with the General Land Office to form the Bureau of Land Management within the Department of the Interior.
It took several years for new agency to integrate and reorganize
The common use of the name sequoia generally refers to Sequoiadendron giganteum, which occurs naturally only in groves on the western slopes of the Sierra Nevada Mountains of California. The etymology of the name has been presumed—initially in The Yosemite Book by Josiah Whitney in 1868—to be in honor of Sequoyah. Giant sequoias are the worlds largest single trees and largest living thing by volume, Giant sequoias grow to an average height of 50–85 m and 6–8 m in diameter. Record trees have been measured to be 94.8 m in height, claims of 17 m diameter have been touted by taking an authors writing out of context, but the widest known at chest height is closer to 8.2 m. Between 2014 and 2016, specimens of coast redwood were found to have larger trunk diameters than all known giant sequoias, the oldest known giant sequoia based on ring count is 3,500 years old. Giant Sequoias are among the oldest living things on Earth, Sequoia bark is fibrous and may be 90 cm thick at the base of the columnar trunk.
It provides significant fire protection for the trees, the leaves are evergreen, awl-shaped, 3–6 millimetres long, and arranged spirally on the shoots. The seed is brown, 4–5 millimetres long and 1 millimetre broad, with a 1-millimetre wide. Some seeds are shed when the cone scales shrink during hot weather in late summer, the giant sequoia regenerates by seed. Young trees start to bear cones at the age of 12 years, Trees up to about 20 years old may produce stump sprouts subsequent to injury, but unlike coast redwoods, shoots do not form on the stumps of mature trees. Giant sequoias of all ages may sprout from their boles when branches are lost to fire or breakage, at any given time, a large tree may be expected to have about 11,000 cones. Cone production is greatest in the portion of the canopy. A mature giant sequoia has been estimated to disperse 300, 000–400,000 seeds per year, the winged seeds may be carried up to 180 metres from the parent tree. Lower branches die fairly readily from shading, but trees less than 100 years old retain most of their dead branches, trunks of mature trees in groves are generally free of branches to a height of 20–50 metres, but solitary trees will retain low branches.
Because of its size, the tree has been studied for its water pull, Sequoias supplement water from the soil with fog, taken up through air roots, at heights to where the root water cannot be pulled. The natural distribution of giant sequoias is restricted to an area of the western Sierra Nevada. They occur in scattered groves, with a total of 68 groves, nowhere does it grow in pure stands, although in a few small areas, stands do approach a pure condition. The northern two-thirds of its range, from the American River in Placer County southward to the Kings River, has only eight disjunct groves, the remaining southern groves are concentrated between the Kings River and the Deer Creek Grove in southern Tulare County
Conservation in the United States
Conservation in the United States can be traced back to the 19th century with the formation of the first National Park. Conservation generally refers to the act of consciously and efficiently using land and/or its natural resources. This can be in the form of setting aside tracts of land for protection from hunting or urban development, or it can take the form of using resources such as metal, water. Usually, this process of conservation occurs through or after legislation on local or national levels is passed, during the 19th century, some Americans developed a deep and abiding passion for nature. Likewise, in 1860, Frederic Edwin Church painted Twilight in the Wilderness, many American writers romanticized and focused upon nature as a subject matter. However, the most notable literary figure upon the early conservation movement proved to be Henry David Thoreau, throughout his work, Thoreau detailed his experiences at the natural setting of Walden Pond and his deep appreciation for nature.
In one instance, he described a deep grief for a tree that was cut down, as he states in Walden, Thoreau was interested in the preservation of nature. This speech became one of Thoreaus most influential contributions to conservationist thought. The early conservation movement in the United States was due to the hard work of John Muir. Muir, who is cited as one of the first American environmentalists, has earned multiple American honors for environmental work. His family home in Martinez, California, is honored as a National Historic Site and so is his home in Portage. He was a former worker who was nearly blinded by an accident at work. After almost losing his sight, Muir decided to see Americas natural wonders, based upon his travels throughout Yosemite and the Sierra Nevada Mountains, Muir wrote a collection of articles for Century magazine, entitled Studies in the Sierra. Early Americans recognized the importance of resources and the necessity of wilderness preservation for sustained yield harvesting of natural resources.
In essence, the preservation of wilderness and landscapes were recognized as critical for future generations, the foundation of the conservation movement is grounded during this period between 1850 and 1920. Ultimately, historical trends and cultural mind-sets were united, which influenced ideas, environmental historians, like Carolyn Merchant, cite Muir as someone who was unwilling to extend his efforts of conservation toward groups of people who were not white. America had its own movement in the 19th century, most often characterized by George Perkins Marsh, author of Man. The expedition into northwest Wyoming in 1871 led by F. V, travels by U. S. President Theodore Roosevelt through the region around Yellowstone provided the impetus for the creation of the Yellowstone Timberland Reserve in 1891
California is the most populous state in the United States and the third most extensive by area. Located on the western coast of the U. S, California is bordered by the other U. S. states of Oregon and Arizona and shares an international border with the Mexican state of Baja California. Los Angeles is Californias most populous city, and the second largest after New York City. The Los Angeles Area and the San Francisco Bay Area are the nations second- and fifth-most populous urban regions, California has the nations most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The Central Valley, an agricultural area, dominates the states center. What is now California was first settled by various Native American tribes before being explored by a number of European expeditions during the 16th and 17th centuries, the Spanish Empire claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its war for independence.
The western portion of Alta California was organized as the State of California, the California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom. If it were a country, California would be the 6th largest economy in the world, fifty-eight percent of the states economy is centered on finance, real estate services and professional, scientific and technical business services. Although it accounts for only 1.5 percent of the states economy, the story of Calafia is recorded in a 1510 work The Adventures of Esplandián, written as a sequel to Amadis de Gaula by Spanish adventure writer Garci Rodríguez de Montalvo. The kingdom of Queen Calafia, according to Montalvo, was said to be a land inhabited by griffins and other strange beasts. This conventional wisdom that California was an island, with maps drawn to reflect this belief, shortened forms of the states name include CA, Cal. Calif. and US-CA.
Settled by successive waves of arrivals during the last 10,000 years, various estimates of the native population range from 100,000 to 300,000. The Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups were diverse in their organization with bands, villages. Trade and military alliances fostered many social and economic relationships among the diverse groups, the first European effort to explore the coast as far north as the Russian River was a Spanish sailing expedition, led by Portuguese captain Juan Rodríguez Cabrillo, in 1542. Some 37 years English explorer Francis Drake explored and claimed a portion of the California coast in 1579. Spanish traders made unintended visits with the Manila galleons on their trips from the Philippines beginning in 1565
Fauna of the United States
The U. S. has many distinctive indigenous species found nowhere else on Earth. With most of the North American continent, the U. S. lies in the Nearctic faunistic realm, an estimated 432 species of mammals characterize the fauna of the continental U. S. There are more than 800 species of bird and more than 100,000 known species of insects, there are 311 known reptiles,295 amphibians and 1154 known fish species in the U. S. The red-tailed hawk is one of the most widely distributed not only in the U. S. Huge parts of the country with the most distinctive indigenous wildlife are protected as national parks, in 2013, the U. S. had more than 6770 national parks or protected areas, all together more than 1,006,619 sq. miles. The first national park was Yellowstone National Park in the state of Wyoming, Yellowstone National Park is widely considered to be the finest megafauna wildlife habitat in the U. S. There are 67 species of mammals in the park, including the wolf, the threatened lynx. The ecoregions and ecology found in the Western United States are extremely varied, the western continental coast of the U. S.
just as the East Coast, varies from a colder-to-warmer climate from north to south. Few species live though-out the entire West Coast, there are some, in most of the contagious Western U. S. are mule deer, white-tailed antelope squirrels, American badgers, coyotes and several species of snakes and lizards are common. While the American black bear lives throughout the U. S. the brown bears and grizzly bears are common in the northwest. Along the West Coast there are species of whales, sea otters, California sea lions, eared seals. In the dry, inland areas of states such as California, Nevada and New Mexico there are some of the world’s most venomous lizards, snakes. The most notorious might be the Gila monster and Mohave rattlesnake, the Sonoran Desert has eleven species of rattlesnakes - more than anywhere else in the world. Along the southwestern border there are jaguars and ocelots, other mammals include the Virginia opossum, which occurs throughout California and coastal areas in Oregon and Washington.
The North American beaver and mountain beaver live in forested areas of Washington, the kit fox lives throughout Arizona, New Mexico and Utah, while the gray fox occurs throughout the Western U. S. The red fox occurs mostly in Oregon and Washington, while the fox is a native to six of the eight Channel Islands in Southern California. The raccoon and spotted skunk occur throughout the Western U. S. while the ring-tailed cat occurs throughout Arizona, New Mexico, Western Texas, Colorado, the American black bear occurs in most western states, including Washington, California and Colorado. The Channel Islands National Park consists of five out of the eight California Channel Islands, the Channel Islands are part of one of the richest marine biospheres of the world
The American bison, commonly known as the American buffalo or simply buffalo, is a North American species of bison that once roamed the grasslands of North America in massive herds. Bison were seen in North Carolina near Buffalo Ford on the Catawba River as late as 1750. Two subspecies or ecotypes have been described, the bison, smaller in size and with a more rounded hump. Furthermore, the bison has been suggested to consist of a northern. However, this is not supported. The wood bison is one of the largest wild species of bovid in the world, surpassed by only the Asian gaur and it is the largest extant land animal in the Americas. The American bison is the mammal of the United States. The term buffalo is considered to be a misnomer for this animal, and could be confused with true buffalos, the Asian water buffalo. The name buffalo is listed in dictionaries as an acceptable name for American buffalo or bison. In reference to animal, the term buffalo dates to 1625 in North American usage when the term was first recorded for the American mammal.
It thus has a longer history than the term bison. The American bison is very related to the wisent or European bison. In Plains Indian languages in general and female buffaloes are distinguished, a bison has a shaggy, dark-brown winter coat, and a lighter-weight, lighter-brown summer coat. As is typical in ungulates, the bison is slightly larger than the female and, in some cases. Plains bison are often in the range of sizes. Head-and-body lengths range from 2 to 3.5 m long, shoulder heights in the species can range from 152 to 186 cm. Weights can range from 318 to 1,000 kg Mature bulls tend to be larger than cows. Cow weights have had reported medians of 450 to 495 kg, with one small sample averaging 479 kg, the heaviest wild bull ever recorded weighed 1,270 kg
Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are called invasive species, some have a negative effect on a local ecosystem. Some introduced species may have no effect or only minor impact. Some species have been introduced intentionally to combat pests and they are called biocontrols and may be regarded as beneficial as an alternative to pesticides in agriculture for example. In some instances the potential for being beneficial or detrimental in the long run remains unknown, a list of some introduced species is given in a separate article. The effects of introduced species on natural environments have gained much scrutiny from scientists, the terminology associated with introduced species is now in flux for various reasons. The term invasive refers only to those species that become established, for practical purposes, this term is applied only to invasive species that cause damage. With respect to plants, these latter are in this case defined as either ornamental or cultivated plants, called an exotic or non-native species.
Such species might be termed naturalized, wild non-native species, if they further spread beyond the place of introduction they are called invasive. The transition from introduction, to establishment and to invasion has been described in the context of plants, introduced species are essentially non-native species. Invasive species are introduced species that spreadwidely or quickly and cause harm, be that to the environment, human health. There have been calls from scientists to consider a species only in terms of their spread. According to a definition, an invasive species is one that has been introduced and become a pest in its new location. The term is used to both a sense of urgency and actual or potential harm. Executive Order 13112 defines invasive species as a species whose introduction does or is likely to cause economic or environmental harm or harm to human health. The biological definition of species, on the other hand, makes no reference to the harm they may cause. From a regulatory perspective, it is neither desirable nor practical to list as undesirable or outright ban all non-native species, regulations require a definitional distinction between non-natives that are deemed especially onerous and all others.
Introduced pest species that are listed as invasive, best fit the definition of an invasive species