1.
Taxonomy (biology)
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Taxonomy is the science of defining groups of biological organisms on the basis of shared characteristics and giving names to those groups. The exact definition of taxonomy varies from source to source, but the core of the remains, the conception, naming. There is some disagreement as to whether biological nomenclature is considered a part of taxonomy, the broadest meaning of taxonomy is used here. The word taxonomy was introduced in 1813 by Candolle, in his Théorie élémentaire de la botanique, the term alpha taxonomy is primarily used today to refer to the discipline of finding, describing, and naming taxa, particularly species. In earlier literature, the term had a different meaning, referring to morphological taxonomy, ideals can, it may be said, never be completely realized. They have, however, a value of acting as permanent stimulants. Some of us please ourselves by thinking we are now groping in a beta taxonomy, turrill thus explicitly excludes from alpha taxonomy various areas of study that he includes within taxonomy as a whole, such as ecology, physiology, genetics, and cytology. He further excludes phylogenetic reconstruction from alpha taxonomy, thus, Ernst Mayr in 1968 defined beta taxonomy as the classification of ranks higher than species. This activity is what the term denotes, it is also referred to as beta taxonomy. How species should be defined in a group of organisms gives rise to practical and theoretical problems that are referred to as the species problem. The scientific work of deciding how to define species has been called microtaxonomy, by extension, macrotaxonomy is the study of groups at higher taxonomic ranks, from subgenus and above only, than species. While some descriptions of taxonomic history attempt to date taxonomy to ancient civilizations, earlier works were primarily descriptive, and focused on plants that were useful in agriculture or medicine. There are a number of stages in scientific thinking. Early taxonomy was based on criteria, the so-called artificial systems. Later came systems based on a complete consideration of the characteristics of taxa, referred to as natural systems, such as those of de Jussieu, de Candolle and Bentham. The publication of Charles Darwins Origin of Species led to new ways of thinking about classification based on evolutionary relationships and this was the concept of phyletic systems, from 1883 onwards. This approach was typified by those of Eichler and Engler, the advent of molecular genetics and statistical methodology allowed the creation of the modern era of phylogenetic systems based on cladistics, rather than morphology alone. Taxonomy has been called the worlds oldest profession, and naming and classifying our surroundings has likely been taking place as long as mankind has been able to communicate
2.
Plant
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Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae. The term is generally limited to the green plants, which form an unranked clade Viridiplantae. This includes the plants, conifers and other gymnosperms, ferns, clubmosses, hornworts, liverworts, mosses and the green algae. Green plants have cell walls containing cellulose and obtain most of their energy from sunlight via photosynthesis by primary chloroplasts and their chloroplasts contain chlorophylls a and b, which gives them their green color. Some plants are parasitic and have lost the ability to produce amounts of chlorophyll or to photosynthesize. Plants are characterized by sexual reproduction and alternation of generations, although reproduction is also common. There are about 300–315 thousand species of plants, of which the great majority, green plants provide most of the worlds molecular oxygen and are the basis of most of Earths ecologies, especially on land. Plants that produce grains, fruits and vegetables form humankinds basic foodstuffs, Plants play many roles in culture. They are used as ornaments and, until recently and in variety, they have served as the source of most medicines. The scientific study of plants is known as botany, a branch of biology, Plants are one of the two groups into which all living things were traditionally divided, the other is animals. The division goes back at least as far as Aristotle, who distinguished between plants, which generally do not move, and animals, which often are mobile to catch their food. Much later, when Linnaeus created the basis of the system of scientific classification. Since then, it has become clear that the plant kingdom as originally defined included several unrelated groups, however, these organisms are still often considered plants, particularly in popular contexts. When the name Plantae or plant is applied to a group of organisms or taxon. The evolutionary history of plants is not yet settled. Those which have been called plants are in bold, the way in which the groups of green algae are combined and named varies considerably between authors. Algae comprise several different groups of organisms which produce energy through photosynthesis, most conspicuous among the algae are the seaweeds, multicellular algae that may roughly resemble land plants, but are classified among the brown, red and green algae. Each of these groups also includes various microscopic and single-celled organisms
3.
Flowering plant
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The flowering plants, also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants, with 416 families, approx. 13,164 known genera and a total of c.295,383 known species, etymologically, angiosperm means a plant that produces seeds within an enclosure, in other words, a fruiting plant. The term angiosperm comes from the Greek composite word meaning enclosed seeds, the ancestors of flowering plants diverged from gymnosperms in the Triassic Period, during the range 245 to 202 million years ago, and the first flowering plants are known from 160 mya. They diversified extensively during the Lower Cretaceous, became widespread by 120 mya, angiosperms differ from other seed plants in several ways, described in the table. These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants, the amount and complexity of tissue-formation in flowering plants exceeds that of gymnosperms. The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings, in the dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium, the soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Among the monocotyledons, the bundles are more numerous in the stem and are scattered through the ground tissue. They contain no cambium and once formed the stem increases in diameter only in exceptional cases, the characteristic feature of angiosperms is the flower. Flowers show remarkable variation in form and elaboration, and provide the most trustworthy external characteristics for establishing relationships among angiosperm species, the function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The floral apparatus may arise terminally on a shoot or from the axil of a leaf, occasionally, as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. There are two kinds of cells produced by flowers. Microspores, which divide to become pollen grains, are the male cells and are borne in the stamens. The female cells called megaspores, which divide to become the egg cell, are contained in the ovule. The flower may consist only of parts, as in willow. Usually, other structures are present and serve to protect the sporophylls, the individual members of these surrounding structures are known as sepals and petals. The outer series is usually green and leaf-like, and functions to protect the rest of the flower, the inner series is, in general, white or brightly colored, and is more delicate in structure. It functions to attract insect or bird pollinators, attraction is effected by color, scent, and nectar, which may be secreted in some part of the flower
4.
Carl Linnaeus
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Carl Linnaeus, also known after his ennoblement as Carl von Linné, was a Swedish botanist, physician, and zoologist, who formalised the modern system of naming organisms called binomial nomenclature. He is known by the father of modern taxonomy. Many of his writings were in Latin, and his name is rendered in Latin as Carolus Linnæus, Linnaeus was born in the countryside of Småland, in southern Sweden. He received most of his education at Uppsala University. He lived abroad between 1735 and 1738, where he studied and also published a first edition of his Systema Naturae in the Netherlands and he then returned to Sweden, where he became professor of medicine and botany at Uppsala. In the 1740s, he was sent on journeys through Sweden to find and classify plants. In the 1750s and 1760s, he continued to collect and classify animals, plants, and minerals, at the time of his death, he was one of the most acclaimed scientists in Europe. The philosopher Jean-Jacques Rousseau sent him the message, Tell him I know no man on earth. The German writer Johann Wolfgang von Goethe wrote, With the exception of Shakespeare and Spinoza, Swedish author August Strindberg wrote, Linnaeus was in reality a poet who happened to become a naturalist. Among other compliments, Linnaeus has been called Princeps botanicorum, The Pliny of the North and he is also considered as one of the founders of modern ecology. In botany, the abbreviation used to indicate Linnaeus as the authority for species names is L. In older publications, sometimes the abbreviation Linn. is found, Linnæus was born in the village of Råshult in Småland, Sweden, on 23 May 1707. He was the first child of Nicolaus Ingemarsson and Christina Brodersonia and his siblings were Anna Maria Linnæa, Sofia Juliana Linnæa, Samuel Linnæus, and Emerentia Linnæa. One of a line of peasants and priests, Nils was an amateur botanist, a Lutheran minister. Christina was the daughter of the rector of Stenbrohult, Samuel Brodersonius, a year after Linnæus birth, his grandfather Samuel Brodersonius died, and his father Nils became the rector of Stenbrohult. The family moved into the rectory from the curates house, even in his early years, Linnæus seemed to have a liking for plants, flowers in particular. Whenever he was upset, he was given a flower, which calmed him. Nils spent much time in his garden and often showed flowers to Linnaeus, soon Linnæus was given his own patch of earth where he could grow plants
5.
Asia
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Asia covers an area of 44,579,000 square kilometres, about 30% of Earths total land area and 8. 7% of the Earths total surface area. The continent, which has long been home to the majority of the population, was the site of many of the first civilizations. Asia is notable for not only its large size and population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, the western boundary with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. The most commonly accepted boundaries place Asia to the east of the Suez Canal, the Ural River, and the Ural Mountains, and south of the Caucasus Mountains, China and India alternated in being the largest economies in the world from 1 to 1800 A. D. The accidental discovery of America by Columbus in search for India demonstrates this deep fascination, the Silk Road became the main East-West trading route in the Asian hitherland while the Straits of Malacca stood as a major sea route. Asia has exhibited economic dynamism as well as robust population growth during the 20th century, given its size and diversity, the concept of Asia—a name dating back to classical antiquity—may actually have more to do with human geography than physical geography. Asia varies greatly across and within its regions with regard to ethnic groups, cultures, environments, economics, historical ties, the boundary between Asia and Africa is the Red Sea, the Gulf of Suez, and the Suez Canal. This makes Egypt a transcontinental country, with the Sinai peninsula in Asia, the border between Asia and Europe was historically defined by European academics. In Sweden, five years after Peters death, in 1730 Philip Johan von Strahlenberg published a new atlas proposing the Urals as the border of Asia, the Russians were enthusiastic about the concept, which allowed them to keep their European identity in geography. Tatishchev announced that he had proposed the idea to von Strahlenberg, the latter had suggested the Emba River as the lower boundary. Over the next century various proposals were made until the Ural River prevailed in the mid-19th century, the border had been moved perforce from the Black Sea to the Caspian Sea into which the Ural River projects. The border between the Black Sea and the Caspian is usually placed along the crest of the Caucasus Mountains, the border between Asia and the loosely defined region of Oceania is usually placed somewhere in the Malay Archipelago. The terms Southeast Asia and Oceania, devised in the 19th century, have had several different geographic meanings since their inception. The chief factor in determining which islands of the Malay Archipelago are Asian has been the location of the possessions of the various empires there. Lewis and Wigen assert, The narrowing of Southeast Asia to its present boundaries was thus a gradual process, Asia is larger and more culturally diverse than Europe. It does not exactly correspond to the borders of its various types of constituents. From the time of Herodotus a minority of geographers have rejected the three-continent system on the grounds there is no or is no substantial physical separation between them
6.
China
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China, officially the Peoples Republic of China, is a unitary sovereign state in East Asia and the worlds most populous country, with a population of over 1.381 billion. The state is governed by the Communist Party of China and its capital is Beijing, the countrys major urban areas include Shanghai, Guangzhou, Beijing, Chongqing, Shenzhen, Tianjin and Hong Kong. China is a power and a major regional power within Asia. Chinas landscape is vast and diverse, ranging from forest steppes, the Himalaya, Karakoram, Pamir and Tian Shan mountain ranges separate China from much of South and Central Asia. The Yangtze and Yellow Rivers, the third and sixth longest in the world, respectively, Chinas coastline along the Pacific Ocean is 14,500 kilometers long and is bounded by the Bohai, Yellow, East China and South China seas. China emerged as one of the worlds earliest civilizations in the basin of the Yellow River in the North China Plain. For millennia, Chinas political system was based on hereditary monarchies known as dynasties, in 1912, the Republic of China replaced the last dynasty and ruled the Chinese mainland until 1949, when it was defeated by the communist Peoples Liberation Army in the Chinese Civil War. The Communist Party established the Peoples Republic of China in Beijing on 1 October 1949, both the ROC and PRC continue to claim to be the legitimate government of all China, though the latter has more recognition in the world and controls more territory. China had the largest economy in the world for much of the last two years, during which it has seen cycles of prosperity and decline. Since the introduction of reforms in 1978, China has become one of the worlds fastest-growing major economies. As of 2016, it is the worlds second-largest economy by nominal GDP, China is also the worlds largest exporter and second-largest importer of goods. China is a nuclear weapons state and has the worlds largest standing army. The PRC is a member of the United Nations, as it replaced the ROC as a permanent member of the U. N. Security Council in 1971. China is also a member of numerous formal and informal multilateral organizations, including the WTO, APEC, BRICS, the Shanghai Cooperation Organization, the BCIM, the English name China is first attested in Richard Edens 1555 translation of the 1516 journal of the Portuguese explorer Duarte Barbosa. The demonym, that is, the name for the people, Portuguese China is thought to derive from Persian Chīn, and perhaps ultimately from Sanskrit Cīna. Cīna was first used in early Hindu scripture, including the Mahābhārata, there are, however, other suggestions for the derivation of China. The official name of the state is the Peoples Republic of China. The shorter form is China Zhōngguó, from zhōng and guó and it was then applied to the area around Luoyi during the Eastern Zhou and then to Chinas Central Plain before being used as an occasional synonym for the state under the Qing
7.
Japan
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Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido, Kyushu and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is also the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭. It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
8.
Korea
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Korea is a historical state in East Asia, since 1945 divided into two distinct sovereign states, North Korea and South Korea. Located on the Korean Peninsula, Korea is bordered by China to the northwest and it is separated from Japan to the east by the Korea Strait and the Sea of Japan. Korea emerged as a political entity after centuries of conflict among the Three Kingdoms of Korea. Later Silla divided into three states during the Later Three Kingdoms period. Goryeo, which had succeeded Goguryeo, defeated the two states and united the Korean Peninsula. Around the same time, Balhae collapsed and its last crown prince fled south to Goryeo, Goryeo, whose name developed into the modern exonym Korea, was a highly cultured state that created the worlds first metal movable type in 1234. However, multiple invasions by the Mongol Yuan Dynasty during the 13th century greatly weakened the nation, following the Yuan Dynastys collapse, severe political strife followed, and Goryeo eventually fell to a coup led by General Yi Seong-gye, who established Joseon in 1388. The first 200 years of Joseon were marked by peace and saw the creation of the Korean alphabet by Sejong the Great in the 14th century. During the later part of the dynasty, however, Koreas isolationist policy earned it the Western nickname of the Hermit Kingdom, by the late 19th century, the country became the object of imperial design by the Empire of Japan. Despite attempts at modernization by the Korean Empire, in 1910 Korea was annexed by Japan and these circumstances soon became the basis for the division of Korea by the two superpowers, exacerbated by their incapability to agree on the terms of Korean independence. To date, both continue to compete with each other as the sole legitimate government of all of Korea. Korea is the spelling of Corea, a name attested in English as early as 1614. It is a derived from Cauli, Marco Polos transcription of the Chinese 高麗. This was the Hanja for the Korean kingdom of Goryeo or Koryŏ, Goryeos name was a continuation of the earlier Goguryeo or Koguryŏ, the northernmost of the Samguk, which was officially known by the shortened form Goryeo after the 5th-century reign of King Jangsu. The original name was a combination of the go with the name of a local Yemaek tribe. The name Korea is now used in English contexts by both North and South Korea. In South Korea, Korea as a whole is referred to as Hanguk, the name references the Samhan—Ma, Jin, and Byeon—who preceded the Three Kingdoms in the southern and central end of the peninsula during the 1st centuries BC and AD. It has been linked with the title khan used by the nomads of Manchuria
9.
Myanmar
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Myanmar, officially the Republic of the Union of Myanmar and also known as Burma, is a sovereign state in South East Asia bordered by Bangladesh, India, China, Laos and Thailand. About one third of Myanmars total perimeter of 5,876 km, forms an uninterrupted coastline of 1,930 km along the Bay of Bengal, the countrys 2014 census revealed a much lower population than expected, with 51 million people recorded. Myanmar is 676,578 square kilometres in size and its capital city is Naypyidaw and its largest city and former capital city is Yangon. Early civilizations in Myanmar included the Tibeto-Burman-speaking Pyu city-states in Upper Burma, the Pagan Kingdom fell due to the Mongol invasions and several warring states emerged. In the 16th century, reunified by the Taungoo Dynasty, the country was for a period the largest empire in the history of Mainland Southeast Asia. The early 19th century Konbaung Dynasty ruled over an area included modern Myanmar and briefly controlled Manipur. The British invaded Myanmar after three Anglo-Burmese Wars in the 19th century and the became a British colony. Myanmar became an independent nation in 1948, initially as a nation and then, following a coup détat in 1962. For most of its independent years, the country has been engrossed in rampant ethnic strife, during this time, the United Nations and several other organisations have reported consistent and systematic human rights violations in the country. In 2011, the junta was officially dissolved following a 2010 general election. While former military leaders still wield enormous power in the country, there is, however, continuing criticism of the governments treatment of the Muslim Rohingya minority and its poor response to the religious clashes. In the landmark 2015 election, Aung San Suu Kyis party won a majority in both houses, Myanmar is a country rich in jade and gems, oil, natural gas and other mineral resources. In 2013, its GDP stood at US$56.7 billion, the income gap in Myanmar is among the widest in the world, as a large proportion of the economy is controlled by supporters of the former military government. As of 2016, according to the Human Development Index, Myanmar had a level of human development. The renaming remains a contested issue, many political and ethnic opposition groups and countries continue to use Burma because they do not recognise the legitimacy of the ruling military government or its authority to rename the country. The countrys official name is the Republic of the Union of Myanmar. Countries that do not officially recognise that name use the long form Union of Burma instead, in English, the country is popularly known as either Burma or Myanmar /ˈmjɑːnˌmɑːr/. Both these names are derived from the name of the majority Burmese Bamar ethnic group, Myanmar is considered to be the literary form of the name of the group, while Burma is derived from Bamar, the colloquial form of the groups name
10.
India
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India, officially the Republic of India, is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and it is bounded by the Indian Ocean on the south, the Arabian Sea on the southwest, and the Bay of Bengal on the southeast. It shares land borders with Pakistan to the west, China, Nepal, and Bhutan to the northeast, in the Indian Ocean, India is in the vicinity of Sri Lanka and the Maldives. Indias Andaman and Nicobar Islands share a border with Thailand. The Indian subcontinent was home to the urban Indus Valley Civilisation of the 3rd millennium BCE, in the following millennium, the oldest scriptures associated with Hinduism began to be composed. Social stratification, based on caste, emerged in the first millennium BCE, early political consolidations took place under the Maurya and Gupta empires, the later peninsular Middle Kingdoms influenced cultures as far as southeast Asia. In the medieval era, Judaism, Zoroastrianism, Christianity, and Islam arrived, much of the north fell to the Delhi sultanate, the south was united under the Vijayanagara Empire. The economy expanded in the 17th century in the Mughal empire, in the mid-18th century, the subcontinent came under British East India Company rule, and in the mid-19th under British crown rule. A nationalist movement emerged in the late 19th century, which later, under Mahatma Gandhi, was noted for nonviolent resistance, in 2015, the Indian economy was the worlds seventh largest by nominal GDP and third largest by purchasing power parity. Following market-based economic reforms in 1991, India became one of the major economies and is considered a newly industrialised country. However, it continues to face the challenges of poverty, corruption, malnutrition, a nuclear weapons state and regional power, it has the third largest standing army in the world and ranks sixth in military expenditure among nations. India is a constitutional republic governed under a parliamentary system. It is a pluralistic, multilingual and multi-ethnic society and is home to a diversity of wildlife in a variety of protected habitats. The name India is derived from Indus, which originates from the Old Persian word Hindu, the latter term stems from the Sanskrit word Sindhu, which was the historical local appellation for the Indus River. The ancient Greeks referred to the Indians as Indoi, which translates as The people of the Indus, the geographical term Bharat, which is recognised by the Constitution of India as an official name for the country, is used by many Indian languages in its variations. Scholars believe it to be named after the Vedic tribe of Bharatas in the second millennium B. C. E and it is also traditionally associated with the rule of the legendary emperor Bharata. Gaṇarājya is the Sanskrit/Hindi term for republic dating back to the ancient times, hindustan is a Persian name for India dating back to the 3rd century B. C. E. It was introduced into India by the Mughals and widely used since then and its meaning varied, referring to a region that encompassed northern India and Pakistan or India in its entirety
11.
Introduced species
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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, governments, 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, also called an exotic or non-native species. Such species might be termed naturalized, established, 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
12.
Deciduous
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In a more general sense, deciduous means the dropping of a part that is no longer needed or falling away after its purpose is finished. In plants it is the result of natural processes, in botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year. In some cases leaf loss coincides with winter—namely in temperate or polar climates, in other parts of the world, including tropical, subtropical, and arid regions, plants lose their leaves during the dry season or other seasons, depending on variations in rainfall. The converse of deciduous is coniferous, where foliage is shed on a different schedule from deciduous trees, plants that are intermediate may be called semi-deciduous, they lose old foliage as new growth begins. Other plants are semi-evergreen and lose their leaves before the growing season. Many deciduous plants flower during the period when they are leafless, the absence of leaves improves wind transmission of pollen for wind-pollinated plants and increases the visibility of the flowers to insects in insect-pollinated plants. This strategy is not without risks, as the flowers can be damaged by frost or, in dry season regions, leaf drop or abscission involves complex physiological signals and changes within plants. The process of photosynthesis steadily degrades the supply of chlorophylls in foliage, the brightest leaf colors are produced when days grow short and nights are cool, but remain above freezing. These other pigments include carotenoids that are yellow, brown, anthocyanin pigments produce red and purple colors, though they are not always present in the leaves. Rather, they are produced in the foliage in late summer, parts of the world that have showy displays of bright autumn colors are limited to locations where days become short and nights are cool. In other parts of the world, the leaves of deciduous trees simply fall off without turning the bright colors produced from the accumulation of anthocyanin pigments, the beginnings of leaf drop starts when an abscission layer is formed between the leaf petiole and the stem. This layer is formed in the spring during active new growth of the leaf, the cells are sensitive to a plant hormone called auxin that is produced by the leaf and other parts of the plant. The elongation of cells break the connection between the different cell layers, allowing the leaf to break away from the plant. It also forms a layer that seals the break, so the plant does not lose sap, in the spring, these proteins are used as a nitrogen source during the growth of new leaves or flowers. Plants with deciduous foliage have advantages and disadvantages compared to plants with evergreen foliage, evergreens suffer greater water loss during the winter and they also can experience greater predation pressure, especially when small. Losing leaves in winter may reduce damage from insects, repairing leaves, removing leaves also reduces cavitation which can damage xylem vessels in plants. This then allows deciduous plants to have xylem vessels with larger diameters, the deciduous characteristic has developed repeatedly among woody plants. Trees include maple, many oaks and nothofagus, elm, aspen, Deciduous shrubs include honeysuckle, viburnum, and many others
