76-526: Quercus crispula , commonly known as mizunara from the Japanese, is a deciduous broad-leaved tree of the genus Quercus . As Quercus mongolica var. crispula , it is considered a variety of Mongolian oak by some authorities, and is widely distributed in Northeast Asia. It prefers a colder climate than the closely related Quercus serrata and Kunugi ( Quercus acutissima ). It grows naturally from
152-733: A ballast tank of a ship traveling from the temperate zone through tropical waters may experience temperature fluctuations as much as 20 °C. Heat challenges during transport may enhance the stress tolerance of species in their non-native range, by selecting for genotypes that will survive a second applied heat stress, such as increased ocean temperature in the founder population. Invasive species often exploit disturbances to an ecosystem ( wildfires , roads , foot trails ) to colonize an area. Large wildfires can sterilize soils, while adding nutrients . Invasive plants that can regenerate from their roots then have an advantage over natives that rely on seeds for propagation. Invasive species can affect
228-589: A few of the traits, and that noninvasive species had these also. Common invasive species traits include fast growth and rapid reproduction , such as vegetative reproduction in plants; association with humans; and prior successful invasions. Domestic cats are effective predators; they have become feral and invasive in places such as the Florida Keys . An introduced species might become invasive if it can outcompete native species for resources. If these species evolved under great competition or predation , then
304-680: A great decrease in the population size and may constrict genetic variation , the individuals begin to show additive variance as opposed to epistatic variance. This conversion can lead to increased variance in the founding populations, which permits rapid evolution . Selection may then act on the capacity to disperse as well as on physiological tolerance to new stressors in the environment, such as changed temperature and different predators and prey. Rapid adaptive evolution through intraspecific phenotypic plasticity, pre-adaptation and post-introduction evolution lead to offspring that have higher fitness. Critically, plasticity permits changes to better suit
380-470: A habitat in ways advantageous to other species. For example, zebra mussels increase habitat complexity on lake floors, providing crevices in which invertebrates live. This increase in complexity, together with the nutrition provided by the waste products of mussel filter-feeding , increases the density and diversity of benthic invertebrate communities. Introduced species may spread rapidly and unpredictably. When bottlenecks and founder effects cause
456-543: A long taproot , or to live on previously uninhabited soil types. For example, barbed goatgrass was introduced to California on serpentine soils , which have low water-retention, low nutrient levels, a high magnesium / calcium ratio, and possible heavy metal toxicity. Plant populations on these soils tend to show low density, but goatgrass can form dense stands on these soils and crowd out native species. Invasive species might alter their environment by releasing chemical compounds, modifying abiotic factors, or affecting
532-403: A major role in exotic species introduction. High demand for the valuable Chinese mitten crab is one explanation for the possible intentional release of the species in foreign waters. Maritime trade has rapidly affected the way marine organisms are transported within the ocean; new means of species transport include hull fouling and ballast water transport. In fact, Molnar et al. 2008 documented
608-621: A narrow belt along the Himalayas to cover mainland and island Southeast Asia as far as Sumatra , Java , Borneo , and Palawan . Finally, oaks of multiple sections ( Cyclobalanopsis , Ilex , Cerris , Quercus and related genera like Lithocarpus and Castanopsis ) extend across east Asia including China, Korea, and Japan. Potential records of Quercus have been reported from Late Cretaceous deposits in North America and East Asia. These are not considered definitive, as macrofossils older than
684-674: A new nomenclature system based on biogeography rather than on taxa . By discarding taxonomy, human health , and economic factors, this model focused only on ecological factors. The model evaluated individual populations rather than entire species. It classified each population based on its success in that environment. This model applied equally to indigenous and to introduced species, and did not automatically categorize successful introductions as harmful. The USDA's National Invasive Species Information Center defines invasive species very narrowly. According to Executive Order 13112, " 'Invasive species' means an alien species whose introduction does or
760-407: A number of years and then experience an explosion in population, a phenomenon known as "the lag effect". Hybrids resulting from invasive species interbreeding with native species can incorporate their genotypes into the gene pool over time through introgression . Similarly, in some instances a small invading population can threaten much larger native populations. For example, Spartina alterniflora
836-554: A particular pest species could pollute soil and surface water. Encroachment of humans into previously remote ecosystems has exposed exotic diseases such as HIV to the wider population. Introduced birds (e.g. pigeons ), rodents and insects (e.g. mosquito , flea , louse and tsetse fly pests) can serve as vectors and reservoirs of human afflictions. Throughout recorded history, epidemics of human diseases, such as malaria , yellow fever , typhus , and bubonic plague , spread via these vectors. A recent example of an introduced disease
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#1732873461037912-485: A range of flavours, colours, and aromas. The spongy bark of the cork oak is used to make traditional wine bottle corks. Almost a third of oak species are threatened with extinction due to climate change, invasive pests , and habitat loss . In culture, the oak tree is a symbol of strength and serves as the national tree of many countries. In Indo-European and related religions, the oak is associated with thunder gods . Individual oak trees of cultural significance include
988-418: A result of either a numerical or fitness advantage of the introduced species. Genetic pollution occurs either through introduction or through habitat modification, where previously isolated species are brought into contact with the new genotypes. Invading species have been shown to adapt to their new environments in a remarkably short amount of time. The population size of invading species may remain small for
1064-508: A single oak tree produces both staminate ('male') flowers in the form of catkins , and small pistillate ('female') flowers, meaning that the trees are monoecious . The fruit is a nut called an acorn , borne in a cup-like structure known as a cupule ; each acorn usually contains one seed and takes 6–18 months to mature, depending on the species. The acorns and leaves contain tannic acid , which helps to guard against fungi and insects. There are some 500 extant species of oaks. Trees in
1140-546: A small area of the west of Cuba ; in Mesoamerica it occurs mainly above 1000 metres. The genus crossed the isthmus of Panama when the northern and southern continents came together and is present as one species, Q. humboldtii , above 1000 metres in Colombia. The oaks of North America are of many sections ( Protobalanus , Lobatae , Ponticae , Quercus , and Virentes ) along with related genera such as Notholithocarpus . In
1216-626: Is a natural phenomenon, but human-facilitated introductions have greatly increased the rate, scale, and geographic range of invasion. For millennia, humans have served as both accidental and deliberate dispersal agents, beginning with their earliest migrations , accelerating in the Age of Discovery , and accelerating again with international trade . Notably invasive plant species include the kudzu vine, giant hogweed , Japanese knotweed , and yellow starthistle . Notably invasive animals include European rabbits , domestic cats , and carp . Invasive species are
1292-488: Is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions , causing ecological, environmental, and/or economic damage. The term can also be used for native species that become harmful to their native environment after human alterations to its food web . Since the 20th century, invasive species have become serious economic, social, and environmental threats worldwide. Invasion of long-established ecosystems by organisms
1368-452: Is from Old English ac (seen in placenames such as Acton , from ac + tun , "oak village" ), which in turn is from Proto-Germanic *aiks , "oak". Oaks are hardwood ( dicotyledonous ) trees, deciduous or evergreen, with spirally arranged leaves , often with lobate margins ; some have serrated leaves or entire leaves with smooth margins. Many deciduous species are marcescent , not dropping dead leaves until spring. In spring,
1444-456: Is highly fire-adapted. It spreads rapidly after burning, and increases the frequency and intensity of fires by providing large amounts of dry detritus during the fire season in western North America. Where it is widespread, it has altered the local fire regimen so much that native plants cannot survive the frequent fires, allowing it to become dominant in its introduced range. Ecological facilitation occurs where one species physically modifies
1520-623: Is likely to cause economic or environmental harm or harm to human health." Typically, an introduced species must survive at low population densities before it becomes invasive in a new location. At low population densities, it can be difficult for the introduced species to reproduce and maintain itself in a new location, so a species might reach a location multiple times before it becomes established. Repeated patterns of human movement, such as ships sailing to and from ports or cars driving up and down highways, offer repeated opportunities for establishment (a high propagule pressure ). In ecosystems ,
1596-600: Is normal, and preserves constellations of genes and genotypes. An example of this is the interbreeding of migrating coyotes with the red wolf , in areas of eastern North Carolina where the red wolf was reintroduced, reducing red wolf numbers. In South Africa's Cape Town region, analysis demonstrated that the restoration of priority source water sub-catchments through the removal of thirsty alien plant invasions (such as Australian acacias, pines and eucalyptus, and Australian black wattle) would generate expected annual water gains of 50 billion liters within 5 years compared to
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#17328734610371672-581: Is now considered invasive in over 60 countries, and has invaded large geographies in several countries prompting aggressive federal efforts at attempting to control it. Primary geomorphological effects of invasive plants are bioconstruction and bioprotection. For example, kudzu ( Pueraria montana ), a vine native to Asia, was widely introduced in the southeastern United States in the early 20th century to control soil erosion . The primary geomorphological effects of invasive animals are bioturbation , bioerosion , and bioconstruction. For example, invasions of
1748-479: Is one of the most problematic invasive plant species in eastern North American forests, where it is highly invasive of the understory , reducing the growth rate of tree seedlings and threatening to modify the forest's tree composition. Native species can be threatened with extinction through the process of genetic pollution . Genetic pollution is unintentional hybridization and introgression , which leads to homogenization or replacement of local genotypes as
1824-510: Is the main cause of introductions – other than for polar regions . Diseases may be vectored by invasive insects: the Asian citrus psyllid carries the bacterial disease citrus greening . The arrival of invasive propagules to a new site is a function of the site's invasibility. Many invasive species, once they are dominant in the area, become essential to the ecosystem of that area, and their removal could be harmful. Economics plays
1900-587: Is the spread of the West Nile virus , which killed humans, birds, mammals, and reptiles. The introduced Chinese mitten crabs are carriers of Asian lung fluke . Waterborne disease agents, such as cholera bacteria ( Vibrio cholerae ), and causative agents of harmful algal blooms are often transported via ballast water. Globally, invasive species management and control are substantial economic burdens, with expenditures reaching approximately $ 1.4 trillion annually. The economic impact of invasive alien species alone
1976-516: The Great Lakes via ballast water. These outcompete native organisms for oxygen and food, and can be transported in the small puddle left in a supposedly empty ballast tank. Regulations attempt to mitigate such risks, not always successfully. Climate change is causing an increase in ocean temperature . This in turn will cause range shifts in organisms, which could harm the environment as new species interactions occur. For example, organisms in
2052-622: The Paleogene , and possibly from before the Eocene are mostly poorly preserved without critical features for certain identification. Amongst the oldest unequivocal records of Quercus are pollen from Austria, dating to the Paleocene -Eocene boundary, around 55 million years ago. The oldest records of Quercus in North America are from Oregon , dating to the Middle Eocene, around 44 million years ago, with
2128-810: The Royal Oak in Britain, the Charter Oak in the United States, and the Guernica Oak in the Basque Country . The generic name Quercus is Latin for "oak", derived from Proto-Indo-European *kwerkwu- , "oak", which is also the origin of the name " fir ", another important or sacred tree in Indo-European culture. The word "cork", for the bark of the cork oak , similarly derives from Quercus . The common name "oak"
2204-591: The economic returns from invasive species are far less than the costs they impose. In the Great Lakes region the sea lamprey is an invasive species. In its original habitat, it had co-evolved as a parasite that did not kill its host. However, in the Great Lakes Region, it acts as a predator and can consume up to 40 pounds of fish in its 12–18 month feeding period. Sea lampreys prey on all types of large fish such as lake trout and salmon . The sea lampreys' destructive effects on large fish negatively affect
2280-844: The extinction of species, loss in biodiversity, and loss of ecosystem services , costs from impacts of invasive species would drastically increase. It is often argued that the key to invasive species management is early detection and rapid response. However, early response only helps when the invasive species is not frequently reintroduced into the managed area, and the cost of response is affordable. Weeds reduce yield in agriculture . Many weeds are accidental introductions that accompany imports of commercial seeds and plants. Introduced weeds in pastures compete with native forage plants, threaten young cattle (e.g., leafy spurge, Euphorbia virgata ) or are unpalatable because of thorns and spines (e.g., yellow starthistle ). Forage loss from invasive weeds on pastures amounts to nearly US$ 1 billion in
2356-436: The oak apple , and a large number of pests and diseases. Oak leaves and acorns contain enough tannin to be toxic to cattle, but pigs are able to digest them safely. Oak timber is strong and hard, and has found many uses in construction and furniture-making. The bark was traditionally used for tanning leather . Wine barrels are made of oak; these are used for aging alcoholic beverages such as sherry and whisky , giving them
Quercus crispula - Misplaced Pages Continue
2432-744: The spatial scale of invasion studies. Small-scale studies tended to show a negative relationship between diversity and invasion, while large-scale studies tended to show the reverse, perhaps a side-effect of invasives' ability to capitalize on increased resource availability and weaker species interactions that are more common when larger samples are considered. However, this pattern does not seem to hold true for invasive vertebrates. Island ecosystems may be more prone to invasion because their species face few strong competitors and predators, and because their distance from colonizing species populations makes them more likely to have "open" niches. For example, native bird populations on Guam have been decimated by
2508-461: The 20th century for the cultivation of shiitake mushrooms. During the Jōmon period , it was important as a preserved food for winter in the eastern part of Japan. It was eaten in mountain villages until recently, but is rarely eaten now. The acorns of Quercus crispula contain astringent tannins and cannot be eaten as they are, but must be processed to become edible. This article about plants in
2584-467: The 958 endangered species under the Endangered Species Act are at risk. The unintentional introduction of forest pest species and plant pathogens can change forest ecology and damage the timber industry . Overall, forest ecosystems in the U.S. are widely invaded by exotic pests, plants, and pathogens. The Asian long-horned beetle ( Anoplophora glabripennis ) was first introduced into
2660-518: The California sea otter ( Enhydra lutris ). Invasive species appear to have specific traits or specific combinations of traits that allow them to outcompete native species . In some cases, the competition is about rates of growth and reproduction. In other cases, species interact with each other more directly. One study found that 86% of invasive species could be identified from such traits alone. Another study found that invasive species often had only
2736-493: The Chinese mitten crab ( Eriocheir sinensis ) have resulted in higher bioturbation and bioerosion rates. A native species can become harmful and effectively invasive to its native environment after human alterations to its food web . This has been the case with the purple sea urchin ( Strongylocentrotus purpuratus ), which has decimated kelp forests along the northern California coast due to overharvesting of its natural predator,
2812-591: The Middle Eocene . Molecular phylogeny shows that the genus is divided into Old World and New World clades , but many oak species hybridise freely, making the genus's history difficult to resolve. Ecologically, oaks are keystone species in habitats from Mediterranean semi-desert to subtropical rainforest . They live in association with many kinds of fungi including truffles . Oaks support more than 950 species of caterpillar , many kinds of gall wasp which form distinctive galls , roundish woody lumps such as
2888-687: The Old World, oaks of section Quercus extend across the whole of Europe including European Russia apart from the far north, and north Africa (north of the Sahara) from Morocco to Libya. In Mediterranean Europe, they are joined by oaks of the sections Cerris and Ilex , which extend across Turkey, the Middle East, Iran, Afghanistan and Pakistan , while section Ponticae is endemic to the western Caucasus in Turkey and Georgia . Oaks of section Cyclobalanopsis extend in
2964-517: The U.S. A decline in pollinator services and loss of fruit production has been caused by honey bees infected by the invasive varroa mite . Introduced rats ( Rattus rattus and R. norvegicus ) have become serious pests on farms, destroying stored grains. The introduction of leaf miner flies ( Agromyzidae ), including the American serpentine leaf miner ( Liriomyza trifolii ), to California has caused losses in California's floriculture industry, as
3040-544: The U.S. in 1996, and was expected to infect and damage millions of acres of hardwood trees. As of 2005 thirty million dollars had been spent in attempts to eradicate this pest and protect millions of trees in the affected regions. The woolly adelgid has inflicted damage on old-growth spruce, fir and hemlock forests and damages the Christmas tree industry. Chestnut blight and Dutch elm disease are plant pathogens with serious impacts. Garlic mustard, Alliaria petiolata ,
3116-637: The acorns ripen in the fall. Mizunara is most widely known outside Japan for its use in barrels to age Japanese and Scotch whisky. It has received international acclaim as a material that can brew a delicate flavor completely different from oak barrels. The heartwood is dull brown, with excellent workability, colorability, high strength, and solid feeling. The wood is used in high-end furniture, building materials, and alcohol barrels. In particular, Hokkaido varieties were considered to be of good quality, and they were called Japanese oak, and were exported and gained prominence. They have also become popular since
Quercus crispula - Misplaced Pages Continue
3192-591: The alteration in ecosystem functionality (due to homogenization of biota communities), invasive species have resulted in negative effects on human well-being, which includes reduced resource availability, unrestrained spread of human diseases, recreational and educational activities, and tourism. Alien species have caused diseases including human immunodeficiency virus (HIV), monkey pox , and severe acute respiratory syndrome (SARS). Invasive species and accompanying control efforts can have long term public health implications. For instance, pesticides applied to treat
3268-551: The ancestors of Equus ferus (modern horses) evolved in North America and radiated to Eurasia before becoming extinct in North America. Upon being introduced to North America in 1493 by Spanish conquistadors , it is debatable whether the feral horses were native or exotic to the continent of their evolutionary ancestors. While invasive species can be studied within many subfields of biology, most research on invasive organisms has been in ecology and biogeography . Much of
3344-478: The availability of resources determines the impact of additional species on the ecosystem. Stable ecosystems have a resource equilibrium, which can be changed fundamentally by the arrival of invasive species. When changes such as a forest fire occur, normal ecological succession favors native grasses and forbs . An introduced species that can spread faster than natives can outcompete native species for food, squeezing them out. Nitrogen and phosphorus are often
3420-467: The behaviour of herbivores , impacting on other species. Some, like Kalanchoe daigremontana , produce allelopathic compounds that inhibit competitors. Others like Stapelia gigantea facilitate the growth of seedlings of other species in arid environments by providing appropriate microclimates and preventing herbivores from eating seedlings. Changes in fire regimens are another form of facilitation. Bromus tectorum , originally from Eurasia,
3496-507: The business-as-usual scenario (which is important as Cape Town experiences significant water scarcity ). This is the equivalent to one-sixth of the city's current supply needs. These annual gains will double within 30 years. The catchment restoration is significantly more cost-effective then other water augmentation solutions (1/10 the unit cost of alternative options). A water fund has been established, and these exotic species are being eradicated. Invasive species can affect human health. With
3572-511: The densities of native forage plants, declining the habitat-use by wild herbivores and threatening the long-term sustenance of dependent carnivores, including the tiger . Invasive species can change the functions of ecosystems. For example, invasive plants can alter the fire regime (cheatgrass, Bromus tectorum ), nutrient cycling (smooth cordgrass Spartina alterniflora ), and hydrology ( Tamarix ) in native ecosystems. Invasive species that are closely related to rare native species have
3648-436: The expense to monitor, control, manage, and research invasive weed species is approximately AU$ 116.4 million per year, with costs directed solely to central and local government. While in some cases, invasive species may offer economic benefits, such as the potential for commercial forestry from invasive trees, these benefits are generally overshadowed by the substantial costs associated with biological invasions. In most cases,
3724-563: The field lacks any official designation but is commonly referred to as "invasion ecology" or more generally "invasion biology". This lack of standard terminology has arisen due to the interdisciplinary nature of the field which borrows terms from disciplines such as agriculture , zoology , and pathology , as well as due to studies being performed in isolation. In an attempt to avoid the ambiguous, subjective, and pejorative vocabulary that so often accompanies discussion of invasive species even in scientific papers, Colautti and MacIsaac proposed
3800-629: The fishing industry and have helped cause the collapse of the population of some species. Economic costs from invasive species can be separated into direct costs through production loss in agriculture and forestry, and management costs. Estimated damage and control costs of invasive species in the U.S. amount to more than $ 138 billion annually. Economic losses can occur through loss of recreational and tourism revenues. When economic costs of invasions are calculated as production loss and management costs, they are low because they do not consider environmental damage; if monetary values were assigned to
3876-404: The genus Quercus consisted of Old World and New World clades. The entire genome of Quercus robur (the pedunculate oak) has been sequenced , revealing an array of mutations that may underlie the evolution of longevity and disease resistance in oaks. In addition, hundreds of oak species have been compared (at RAD-seq loci), allowing a detailed phylogeny to be constructed. However,
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#17328734610373952-542: The genus Quercus is a stub . You can help Misplaced Pages by expanding it . Quercus See also List of Quercus species . An oak is a hardwood tree or shrub in the genus Quercus of the beech family . They have spirally arranged leaves, often with lobed edges, and a nut called an acorn , borne within a cup. The genus is widely distributed in the Northern Hemisphere; it includes some 500 species, both deciduous and evergreen . Fossil oaks date back to
4028-625: The genus are often large and slow-growing; Q. alba can reach an age of 600 years, a diameter of 13 feet (4.0 m) and a height of 145 feet (44 m). The Granit oak in Bulgaria, a Q. robur specimen, has an estimated age of 1637 years, making it the oldest oak in Europe. The Wi'aaSal tree, a live oak in the reservation of the Pechanga Band of Indians , California, is at least 1000 years old, and might be as much as 2000 years old, which would make it
4104-446: The governments of California and New Zealand have announced more stringent control for vessel hull fouling within their respective jurisdictions. Another vector of non-native aquatic species is ballast water taken up at sea and released in port by transoceanic vessels. Some 10,000 species are transported via ballast water each day. Many of these are harmful. For example, freshwater zebra mussels from Eurasia most likely reached
4180-1126: The high signal of introgressive hybridization (the transfer of genetic material by repeated backcrossing with hybrid offspring) in the genus has made it difficult to resolve an unambiguous, unitary history of oaks. The phylogeny from Hipp et al. 2019 is: CTB lineage [REDACTED] Cyclobalanoides Glauca [REDACTED] Acuta [REDACTED] Semiserrata East Asian Cerris [REDACTED] West Eurasian Cerris [REDACTED] Early-diverging Ilex [REDACTED] East Asian Ilex [REDACTED] Himalaya-Mediterranean [REDACTED] Himalayan subalpine [REDACTED] Agrifoliae [REDACTED] Palustres [REDACTED] Coccineae (Rubrae) [REDACTED] Phellos (Laurifoliae) [REDACTED] Texas red oaks [REDACTED] Erythromexicana [REDACTED] [REDACTED] [REDACTED] [REDACTED] Dumosae [REDACTED] Prinoids [REDACTED] Albae [REDACTED] Roburoids [REDACTED] Stellatae [REDACTED] Texas white oaks [REDACTED] Leucomexicana [REDACTED] Invasive species An invasive species
4256-489: The individual to its environment. Pre-adaptations and evolution after the introduction reinforce the success of the introduced species. The enemy release hypothesis states that evolution leads to ecological balance in every ecosystem. No single species can occupy a majority of an ecosystem due to the presences of competitors, predators, and diseases. Introduced species moved to a novel habitat can become invasive, with rapid population growth, when these controls do not exist in
4332-619: The introductions of the amethyst gem clam and the European green crab . The gem clam was introduced into California's Bodega Harbor from the US East Coast a century ago. On its own, it never displaced native clams ( Nutricola spp.). In the mid-1990s, the introduction of the European green crab resulted in an increase of the amethyst gem at the expense of the native clams. In India, multiple invasive plants have invaded 66% of natural areas, reducing
4408-538: The invaded habitats and bioregions adversely, causing ecological, environmental, or economic damage. The European Union defines "Invasive Alien Species" as those that are outside their natural distribution area, and that threaten biological diversity . Biotic invasion is one of the five top drivers for global biodiversity loss , and is increasing because of tourism and globalization . This may be particularly true in inadequately regulated fresh water systems, though quarantines and ballast water rules have improved
4484-646: The invasive brown tree snake . In New Zealand the first invasive species were the dogs and rats brought by Polynesian settlers around 1300. These and other introductions devastated endemic New Zealand species. The colonization of Madagascar brought similar harm to its ecosystems. Logging has caused harm directly by destroying habitat, and has allowed non-native species such as prickly pear and silver wattle to invade. The water hyacinth forms dense mats on water surfaces, limiting light penetration and hence harming aquatic organisms, and causing substantial management costs. The shrub lantana ( Lantana camara )
4560-510: The largest number of oak species, with approximately 160 species in Mexico, of which 109 are endemic, and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species. In the Americas, Quercus is widespread from Vancouver and Nova Scotia in the south of Canada, south to Mexico and across the whole of the eastern United States. It is present in
4636-443: The limiting factors in these situations. Every species occupies an ecological niche in its native ecosystem; some species fill large and varied roles, while others are highly specialized. Invading species may occupy unused niches, or create new ones. For example, edge effects describe what happens when part of an ecosystem is disturbed, as when land is cleared for agriculture . The boundary between remaining undisturbed habitat and
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#17328734610374712-501: The mountains of Japan to the subalpine zone. Along with beech, it is one of the main tree species of deciduous broad-leaved forest in Japan, preferring slightly brighter places than beech. The tree height reaches 35 m in large ones. The leaves are dull green and have sharp serrations (jagged contours) that are more wavy than a typical oak. Flowers of about 5 cm in length bloom in May–June, and
4788-630: The new ecosystem. Non-native species have many vectors , but most are associated with human activity. Natural range extensions are common, but humans often carry specimens faster and over greater distances than natural forces. An early human vector occurred when prehistoric humans introduced the Pacific rat ( Rattus exulans ) to Polynesia. Vectors include plants or seeds imported for horticulture . The pet trade moves animals across borders, where they can escape and become invasive. Organisms stow away on transport vehicles. Incidental human assisted transfer
4864-523: The new environment may host fewer able competitors, allowing the invader to proliferate. Ecosystems used to their fullest capacity by native species can be modeled as zero-sum systems, in which any gain for the invader is a loss for the native. However, such unilateral competitive superiority (and extinction of native species with increased populations of the invader) is not the rule. An invasive species might be able to use resources previously unavailable to native species, such as deep water accessed by
4940-528: The newly cleared land itself forms a distinct habitat, creating new winners and losers and possibly hosting species that would not thrive outside the boundary habitat. In 1958, Charles S. Elton claimed that ecosystems with higher species diversity were less subject to invasive species because fewer niches remained unoccupied. Other ecologists later pointed to highly diverse, but heavily invaded ecosystems, arguing that ecosystems with high species diversity were more susceptible to invasion. This debate hinged on
5016-496: The oldest oak in the US. Among the smallest oaks is Q. acuta , the Japanese evergreen oak. It forms a bush or small tree to a height of some 30 feet (9.1 m). The genus Quercus is native to the Northern Hemisphere and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas , Asia, Europe, and North Africa. North America has
5092-855: The oldest records in Asia from the Middle Eocene of Japan; both forms have affinities to the Cyclobalanopsis group. Quercus forms part, or rather two parts, of the Quercoideae subfamily of the Fagaceae , the beech family. Modern molecular phylogenetics suggests the following relationships: Fagus (beeches) Trigonobalanus (3 evergreen species) Lithocarpus (stone oaks) Chrysolepis (chinquapins) Quercus pro parte Notholithocarpus (tan oak) Quercus pro parte Castanopsis (also called chinquapins) Castanea (chestnuts) Molecular techniques for phylogenetic analysis show that
5168-476: The pathways of hundreds of marine invasive species and found that shipping was the dominant mechanism for the transfer of invasive species. Many marine organisms can attach themselves to vessel hulls. Such organisms are easily transported from one body of water to another, and are a significant risk factor for a biological invasion event. Controlling for vessel hull fouling is voluntary and there are no regulations currently in place to manage hull fouling. However,
5244-464: The potential to hybridize with the native species. Harmful effects of hybridization have led to a decline and even extinction of native species. For example, hybridization with introduced cordgrass, Spartina alterniflora , threatens the existence of California cordgrass ( Spartina foliosa ) in San Francisco Bay . Invasive species cause competition for native species and because of this 400 of
5320-412: The situation. Invasive species may drive local native species to extinction via competitive exclusion, niche displacement, or hybridisation with related native species. Therefore, besides their economic ramifications, alien invasions may result in extensive changes in the structure, composition and global distribution of the biota at sites of introduction, leading ultimately to the homogenisation of
5396-495: The spread of biological invasions, mitigate further impacts, and restore affected ecosystems. For example, the damage caused by 79 invasive species between 1906 and 1991 in the United States has been estimated at US$ 120 billion. Similarly, in China , invasive species have been reported to reduce the country's gross domestic product (GDP) by 1.36% per year. The management of biological invasions can be costly. In Australia , for instance,
5472-711: The subset of established non-native alien or naturalized species that are a threat to native species and biodiversity. The term "invasive" is poorly defined and often very subjective. Invasive species may be plants, animals, fungi, and microbes; some include native species that have invaded human habitats such as farms and landscapes. Some broaden the term to include indigenous or "native" species that have colonized natural areas. Some sources name Homo sapiens as an invasive species, but broad appreciation of human learning capacity and their behavioral potential and plasticity may argue against any such fixed categorization. The definition of "native" can be controversial. For example,
5548-502: The work has been influenced by Charles Elton's 1958 book The Ecology of Invasion by Animals and Plants which creates a generalized picture of biological invasions. Studies remained sparse until the 1990s. This research, largely field observational studies, has disproportionately been concerned with terrestrial plants . The rapid growth of the field has driven a need to standardize the language used to describe invasive species and events. Despite this, little standard terminology exists;
5624-405: The world's fauna and flora and the loss of biodiversity . It is difficult to unequivocally attribute extinctions to a species invasion, though there is for example strong evidence that the extinction of about 90 amphibian species was caused by the chytrid fungus spread by international trade. Multiple successive introductions of different non-native species can worsen the total effect, as with
5700-416: Was estimated to exceed $ 423 billion annually as of 2019. This cost has exhibited a significant increase, quadrupling every decade since 1970, underscoring the escalating financial implications of these biological invasions. Invasive species contribute to ecological degradation , altering ecosystem functionality and reducing the services ecosystems provide. This necessitates additional expenditures to control
5776-462: Was introduced in the San Francisco Bay and hybridized with native Spartina foliosa . The higher pollen count and male fitness of the invading species resulted in introgression that threatened the native populations due to lower pollen counts and lower viability of the native species. Reduction in fitness is not always apparent from morphological observations alone. Some degree of gene flow
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