Invasive species
[4] Some sources name Homo sapiens as an invasive species,[6][7] but broad appreciation of human learning capacity and their behavioral potential and plasticity may argue against any such fixed categorization.[12][10] 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 a new nomenclature system based on biogeography rather than on taxa.[29] Logging has caused harm directly by destroying habitat, and has allowed non-native species such as prickly pear and silver wattle to invade.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.High demand for the valuable Chinese mitten crab is one explanation for the possible intentional release of the species in foreign waters.[69] These outcompete native organisms for oxygen and food, and can be transported in the small puddle left in a supposedly empty ballast tank.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 the world's fauna and flora and the loss of biodiversity.For example, invasive plants can alter the fire regime (cheatgrass, Bromus tectorum), nutrient cycling (smooth cordgrass Spartina alterniflora), and hydrology (Tamarix) in native ecosystems.[94][95] The Asian long-horned beetle (Anoplophora glabripennis) was first introduced into the U.S. in 1996, and was expected to infect and damage millions of acres of hardwood trees.Genetic pollution is unintentional hybridization and introgression, which leads to homogenization or replacement of local genotypes as a result of either a numerical or fitness advantage of the introduced species.[108][109] Alien species have caused diseases including human immunodeficiency virus (HIV), monkey pox, and severe acute respiratory syndrome (SARS).[96] 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.In Australia, for instance, 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.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).They can damage environmental services including water quality, plant and animal diversity, and species abundance, though the extent of this is under-researched.aegypti, totalled very high economic costs, followed by non-graminoid terrestrial flowering and aquatic plants (Ambrosia artemisiifolia, Ludwigia sp.Over 90% of alien species currently recorded in France had no costs reported in the literature, resulting in high biases in taxonomic, regional and activity sector coverages.[131] The introduced mesquite is an aggressive invasive species in India, but is the preferred nesting site of native waterbirds in small cities like Udaipur in Rajasthan.[135] Non-native species can provide ecosystem services, functioning as biocontrol agents to limit the effects of invasive agricultural pests.For example, the bee Lasioglossum leucozonium, shown by population genetic analysis to be an invasive species in North America,[137] has become an important pollinator of caneberry (Rubus spp.)Although primarily targeted at other, more general environmental concerns, the Convention on Biological Diversity does specify some steps that its members should take to control invasive species.[147] In the United States this is especially a concern for wildland firefighters because quagga and zebra mussel invasion and wildfires co-occur in the American West.A 2019 study suggests that if eradications of invasive animals were conducted on just 169 islands, the survival prospects of 9.4% of the Earth's most highly threatened terrestrial insular vertebrates would be improved.[153][154] Rodents were carried to South Georgia, an island in the southern Atlantic Ocean with no permanent inhabitants, in the 18th century by sealing and whaling ships.[161][162][163][164] Joe Roman, a Harvard and University of Vermont conservation biologist and recipient of the Rachel Carson Environmental award, runs a website named "Eat The Invaders".[165][166][160] In the 21st century, organizations including Reef Environmental Educational Foundation and the Institute for Applied Ecology have published cookbooks and recipes using invasive species as ingredients.[172] Skeptics point out that once a foreign species has entrenched itself in a new place—such as the Indo-Pacific lionfish that has now virtually taken over the waters of the Western Atlantic, Caribbean and Gulf of Mexico—eradication is almost impossible.[174] Invasive populations of Bromus tectorum exist with resistance to Ustilago bullata used as a biocontrol, and a similar problem has been reported in Microstegium vimineum subject to Bipolaris microstegii and B.[181][182][183] Weed risk assessments attempt to predict the chances that a specific plant will have negative effects in a new environment, often using a standardized questionnaire.
North American beaver dam in Tierra del FuegoAtlantaCanada goldenrodintroduced specieshabitatsbioregionsfood webearliest migrationsAge of Discoveryinternational tradegiant hogweedJapanese knotweedyellow starthistleEuropean rabbitsdomestic catsGlossary of invasion biology termsHomo sapiensplasticityEquus ferusevolvedNorth AmericaEurasiaconquistadorsferal horsesecologybiogeographyCharles Elton'sterrestrial plantsagriculturezoologypathologyhuman healthpropagule pressureecosystemsforest fireecological successiongrassesNitrogenphosphorusecological nicheedge effectsCharles S. Eltonspecies diversityspatial scalediversitybrown tree snakeIsland ecosystemsNew ZealandMadagascarprickly pearsilver wattlewater hyacinthLantana camaraPueraria montanasoutheastern United Statessoil erosionbioturbationbioerosionEriocheir sinensisStrongylocentrotus purpuratusEnhydra lutrisReynoutria japonicaworld's worst invasive specieswoodpeckerconsidered invasive speciesnegatively impact wildlifenative speciesreproductionvegetative reproductionFlorida Keyscompetitionpredationzero-sumunilateralLantanacitrusSdei Hemedtaprootbarbed goatgrassCaliforniaserpentine soilsmagnesiumcalciumheavy metalabioticherbivoresKalanchoe daigremontanaallelopathic compoundsStapelia giganteafacilitatemicroclimatesfire regimensBromus tectorumdetritusEcological facilitationzebra musselsinvertebratesfilter-feedingbenthicbottlenecksfounder effectsgenetic variationrapid evolutionpre-adaptationenemy release hypothesisvectorsChinese mitten crabhorticulturepet tradepolar regionsAsian citrus psyllidcitrus greeningpropagulesde-ballastingballast waterGreat LakesClimate changeocean temperaturewildfiresfoot trailssterilizenutrientsbiological diversitybiodiversity lossglobalizationfresh water