Array ( [0] => {{short description|Biological process occurring in plants}} [1] => [[File:Pollination Diagram.svg|thumb|upright=1.25|Diagram illustrating the process of pollination]] [2] => [[File:Bee carpenter with pollen.jpg|thumb|upright=1.25|Female [[carpenter bee]] with pollen collected from a [[night-blooming cereus]]]]'''Pollination''' is the transfer of [[pollen]] from an [[Stamen|anther]] of a plant to the [[stigma (botany)|stigma]] of a plant, later enabling [[fertilisation]] and the production of [[seed]]s.{{cite book | vauthors = Barrows EM | date = 2011 | title = Animal Behavior Desk Reference. A Dictionary of Animal Behavior, Ecology, and Evolution. | edition = Third | publisher = CRC Press LCC | location = Boca Raton, FL. | pages = 794 }} Pollinating agents can be animals such as insects, for example beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants.{{Cite web |title=About Pollinators |url=https://www.pollinator.org/pollinators |access-date=2023-11-03 |website=Pollinator.org |language=en-US}} When [[self-pollination]] occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce [[hybrid (biology)|hybrid]] offspring in nature and in [[plant breeding]] work. [3] => [4] => In [[angiosperm]]s, after the pollen grain ([[gametophyte]]) has landed on the [[stigma (botany)|stigma]], it germinates and develops a [[pollen tube]] which grows down the [[Gynoecium|style]] until it reaches an [[ovary (botany)|ovary]]. Its two [[gamete]]s travel down the tube to where the gametophyte(s) containing the female gametes are held within the [[carpel]]. After entering an ovule through the [[Micropyle (botany)|micropyle]], one male nucleus fuses with the [[Polar body|polar bodies]] to produce the [[endosperm]] [[Tissue (biology)|tissues]], while the other fuses with the [[egg cell]] to produce the [[embryo]].{{cite book |last1=Fritsch|first1= Felix Eugene|last2= Salisbury |first2=Edward James | name-list-style = vanc |title= An introduction to the structure and reproduction of plants |publisher= G. Bell |year=1920 |url=https://archive.org/details/cu31924001698905}}{{cite book | last = Mauseth | first = James D. | name-list-style = vanc | title = Botany: An Introduction to Plant Biology. | publisher = Jones & Bartlett | date = 2008 | isbn = 978-0-7637-5345-0 }} Hence the term: "[[double fertilisation]]". This process would result in the production of a seed, made of both nutritious tissues and embryo. [5] => [6] => In [[gymnosperm]]s, the ovule is not contained in a carpel, but exposed on the surface of a dedicated support organ, such as the scale of a cone, so that the penetration of carpel tissue is unnecessary. Details of the process vary according to the [[division (botany)|division]] of gymnosperms in question. Two main modes of fertilisation are found in gymnosperms: [[cycad]]s and ''[[Ginkgo]]'' have motile sperm that swim directly to the egg inside the ovule, whereas [[conifer]]s and [[gnetophyte]]s have sperm that are unable to swim but are conveyed to the egg along a pollen tube. [7] => [8] => The study of pollination spans many disciplines, such as [[botany]], [[horticulture]], [[entomology]], and [[ecology]]. The pollination process as an interaction between flower and [[pollinator|pollen vector]] was first addressed in the 18th century by [[Christian Konrad Sprengel]]. It is important in horticulture and [[agriculture]], because [[fruit]]ing is dependent on fertilisation: the result of pollination. The study of pollination by insects is known as ''[[anthecology]]''. There are also studies in [[economics]] that look at the positives and negatives of pollination, focused on bees, and how the process affects the pollinators themselves. [9] => [10] => ==Process of pollination== [11] => [[File:Pollen grains observed in aeroplankton of South Europe.png|thumb|upright=1.5| {{center|Pollen grains observed in [[aeroplankton]]
of South EuropeDenisow, B. and Weryszko-Chmielewska, E. (2015) "Pollen grains as airborne allergenic particles". ''Acta Agrobotanica'', '''68'''(4). {{doi|10.5586/aa.2015.045}}.}}]] [12] => [13] => Pollen [[germination]] has three stages; hydration, activation and pollen tube emergence. The pollen grain is severely dehydrated so that its mass is reduced, enabling it to be more easily transported from flower to flower. Germination only takes place after rehydration, ensuring that premature germination does not take place in the anther. Hydration allows the plasma membrane of the pollen grain to reform into its normal bilayer organization providing an effective osmotic membrane. Activation involves the development of [[actin]] filaments throughout the cytoplasm of the cell, which eventually become concentrated at the point from which the pollen tube will emerge. Hydration and activation continue as the pollen tube begins to grow.{{cite book | last = Raghavan | first = Valayamghat | name-list-style = vanc |title=Molecular Embryology of Flowering Plants |url=https://books.google.com/books?id=LQfaytKsOu4C&pg=PA210 |year=1997 |publisher=Cambridge University Press |isbn=978-0-521-55246-2 |pages=210–216}} [14] => In conifers, the reproductive structures are borne on cones. The cones are either pollen cones (male) or ovulate cones (female), but some species are [[monoecious]] and others [[dioecious]]. A pollen cone contains hundreds of microsporangia carried on (or borne on) reproductive structures called sporophylls. Spore mother cells in the microsporangia divide by [[meiosis]] to form haploid microspores that develop further by two mitotic divisions into immature male gametophytes (pollen grains). The four resulting cells consist of a large tube cell that forms the [[pollen tube]], a generative cell that will produce two sperm by [[mitosis]], and two prothallial cells that degenerate. These cells comprise a very reduced [[microgametophyte]], that is contained within the resistant. [15] => [16] => The pollen grains are dispersed by the wind to the female, ovulate cone that is made up of many overlapping scales (sporophylls, and thus megasporophylls), each protecting two ovules, each of which consists of a megasporangium (the nucellus) wrapped in two layers of tissue, the integument and the cupule, that were derived from highly modified branches of ancestral gymnosperms. When a pollen grain lands close enough to the tip of an ovule, it is drawn in through the micropyle ( a pore in the integuments covering the tip of the ovule) often by means of a drop of liquid known as a pollination drop. The pollen enters a pollen chamber close to the nucellus, and there it may wait for a year before it germinates and forms a pollen tube that grows through the wall of the megasporangium (=nucellus) where fertilisation takes place. During this time, the megaspore mother cell divides by meiosis to form four haploid cells, three of which degenerate. The surviving one develops as a megaspore and divides repeatedly to form an immature female gametophyte (egg sac). Two or three archegonia containing an egg then develop inside the gametophyte. Meanwhile, in the spring of the second year two sperm cells are produced by mitosis of the body cell of the male gametophyte. The pollen tube elongates and pierces and grows through the megasporangium wall and delivers the sperm cells to the female gametophyte inside. Fertilisation takes place when the nucleus of one of the sperm cells enters the egg cell in the megagametophyte's archegonium.{{cite journal |title=Sexual reproduction of interior spruce (Pinaceae). I. Pollen germination to archegonial maturation |last1=Runions |first1=C. John |last2=Owens |first2=John N. | name-list-style = vanc |journal=International Journal of Plant Sciences |volume=160 |issue=4 |date=1999 |pages=631–640 |doi=10.1086/314170|s2cid=2766822 }} [17] => [18] => In flowering plants, the anthers of the flower produce microspores by meiosis. These undergo mitosis to form male gametophytes, each of which contains two haploid cells. Meanwhile, the ovules produce megaspores by meiosis, further division of these form the female gametophytes, which are very strongly reduced, each consisting only of a few cells, one of which is the egg. When a pollen grain adheres to the stigma of a carpel it germinates, developing a pollen tube that grows through the tissues of the style, entering the ovule through the micropyle. When the tube reaches the egg sac, two sperm cells pass through it into the female gametophyte and fertilisation takes place. [19] => [20] => == Methods == [21] => [22] => Pollination may be biotic or abiotic. Biotic pollination relies on living [[pollinator]]s to move the [[pollen]] from one flower to another. Abiotic pollination relies on wind, water or even rain. Adding natural habitat areas into farm systems generally improves pollination, as farms that are closer to natural habitat have higher crop yield because they are visited by more pollinators.{{Cite web |title=About Pollinators |url=https://www.pollinator.org/pollinators |access-date=2023-11-10 |website=Pollinator.org |language=en-US}} [23] => [24] => === Biotic pollination=== [25] => [[File:Hummingbird in ggp 7.jpg|thumb|[[Hummingbird]]s typically feed on red flowers]] [26] => [[File:Melissodes desponsa, f, face, Maine, Du Clos 2015-12-01-17.37 (24469964305).jpg|thumb|A bee ([[Mellisodes]] desponsus) covered in pollen]] [27] => {{main|Pollinator}} [28] => [29] => About 80% of [[Flowering plant|angiosperms]] rely on biotic pollination.{{Cite journal |vauthors=Ackerman JD |date=2000-03-01 |title=Abiotic pollen and pollination: Ecological, functional, and evolutionary perspectives |journal=Plant Systematics and Evolution |volume=222 |issue=1–4 |pages=167–185 |doi=10.1007/BF00984101 |s2cid=36015720}} (also called pollen vectors): organisms that carry or move the pollen grains from the [[Stamen|anther]] of one flower to the receptive part of the carpel or pistil (stigma) of another.{{Cite web | title=Types of Pollination, Pollinators and Terminology | work=CropsReview.Com | access-date=2015-10-20 | url=http://www.cropsreview.com/types-of-pollination.html}} Between 100,000 and 200,000 species of animal act as pollinators of the world's 250,000 species of flowering plant.{{cite book | last = Abrol | first = Dharam P. | title = Pollination Biology | name-list-style = vanc |year=2012 |chapter=Non Bee Pollinators-Plant Interaction |volume=Chapter 9 |pages=265–310 |doi=10.1007/978-94-007-1942-2_9|isbn=978-94-007-1941-5 }} The majority of these pollinators are [[insect]]s, but about 1,500 species of birds and mammals visit flowers and may transfer pollen between them. Besides birds and bats which are the most frequent visitors, these include monkeys, lemurs, squirrels, rodents and possums. [30] => [31] => [[Entomophily]], pollination by [[insect]]s, often occurs on plants that have developed colored petals and a strong [[Floral scent|scent]] to attract insects such as bees, wasps, and occasionally ants ([[Hymenoptera]]), [[beetle]]s ([[Coleoptera]]), moths and butterflies ([[Lepidoptera]]), and flies ([[Diptera]]). The existence of insect pollination dates back to the [[dinosaur]] era.{{Cite web | title=First ever record of insect pollination from 100 million years ago | work=ScienceDaily | access-date=2015-10-20 | url=https://www.sciencedaily.com/releases/2012/05/120514153113.htm }} [32] => [33] => In [[zoophily]], pollination is performed by vertebrates such as [[bird]]s and [[bat]]s, particularly, [[hummingbird]]s, [[sunbird]]s, [[spiderhunter]]s, [[honeyeater]]s, and [[fruit bat]]s. [[Ornithophily]] or bird pollination is the pollination of flowering plants by birds. [[Chiropterophily]] or bat pollination is the pollination of flowering plants by bats. Plants adapted to use bats or moths as pollinators typically have white petals, strong [[Floral scent|scent]] and flower at night, whereas plants that use birds as pollinators tend to produce copious nectar and have red petals.{{cite journal | vauthors = Rodríguez-Gironés MA, Santamaría L | title = Why are so many bird flowers red? | journal = PLOS Biology | volume = 2 | issue = 10 | pages = e350 | date = October 2004 | pmid = 15486585 | pmc = 521733 | doi = 10.1371/journal.pbio.0020350 | doi-access = free }} [34] => [[File:Bee Leg with Pollen Bulb.jpg|thumb|Hind leg of a honey bee with pollen pellet stuck on the pollen basket or corbicula. When the worker bee is collecting pollen, their legs make the transfer of pollen from the inner basitarsal combs to the outer pollen basket (shown in figure).]] [35] => Insect pollinators such as [[honey bee]]s (''Apis'' spp.),{{cite journal | vauthors = Hill PS, Wells PH, Wells H | title = Spontaneous flower constancy and learning in honey bees as a function of colour | journal = Animal Behaviour | volume = 54 | issue = 3 | pages = 615–27 | date = September 1997 | pmid = 9299046 | doi = 10.1006/anbe.1996.0467 | s2cid = 24674731 }} [36] => [[bumblebee]]s (''Bombus'' spp.),{{cite journal | vauthors = Stout JC, Allen JA, Goulson D | title = The influence of relative plant density and floral morphological complexity on the behaviour of bumblebees | journal = Oecologia | volume = 117 | issue = 4 | pages = 543–550 | date = December 1998 | pmid = 28307680 | doi = 10.1007/s004420050691 | bibcode = 1998Oecol.117..543S | s2cid = 5829708 }}{{cite journal | vauthors = Chittka L, Gumbert A, Kunze J | year=1997 | title=Foraging dynamics of bumble bees: correlates of movement within and between plant species | journal=Behavioral Ecology | volume=8 | issue=3 | pages=239–249 | doi=10.1093/beheco/8.3.239}} and [[Butterfly|butterflies]] (e.g., ''Thymelicus flavus''){{cite journal | vauthors = Goulson D, Ollerton J, Sluman C | year=1997 | title=Foraging strategies in the small skipper butterfly, ''Thymelicus flavus'': when to switch? | journal=Animal Behaviour | volume=53 | issue= 5| pages=1009–1016 | doi=10.1006/anbe.1996.0390| s2cid=620334 }} have been observed to engage in [[flower constancy]], which means they are more likely to transfer pollen to other conspecific plants.{{cite book | vauthors = Harder LD, Williams NM, Jordan CY, Nelson WA | chapter = The effects of Floral design and display on pollinator economics and pollen dispersal | pages = 297–317 | veditors = Chittka L, Thomson JD | title = Cognitive Ecology of Pollination: Animal Behavior and Floral Evolution | date = 2001 | publisher = Cambridge University Press }} This can be beneficial for the pollinators, as flower constancy prevents the loss of pollen during interspecific flights and pollinators from clogging stigmas with pollen of other flower species. It also improves the probability that the pollinator will find productive flowers easily accessible and recognisable by familiar clues.{{cite journal | vauthors = Chittka L, Thomson JD, Waser NM | year=1999 | title=Flower constancy, insect psychology, and plant evolution | journal=Naturwissenschaften | volume=86 | issue= 8| pages=361–377 | doi=10.1007/s001140050636| bibcode=1999NW.....86..361C | s2cid=27377784 }} [37] => [38] => Some flowers have specialized mechanisms to [[pollination trap|trap pollinators]] to increase effectiveness. Other flowers will attract pollinators by odor. For example, bee species such as ''[[Euglossa cordata]]'' are attracted to orchids this way, and it has been suggested that the bees will become intoxicated during these visits to the orchid flowers, which last up to 90 minutes.{{cite journal | vauthors = Dressler RL | title = Pollination by Euglossine Bees | journal = Evolution; International Journal of Organic Evolution | volume = 22 | issue = 1 | pages = 202–210 | date = March 1968 | pmid = 28564982 | doi = 10.2307/2406664 | jstor = 2406664 }} However, in general, plants that rely on pollen vectors tend to be adapted to their particular type of vector, for example day-pollinated species tend to be brightly coloured, but if they are pollinated largely by birds or specialist mammals, they tend to be larger and have larger nectar rewards than species that are strictly insect-pollinated. They also tend to spread their rewards over longer periods, having long flowering seasons; their specialist pollinators would be likely to starve if the pollination season were too short.{{cite web | last1 = Potts | first1 = Brad | last2 = Gore | first2 = Peter | name-list-style = vanc | title = Reproductive Biology and Controlled Pollination of Eucalyptus | publisher = School of Plant Science, University of Tasmania | date = 1995 | url = https://eprints.utas.edu.au/7447/1/Potts_and_Gore_reproductive_biology_manual.pdf }} [39] => [40] => As for the types of pollinators, reptile pollinators are known, but they form a minority in most ecological situations. They are most frequent and most ecologically significant in island systems, where insect and sometimes also bird populations may be unstable and less species-rich. Adaptation to a lack of animal food and of predation pressure, might therefore favour reptiles becoming more herbivorous and more inclined to feed on pollen and nectar.{{cite journal | vauthors = Olesen JM, Valido A | title = Lizards as pollinators and seed dispersers: an island phenomenon. | journal = Trends in Ecology & Evolution | date = April 2003 | volume = 18 | issue = 4 | pages = 177–81 | doi = 10.1016/S0169-5347(03)00004-1 }} Most species of lizards in the families that seem to be significant in pollination seem to carry pollen only incidentally, especially the larger species such as [[Varanidae]] and [[Iguanidae]], but especially several species of the [[Gekkonidae]] are active pollinators, and so is at least one species of the [[Lacertidae]], ''[[Podarcis lilfordi]]'', which pollinates various species, but in particular is the major pollinator of ''[[Euphorbia dendroides]]'' on various Mediterranean islands.{{cite journal | last = Godínez-Álvarez | first = Héctor | name-list-style = vanc | title = Pollination and seed dispersal by lizards. | journal = Revista Chilena de Historia Natural | volume = 77 | pages = 569–577 | date = 2004 | issue = 3 | doi = 10.4067/S0716-078X2004000300015 | doi-access = free }} [41] => [42] => Mammals are not generally thought of as pollinators, but some rodents, bats and marsupials are significant pollinators and some even specialise in such activities. In South Africa certain species of ''[[Protea]]'' (in particular ''Protea humiflora'', ''P. amplexicaulis'', ''P. subulifolia'', ''P. decurrens'' and ''P. cordata'') are adapted to pollination by rodents (particularly [[Cape Spiny Mouse]], ''Acomys subspinosus''){{cite journal | vauthors = Wiens D, Rourke JP, Casper BB, Rickart EA, LaPine TR, Peterson CJ, Channing A | title = Nonflying Mammal Pollination of Southern African Proteas. | journal = Annals of the Missouri Botanical Garden | volume = 70 | issue = 1 | date = 1983 | doi = 10.2307/2399006 | jstor = 2399006 | url = https://www.biodiversitylibrary.org/part/31073 }} and [[elephant shrew]]s (''Elephantulus'' species).{{cite journal | vauthors = Fleming PA, Nicolson SW | title = Arthropod fauna of mammal-pollinated Protea humiflora: ants as an attractant for insectivore pollinators? | journal = African Entomology | date = March 2003 | volume = 11 | issue = 1 | pages = 9–14 | url = https://www.ingentaconnect.com/content/sabinet/ento/2003/00000011/00000001/art00002 }} The flowers are borne near the ground, are yeasty smelling, not colourful, and sunbirds reject the nectar with its high [[xylose]] content. The mice apparently can digest the xylose and they eat large quantities of the pollen.{{cite web |url=http://www.proteaatlas.org.za/p52prhumi.htm |title=Who is pollinating Pr humiflora |url-status=live|archive-url=https://web.archive.org/web/20130219070835/http://protea.worldonline.co.za/p52prhumi.htm |archive-date=2013-02-19 |first1= Trish|last1 = Fleming|first2= Sue|last2=Nicholson | name-list-style = vanc }} In Australia pollination by flying, gliding and earthbound mammals has been demonstrated.{{cite journal | vauthors = Goldingay RL, Carthew SM, Whelan RJ |title=The Importance of Non-Flying Mammals in Pollination |journal= Oikos |volume= 61| issue = 1 |date=May 1991 |pages= 79–87 |jstor=3545409|doi=10.2307/3545409 }} Examples of pollen vectors include many species of wasps, that transport pollen of many plant species, being potential or even efficient pollinators.{{cite journal | vauthors = Sühs RB, Somavilla A, Köhler A, Putzke J |url=http://www.ufrgs.br/seerbio/ojs/index.php/rbb/article/view/1123 |title=Pollen vector wasps (Hymenoptera, Vespidae) of ''Schinus terebinthifolius'' Raddi (Anacardiaceae) |year=2009 |pages=138–143 |journal=Brazilian Journal of Biosciences |volume=7 |issue=2}} [43] => [44] => {{Excerpt|Pollinator|Other invertebrates}} [45] => [46] => === Abiotic pollination=== [47] => Abiotic pollination uses nonliving methods such as wind and water to move pollen from one [[flower]] to another. This allows the plant to spend energy directly on pollen rather than on attracting pollinators with flowers and [[nectar]]. Pollination by wind is more common amongst abiotic pollination. [48] => [49] => ==== By wind ==== [50] => [[File:Pollen from Dactylis glomerata.jpg|alt=Cat grass (Dactylis glomerata) spreading pollen by wind|thumb|Cat grass (''[[Dactylis glomerata]]'') spreading pollen by wind]] [51] => Some 98% of abiotic pollination is [[anemophily]], i.e., pollination by wind. This probably arose from insect pollination (entomophily), most likely due to changes in the environment or the availability of pollinators.{{Cite book |url=https://books.google.com/books?id=3zfLBAAAQBAJ&pg=PA34 |title=Principles of Pollination Ecology |vauthors=Faegri K, Van der Pijl L |date=2013-10-22 |publisher=Elsevier |isbn=9781483293035 |page=34}}{{cite journal |vauthors=Whitehead DR |date=March 1969 |title=Wind Pollination in the Angiosperms: Evolutionary and Environmental Considerations |journal=Evolution; International Journal of Organic Evolution |volume=23 |issue=1 |pages=28–35 |doi=10.2307/2406479 |jstor=2406479 |pmid=28562955}}{{Cite journal |last1=Culley |first1=Theresa M. |last2=Weller |first2=Stephen G. |last3=Sakai |first3=Ann K. |name-list-style=vanc |date=2002-08-01 |title=The evolution of wind pollination in angiosperms |journal=Trends in Ecology & Evolution |volume=17 |issue=8 |pages=361–369 |doi=10.1016/S0169-5347(02)02540-5}} The transfer of pollen is more efficient than previously thought; wind pollinated plants have developed to have specific heights, in addition to specific floral, [[stamen]] and stigma positions that promote effective pollen dispersal and transfer.{{cite journal |vauthors=Friedman J, Barrett SC |date=June 2009 |title=Wind of change: new insights on the ecology and evolution of pollination and mating in wind-pollinated plants |journal=Annals of Botany |volume=103 |issue=9 |pages=1515–27 |doi=10.1093/aob/mcp035 |pmc=2701749 |pmid=19218583}} [52] => [53] => ==== By water ==== [54] => Pollination by water, [[hydrophily]], uses water to transport pollen, sometimes as whole anthers; these can travel across the surface of the water to carry dry pollen from one flower to another.{{Cite journal |last=Cox |first=Paul Alan |name-list-style=vanc |date=1988 |title=Hydrophilous Pollination |journal=Annual Review of Ecology and Systematics |volume=19 |pages=261–279 |doi=10.1146/annurev.es.19.110188.001401 |jstor=2097155}} In ''[[Vallisneria spiralis]]'', an unopened male flower floats to the surface of the water, and, upon reaching the surface, opens up and the fertile anthers project forward. The female flower, also floating, has its stigma protected from the water, while its [[sepal]]s are slightly depressed into the water, allowing the male flowers to tumble in. [55] => [56] => ==== By rain ==== [57] => [58] => Rain pollination is used by a small percentage of plants. Heavy rain discourages insect pollination and damages unprotected flowers, but can itself disperse pollen of suitably adapted plants, such as ''[[Ranunculus flammula]]'', ''[[Narthecium ossifragum]]'', and ''[[Caltha palustris]]''. In these plants, excess rain drains allowing the floating pollen to come in contact with the stigma. In some orchids ombrophily occurs, and rain water splashes cause the anther cap to be removed, allowing for the pollen to be exposed. After exposure, raindrops causes the pollen to be shot upward, when the stipe pulls them back, and then fall into the cavity of the stigma. Thus, for the orchid ''[[Acampe rigida]]'', this allows the plant to self-pollinate, which is useful when biotic pollinators in the environment have decreased.{{cite journal |vauthors=Fan XL, Barrett SC, Lin H, Chen LL, Zhou X, Gao JY |date=October 2012 |title=Rain pollination provides reproductive assurance in a deceptive orchid |url= |journal=Annals of Botany |volume=110 |issue=5 |pages=953–8 |doi=10.1093/aob/mcs165 |pmc=3448421 |pmid=22851311 |doi-access=free}} [59] => [60] => ==== Switching methods ==== [61] => It is possible for a plant to have varying pollination methods, including both biotic and abiotic pollination. The orchid ''[[Oeceoclades maculata]]'' uses both rain and butterflies, depending on its environmental conditions.{{Cite journal |last1=Aguiar |first1=João M. R. B. V. |last2=Pansarin |first2=Ludmila M. |last3=Ackerman |first3=James D. |last4=Pansarin |first4=Emerson R. |name-list-style=vanc |date=2012 |title=Biotic versus abiotic pollination in Oeceoclades maculata (Lindl.) Lindl. (Orchidaceae) |journal=Plant Species Biology |volume=27 |issue=1 |pages=86–95 |doi=10.1111/j.1442-1984.2011.00330.x}} [62] => [63] => =={{anchor|Mechanics}}Mechanism== [64] => [[File:Diadasia Bee Straddles Cactus Flower Carpels close-up.jpg|thumb|upright|''[[Diadasia]]'' bee straddles [[cactus]] [[carpels]]]] [65] => [66] => Pollination can be accomplished by '''cross-pollination''' or by [[self-pollination]]: [67] => * Cross-pollination, also called ''[[allogamy]]'', occurs when pollen is delivered from the stamen of one flower to the stigma of a flower on another plant of the same species.{{cite book |title=Biology |last1=Campbell |first1=Neil A. |last2=Reece |first2=Jane B. | name-list-style = vanc |year=2002 |publisher=Pearson Education |isbn=978-0-201-75054-6 |pages=600–612 |edition=6th }} Plants adapted for cross-pollination have several mechanisms to prevent self-pollination; the reproductive organs may be arranged in such a way that self-fertilisation is unlikely, or the stamens and carpels may mature at different times. [68] => * Self-pollination occurs when pollen from one flower pollinates the same flower or other flowers of the same individual.{{Cite book | vauthors = Cronk JK, Fennessy MS | title=Wetland plants: biology and ecology | year=2001 | publisher=Lewis Publishers | location=Boca Raton, Fla. | isbn=978-1-56670-372-7 | page=166}} It is thought to have evolved under conditions when pollinators were not reliable vectors for pollen transport, and is most often seen in short-lived annual species and plants that colonize new locations.{{Cite book| title=Understanding flowers and flowering: an integrated approach| year=2007| last = Glover | first = Beverly J.| name-list-style = vanc | publisher=Oxford University Press| page=127| isbn=978-0-19-856596-3}} Self-pollination may include ''autogamy'', where pollen is transferred from anther (male part) to the stigma (female part) of the same flower; or ''geitonogamy'', when pollen is transferred from anther of a flower to stigma of another flower on the same plant. Plants adapted to self-fertilize often have similar stamen and carpel lengths. Plants that can pollinate themselves and produce viable offspring are called self-fertile. Plants that cannot fertilize themselves are called self-sterile, a condition which mandates cross-pollination for the production of offspring.{{cite book|title=New Living Science: Biology for Class 9|url=https://books.google.com/books?id=o9pZiJdmedwC&pg=PA56 |publisher=Ratna Sagar |isbn=978-81-8332-565-3 |pages=56–61}} [69] => *''[[Cleistogamy]]'': is self-pollination that occurs before the flower opens. The pollen is released from the anther within the flower or the pollen on the anther grows a tube down the style to the ovules. It is a type of sexual breeding, in contrast to asexual systems such as apomixis. Some ''cleistogamous'' flowers never open, in contrast to ''[[chasmogamous]]'' flowers that open and are then pollinated. Cleistogamous flowers are by necessity found on self-compatible or self-fertile plants.{{Cite journal | last1=Culley | first1=Theresa M. | last2=Klooster | first2=Matthew R. | name-list-style = vanc |year=2007 | title=The cleistogamous breeding system: a review of its frequency, evolution, and ecology in angiosperms | journal=The Botanical Review | url=http://www.accessmylibrary.com/coms2/summary_0286-30779368_ITM | doi=10.1663/0006-8101(2007)73[1:TCBSAR]2.0.CO;2 | volume=73 | pages=1–30| s2cid=12223087 }} Although certain orchids and grasses are entirely cleistogamous, other plants resort to this strategy under adverse conditions. Often there may be a mixture of both cleistogamous and chasmogamous flowers, sometimes on different parts of the plant and sometimes in mixed inflorescences. The [[Amphicarpaea bracteata|ground bean]] produces cleistogamous flowers below ground, and mixed cleistogamous and chasmogamous flowers above.{{cite book| last1 = Baskin | first1 = Carol C.| last2 = Baskin | first2 = Jerry M. | name-list-style = vanc |title=Seeds: Ecology, Biogeography, and Evolution of Dormancy and Germination |url=https://books.google.com/books?id=uGJL_Ys6wlQC&pg=PA215 |year=2001 |publisher=Elsevier |isbn=978-0-12-080263-0 |page=215}} [70] => [71] => [72] => File:Geranium incanum 9154s.jpg|''Geranium incanum'', like most geraniums and pelargoniums, sheds its anthers, sometimes its stamens as well, as a barrier to self-pollination. This young flower is about to open its anthers, but has not yet fully developed its pistil. [73] => File:Geranium incanum 9159s.jpg|The lower two of these ''Geranium incanum'' flowers have opened their anthers, but not yet their stigmas. Note the change of colour that signals to pollinators that they are ready for visits. The uppermost flower is somewhat more mature than the others and has already shed its stamens. [74] => File:Geranium incanum 9156s.jpg|This ''Geranium incanum'' flower has shed its stamens, and deployed the tips of its pistil without accepting pollen from its own anthers. (It might of course still receive pollen from younger flowers on the same plant.) [75] => [76] => [77] => An estimated 48.7% of plant species are either [[Dioecy#In botany|dioecious]] or [[Self-incompatibility in plants|self-incompatible]] obligate out-crossers.{{cite journal | vauthors = Igic B, Kohn JR | title = The distribution of plant mating systems: study bias against obligately outcrossing species | journal = Evolution; International Journal of Organic Evolution | volume = 60 | issue = 5 | pages = 1098–103 | date = May 2006 | pmid = 16817548 | doi = 10.1554/05-383.1 | s2cid = 40964 }} It is also estimated that about 42% of flowering plants have a mixed mating system in nature.{{cite journal | vauthors = Goodwillie C, Kalisz S, Eckert CG | date = 2005 | title = The evolutionary enigma of mixed mating systems in plants: Occurrence, theoretical explanations, and empirical evidence. | journal = Annu. Rev. Ecol. Evol. Syst. | volume = 36 | pages = 47–79 | doi = 10.1146/annurev.ecolsys.36.091704.175539 }} In the most common kind of mixed mating system, individual plants produce a single type of flower and fruits may contain self-pollinated, out-crossed or a mixture of progeny types. [78] => [79] => Pollination also requires consideration of [[pollenizer]]s, the plants that serve as the pollen source for other plants. Some plants are ''[[Self-compatibility in plants|self-compatible]]'' (''self-fertile'') and can pollinate and fertilize themselves. Other plants have chemical or physical barriers to [[self-pollination]]. [80] => [81] => In agriculture and [[horticulture]] pollination management, a good pollenizer is a plant that provides compatible, viable and plentiful pollen and blooms at the same time as the plant that is to be pollinated or has pollen that can be stored and used when needed to pollinate the desired flowers. [[Hybrid (biology)|Hybridization]] is effective pollination between flowers of different [[species]], or between different breeding lines or populations. see also [[Heterosis]]. [82] => [83] => [[Peach]]es are considered self-fertile because a commercial crop can be produced without cross-pollination, though cross-pollination usually gives a better crop. Apples are considered [[Self-incompatibility in plants|self-incompatible]], because a commercial crop must be cross-pollinated. Many commercial fruit tree varieties are [[grafting|grafted]] [[cloning|clone]]s, [[genetics|genetically]] identical. An orchard block of apples of one variety is genetically a single plant. Many growers now consider this a mistake. One means of correcting this mistake is to graft a limb of an appropriate pollenizer (generally a variety of [[crabapple]]) every six trees or so.{{Citation needed|date=August 2009}} [84] => [85] => [[File:Hymenoptera,_Vespidae,_Polistinae,_Mischocyttarus_rotundicollis.jpg|thumb|The wasp ''[[Mischocyttarus]]'' rotundicollis transporting pollen grains of ''[[Schinus terebinthifolius]]'' ]] [86] => [87] => ==Coevolution== [88] => {{Main|Pollination syndrome}} [89] => [90] => The first fossil record for [[abiotic]] pollination is from [[fern]]-like plants in the late [[Carboniferous]] period. [[Gymnosperm]]s show evidence for biotic pollination as early as the [[Triassic]] period. Many fossilized pollen grains show characteristics similar to the biotically dispersed pollen today. Furthermore, the gut contents, wing structures, and mouthpart [[Morphology (biology)|morphology]] of fossilized [[Coleoptera|beetles]] and [[Diptera|flies]] suggest that they acted as early pollinators. The association between [[Coleoptera|beetles]] and [[angiosperm]]s during the early [[Cretaceous]] period led to parallel radiations of angiosperms and insects into the late Cretaceous. The evolution of nectaries in late Cretaceous flowers signals the beginning of the [[mutualism (biology)|mutualism]] between [[hymenoptera]]ns and angiosperms. [91] => [92] => [[Bee]]s provide a good example of the mutualism that exists between [[hymenoptera]]ns and angiosperms. Flowers provide bees with nectar (an energy source) and pollen (a source of protein). When bees go from flower to flower collecting pollen they are also depositing pollen grains onto the flowers, thus pollinating them. While pollen and nectar, in most cases, are the most notable reward attained from flowers, bees also visit flowers for other resources such as oil, fragrance, resin and even waxes.{{cite book| first = W. Scott | last = Armbruster | name-list-style = vanc |author-link1=Evolution and ecological implicationsof "specialized" pollinator rewards|editor1-last=Patiny|editor1-first=Sébastien|title=Evolution of Plant-Pollinator Relationships|date=2012|publisher=Cambridge University Press|location=Cambridge, UK|pages=45–67|chapter=3}} It has been estimated that bees originated with the origin or diversification of [[Flowering plant|angiosperms]].{{cite journal | vauthors = Cardinal S, Danforth BN | title = Bees diversified in the age of eudicots | journal = Proceedings. Biological Sciences | volume = 280 | issue = 1755 | pages = 20122686 | date = March 2013 | pmid = 23363629 | pmc = 3574388 | doi = 10.1098/rspb.2012.2686 }} In addition, cases of [[coevolution]] between bee species and flowering plants have been illustrated by specialized adaptations. For example, long legs are selected for in ''Rediviva neliana'', a bee that collects oil from ''Diascia capsularis'', which have long spur lengths that are selected for in order to deposit pollen on the oil-collecting bee, which in turn selects for even longer legs in ''R. neliana'' and again longer spur length in ''D. capsularis'' is selected for, thus, continually driving each other's evolution.{{cite journal | vauthors = Steiner KE, Whitehead VB | title = Pollinator Adaptation to Oil-Secreting Flowers-Rediviva and Diascia | journal = Evolution; International Journal of Organic Evolution | volume = 44 | issue = 6 | pages = 1701–1707 | date = September 1990 | pmid = 28564320 | doi = 10.2307/2409348 | jstor = 2409348 }} [93] => [94] => ==In agriculture== [95] => {{Main|List of crop plants pollinated by bees}} [96] => [[File:Pollinator-dependence.png|thumb|What crops are dependent on pollinators?]] [97] => [[File:Bee pollinating a rose.jpg|thumb|An ''[[Andrena]]'' bee gathers pollen from the [[stamens]] of a [[rose]]. The female [[carpel]] structure appears rough and globular to the left.]]The most essential staple food crops on the planet, like [[wheat]], [[maize]], [[rice]], [[soybean]]s and [[sorghum]]{{cite web|title=FAOstats Food Supply - Crops Primary Equivalent |url=http://www.fao.org/faostat/en/#data/CC |author=[[Food and Agriculture Organization]] of the [[United Nations]], Statistics Division |year=2017 }}FAO 2015. FAO Statistical Pocketbook 2015, {{ISBN|978-92-5-108802-9}}, p. 28 are wind pollinated or self pollinating. When considering the top 15 crops contributing to the human diet globally in 2013, slightly over 10% of the total human diet of plant crops (211 out of 1916 kcal/person/day) is dependent upon insect pollination. [98] => [99] => [[Pollination management]] is a branch of agriculture that seeks to protect and enhance present pollinators and often involves the culture and addition of pollinators in [[monoculture]] situations, such as commercial fruit [[orchard]]s. The largest managed pollination event in the world is in [[California almond]] orchards, where nearly half (about one million [[beehive (beekeeping)|hives]]) of the US [[honey bee]]s are trucked to the almond orchards each spring. [[New York (state)|New York]]'s [[apple]] crop requires about 30,000 hives; [[Maine]]'s [[blueberry]] crop uses about 50,000 hives each year. The US solution to the pollinator shortage, so far, has been for commercial beekeepers to become pollination [[independent contractor|contractor]]s and to migrate. Just as the [[combine harvester]]s follow the [[wheat]] [[harvest]] from [[Texas]] to [[Manitoba]], beekeepers follow the bloom from south to north, to provide pollination for many different crops.{{citation needed|date=April 2018}} [100] => [101] => In America, bees are brought to commercial plantings of [[cucumber]]s, [[squash (fruit)|squash]], [[melon]]s, [[strawberry|strawberries]], and many other crops. Honey bees are not the only managed pollinators: a few other [[species]] of bees are also raised as pollinators. The [[alfalfa leafcutter bee]] is an important pollinator for [[alfalfa]] [[seed]] in western United States and Canada. [[Bumblebee]]s are increasingly raised and used extensively for [[greenhouse]] [[tomato]]es and other crops. [102] => [103] => The [[ecology|ecological]] and financial importance of natural pollination by insects to [[agriculture|agricultural]] [[crops]], improving their quality and quantity, becomes more and more appreciated and has given rise to new financial opportunities. The vicinity of a [[forest]] or wild [[grassland]]s with native pollinators near agricultural crops, such as apples, almonds or [[coffee]] can improve their yield by about 20%.{{Cite thesis |title=Pollinator biodiversity and economic value of pollination services in Uganda |url=http://makir.mak.ac.ug/handle/10570/2624 |publisher=Makerere University |date=2010-09-28 |degree=PhD |language=en |first=Theodore B. M. |last=Munyuli}} The benefits of native pollinators may result in forest owners demanding payment for their contribution in the improved crop results – a simple example of the economic value of ecological services. Farmers can also raise native crops in order to promote native bee pollinator species as shown with the native sweat bees ''[[Lasioglossum vierecki|L. vierecki]]'' in Delaware{{cite web | vauthors = Kuehn F | date = 2015 | title = Farming for native bees. World Wide Web electronic publication. | url = http://mysare.sare.org/mySARE/ProjectReport.aspx?do=viewRept&pn=LNE07-261&y=2011&t=1 | archive-url = https://web.archive.org/web/20150930233624/http://mysare.sare.org/mySARE/ProjectReport.aspx?do=viewRept&pn=LNE07-261&y=2011&t=1 | archive-date = 30 September 2015 | work = Sustainable Agriculture Research & Education (SARE) }} and ''[[Lasioglossum leucozonium|L. leucozonium]]'' in southwest Virginia.{{cite thesis | last = Adamson | first = Nancy Lee | name-list-style = vanc | degree = Ph.D. | url = http://www.step-project.net/NPDOCS/Adamson_NL_D_2011.pdf | title = An Assessment of Non-Apis Bees as Fruit and Vegetable Crop Pollinators in Southwest Virginia | date = 2011 }} [104] => [105] => The [[American Institute of Biological Sciences]] reports that native insect pollination saves the United States [[Agriculture|agricultural]] economy nearly an estimated $3.1 billion annually through natural crop production;{{cite journal | vauthors = Losey JE, Vaughan M | title = The economic value of ecological services provided by insects. | journal = BioScience | date = April 2006 | volume = 56 | issue = 4 | pages = 311–23 | doi = 10.1641/0006-3568(2006)56[311:TEVOES]2.0.CO;2 | doi-access = free }} pollination produces some $40 billion worth of products annually in the United States alone.{{cite web|url=http://www.fs.fed.us/wildflowers/pollinators/documents/factsheet_pollinator.pdf |title=US Forest Department: Pollinator Factsheet |access-date=2014-04-18|archive-date=June 23, 2022|archive-url=https://web.archive.org/web/20220623171524/http://www.fs.fed.us/wildflowers/pollinators/documents/factsheet_pollinator.pdf}} [106] => [107] => Pollination of food crops has become an [[environmental movement|environmental issue]], due to two trends. The trend to [[monoculture]] means that greater concentrations of pollinators are needed at bloom time than ever before, yet the area is [[forage (honeybee)|forage]] poor or even deadly to bees for the rest of the season. The other trend is the [[pollinator decline|decline of pollinator populations]], due to [[pesticide]] misuse and overuse, new diseases and [[parasite]]s of bees, [[clearfelling|clearcut logging]], decline of beekeeping, [[suburb]]an development, removal of [[hedge (barrier)|hedge]]s and other [[Habitat (ecology)|habitat]] from [[farm]]s, and public concern about bees. Widespread [[agricultural aircraft|aerial spraying]] for [[mosquito]]es due to [[West Nile fever|West Nile]] fears is causing an acceleration of the loss of pollinators. Changes in land use, harmful pesticides, and advancing climate change threaten wild pollinators, key insect species that increase yields of three-fourths of crop varieties and are critical to growing healthy foods. {{Cite web |last=Communications |first=Todd Datz Harvard Chan School |date=2022-12-14 |title=New study shows impact pollinators have on human health |url=https://news.harvard.edu/gazette/story/2022/12/new-study-shows-impact-pollinators-have-on-human-health/ |access-date=2023-11-08 |website=Harvard Gazette |language=en-US}} [108] => [109] => In some situations, farmers or horticulturists may aim to restrict natural pollination to only permit breeding with the preferred individuals plants. This may be achieved through the use of [[pollination bags]]. [110] => [111] => ===Improving pollination in areas with suboptimal bee densities=== [112] => [113] => In some instances growers' demand for beehives far exceeds the available supply. The number of managed beehives in the US has steadily declined from close to 6 million after WWII, to less than 2.5 million today. In contrast, the area dedicated to growing bee-pollinated crops has grown over 300% in the same time period. Additionally, in the past five years there has been a decline in winter managed beehives, which has reached an unprecedented rate of colony losses at near 30%.{{cite journal | vauthors = Biesmeijer JC, Roberts SP, Reemer M, Ohlemüller R, Edwards M, Peeters T, Schaffers AP, Potts SG, Kleukers R, Thomas CD, Settele J, Kunin WE | display-authors = 6 | title = Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands | journal = Science | volume = 313 | issue = 5785 | pages = 351–4 | date = July 2006 | pmid = 16857940 | doi = 10.1126/science.1127863 | bibcode = 2006Sci...313..351B | s2cid = 16273738 }}{{cite journal | vauthors = Cox-Foster DL, Conlan S, Holmes EC, Palacios G, Evans JD, Moran NA, Quan PL, Briese T, Hornig M, Geiser DM, Martinson V, vanEngelsdorp D, Kalkstein AL, Drysdale A, Hui J, Zhai J, Cui L, Hutchison SK, Simons JF, Egholm M, Pettis JS, Lipkin WI | display-authors = 6 | title = A metagenomic survey of microbes in honey bee colony collapse disorder | journal = Science | volume = 318 | issue = 5848 | pages = 283–7 | date = October 2007 | pmid = 17823314 | doi = 10.1126/science.1146498 | bibcode = 2007Sci...318..283C | s2cid = 14013425 | doi-access = free }}{{cite journal | vauthors = Woteki C | title = The road to pollinator health | journal = Science | volume = 341 | issue = 6147 | pages = 695 | date = August 2013 | pmid = 23950499 | doi = 10.1126/science.1244271 | bibcode = 2013Sci...341..695W | author-link = Catherine Woteki | doi-access = free }}{{cite web |url=http://www.efsa.europa.eu/en/press/news/130116|title=EFSA Press Release: EFSA identifies risks to bees from neonicotinoids |publisher=Efsa.europa.eu |date= 2013-01-16|access-date=2014-04-18}} At present, there is an enormous demand for beehive rentals that cannot always be met. There is a clear need across the agricultural industry for a management tool to draw pollinators into cultivations and encourage them to preferentially visit and pollinate the flowering crop. By attracting pollinators like honey bees and increasing their foraging behavior, particularly in the center of large plots, we can increase grower returns and optimize yield from their plantings. ISCA Technologies,{{cite web |url=http://www.iscatech.com/exec/index.html |title=ISCA Technologies: A Leader of Innovative Pest Management Tools and Solutions |publisher=Iscatech.com |access-date=2014-04-18 |url-status=dead |archive-url=https://web.archive.org/web/20140410230851/http://www.iscatech.com/exec/index.html |archive-date=2014-04-10}} from [[Riverside, California]], created a semiochemical formulation called SPLAT Bloom, that modifies the behavior of honey bees, inciting them to visit flowers in every portion of the field.{{Advert inline|date=June 2022}} [114] => [115] => ==Environmental impacts== [116] => [117] => Loss of pollinators, also known as [[pollinator decline]] (of which [[colony collapse disorder]] is perhaps the most well known) has been noticed in recent years. These loss of pollinators have caused a disturbance in early plant regeneration processes such as seed dispersal and pollination. Early processes of plant regeneration greatly depend on plant-animal interactions and because these interactions are interrupted, biodiversity and ecosystem functioning are threatened.{{cite journal | vauthors = Neuschulz EL, Mueller T, Schleuning M, Böhning-Gaese K | title = Pollination and seed dispersal are the most threatened processes of plant regeneration | journal = Scientific Reports | volume = 6 | issue = 1 | pages = 29839 | date = July 2016 | pmid = 27435026 | pmc = 4951728 | doi = 10.1038/srep29839 | bibcode = 2016NatSR...629839N }} Pollination by animals aids in the genetic variability and diversity within plants because it allows for out-crossing instead for self-crossing. Without this genetic diversity there would be a lack of traits for natural selection to act on for the survival of the plant species. [[Seed dispersal]] is also important for plant fitness because it allows plants the ability to expand their populations. More than that, it permits plants to escape environments that have changed and have become difficult to reside in. All of these factors show the importance of pollinators for plants, which are a significant part of the foundation for a stable ecosystem. If only a few species of plants depended on Loss of pollinators is especially devastating because there are so many plant species rely on them. More than 87.5% of [[Flowering plant|angiosperms]], over 75% of tropical tree species, and 30-40% of tree species in temperate regions depend on pollination and seed dispersal. [118] => [119] => Factors that contribute to pollinator decline include [[habitat destruction]], [[pesticide]], [[parasitism]]/[[diseases]], and [[climate change]].{{cite journal | first = David Ward | last = Roubik | name-list-style = vanc | title = Ups and Downs in Pollinator Populations: When is there a Decline? | journal = Conservation Ecology | date = June 2001 | volume = 5 | issue = 1 | page = 2 | doi = 10.5751/ES-00255-050102 | hdl = 10535/3364 | hdl-access = free }} The more destructive forms of human disturbances are land use changes such as fragmentation, selective logging, and the conversion to secondary forest habitat. [[Defaunation]] of [[frugivore]]s is also an important driver.{{cite journal | vauthors = Carvalho CS, Galetti M, Colevatti RG, Jordano P | title = Defaunation leads to microevolutionary changes in a tropical palm | journal = Scientific Reports | volume = 6 | pages = 31957 | date = August 2016 | pmid = 27535709 | pmc = 4989191 | doi = 10.1038/srep31957 | bibcode = 2016NatSR...631957C }} These alterations are especially harmful due to the sensitivity of the pollination process of plants. Research on tropical palms found that defaunation has caused a decline in seed dispersal, which causes a decrease in genetic variability in this species. Habitat destruction such as fragmentation and selective logging remove areas that are most optimal for the different types of pollinators, which removes pollinators food resources, nesting sites, and leads to isolation of populations.{{cite journal | vauthors = Connolly CN | title = The risk of insecticides to pollinating insects | journal = Communicative & Integrative Biology | volume = 6 | issue = 5 | pages = e25074 | date = September 2013 | pmid = 24265849 | pmc = 3829947 | doi = 10.4161/cib.25074 }} The effect of pesticides on pollinators has been debated because it is difficult to determine that a single pesticide is the cause as opposed to a mixture or other threats. Whether exposure alone causes damage, or if the duration and potency are also factors is unknown. However, [[insecticide]]s have negative effects, as in the case of [[neonicotinoid]]s that harm bee colonies. Many researchers believe it is the synergistic effects of these factors which are ultimately detrimental to pollinator populations. [120] => [121] => In the agriculture industry, climate change is causing a "pollinator crisis". This crisis is affecting the production of crops, and the relating costs, due to a decrease in pollination processes.Maglianesi Sandoz, M.A. (2016). Efectos del cambio climático sobre la polinización y la producción agrícola en América Tropical. ''Revista Ingeniería'', ''26''(1), 11-20. This disturbance can be phenological or spatial. In the first case, species that normally occur in similar seasons or time cycles, now have different responses to environmental changes and therefore no longer interact. For example, a tree may flower sooner than usual, while the pollinator may reproduce later in the year and therefore the two species no longer coincide in time. Spatial disturbances occur when two species that would normally share the same distribution now respond differently to climate change and are shifting to different regions.Butt N, Seabrook L, Maron M, Law BS, Dawson TP, et al. Cascading effects of climate extremes on vertebrate fauna through changes to low latitude tree flowering and fruiting phenology. Global Change Biology. 2015; 21:3267–3277.Visser ME, Both C. Shifts in phenology due to global climate change: the need for a yardstick. Proceedings of the Royal Society of London B. 2005; 272:2561–2569 [122] => [123] => === Examples of affected pollinators === [124] => The most known and understood pollinator, bees, have been used as the prime example of the decline in pollinators. Bees are essential in the pollination of agricultural crops and wild plants and are one of the main insects that perform this task.{{cite journal | vauthors = Potts SG, Biesmeijer JC, Kremen C, Neumann P, Schweiger O, Kunin WE | title = Global pollinator declines: trends, impacts and drivers | journal = Trends in Ecology & Evolution | volume = 25 | issue = 6 | pages = 345–53 | date = June 2010 | pmid = 20188434 | doi = 10.1016/j.tree.2010.01.007 | citeseerx = 10.1.1.693.292 }} Out of the bees species, the honey bee or ''[[Western honey bee|Apis mellifera]]'' has been studied the most and in the United States, there has been a loss of 59% of colonies from 1947 to 2005. The decrease in populations of the honey bee have been attributed to pesticides, genetically modified crops, fragmentation, parasites and diseases that have been introduced.{{cite journal | vauthors = Fairbrother A, Purdy J, Anderson T, Fell R | title = Risks of neonicotinoid insecticides to honeybees | journal = Environmental Toxicology and Chemistry | volume = 33 | issue = 4 | pages = 719–31 | date = April 2014 | pmid = 24692231 | pmc = 4312970 | doi = 10.1002/etc.2527 }} There has been a focus on neonicotinoids effects on honey bee populations. Neonicotinoids insecticides have been used due to its low mammalian toxicity, target specificity, low application rates, and broad spectrum activity. However, the insecticides are able to make its way throughout the plant, which includes the pollen and nectar. Due to this, it has been shown to effect on the nervous system and colony relations in the honey bee populations. [125] => [126] => [[Butterfly|Butterflies]] too have suffered due to these modifications. Butterflies are helpful ecological indicators since they are sensitive to changes within the environment like the season, altitude, and above all, [[human impact on the environment]]. Butterfly populations were higher within the natural forest and were lower in open land. The reason for the difference in density is the fact that in open land the butterflies would be exposed to desiccation and predation. These open regions are caused by habitat destruction like logging for timber, livestock grazing, and firewood collection. Due to this destruction, butterfly species' diversity can decrease and it is known that there is a correlation in butterfly diversity and plant diversity.{{Cite journal |last1=Humpden |first1=Nyamweya N. |last2=Nathan |first2=Gichuki N. | name-list-style = vanc |date=2010-06-01 |title=Effects of plant structure on butterfly diversity in Mt. Marsabit Forest – northern Kenya |journal=African Journal of Ecology |volume=48 |issue=2 |pages=304–312 |doi=10.1111/j.1365-2028.2009.01151.x}} [127] => [128] => === Food security and pollinator decline === [129] => [130] => Besides the imbalance of the ecosystem caused by the decline in pollinators, it may jeopardise [[food security]]. Pollination is necessary for plants to continue their populations and 3/4 of the plant species that contribute to the world's food supply are plants that require pollinators.{{cite journal | vauthors = Tylianakis JM | title = Ecology. The global plight of pollinators | journal = Science | volume = 339 | issue = 6127 | pages = 1532–3 | date = March 2013 | pmid = 23449995 | doi = 10.1126/science.1235464 | s2cid = 10735480 | doi-access = free }} Insect pollinators, like bees, are large contributors to crop production, over 200 billion dollars worth of crop species are pollinated by these insects. Pollinators are also essential because they improve crop quality and increase genetic diversity, which is necessary in producing fruit with nutritional value and various flavors.{{Cite journal |last1=Sluijs |first1=Jeroen P. van der |last2=Vaage |first2=Nora S. | name-list-style = vanc |date=2016-06-01 |title=Pollinators and Global Food Security: the Need for Holistic Global Stewardship |journal=Food Ethics |volume=1 |issue=1 |pages=75–91 |doi=10.1007/s41055-016-0003-z|doi-access=free }} Crops that do not depend on animals for pollination but on the wind or self-pollination, like corn and potatoes, have doubled in production and make up a large part of the human diet but do not provide the micronutrients that are needed.{{cite journal | vauthors = Eilers EJ, Kremen C, Smith Greenleaf S, Garber AK, Klein AM | title = Contribution of pollinator-mediated crops to nutrients in the human food supply | journal = PLOS ONE | volume = 6 | issue = 6 | pages = e21363 | date = 2011-06-22 | pmid = 21731717 | pmc = 3120884 | doi = 10.1371/journal.pone.0021363 | bibcode = 2011PLoSO...621363E | doi-access = free }} The essential nutrients that are necessary in the human diet are present in plants that rely on animal pollinators. There have been issues in vitamin and mineral deficiencies and it is believed that if pollinator populations continue to decrease these deficiencies will become even more prominent. [131] => [132] => ==Plant–pollinator networks== [133] => {{see also|Pollination network}} [134] => [135] => Wild pollinators often visit a large number of plant species and plants are visited by a large number of pollinator species. All these relations together form a network of interactions between plants and pollinators. Surprising similarities were found in the structure of networks consisting out of the interactions between plants and pollinators. This structure was found to be similar in very different ecosystems on different continents, consisting of entirely different species.{{cite journal | vauthors = Bascompte J, Jordano P, Melián CJ, Olesen JM | title = The nested assembly of plant-animal mutualistic networks | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 100 | issue = 16 | pages = 9383–7 | date = August 2003 | pmid = 12881488 | pmc = 170927 | doi = 10.1073/pnas.1633576100 | bibcode = 2003PNAS..100.9383B | doi-access = free }} [136] => [137] => The structure of plant-pollinator networks may have large consequences for the way in which pollinator communities respond to increasingly harsh conditions. Mathematical models, examining the consequences of this network structure for the stability of pollinator communities suggest that the specific way in which plant-pollinator networks are organized minimizes competition between pollinators{{cite journal | vauthors = Bastolla U, Fortuna MA, Pascual-García A, Ferrera A, Luque B, Bascompte J | title = The architecture of mutualistic networks minimizes competition and increases biodiversity | journal = Nature | volume = 458 | issue = 7241 | pages = 1018–20 | date = April 2009 | pmid = 19396144 | doi = 10.1038/nature07950 | bibcode = 2009Natur.458.1018B | s2cid = 4395634 }} and may even lead to strong indirect facilitation between pollinators when conditions are harsh.{{cite journal | vauthors = Lever JJ, van Nes EH, Scheffer M, Bascompte J | title = The sudden collapse of pollinator communities | journal = Ecology Letters | volume = 17 | issue = 3 | pages = 350–9 | date = March 2014 | pmid = 24386999 | doi = 10.1111/ele.12236 | hdl = 10261/91808 | hdl-access = free }} This means that pollinator species together can survive under harsh conditions. But it also means that pollinator species collapse simultaneously when conditions pass a critical point. This simultaneous collapse occurs, because pollinator species depend on each other when surviving under difficult conditions. [138] => [139] => Such a community-wide collapse, involving many pollinator species, can occur suddenly when increasingly harsh conditions pass a critical point and recovery from such a collapse might not be easy. The improvement in conditions needed for pollinators to recover, could be substantially larger than the improvement needed to return to conditions at which the pollinator community collapsed. [140] => [141] => == Economics of commercial honeybee pollination == [142] => [[File:October18 finding ferrier fig01 450px.png|thumb|The graph shows the number of honeybee colonies in the U.S. from 1982 to 2015,]] [143] => While there are 200,000 - 350,000 different species of animals that help pollination, honeybees are responsible for majority of the pollination for consumed crops, providing between $235 and $577 US billion of benefits to global food production.{{Cite web|url=http://www.fao.org/news/story/en/item/384726/icode/|title=FAO - News Article: Pollinators vital to our food supply under threat|website=www.fao.org|language=en|access-date=2020-03-19}} The western honey bee (''Apis mellifera'' L.) provides highly valued pollination services for a wide variety of agricultural crops, and ranks as the most frequent single species of pollinator for crops worldwide.{{Cite journal |last=Hung |first=Keng-Lou James |last2=Kingston |first2=Jennifer M. |last3=Albrecht |first3=Matthias |last4=Holway |first4=David A. |last5=Kohn |first5=Joshua R. |date=2018-01-10 |title=The worldwide importance of honey bees as pollinators in natural habitats |url=https://royalsocietypublishing.org/doi/10.1098/rspb.2017.2140 |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=285 |issue=1870 |pages=20172140 |doi=10.1098/rspb.2017.2140 |issn=0962-8452 |pmc=5784195 |pmid=29321298}} Since the early 1900s, beekeepers in the United States started renting out their colonies to farmers to increase the farmer's crop yields, earning additional revenue from providing [[Pollination management|privatized pollination]]. As of 2016, 41% of an average US beekeeper's revenue comes from providing such pollination service to farmers, making it the biggest proportion of their income, with the rest coming from sales of honey, beeswax, government subsidy, etc.{{Cite web|url=https://www.ers.usda.gov/amber-waves/2018/july/driven-by-almonds-pollination-services-now-exceed-honey-as-a-source-of-beekeeper-revenue/|title=USDA ERS - Driven by Almonds, Pollination Services Now Exceed Honey as a Source of Beekeeper Revenue|website=www.ers.usda.gov|access-date=2020-03-11}} This is an example of how a [[Externality|positive externality]], pollination of crops from beekeeping and honey-making, was successfully accounted for and incorporated into the overall market for agriculture. On top of assisting food production, pollination service provide beneficial [[Spillover (economics)|spillovers]] as bees [[Germination|germinate]] not only the crops, but also other plants around the area that they are set loose to pollinate, increasing [[biodiversity]] for the local [[ecosystem]].{{Cite web|url=https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=295868|title=Pollinator Biodiversity|website=www.nsf.gov|language=en|access-date=2020-03-19}} There is even further spillover as biodiversity increases ecosystem resistance for wildlife and crops.{{cite journal | vauthors = Isbell F, Craven D, Connolly J, Loreau M, Schmid B, Beierkuhnlein C, Bezemer TM, Bonin C, Bruelheide H, de Luca E, Ebeling A, Griffin JN, Guo Q, Hautier Y, Hector A, Jentsch A, Kreyling J, Lanta V, Manning P, Meyer ST, Mori AS, Naeem S, Niklaus PA, Polley HW, Reich PB, Roscher C, Seabloom EW, Smith MD, Thakur MP, Tilman D, Tracy BF, van der Putten WH, van Ruijven J, Weigelt A, Weisser WW, Wilsey B, Eisenhauer N | display-authors = 6 | title = Biodiversity increases the resistance of ecosystem productivity to climate extremes | journal = Nature | volume = 526 | issue = 7574 | pages = 574–7 | date = October 2015 | pmid = 26466564 | doi = 10.1038/nature15374 | bibcode = 2015Natur.526..574I | hdl = 11299/184546 | s2cid = 4465811 | hdl-access = free }} Due to their role of pollination in crop production, commercial honeybees are considered to be livestock by the [[United States Department of Agriculture|US Department of Agriculture]]. The impact of pollination varies by crop. For example, [[almond]] production in the United States, an $11 billion industry based almost exclusively in the state of California, is heavily dependent on imported honeybees for pollination of almond trees. Almond industry uses up to 82% of the services in the pollination market. Each February, around 60% of the all bee colonies in the US are moved to California's [[Central Valley (California)|Central Valley]].{{cite news |last=McGivney |first=Annette | name-list-style = vanc |url= https://www.theguardian.com/environment/2020/jan/07/honeybees-deaths-almonds-hives-aoe|title='Like sending bees to war': the deadly truth behind your almond milk obsession|date=2020-01-08|work=The Guardian|access-date=2020-03-11|language=en-GB|issn=0261-3077}} [144] => [145] => Over the past decade, beekeepers across the US have reported that the mortality rate of their bee colonies has stayed constant at about 30% every year, making the deaths an expected cost of business for the beekeepers. While the exact cause of this phenomenon is unknown, according to the [[United States Department of Agriculture|US Department of Agriculture]] [[Colony collapse disorder|Colony Collapse Disorder]] Progress Report it can be traced to factors such as pollution, pesticides, and pathogens from evidences found in areas of the colonies affected and the colonies themselves.{{cite web | author = CCD Steering Committee | date = June 2010 | title = Colony Collapse Disorder Progress Report | url = https://www.ars.usda.gov/is/br/ccd/ccdprogressreport2010.pdf | publisher = United States Department of Agriculture }} Pollution and pesticides are detrimental to the health of the bees and their colonies as the bees' ability to pollinate and return to their colonies are great greatly compromised.{{cite journal | vauthors = Henry M, Béguin M, Requier F, Rollin O, Odoux JF, Aupinel P, Aptel J, Tchamitchian S, Decourtye A | display-authors = 6 | title = A common pesticide decreases foraging success and survival in honey bees | journal = Science | volume = 336 | issue = 6079 | pages = 348–50 | date = April 2012 | pmid = 22461498 | doi = 10.1126/science.1215039 | bibcode = 2012Sci...336..348H | s2cid = 41186355 | url = https://hal.archives-ouvertes.fr/hal-00731655/file/51503_20120420060922456_1.pdf }} Moreover, California's Central Valley is determined by the [[World Health Organization]] as the location of country's worst [[air pollution]].{{Cite news |last=Carroll |first=Rory | name-list-style = vanc |url=https://www.theguardian.com/us-news/2016/may/13/california-san-joaquin-valley-porterville-pollution-poverty|title=Life in San Joaquin valley, the place with the worst air pollution in America|date=2016-05-13|work=The Guardian|access-date=2020-03-12|language=en-GB|issn=0261-3077}} Almond pollinating bees, approximately 60% of the bees in the US as mentioned above, will be mixed with bees from thousands of other hives provided by different beekeepers, making them exponentially susceptible to diseases and [[Varroa destructor|mites]] that any of them could be carrying. The deaths do not stop at commercial honeybees as there is evidence of significant pathogen spillover to other pollinators including wild bumble bees, infecting up to 35-100% of wild bees within 2 km radius of commercial pollination.{{cite journal | vauthors = Otterstatter MC, Thomson JD | title = Does pathogen spillover from commercially reared bumble bees threaten wild pollinators? | journal = PLOS ONE | volume = 3 | issue = 7 | pages = e2771 | date = July 2008 | pmid = 18648661 | pmc = 2464710 | doi = 10.1371/journal.pone.0002771 | bibcode = 2008PLoSO...3.2771O | doi-access = free }} The negative [[externality]] of private pollination services is the decline of biodiversity through the deaths of commercial and wild bees. [[File:US_almond_pollination_share.png|thumb|The graph shows the average dollar amount per colonies received by beekeepers depending on the pollinated crop.]]Despite losing about a third of their workforce every year, beekeepers continue to rent out their bees to almond farms due to the high pay from the almond industry. In 2016, a colony rented out for almond pollination gave beekeepers an income of $165 per colony rented, around three times from average of other crops that use the pollination rental service.{{Cite web|url=https://www.ers.usda.gov/amber-waves/2018/july/driven-by-almonds-pollination-services-now-exceed-honey-as-a-source-of-beekeeper-revenue/|title=USDA ERS - Driven by Almonds, Pollination Services Now Exceed Honey as a Source of Beekeeper Revenue|website=www.ers.usda.gov|access-date=2020-03-12}} However, a recent study published in Oxford Academic's Journal of Economic [[Entomology]] found that once the costs for maintaining bees specifically for almond pollination, including [[overwintering]], summer management, and the replacement dying bees are considered, almond pollination is barely or not profitable for average beekeepers.{{cite journal | vauthors = Degrandi-Hoffman G, Graham H, Ahumada F, Smart M, Ziolkowski N | title = The Economics of Honey Bee (Hymenoptera: Apidae) Management and Overwintering Strategies for Colonies Used to Pollinate Almonds | journal = Journal of Economic Entomology | volume = 112 | issue = 6 | pages = 2524–2533 | date = December 2019 | pmid = 31504631 | doi = 10.1093/jee/toz213 | doi-access = free }} [146] => [147] => == See also == [148] => *[[Canadian Pollination Initiative]] [149] => *[[Cheating (biology)]] [150] => *[[Floral color change]] [151] => *[[Pollinator-mediated selection]] [152] => *[[Fruit tree pollination]] [153] => *[[Hand-pollination]] [154] => *[[Paul Knuth]] [155] => *[[Hermann Müller (German botanist)|Hermann Müller (botanist)]] [156] => *[[Plant reproductive morphology]] [157] => *[[Pollen DNA barcoding]] [158] => *[[Polli:Nation]] [159] => [160] => == References == [161] => {{Reflist|refs= [162] => Hagerup, O. 1950. [http://www.royalacademy.dk/Publications/Low/195_Hagerup,%20O.pdf Rain-pollination.] I kommission hos E. Munksgaard. Retrieved 26 May 2018. [163] => }} [164] => [165] => ==Notes== [166] => {{refbegin}} [167] => * {{cite journal | vauthors = Crepet WL, Friis EM, Nixon KC | date = 1991 | title = Fossil evidence for the evolution of biotic pollination [and discussion]. | journal = Philosophical Transactions: Biological Sciences | volume = 333 | issue = 1267 | pages = 187–195 | doi = 10.1098/rstb.1991.0067 }} [168] => * {{cite book | vauthors = Dafni A, Kevan PG, Husband BC | date = 2005 | title = Practical Pollination Biology | publisher = Enviroquest, Ltd. | isbn = 978-0-9680123-0-7 }} [169] => * {{cite journal | vauthors = Labandeira CC, Kvacek J, Mostovski MB | date = 2007 | title = Pollination drops, pollen and insect pollination of Mesozoic gymnosperms. | journal = [[Taxon (journal)|Taxon]] | volume = 56 | issue = 3 | pages = 663–695 | doi = 10.2307/25065852 | jstor = 25065852 }} [170] => * {{cite book | vauthors = Sihag RC | date = 1997 | title = Pollination Biology: Basic and Applied Principles. | publisher = Rajendra Scientific Publishers | location = Hisar | pages = 210 }} [171] => {{refend}} [172] => ==Further reading== [173] => * {{cite book |isbn=9780691203751 |title=Pollination: The Enduring Relationship Between Plant and Pollinator |last1=Walker |first1=Timothy |author-link=Timothy Walker (botanist)|date=6 October 2020 |pages=1–224|publisher=Princeton University Press }} [174] => [175] => == External links == [176] => {{Wiktionary}} [177] => {{Commons category|Pollination}} [178] => *[http://nas-sites.org/pollinators/ Resources on Pollinators] from the [[National Academies]] [179] => *[http://pollinator.com The Pollination Home page] [180] => *[http://www.hydroponicsonline.com/blog/hydroponic-pollination-blue-bottle-flies Pollination in Hydroponics] [181] => *[https://web.archive.org/web/20110224205808/http://www.cas.vanderbilt.edu/bioimages/pages/pollination.htm Pollination syndromes images at bioimages.vanderbilt.edu] [182] => *{{Cite EB1911|wstitle=Pollination|short=x}} [183] => [184] => {{pollination}} [185] => {{Botany}} [186] => [187] => {{Authority control}} [188] => [189] => [[Category:Pollination| ]] [190] => [[Category:Horticulture]] [191] => [[Category:Plant sexuality]] [] => )
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Pollination

Pollination is the process by which pollen is transferred from the male reproductive organs of a flower to the female reproductive organs, resulting in fertilization and the production of seeds. This transfer of pollen may occur within a single flower or between different flowers of the same plant, as well as between flowers of different plants.

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This transfer of pollen may occur within a single flower or between different flowers of the same plant, as well as between flowers of different plants. Pollination is crucial for the reproduction of flowering plants and plays a vital role in ecosystem functioning and food production. Various agents, including wind, water, animals, and insects, can contribute to pollination. The Wikipedia page on pollination provides a comprehensive overview of this process, including its types, mechanisms, and the different agents involved. Apart from natural pollination, the page also discusses human-assisted pollination techniques used in agriculture and horticulture. It delves into specific pollinators like bees, butterflies, birds, and bats, highlighting their adaptations and importance in pollination. Furthermore, information on the effects of pollution, habitat loss, and climate change on pollination is presented. The page also explores the role of pollination in the production of various crops and the economic significance of pollinators in global food systems. Overall, the Wikipedia page on pollination offers a detailed account of this essential biological process and its significance in maintaining biodiversity and supporting human livelihoods.

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