Editing Pollination (section)

==Environmental impacts==

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.<ref name=":02">{{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 }}</ref> 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.<ref name=":02" />

Factors that contribute to pollinator decline include [[habitat destruction]], [[pesticide]], [[parasitism]]/[[diseases]], and [[climate change]].<ref name=":3">{{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 }}</ref> The more destructive forms of human disturbances are land use changes such as fragmentation, selective logging, and the conversion to secondary forest habitat.<ref name=":02" /> [[Defaunation]] of [[frugivore]]s is also an important driver.<ref name=":7">{{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 }}</ref> These alterations are especially harmful due to the sensitivity of the pollination process of plants.<ref name=":02" /> Research on tropical palms found that defaunation has caused a decline in seed dispersal, which causes a decrease in genetic variability in this species.<ref name=":7" /> 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.<ref name=":4">{{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 }}</ref> 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.<ref name=":4" /> Whether exposure alone causes damage, or if the duration and potency are also factors is unknown.<ref name=":4" /> 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.<ref name=":3" />

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.<ref>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.</ref> 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.<ref>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.</ref><ref>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</ref>

=== Examples of affected pollinators ===
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.<ref name=":6">{{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 | bibcode = 2010TEcoE..25..345P | citeseerx = 10.1.1.693.292 }}</ref> 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.<ref name=":6" /> The decrease in populations of the honey bee have been attributed to pesticides, genetically modified crops, fragmentation, parasites and diseases that have been introduced.<ref name=":8">{{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 }}</ref> 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.<ref name=":8" />

[[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.<ref name=":1">{{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|bibcode=2010AfJEc..48..304H }}</ref>

=== Food security and pollinator decline ===

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.<ref name=":2">{{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 }}</ref> Insect pollinators, like bees, are large contributors to crop production, over 200&nbsp;billion dollars worth of crop species are pollinated by these insects.<ref name=":4" />  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.<ref name=":9">{{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 (journal)|Food Ethics]] |volume=1 |issue=1 |pages=75–91 |doi=10.1007/s41055-016-0003-z|doi-access=free }}</ref> 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.<ref name=":5">{{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 }}</ref> The essential nutrients that are necessary in the human diet are present in plants that rely on animal pollinators.<ref name=":5" /> 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.<ref name=":9" />