Pollinator decline

Last updated
A dead carpenter bee A Dead carpenter bee (Xylocopa pubescens).jpg
A dead carpenter bee

Pollinator decline is the reduction in abundance of insect and other animal pollinators in many ecosystems worldwide that began being recorded at the end of the 20th century. Multiple lines of evidence exist for the reduction of wild pollinator populations at the regional level, especially within Europe and North America. [1] [2] [3] [4] Similar findings from studies in South America, China and Japan make it reasonable to suggest that declines are occurring around the globe. [5] [6] [7] [8] The majority of studies focus on bees, particularly honeybee and bumblebee species, with a smaller number involving hoverflies and lepidopterans. [9] [1] [10] [11] [12]

Contents

The picture for domesticated pollinator species is less clear. Although the number of managed honey bee colonies in Europe and North America declined by 25% and 59% between 1985-2005 and 1947-2005 respectively, overall global stocks increased due to major hive number increases in countries such as China and Argentina. [13] [14] [15] Nevertheless, in the time managed honeybee hives increased by 45% demand for animal pollinated crops tripled, highlighting the danger of relying on domesticated populations for pollination services. [15]

Pollinators participate in the sexual reproduction of many plants by ensuring cross-pollination, essential for some species and a major factor in ensuring genetic diversity for others. Since plants are the primary food source for animals, the possible reduction or disappearance of pollinators has been referred to as an "armageddon" by some journalists.

Evidence

The declines in abundance and diversity of insect pollinators over the twentieth century have been documented in highly industrialized regions of the world, particularly northwestern Europe and eastern North America. [16] [17] [18]

Colony collapse disorder has attracted much public attention. According to a 2013 blog the winter losses of beehives had increased in recent years in Europe and the United States, with a hive failure rate up to 50%. [19]

A 2017 German study, using 1,500 samples from 63 sites, indicated that the biomass of flying insects in that area had declined by three-quarters in the previous 25 years. [20] One 2009 study stated that while the bee population had increased by 45% over the past 50 years, the amount of crops which use bees had increased by 300%; although there is absolutely no evidence this has caused any problems, the authors propose it might cause "future pollination problems". [21]

In mathematical models of the networks linking different plants and their many pollinators, [22] such a network can continue to function very well under increasingly harsh conditions, but when conditions become extremely harsh, the entire network fails simultaneously. [23]

A 2021 study described as the "first long-term assessment of global bee decline", which analyzed GBIF-data of over a century, found that the number of bee species declined steeply worldwide after the 1990s, shrinking by a quarter in 2006–2015 compared to before 1990. [24] [25]

Possible explanations

Although the existence of pollinator decline can be difficult to determine, a number of possible reasons for the theoretical concept have been proposed, such as exposure to pathogens, parasites, and pesticides; habitat destruction; climate change; market forces; intra- and interspecific competition with native and invasive species; and genetic alterations. [26] [27]

Honey bees are an invasive species throughout most of the world where they have been introduced, and the constant growth in the amount of these pollinators may possibly cause a decrease in native species. [21] Light pollution has been suggested a number of times as a possible reason for the possible decline in flying insects. [28] [29] [30] [31] One study found that air pollution, such as from cars, has been inhibiting the ability of pollinators such as bees and butterflies to find the fragrances of flowers. Pollutants such as ozone, hydroxyl, and nitrate radicals bond quickly with volatile scent molecules of flowers, which consequently travel shorter distances intact. Pollinators must thus travel longer distances to find flowers. [32]

Pollinators may also face an increased risk of extinction because of global warming due to alterations in the seasonal behaviour of species. Climate change can cause bees to emerge at times in the year when flowering plants were not available. [33]

Consequences

Seven out of the ten most important crops in the world, in terms of volume, are pollinated by wind (maize, rice and wheat) or have vegetative propagation (banana, sugar cane, potato, beet, and cassava) and thus do not require animal pollinators for food production. [34] Additionally crops such as sugar beet, spinach and onions are self-pollinating and do not require insects. [35] Nonetheless, an estimated 87.5% of the world's flowering plant species are animal-pollinated, [36] and 60% of crop plant species [37] use animal pollinators. This includes the majority of fruits, many vegetables, and also fodder. [38] According to the USDA 80% of insect crop pollination in the US is due to honey bees. [39]

A study which examined how fifteen plant species said to be dependent on animals for pollination would be impacted by pollinator decline, by excluding pollinators from them with domes, found that while most species do not suffer any impacts from decline in terms of reduced fertilization rates (seed set), three species did. [40]

The expected direct reduction in total agricultural production in the US in the absence of animal pollination is expected to be 3 to 8%, with smaller impacts on agricultural production diversity. [41] Of all the possible consequences, the most important effect of pollinator decline for humans in Brazil, according to one 2016 study, would be the drop in income from high-value cash crops, and would impact the agricultural sector the most. [34] A 2000 study about the economic effects of the honey bee on US food crops calculated that it helped to produce US$14.6 billion in monetary value. [42] In 2009 another study calculated the worldwide value of the 100 crops that need pollinators at €153 billion (not including production costs). [43] Despite the dire predictions, the theorised decline in pollinators has had no effect on food production, with yields of both animal-pollinated and non-animal-pollinated crops increasing at the same rate, over the period of supposed pollinator decline. [44]

Possible nutritional consequences

A 2015 study looked at the nutritional consequences of pollinator decline. It investigated if four third world populations might in the future potentially be at possible risk of malnutrition, assuming humans did not change their diet or have access to supplements, but concluded that this cannot be reliably predicted. According to their model, the size of the effect that pollinator decline had on a population depends on the local diet, and vitamin A is the most likely nutrient to become deficient, as it is already deficient. [45]

More studies also identified vitamin A as the most pollinator-dependent nutrient. [46] [47] Another 2015 study also modeled what would happen should 100% of pollinators die off. In that scenario, 71 million people in low-income countries would become deficient in vitamin A, and the vitamin A intake of 2.2 billion people who are already consuming less than the recommended amount would further decline. Similarly, 173 million people would become deficient in folate, and 1.23 million people would further lessen their intake. Additionally, the global fruit supply would decrease by 22.9%, the global vegetable supply would decrease by 16.3%, and the global supply of nuts and seeds would decrease by 22.1%. This would lead to 1.42 million additional deaths each year from diseases, as well as 27 million disability-adjusted life years. In a less extreme scenario wherein only 50% of pollinators die off, 700,000 additional deaths would occur each year, as well as 13.2 million disability-adjusted years. [48]

A melon plant, a crop requiring a pollinator and a good source of vitamin A Melon plant.jpg
A melon plant, a crop requiring a pollinator and a good source of vitamin A

One study estimated that 70% of dietary vitamin A worldwide is found in crops that are animal pollinated, as well as 55% of folate. At present, eating plants which are pollinated by animals is responsible for only 9%, 20%, and 29% of calcium, fluoride, and iron intake, respectively, with most coming from meat and dairy. 74% of all globally produced lipids are found in oils from plants that are animal pollinated, as well as 98% of vitamin C. [47]

Solutions

Several scholars have called for application of the precautionary principle. [27] [49]

Efforts are being made to sustain pollinator diversity in agricultural and natural ecosystems by some environmental groups. [50] In 2014 the Obama administration published "the Economic Challenge Posed by Declining Pollinator Populations" fact sheet, which stated that the 2015 budget proposal recommended congress appropriate approximately $50 million for pollinator habitat maintenance and to double the area in the Conservation Reserve Program dedicated to pollinator health, as well as recommending to "increase funding for surveys to determine the impacts on pollinator losses". [51]

Some international initiatives highlight the need for public participation and awareness of pollinator conservation. [52] Pollinators and their health have become growing concerns for the public. Around 18 states within America have responded to these concerns by creating legislation to address the issue. According to the National Conference of State Legislatures, the enacted legislation in those states addresses five specific areas relating to pollinator decline: awareness, research, pesticides, habitat protection and beekeeping. [53]

A 2021 global assessment of the drivers of pollinator decline found that "global policy responses should focus on reducing pressure from changes in land cover and configuration, land management and pesticides, as these were considered very important drivers in most regions". [54]

See also

Related Research Articles

<span class="mw-page-title-main">Bee</span> Clade of insects

Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamily Apoidea. They are currently considered a clade, called Anthophila. There are over 20,000 known species of bees in seven recognized biological families. Some species – including honey bees, bumblebees, and stingless bees – live socially in colonies while most species (>90%) – including mason bees, carpenter bees, leafcutter bees, and sweat bees – are solitary.

<span class="mw-page-title-main">Honey bee</span> Colonial flying insect of genus Apis

A honey bee is a eusocial flying insect within the genus Apis of the bee clade, all native to mainland Afro-Eurasia. After bees spread naturally throughout Africa and Eurasia, humans became responsible for the current cosmopolitan distribution of honey bees, introducing multiple subspecies into South America, North America, and Australia.

<span class="mw-page-title-main">Pollinator</span> Animal that moves pollen from the male anther of a flower to the female stigma

A pollinator is an animal that moves pollen from the male anther of a flower to the female stigma of a flower. This helps to bring about fertilization of the ovules in the flower by the male gametes from the pollen grains.

<span class="mw-page-title-main">Insecticide</span> Pesticide used against insects

Insecticides are pesticides used to kill insects. They include ovicides and larvicides used against insect eggs and larvae, respectively. Insecticides are used in agriculture, medicine, industry and by consumers. Insecticides are claimed to be a major factor behind the increase in the 20th-century's agricultural productivity. Nearly all insecticides have the potential to significantly alter ecosystems; many are toxic to humans and/or animals; some become concentrated as they spread along the food chain.

<span class="mw-page-title-main">Bumblebee</span> Genus of insect

A bumblebee is any of over 250 species in the genus Bombus, part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related genera are known from fossils. They are found primarily in higher altitudes or latitudes in the Northern Hemisphere, although they are also found in South America, where a few lowland tropical species have been identified. European bumblebees have also been introduced to New Zealand and Tasmania. Female bumblebees can sting repeatedly, but generally ignore humans and other animals.

<span class="mw-page-title-main">Pollination</span> Biological process occurring in plants

Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, for example beetles; birds, butterflies, 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. When self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work.

<span class="mw-page-title-main">Pollination management</span> Horticultural practices to enhance pollination

Pollination management is the horticultural practices that accomplish or enhance pollination of a crop, to improve yield or quality, by understanding of the particular crop's pollination needs, and by knowledgeable management of pollenizers, pollinators, and pollination conditions.

<i>Bombus terrestris</i> Species of bee

Bombus terrestris, the buff-tailed bumblebee or large earth bumblebee, is one of the most numerous bumblebee species in Europe. It is one of the main species used in greenhouse pollination, and so can be found in many countries and areas where it is not native, such as Tasmania. Moreover, it is a eusocial insect with an overlap of generations, a division of labour, and cooperative brood care. The queen is monandrous which means she mates with only one male. B. terrestris workers learn flower colours and forage efficiently.

<span class="mw-page-title-main">Palynivore</span> Group of herbivorous animals

In zoology, a palynivore /pəˈlɪnəvɔːɹ/, meaning "pollen eater" is an herbivorous animal which selectively eats the nutrient-rich pollen produced by angiosperms and gymnosperms. Most true palynivores are insects or mites. The category in its strictest application includes most bees, and a few kinds of wasps, as pollen is often the only solid food consumed by all life stages in these insects. However, the category can be extended to include more diverse species. For example, palynivorous mites and thrips typically feed on the liquid content of the pollen grains without actually consuming the exine, or the solid portion of the grain. Additionally, the list is expanded greatly if one takes into consideration species where either the larval or adult stage feeds on pollen, but not both. There are other wasps which are in this category, as well as many beetles, flies, butterflies, and moths. One such example of a bee species that only consumes pollen in its larval stage is the Apis mellifera carnica. There is a vast array of insects that will feed opportunistically on pollen, as will various birds, orb-weaving spiders and other nectarivores.

<span class="mw-page-title-main">Insect biodiversity</span>

Insect biodiversity accounts for a large proportion of all biodiversity on the planet—over half of the estimated 1.5 million organism species described are classified as insects.

Neonicotinoids are a class of neuro-active insecticides chemically similar to nicotine, developed by scientists at Shell and Bayer in the 1980s.

<span class="mw-page-title-main">Environmental impact of pesticides</span> Environmental effect

The environmental effects of pesticides describe the broad series of consequences of using pesticides. The unintended consequences of pesticides is one of the main drivers of the negative impact of modern industrial agriculture on the environment. Pesticides, because they are toxic chemicals meant to kill pest species, can affect non-target species, such as plants, animals and humans. Over 98% of sprayed insecticides and 95% of herbicides reach a destination other than their target species, because they are sprayed or spread across entire agricultural fields. Other agrochemicals, such as fertilizers, can also have negative effects on the environment.

<span class="mw-page-title-main">Western honey bee</span> European honey bee

The western honey bee or European honey bee is the most common of the 7–12 species of honey bees worldwide. The genus name Apis is Latin for "bee", and mellifera is the Latin for "honey-bearing" or "honey carrying", referring to the species' production of honey.

<i>Bombus hortorum</i> Species of bee

Bombus hortorum, the garden bumblebee or small garden bumblebee, is a species of bumblebee found in most of Europe north to 70°N, as well as parts of Asia and New Zealand. It is distinguished from most other bumblebees by its long tongue used for feeding on pollen in deep-flowered plants. Accordingly, this bumblebee mainly visits flowers with deep corollae, such as deadnettles, ground ivy, vetches, clovers, comfrey, foxglove, and thistles. They have a good visual memory, which aids them in navigating the territory close to their habitat and seeking out food sources.

<span class="mw-page-title-main">Colony collapse disorder</span> Aspect of apiculture

Colony collapse disorder (CCD) is an abnormal phenomenon that occurs when the majority of worker bees in a honey bee colony disappear, leaving behind a queen, plenty of food, and a few nurse bees to care for the remaining immature bees. While such disappearances have occurred sporadically throughout the history of apiculture, and have been known by various names, the syndrome was renamed colony collapse disorder in early 2007 in conjunction with a drastic rise in reports of disappearances of western honey bee colonies in North America. Beekeepers in most European countries had observed a similar phenomenon since 1998, especially in Southern and Western Europe; the Northern Ireland Assembly received reports of a decline greater than 50%. The phenomenon became more global when it affected some Asian and African countries as well.

<i>Bombus impatiens</i> Species of insect

Bombus impatiens, the common eastern bumble bee, is the most commonly encountered bumblebee across much of eastern North America. They can be found in the Eastern temperate forest region of the eastern United States, southern Canada, and the eastern Great Plains. Because of their great adaptability, they can live in country, suburbs, and even urban cities. This adaptability makes them a great pollinator species, leading to an increase in their commercial use by the greenhouse industry. This increase consequently led to their farther spread outside their previous distribution range. They are considered one of the most important species of pollinator bees in North America.

<i>Bombus ruderatus</i> Species of bee

Bombus ruderatus, the large garden bumblebee or ruderal bumblebee, is a species of long-tongued bumblebee found in Europe and in some parts of northern Africa. This species is the largest bumblebee in Britain and it uses its long face and tongue to pollinate hard-to-reach tubed flowers. Bumblebees are key pollinators in many agricultural ecosystems, which has led to B. ruderatus and other bumblebees being commercially bred and introduced into non-native countries, specifically New Zealand and Chile. Since its introduction in Chile, B. ruderatus has spread into Argentina as well. Population numbers have been declining and it has been placed on the Biodiversity Action Plan to help counteract these declines.

<span class="mw-page-title-main">Decline in insect populations</span> Ecological trend recorded since the late 20th century

Insects are the most numerous and widespread class in the animal kingdom, accounting for up to 90% of all animal species. In the 2010s, multiple reports about the widespread decline in insect populations across multiple orders have emerged. The reported severity had shocked many observers, even though it was preceded by the earlier findings of pollinator decline, as well as anecdotal evidence of greater apparent abundance of insects earlier in the 20th century, such as the windscreen phenomenon. Possible causes are similar to those causing other biodiversity loss, namely habitat destruction, including intensive agriculture; the use of pesticides ; urbanisation, and industrialisation; introduced species; and - to a lesser degree and only for some regions - climate change.

Bombus hypocrita, also known as the short-tongued bumblebee, is a Japanese bumblebee commonly used in commercial pollination. These short-tongued bumblebees have a proboscis about 7-9mm long, which is folded under their head when flying. Bumblebees are a small fuzzy insect with yellow and black banding along their abdomen. They are round and covered in pile, the hair-like structures that give them their distinct fuzzy appearance.

<span class="mw-page-title-main">Pollinator garden</span> Type of garden

A pollinator garden is a type of garden designed with the intent of growing specific nectar and pollen-producing plants, in a way that attracts pollinating insects known as pollinators. Pollinators aid in the production of one out of every three bites of food consumed by humans, and pollinator gardens are a way to offer support for these species. In order for a garden to be considered a pollinator garden, it should provide various nectar producing flowers, shelter or shelter-providing plants for pollinators, and avoid the use of pesticides.

References

  1. 1 2 Powney, Gary D.; Carvell, Claire; Edwards, Mike; Morris, Roger K. A.; Roy, Helen E.; Woodcock, Ben A.; Isaac, Nick J. B. (26 March 2019). "Widespread losses of pollinating insects in Britain". Nature Communications. 10 (1): 1018. Bibcode:2019NatCo..10.1018P. doi: 10.1038/s41467-019-08974-9 . PMC   6435717 . PMID   30914632. S2CID   85528078.
  2. ↑ Soroye, Peter; Newbold, Tim; Kerr, Jeremy (7 February 2020). "Climate change contributes to widespread declines among bumble bees across continents". Science. 367 (6478): 685–688. Bibcode:2020Sci...367..685S. doi: 10.1126/science.aax8591 . PMID   32029628. S2CID   211049610.
  3. ↑ Goulson, D.; Nicholls, E.; Botias, C.; Rotheray, E. L. (27 March 2015). "Bee declines driven by combined stress from parasites, pesticides, and lack of flowers". Science. 347 (6229): 1255957. doi: 10.1126/science.1255957 . PMID   25721506. S2CID   206558985.
  4. ↑ Potts, Simon G.; Biesmeijer, Jacobus C.; Kremen, Claire; Neumann, Peter; Schweiger, Oliver; Kunin, William E. (June 2010). "Global pollinator declines: trends, impacts and drivers". Trends in Ecology & Evolution. 25 (6): 345–353. doi:10.1016/j.tree.2010.01.007. PMID   20188434.
  5. ↑ Schmid-Hempel, Regula; Eckhardt, Michael; Goulson, David; Heinzmann, Daniel; Lange, Carlos; Plischuk, Santiago; Escudero, Luisa R.; Salathé, Rahel; Scriven, Jessica J.; Schmid-Hempel, Paul (July 2014). "The invasion of southern South America by imported bumblebees and associated parasites". Journal of Animal Ecology. 83 (4): 823–837. doi: 10.1111/1365-2656.12185 . PMID   24256429.
  6. ↑ Xie, Zhenghua; Williams, Paul H.; Tang, Ya (1 December 2008). "The effect of grazing on bumblebees in the high rangelands of the eastern Tibetan Plateau of Sichuan". Journal of Insect Conservation. 12 (6): 695–703. doi:10.1007/s10841-008-9180-3. S2CID   19979709.
  7. ↑ Williams, Paul; Tang, Ya; Yao, Jian; Cameron, Sydney (1 June 2009). "The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini)". Systematics and Biodiversity. 7 (2): 101–189. doi:10.1017/S1477200008002843. S2CID   86166557.
  8. ↑ Inoue, Maki N.; Yokoyama, Jun; Washitani, Izumi (1 April 2008). "Displacement of Japanese native bumblebees by the recently introduced Bombus terrestris (L.) (Hymenoptera: Apidae)". Journal of Insect Conservation. 12 (2): 135–146. doi:10.1007/s10841-007-9071-z. S2CID   33992235.
  9. ↑ Biesmeijer, J. C. (21 July 2006). "Parallel Declines in Pollinators and Insect-Pollinated Plants in Britain and the Netherlands". Science. 313 (5785): 351–354. Bibcode:2006Sci...313..351B. doi:10.1126/science.1127863. PMID   16857940. S2CID   16273738.
  10. ↑ Fox, Richard; Oliver, Tom H.; Harrower, Colin; Parsons, Mark S.; Thomas, Chris D.; Roy, David B. (August 2014). "Long‐term changes to the frequency of occurrence of British moths are consistent with opposing and synergistic effects of climate and land‐use changes". Journal of Applied Ecology. 51 (4): 949–957. doi:10.1111/1365-2664.12256. PMC   4413814 . PMID   25954052.
  11. ↑ Forister, Matthew L.; Jahner, Joshua P.; Casner, Kayce L.; Wilson, Joseph S.; Shapiro, Arthur M. (2011). "The race is not to the swift: Long-term data reveal pervasive declines in California's low-elevation butterfly fauna". Ecology. 92 (12): 2222–2235. doi:10.1890/11-0382.1. PMID   22352162.
  12. ↑ Semmens, Brice X.; Semmens, Darius J.; Thogmartin, Wayne E.; Wiederholt, Ruscena; López-Hoffman, Laura; Diffendorfer, Jay E.; Pleasants, John M.; Oberhauser, Karen S.; Taylor, Orley R. (September 2016). "Quasi-extinction risk and population targets for the Eastern, migratory population of monarch butterflies (Danaus plexippus)". Scientific Reports. 6: 23265. Bibcode:2016NatSR...623265S. doi:10.1038/srep23265. PMC   4800428 . PMID   26997124.
  13. ↑ Potts, Simon G.; Roberts, Stuart P. M.; Dean, Robin; Marris, Gay; Brown, Mike A.; Jones, Richard; Neumann, Peter; Settele, Josef (1 January 2010). "Declines of managed honey bees and beekeepers in Europe". Journal of Apicultural Research. 49 (1): 15–22. doi:10.3896/IBRA.1.49.1.02. S2CID   67794397.
  14. ↑ vanEngelsdorp, Dennis; Hayes, Jerry Jr.; Underwood, Robyn M.; Pettis, Jeffery (30 December 2008). "A Survey of Honey Bee Colony Losses in the U.S., Fall 2007 to Spring 2008". PLOS ONE. 3 (12): e4071. Bibcode:2008PLoSO...3.4071V. doi: 10.1371/journal.pone.0004071 . PMC   2606032 . PMID   19115015.
  15. 1 2 Aizen, Marcelo A.; Harder, Lawrence D. (June 2009). "The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination". Current Biology. 19 (11): 915–918. doi: 10.1016/j.cub.2009.03.071 . PMID   19427214. S2CID   12353259.
  16. ↑ Potts, Simon G.; Biesmeijer, Jacobus C.; Kremen, Claire; Neumann, Peter; Schweiger, Oliver; Kunin, William E. (June 2010). "Global pollinator declines: trends, impacts and drivers". Trends in Ecology & Evolution. 25 (6): 345–353. doi:10.1016/j.tree.2010.01.007. PMID   20188434.
  17. ↑ Goulson, D.; Nicholls, E.; Botias, C.; Rotheray, E. L. (27 March 2015). "Bee declines driven by combined stress from parasites, pesticides, and lack of flowers". Science. 347 (6229): 1255957. doi: 10.1126/science.1255957 . PMID   25721506. S2CID   206558985.
  18. ↑ Potts, Simon G.; Imperatriz-Fonseca, Vera; Ngo, Hien T.; Aizen, Marcelo A.; Biesmeijer, Jacobus C.; Breeze, Thomas D.; Dicks, Lynn V.; Garibaldi, Lucas A.; Hill, Rosemary; Settele, Josef; Vanbergen, Adam J. (December 2016). "Safeguarding pollinators and their values to human well-being". Nature. 540 (7632): 220–229. Bibcode:2016Natur.540..220P. doi:10.1038/nature20588. hdl: 11336/66239 . PMID   27894123. S2CID   205252584.
  19. ↑ "Declining Bee Populations Pose a Threat to Global Agriculture". Yale Environment 360. 30 April 2013.
  20. ↑ Editor, Damian Carrington Environment (18 October 2017). "Warning of 'ecological Armageddon' after dramatic plunge in insect numbers". The Guardian.{{cite news}}: |last1= has generic name (help)
  21. 1 2 Aizen, Marcelo A.; Harder, Lawrence D. (9 June 2009). "The Global Stock of Domesticated Honey Bees Is Growing Slower Than Agricultural Demand for Pollination". Current Biology. 19 (11): 915–918. doi: 10.1016/j.cub.2009.03.071 . PMID   19427214. S2CID   12353259 . Retrieved 10 September 2020.
  22. ↑ Bascompte, J.; Jordano, P.; Melián, C. J.; Olesen, J. M. (2003). "The nested assembly of plant–animal mutualistic networks". Proceedings of the National Academy of Sciences. 100 (16): 9383–9387. Bibcode:2003PNAS..100.9383B. doi: 10.1073/pnas.1633576100 . PMC   170927 . PMID   12881488.
  23. ↑ Lever, J. J.; Nes, E. H.; Scheffer, M.; Bascompte, J. (2014). "The sudden collapse of pollinator communities". Ecology Letters. 17 (3): 350–359. doi:10.1111/ele.12236. hdl: 10261/91808 . PMID   24386999.
  24. ↑ Shah, Karina. "A quarter of all known bee species haven't been seen since the 1990s". New Scientist. Retrieved 11 February 2021.
  25. ↑ Zattara, Eduardo E.; Aizen, Marcelo A. (22 January 2021). "Worldwide occurrence records suggest a global decline in bee species richness". One Earth. 4 (1): 114–123. Bibcode:2021OEart...4..114Z. doi: 10.1016/j.oneear.2020.12.005 . hdl: 11336/183742 . ISSN   2590-3330.
  26. ↑ Council, National Research; Studies, Division on Earth Life; Resources, Board on Agriculture Natural; Sciences, Board on Life; America, Committee on the Status of Pollinators in North (2007). 3 Causes of Pollinator Declines and Potential Threats | Status of Pollinators in North America | The National Academies Press. doi:10.17226/11761. ISBN   978-0-309-10289-6. It is difficult to determine whether North American pollinator species are declining, and no less challenging is determining the causes of putative declines or local extirpations. Many explanations have been invoked to account for declines in pollinator populations in North America, including, among others, exposure to pathogens, parasites, and pesticides; habitat fragmentation and loss; climate change; market forces; intra- and inter-specific competition with native and invasive species; and genetic alterations. Careful evaluation of the literature allows some causes to be assigned, but explanations are ambiguous or elusive for other species losses. ... The best evidence of specific pollinator decline is seen in the western honey bee, Apis mellifera L., the primary commercial pollinator of agricultural crops in North America and the most widely used, actively managed pollinator in the world. The population losses among honey bees are elucidated in a large body of literature...
  27. 1 2 Rhodes, Christopher J. (2018). "Pollinator Decline – An Ecological Calamity in the Making?". Science Progress. SAGE Publications. 101 (2): 121–160. doi: 10.3184/003685018x15202512854527 . ISSN   0036-8504. PMC   10365189 . PMID   29669627. S2CID   4975400. [To] know whether or not a wholesale decline in flying pollinators ... is occurring across the world is very difficult, due to an insufficiency of geographically widespread and long-term data. Bees, as the best documented species, can be seen to be suffering from chronic exposure to a range of stressors, which include: a loss of abundance and diversity of flowers, and a decline in suitable habitat for them to build nests; long-term exposure to agrochemicals, including pesticides such as neonicotinoids; and infection by parasites and pathogens, many inadvertently spread by the actions of humans. [Climate] change may impact further on particular pollinators... Moreover, the co-operative element of various different stress factors should be noted; thus, for example, exposure to pesticides is known to diminish detoxification mechanisms and also immune responses, hence lowering the resistance of bees to parasitic infections. [For] wild non-bee insects – principally moths and butterflies – where data are available, the picture is also one of significant population losses. Alarmingly, a recent study in Germany indicated that a decline in the biomass of flying insects had occurred by 76% in less than three decades, as sampled in nature reserves across the country. Accordingly, to fully answer the question ... 'pollinator decline - an ecological calamity in the making?' will require many more detailed, more geographically encompassing, more species-inclusive, and longer-term studies, but the available evidence points to a clear 'probably', and the precautionary principle would suggest this is not a prospect we can afford to ignore.
  28. ↑ "Light pollution a reason for insect decline!?". www.igb-berlin.de. 19 June 2018. Retrieved 2023-02-18.
  29. ↑ "Nighttime Light Pollution May Be Cause of Insect Population Decline". www.photonics.com. September 2018. Retrieved 2023-02-18.
  30. ↑ Insects, bats and artificial light at night: Measures to reduce the negative effects of light pollution in: dspace.library.uu.nl, retrieved 28 July 2018, author: Claudia Rieswijk (2015), Faculty of Science Theses (Master thesis), Utrecht university
  31. ↑ Longcore, Travis; Rich, Catherine (2004). "Ecological light pollution". Frontiers in Ecology and the Environment. 2 (4): 191–198. doi:10.1890/1540-9295(2004)002[0191:ELP]2.0.CO;2.
  32. ↑ "Flowers' fragrance diminished by air pollution, University of Virginia study indicates". EurekAlert!. 10 April 2008.
  33. ↑ Gosden, Emily (2014-03-29). "Bees and the crops they pollinate are at risk from climate change, IPCC report to warn". The Daily Telegraph . Archived from the original on 2014-03-29. Retrieved 2023-02-18.
  34. 1 2 Novais, Samuel M. A.; Nunes, Cássio A.; Santos, Natália B.; D'Amico, Ana R.; Fernandes, G. Wilson; Quesada, Maurício; Braga, Rodrigo F.; Neves, Ana Carolina O. (30 November 2016). "Effects of a Possible Pollinator Crisis on Food Crop Production in Brazil". PLOS ONE. 13 (5): e0167292. Bibcode:2016PLoSO..1167292N. doi: 10.1371/journal.pone.0167292 . PMC   5130262 . PMID   27902787.
  35. ↑ Christoph Künast; Michael Riffel; Robert de Graeff; Gavin Whitmore (August 2013). Pollinators and agriculture - Agricultural productivity and pollinator protection (PDF) (Report). European Landowners' Organization and the European Crop Protection Association. p. 20. Retrieved 9 September 2020.
  36. ↑ Ollerton, J.; Winfree, R.; Tarrant, S. (2011). "How many flowering plants are pollinated by animals?". Oikos. 120 (3): 321–326. CiteSeerX   10.1.1.464.6928 . doi:10.1111/j.1600-0706.2010.18644.x.
  37. ↑ Roubik, D.W., 1995. "Pollination of Cultivated Plants in the Tropics". In: Agricultural Services Bulletin 118. Food Agriculture Organization of the United Nations, Rome, Italy. Pages 142–148
  38. ↑ "Pollinators". Natural Lands Project. Washington College.
  39. ↑ Berenbaum, May R. (2016). "How it takes honey to make a honey bee — and pollen and nectar to make a pollinator". 2016 International Congress of Entomology. Entomological Society of America. doi:10.1603/ICE.2016.94268.
  40. ↑ Lundgren, Rebekka Laura; Lázaro, Amparo; Totland, Orjan (October 2013). "Experimental pollinator decline affects plant reproduction and is mediated by plant mating system". Journal of Pollination Ecology. 11 (7): 46–56. doi: 10.26786/1920-7603(2013)5 . hdl: 10261/101893 . Retrieved 10 September 2020.
  41. ↑ Aizen, Marcelo A.; Garibaldi, Lucas A.; Cunningham, Saul A.; Klein, Alexandra M. (June 2009). "How much does agriculture depend on pollinators? Lessons from long-term trends in crop production". Annals of Botany. 103 (9): 1579–1588. doi: 10.1093/aob/mcp076 . PMC   2701761 . PMID   19339297.
  42. ↑ Roger Morse; Nicholas Calderone (2000). "The Value of Honey Bees As Pollinators of U.S. Crops in 2000" (PDF). Cornell University. Archived from the original (PDF) on 2014-07-22. Retrieved 2016-02-08.
  43. ↑ Gallai, N.; Salles, J. M.; Settele, J.; Vaissière, B. E. (2009). "Economic valuation of the vulnerability of world agriculture confronted with pollinator decline" (PDF). Ecological Economics. 68 (3): 810–821. doi:10.1016/j.ecolecon.2008.06.014. S2CID   54818498.
  44. ↑ Petherick, Anna (16 October 2008). "Agriculture unaffected by pollinator declines". Nature. Retrieved 9 September 2020.
  45. ↑ Ellis, Alicia M.; Myers, Samuel S.; Ricketts, Taylor H. (2015-01-09). "Do Pollinators Contribute to Nutritional Health?". PLOS ONE. 10 (1): e114805. Bibcode:2015PLoSO..10k4805E. doi: 10.1371/journal.pone.0114805 . ISSN   1932-6203. PMC   4289064 . PMID   25575027.
  46. ↑ Chaplin-Kramer, Rebecca; Dombeck, Emily; Gerber, James; Knuth, Katherine A.; Mueller, Nathaniel D.; Mueller, Megan; Ziv, Guy; Klein, Alexandra-Maria (2014). "Global malnutrition overlaps with pollinator-dependent micronutrient production". Proceedings: Biological Sciences. 281 (1794): 20141799. doi:10.1098/rspb.2014.1799. JSTOR   43601745. PMC   4211458 . PMID   25232140.
  47. 1 2 Eilers, Elisabeth J.; Kremen, Claire; Greenleaf, Sarah Smith; Garber, Andrea K.; Klein, Alexandra-Maria (2011-06-22). "Contribution of Pollinator-Mediated Crops to Nutrients in the Human Food Supply". PLOS ONE. 6 (6): e21363. Bibcode:2011PLoSO...621363E. doi: 10.1371/journal.pone.0021363 . ISSN   1932-6203. PMC   3120884 . PMID   21731717.
  48. ↑ Smith, Matthew R.; Singh, Gitanjali M.; Mozaffarian, Dariush; Myers, Samuel S. (2015-11-14). "Effects of decreases of animal pollinators on human nutrition and global health: a modelling analysis". The Lancet. 386 (10007): 1964–1972. doi: 10.1016/S0140-6736(15)61085-6 . ISSN   0140-6736. PMID   26188748. S2CID   12623217.
  49. ↑ McDonald-Gibson, Charlotte (29 April 2013). "'Victory for bees' as European Union bans neonicotinoid pesticides blamed for destroying bee population". The Independent. Archived from the original on 1 May 2013. Retrieved 1 May 2013. Environmentalists hailed a 'victory for bees' today after the European Union voted for a ban on the nerve-agent pesticides blamed for the dramatic decline global bee populations. ... Dr Lynn Dicks, a research associate at the University of Cambridge, said that despite the contradictory studies, the EU was right to err on the side of caution. 'This is a victory for the precautionary principle, which is supposed to underlie environmental regulation,' she said.
  50. ↑ Vandever, Mark. "Native Pollinators in Agricultural Ecosystems". USGS. Retrieved 24 February 2019.
  51. ↑ Office of the Press Secretary (June 20, 2014). "The Economic Challenge Posed by Declining Pollinator Populations" (Factsheet). whitehouse.gov . Retrieved 31 August 2015– via National Archives.
  52. ↑ Byrne, A.; Fitzpatrick, U. (2009). "Bee conservation policy at the global, regional and national levels" (PDF). Apidologie. 40 (3): 194–210. doi:10.1051/apido/2009017. S2CID   39864604.
  53. ↑ Legislatures, National Conference of State. "Pollinator Health". www.ncsl.org. Retrieved 2017-11-29.
  54. ↑ Dicks, Lynn V.; Breeze, Tom D.; Ngo, Hien T.; Senapathi, Deepa; An, Jiandong; Aizen, Marcelo A.; Basu, Parthiba; Buchori, Damayanti; Galetto, Leonardo; Garibaldi, Lucas A.; Gemmill-Herren, Barbara (2021-08-16). "A global-scale expert assessment of drivers and risks associated with pollinator decline". Nature Ecology & Evolution. 5 (10): 1453–1461. doi:10.1038/s41559-021-01534-9. ISSN   2397-334X. PMID   34400826. S2CID   237148742.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.