Aeroplankton
Aeroplankton (or aerial plankton) are tiny lifeforms that float and drift in the air, carried by wind. Most of the living things that make up aeroplankton are very small to microscopic in size, and many can be difficult to identify because of their tiny size. Scientists collect them for study in traps and sweep nets from aircraft, kites or balloons.[1] The study of the dispersion of these particles is called aerobiology.
Aeroplankton is made up mostly of microorganisms, including viruses, about 1,000 different species of bacteria, around 40,000 varieties of fungi, and hundreds of species of protists, algae, mosses, and liverworts that live some part of their life cycle as aeroplankton, often as spores, pollen, and wind-scattered seeds. Additionally, microorganisms are swept into the air from terrestrial dust storms, and an even larger amount of airborne marine microorganisms are propelled high into the atmosphere in sea spray. Aeroplankton deposits hundreds of millions of airborne viruses and tens of millions of bacteria every day on every square meter around the planet.
Small, drifting aeroplankton are found everywhere in the atmosphere, reaching concentration up to 106 microbial cells per cubic metre. Processes such as
Overview
Part of a series on |
Plankton |
---|
The atmosphere is the least understood biome on Earth despite its critical role as a microbial transport medium.
Changes in species geographic distributions can have strong ecological and socioeconomic consequences.
The field of bioaerosol research studies the taxonomy and community composition of airborne microbial organisms, also referred to as the air microbiome. A recent series of technological and analytical advancements include high-volumetric air samplers, an ultra-low biomass processing pipeline, low-input DNA sequencing libraries, as well as high-throughput sequencing technologies. Applied in unison, these methods have enabled comprehensive and meaningful characterization of the airborne microbial organismal dynamics found in the near-surface atmosphere.[17] Previous studies investigating bioaerosols using amplicon sequencing predominantly focussed on the bacterial fraction of the air microbiome, while fungal and plant pollen fractions frequently remained understudied.[18][19][20][21][22][23][24][25] Airborne microbial organisms also impact agricultural productivity, as bacterial and fungal species distributed by air movement act as plant blights.[26] Furthermore, atmospheric processes, such as cloud condensation and ice nucleation events were shown to depend on airborne microbial particles.[27] Therefore, understanding the dynamics of microbial organisms in air is crucial for insights into the atmosphere as an ecosystem, but also will inform on human wellbeing and respiratory health.[28]
In recent years, next generation DNA sequencing technologies, such as metabarcoding as well as coordinated metagenomics and metatranscriptomics studies, have been providing new insights into microbial ecosystem functioning, and the relationships that microorganisms maintain with their environment. There have been studies in soils,[29] the ocean,[30][31] the human gut,[32] and elsewhere.[33][34][35][36]
In the atmosphere, though, microbial gene expression and metabolic functioning remain largely unexplored, in part due to low biomass and sampling difficulties.
Types
Pollen grains
Effective pollen dispersal is vital for maintenance of genetic diversity and fundamental for connectivity between spatially separated populations.[45] An efficient transfer of the pollen guarantees successful reproduction in flowering plants. No matter how pollen is dispersed, the male-female recognition is possible by mutual contact of stigma and pollen surfaces. Cytochemical reactions are responsible for pollen binding to a specific stigma.[46][47]
Allergic diseases are considered to be one of the most important contemporary public health problems affecting up to 15–35% of humans worldwide.[48] There is a body of evidence suggesting that allergic reactions induced by pollen are on the increase, particularly in highly industrial countries.[48][49][47]
Fungal spores
Considering this aspect, aeromycological research is considered capable of predicting future symptoms of plant diseases in both crops and wild plants.[55][56] Fungi capable of travelling extensive distances with wind despite natural barriers, such as tall mountains, may be particularly relevant to understanding the role of fungi in plant disease.[59][60][55][61] Notably, the presence of numerous fungal organisms pathogenic to plants has been determined in mountainous regions.[58]
A wealth of correlative evidence suggests
Pteridophyte spores
Pteridophytes are vascular plants that disperse spores, such as fern spores. Pteridophyte spores are similar to pollen grains and fungal spores, and are also components of aeroplankton.[68][69] Fungal spores usually rank first among bioaerosol constituents due to their count numbers which can reach to between 1,000 and 10,000 per cubic metre (28 and 283/cu ft), while pollen grains and fern spores can each reach to between 10 and 100 per cubic metre (0.28 and 2.83/cu ft).[49][70]
Arthropods
Many small animals, mainly arthropods (such as insects and spiders), are also carried upwards into the atmosphere by air currents and may be found floating several thousand feet up. Aphids, for example, are frequently found at high altitudes.
Enough lift for ballooning may occur, even in windless conditions, if an
Nematodes
Unicellular microorganisms
A stream of
The presence of airborne
Airborne bacteria are emitted by most Earth surfaces (plants, oceans, land, and urban areas) to the atmosphere via a variety of mechanical processes such as
The environmental role of airborne cyanobacteria and microalgae is only partly understood. While present in the air, cyanobacteria and microalgae can contribute to
Airborne microalgae and cyanobacteria are the most poorly studied organisms in aerobiology and phycology.[119][120][93] This lack of knowledge may result from the lack of standard methods for both sampling and further analysis, especially quantitative analytical methods.[112] Few studies have been performed to determine the number of cyanobacteria and microalgae in the atmosphere [121][122] However, it was shown in 2012 that the average quantity of atmospheric algae is between 100 and 1000 cells per cubic meter of air.[70] As of 2019, about 350 taxa of cyanobacteria and microalgae have been documented in the atmosphere worldwide.[112][113] Cyanobacteria and microalgae end up in the air as a consequence of their emission from soil, buildings, trees, and roofs.[112][123][124][93]
Biological particles are known to represent a significant fraction (~20–70%) of the total number of
Bioaerosols
Historically, the first investigations of the occurrence and dispersion of microorganisms and spores in the air can be traced back to the early 19th century.[154][155][156] Since then, the study of bioaerosols has come a long way, and air samples collected with aircraft, balloons, and rockets have shown that bioaerosols released from land and ocean surfaces can be transported over long distances and up to very high altitudes, i.e., between continents and beyond the troposphere.[157][104][158][159][160][161][162][163][164][165][107][136]
-
Global bioaerosol cyclingAfter emission from the biosphere, bioaerosol particles interact with other aerosol particles and trace gases in the atmosphere and can be involved in the formation of clouds and precipitation. After dry or wet deposition to the Earth's surface, viable bioparticles can contribute to biological reproduction and further emission. This feedback can be particularly efficient when coupled to the water cycle (bioprecipitation).[166][152][136]
-
Global ecosystem interactions of bioaerosol particlesKey aspects and areas of research required to determine and quantify the interactions and effects of biogenic aerosol particles in the Earth system, including primary biological aerosols directly emitted to the atmosphere and secondary organic aerosols formed upon oxidation and gas-to-particle conversion of volatile organic compounds.[136]
Bioaerosols play a key role in the dispersal of reproductive units from plants and microbes (pollen, spores, etc.), for which the atmosphere enables transport over geographic barriers and long distances.[157][141][109][70][150] Bioaerosols are thus highly relevant for the spread of organisms, allowing genetic exchange between habitats and geographic shifts of biomes. They are central elements in the development, evolution, and dynamics of ecosystems.[136]
Dispersal
A
However, wind-drifted species vary in their
Transport and distribution
Once aerosolized, microbial cells enter the planetary boundary layer, defined as the air layer near the ground directly influenced by the planetary surface. The concentration and taxonomic diversity of airborne microbial communities in the planetary boundary layer has been recently described,[184][185][6] though the functional potential of airborne microbial communities remains unknown.[186]
From the planetary boundary layer, the microbial community might eventually be transported upwards by air currents into the free troposphere (air layer above the planetary boundary layer) or even higher into the stratosphere.[108][187][105][188] Microorganisms might undergo a selection process during their way up into the troposphere and the stratosphere.[189][6]
Subject to gravity,
Possible processes in the way atmospheric
Over space and time
Microorganisms attached to aerosols can travel intercontinental distances, survive, and further colonize remote environments. Airborne microbes are influenced by environmental and climatic patterns that are predicted to change in the near future, with unknown consequences.[16] Airborne microbial communities play significant roles in public health and meteorological processes,[202][203][11][204][205] so it is important to understand how these communities are distributed over time and space.[186]
-
Atmosphere layers, temperature and airborne emission sources
Most studies have focused on
There are some metagenomic studies on airborne microbial communities over specific sites.[212][213][214][17][21] Metagenomic investigations of complex microbial communities in many ecosystems (for example, soil, seawater, lakes, feces and sludge) have provided evidence that microorganism functional signatures reflect the abiotic conditions of their environment, with different relative abundances of specific microbial functional classes.[215][216][217][218] This observed correlation of microbial-community functional potential and the physical and chemical characteristics of their environments could have resulted from genetic modifications (microbial adaptation [219][220][221][21]) and/or physical selection. The latter refers to the death of sensitive cells and the survival of resistant or previously adapted cells. This physical selection can occur when microorganisms are exposed to physiologically adverse conditions.[186]
The presence of a specific microbial functional signature in the atmosphere has not been investigated yet.[186] Microbial strains of airborne origin have been shown to survive and develop under conditions typically found in cloud water (i.e., high concentrations of H2O2, typical cloud carbonaceous sources, ultraviolet – UV – radiation etc.[206][222][210] While atmospheric chemicals might lead to some microbial adaptation, physical and unfavorable conditions of the atmosphere such as UV radiation, low water content and cold temperatures might select which microorganisms can survive in the atmosphere. From the pool of microbial cells being aerosolized from Earth's surfaces, these adverse conditions might act as a filter in selecting cells already resistant to unfavorable physical conditions. Fungal cells and especially fungal spores might be particularly adapted to survive in the atmosphere due to their innate resistance [223] and might behave differently than bacterial cells. Still, the proportion and nature (i.e., fungi versus bacteria) of microbial cells that are resistant to the harsh atmospheric conditions within airborne microbial communities are unknown.[186]
Airborne microbial transport is central to dispersal outcomes [224] and several studies have demonstrated diverse microbial biosignatures are recoverable from the atmosphere. Microbial transport has been shown to occur across inter-continental distances above terrestrial habitats.[225][226][200] Variation has been recorded seasonally, with underlying land use,[197] and due to stochastic weather events such as dust storms.[227][2] There is evidence specific bacterial taxa (e.g., Actinomycetota and some Gammaproteobacteria) are preferentially aerosolized from oceans.[228][6]
Over urban areas
As a result of rapid industrialization and urbanization, global megacities have been impacted by extensive and intense
Recent advances in airborne particle
Clouds
The outdoor atmosphere harbors diverse microbial assemblages composed of bacteria, fungi and viruses
Living airborne microorganisms may end up concretizing aerial dispersion by
Aerosols affect
After the tantalizing detection of
Airborne microbiomes
While the physical and chemical properties of airborne
Throughout Earth's history, microbial communities have changed the climate, and climate has shaped microbial communities.[273] Microorganisms can modify ecosystem processes or biogeochemistry on a global scale, and we start to uncover their role and potential involvement in changing the climate.[274] However, the effects of climate change on microbial communities (i.e., diversity, dynamics, or distribution) are rarely addressed.[275] In the case of fungal aerobiota, its composition is likely influenced by dispersal ability, rather than season or climate.[276] Indeed, the origin of air masses from marine, terrestrial, or anthropogenic-impacted environments, mainly shapes the atmospheric air microbiome.[200] However, recent studies have shown that meteorological factors and seasonality influence the composition of airborne bacterial communities.[200][277][278] This evidence suggests that climatic conditions may act as an environmental filter for the aeroplankton, selecting a subset of species from the regional pool, and raises the question of the relative importance of the different factors affecting both bacterial and eukaryal aeroplankton.[16]
In 2020, Archer et al. reported evidence for a dynamic microbial presence at the ocean–atmosphere interface at the
Airborne DNA
In 2021, researchers demonstrated that environmental DNA (eDNA) can be collected from air and used to identify mammals.[279][280][281][282] In 2023, scientists developed a specialized sampling probe and aircraft surveys to assess biodiversity of multiple taxa, including mammals, using air eDNA.[283]
Gallery
-
Airbornefungal spores
See also
References
- ^ A. C. Hardy and P. S. Milne (1938) Studies in the Distribution of Insects by Aerial Currents. Journal of Animal Ecology, 7(2):199-229
- ^ PMID 31754205. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ S2CID 4576024.
- ^ PMID 29481623.
- PMID 27252689.
- ^ PMID 31595018. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- S2CID 206653576.
- ^ S2CID 2276891.
- ^ PMID 19453609.
- ^ PMID 25902536.
- ^ S2CID 4207803.
- PMID 27001166.
- S2CID 14608948.
- S2CID 203880534.
- .
- ^ PMID 34642388. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ PMID 31659049.
- S2CID 1655154.
- ^ PMID 24083487.
- PMID 17981945.
- ^ PMID 24349140.
- S2CID 38303883.
- S2CID 85262700.
- PMID 21803902.
- ^ PMID 17182744.
- doi:10.1139/b95-128.
- PMID 27152346.
- S2CID 228089556. Modified text from this source, which is available under a Creative Commons Attribution 4.0 International License.
- PMID 21776033.
- PMID 20844569.
- PMID 18725995.
- PMID 24843156.
- PMID 24883185.
- PMID 25535937.
- ^ PMID 30867542. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ See also: Pollen DNA barcoding
- PMID 25351142.
- PMID 22623790.
- PMID 24349140.
- S2CID 27205968.
- PMID 27252689.
- .
- ^ PMID 28792539.
- .
- S2CID 6382777.
- PMID 15075396.
- ^ doi:10.5586/aa.2015.045. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ ISBN 9780615461823.
- ^ ISBN 978-94-007-4880-4.
- ^ doi:10.1371/journal.ppat.1003371. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ Figure adapted from: Ingold CT (1971) Fungal spores: their liberation and dispersal, Oxford: Clarendon Press.
- ISBN 9780080919409.
- S2CID 6588557.
- S2CID 84241303.
- ^ S2CID 129157372.
- ^ S2CID 37133585. Retrieved 5 August 2021.
- S2CID 84305807.
- ^ PMID 33890180. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ISBN 978-1-4020-5496-9.
- .
- S2CID 29293277.
- .
- .
- .
- .
- .
- .
- S2CID 16407560.
- ^ Weryszko-Chmielewska, E. (2007). "Zakres badań i znaczenie aerobiologii". Aerobiologia. Lublin: Wydawnictwo Akademii Rolniczej, pages 6-10 (in Polish).
- ^ S2CID 98741728.
- doi:10.1371/journal.pbio.2004405.g007. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- OCLC 54027960.
- JSTOR 3704941.
- hdl:10919/29114.
- ^ JSTOR 3705494.
- ^ S2CID 4707752.
- ^ "Leap forward for 'flying' spiders". BBC News. 12 July 2006. Retrieved 23 July 2014.
- PMID 29983315.
- arXiv:1309.4731 [physics.bio-ph].
- S2CID 221110776. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ S2CID 32516212.
- ^ JSTOR 1948560.
- ^ .
- ^ PMID 29717144. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ Hendriksen, N. B. (1982) "Anhydrobiosis in nematodes: studies on Plectus sp." In: New trends in soil biology (Eds: Lebrun, P. André, H. M., De Medts, A., Grégoire-Wibo, C. Wauthy, G.) pages 387–394, Louvain-la-Neurve, Belgium.
- .
- ^ Andrássy, I. (2009) "Free-living nematodes of Hungary III (Nematoda errantia)". Pedozoologica Hungarica No. 5. Hungarian Natural History Museum and Systematic Zoology, Research Group of the Hungarian Academy of Sciences.
- ^ S2CID 9941895.
- .
- ^ Living Bacteria Are Riding Earth's Air Currents Smithsonian Magazine, 11 January 2016.
- ^ Robbins, Jim (13 April 2018). "Trillions Upon Trillions of Viruses Fall From the Sky Each Day". The New York Times. Retrieved 14 April 2018.
- ^ PMID 29379178.
- ^ PMID 32913356. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- PMID 20161650.
- PMID 25826054.
- S2CID 49427202.
- PMID 29419777.
- .
- PMID 33262740.
- ^ PMID 28267145.
- ^ S2CID 43969729.
- ^ .
- PMID 12583913.
- ^ PMID 23359712.
- ^ PMID 30154759.
- S2CID 17601337.
- ^ PMID 23220959.
- ^ ISBN 9781119132318.
- ^ .
- .
- ^ PMID 30967843. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ PMID 31351382.
- ^ PMID 21196350.
- PMID 5223702.
- .
- PMID 30483227.
- PMID 17011621.
- PMID 28823424.
- ^ S2CID 83855537.
- S2CID 85314169.
- ^ Schlichting HE Jr. (1964) "Meteorological conditions affecting the dispersal of airborne algae and Protozoa". Lloydia, 27: 64–78.
- S2CID 85653057.
- S2CID 84781386.
- PMID 16780831.
- .
- ^ .
- S2CID 725976.
- .
- PMID 16807133.
- ^ Galán Soldevilla C., Cariñanos González P., Alcázar Teno P., Domínguez Vilches E. (2007). "Management and Quality Manual". Spanish Aerobiology Network (REA), Cordoba: Servicio de Publicaciones.
- PMID 24722630.
- ^ PMID 28779070.
- .
- .
- S2CID 10572570.
- ^ doi:10.1016/j.atmosres.2016.07.018. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ PMID 23263871.
- .
- PMID 29784790.
- PMID 30337908.
- ^ .
- PMID 29481623.
- S2CID 44328547.
- S2CID 4790872.
- .
- .
- .
- ISBN 9781000115048.
- .
- ^ PMID 20980313.
- ISBN 9781118591970.
- ^ PMID 16302183.
- ^ .
- ^ Ehrenberg C.G. (1830) "Neue Beobachtungen über blutartige Erscheinungen in Aegypten, Arabien und Sibirien, nebst einer Übersicht und Kritik der früher bekannten". Ann. Phys. Chem., 94: 477–514.
- ^ Pasteur L. (1860) "Expériences relatives aux generations dites spontanées". C. R. Hebd. Seances Acad. Sci., 50: 303–307
- ^ Pasteur L. (1860) "Suite à une précédente communication relative aux generations dites spontanées". C. R. Hebd. Seances Acad. Sci., 51: 675–678.
- ^ S2CID 4207803.
- S2CID 17512396.
- .
- S2CID 82040406.
- S2CID 54218062.
- PMID 6052629.
- hdl:2297/34677.
- PMID 18335093.
- PMID 16825614.
- S2CID 206901179.
- .
- ^ ISBN 9789057821097.
- S2CID 17576931.
- PMID 21352441.
- ^ S2CID 13892871.
- S2CID 19508548.
- ^ T.Y. Chuang and W.H. Ko. 1981. Propagule size: Its relation to population density of microorganisms in soil. Soil Biology and Biochemistry. 13(3).
- .
- S2CID 15256569.
- S2CID 45667054.
- S2CID 18458173.
- ^ a b Carroll, J.J. and Viglierchio, D.R. (1981). "On the transport of nematodes by the wind". Journal of Nematology, 13(4): 476.
- .
- S2CID 42270008.
- ^ .
- S2CID 129825037.
- ^ doi:10.3390/atmos11121296. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- S2CID 201834075.
- ^ PMID 28363180.
- ^ S2CID 234687848. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- .
- hdl:2297/34677.
- S2CID 134665478.
- .
- ^ S2CID 16731037.
- PMID 21255051.
- S2CID 52334609.
- PMID 30805335.
- S2CID 84270694.
- ^ S2CID 92236469.
- ^ PMID 21048802.
- ^ .
- ^ .
- ^ PMID 30420511.
- .
- S2CID 95932745.
- doi:10.1890/01-0619.
- .
- PMID 17630335.
- ^ .
- S2CID 129578943.
- .
- PMID 19854931.
- ^ PMID 23263871.
- PMID 20487025.
- PMID 31551441.
- PMID 30867542.
- PMID 24456276.
- PMID 21593798.
- PMID 30952929.
- S2CID 161283.
- PMID 20927138.
- S2CID 8638694.
- S2CID 22286095.
- PMID 27080578.
- .
- PMID 28421279.
- S2CID 19575573.
- PMID 24784743.
- S2CID 3290942.
- PMID 23254516.
- PMID 29789621.
- PMID 25942499.
- S2CID 205071037.
- PMID 28717138.
- doi:10.1038/ngeo2893.
- PMID 25454230.
- ^ Walton, H., Dajnak, D., Beevers, S., Williams, M., Watkiss, P. and Hunt, A. (2015) "Understanding the health impacts of air pollution in London". King's College London, Transport for London and the Greater London Authority, 1(1): 6–14.
- .
- S2CID 205559548.
- S2CID 205240719.
- PMID 27518660.
- S2CID 26769029.
- PMID 27392261.
- S2CID 14761200.
- ^ PMID 25906115.
- ^ PMID 32127018. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- PMID 27717408.
- ISSN 1558-7452.
- ISBN 9781119132318.
- PMID 28320526.
- .
- .
- .
- .
- ISBN 9781119132318.
- S2CID 52107037.
- .
- .
- .
- PMID 22537388.
- .
- S2CID 129784139.
- S2CID 58612273.
- ^ S2CID 4321239.
- ^ .
- S2CID 36030601.
- .
- .
- ^ PMID 29459666.
- S2CID 61155774.
- ^ S2CID 221655755.
- ^ S2CID 237820246.
- ^ PMID 32605663. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- S2CID 237409945. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- S2CID 155102440.
- S2CID 1522347.
- S2CID 190637591.
- PMID 31801876.
- S2CID 21687542.
- S2CID 222301690.
- S2CID 245772800.
- S2CID 245772825.
- PMID 33850648. Modified text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License.
- ^ Researchers can now collect and sequence DNA from the air Live Science , 6 April 2021.
- PMID 37077310.
General reference
- Cox, Christopher S.; Wathes, Christopher M. (25 November 2020). Bioaerosols Handbook. CRC Press. ISBN 9781000115048.