Temperature and the size of freshwater phytoplankton

Hydrobiologia, Journal Year: 2020, Volume and Issue: 848(1), P. 143 - 155

Published: April 18, 2020

Language: Английский

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Continental erosion and the Cenozoic rise of marine diatoms

Proceedings of the National Academy of Sciences, Journal Year: 2015, Volume and Issue: 112(14), P. 4239 - 4244

Published: March 23, 2015

Significance Diatoms are silica-precipitating microalgae responsible for roughly one-fifth of global primary production. The mechanisms that led these microorganisms to become one the most prominent producers on Earth remain unclear. We explore linkage between erosion continental silicates and ecological success marine diatoms over last 40 My. show diversification geographic expansion coincide with periods increased weathering fluxes silicic acid input oceans. On geological time scales, ocean’s biologically driven sequestration organic carbon (the biological pump) is proportional flux inorganic nutrients Our results suggest strength efficiency pump time.

Language: Английский

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Deep maxima of phytoplankton biomass, primary production and bacterial production in the Mediterranean Sea

Biogeosciences, Journal Year: 2021, Volume and Issue: 18(5), P. 1749 - 1767

Published: March 15, 2021

Abstract. The deep chlorophyll maximum (DCM) is a ubiquitous feature of phytoplankton vertical distribution in stratified waters that relevant to our understanding the mechanisms underpin variability photoautotroph ecophysiology across environmental gradients and has implications for remote sensing aquatic productivity. During PEACETIME (Process studies at air-sea interface after dust deposition Mediterranean Sea) cruise, carried out from 10 May 11 June 2017, we obtained 23 concurrent profiles a, carbon biomass primary production, as well heterotrophic prokaryotic western central basins. Our main aims were quantify relative role photoacclimation enhanced growth underlying DCM assess trophic coupling between production. We found coincided with both production but not rate phytoplankton, which averaged 0.3 d−1 was relatively constant euphotic layer. Photoacclimation explained most increased DCM, ratio (C:Chl a) decreased ca. 90–100 (g:g) surface 20–30 base layer, while 6 mg C m−3 10–15 DCM. As result photoacclimation, there an uncoupling a-specific carbon-specific productivity fucoxanthin total markedly depth, suggesting contribution diatoms fixation zone associated rates activity, also showed peak linked warmer temperatures. Considering turnover measured nutrient diffusive fluxes nutricline able supply only minor fraction nitrogen phosphorus requirements. Thus maxima fuelled by new nutrients likely resulted cell sinking upper layers combination high photosynthetic efficiency diatom-rich, low-light acclimated community largely sustained regenerated nutrients. Further temporal spatial resolution will be required ascertain if peaks persist Sea throughout stratification season.

Language: Английский

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Cell size as driver and sentinel of phytoplankton community structure and functioning

Functional Ecology, Journal Year: 2021, Volume and Issue: 36(2), P. 276 - 293

Published: Dec. 12, 2021

Abstract Body size is a decisive functional trait in many organisms, especially for phytoplankton, which span several orders of magnitude cell volume. Therefore, the analysis as driving species’ performance has received wide attention aquatic ecology, amended recent decades by studies documenting changes phytoplankton response to abiotic or biotic factors environment. We performed systematic literature review provide an overarching, partially quantitative synthesis driver and sentinel ecology. found consistent significant allometric relationships between sizes species (cellular rates carbon fixation, respiration exudation well resource affinities, uptake content). Size scaling became weaker, absent even negative when addressing C‐ volume‐specific growth. C‐specific photosynthesis population growth rate peaked at intermediate around 100 µm 3 . Additionally, we rich on changing warming, nutrients pollutants. Whereas small cells tended dominate under oligotrophic warm conditions, there are few notable exceptions, indicates that other environmental constraints alter this general trend. Grazing seems likely explanation, reviewed understand both how affects edibility structure grazing. Cell also predisposes strength outcome competitive interactions algal species. Finally, address community context, where size‐abundance describes composition thereby biodiversity assemblages. conclude (a) highly predictive metabolism cellular scale, with less strong nonlinear implications specific (b) suitable responses environments. A free Plain Language Summary can be within Supporting Information article.

Language: Английский

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Thoughts on the evolution and ecological niche of diatoms

Ecological Monographs, Journal Year: 2021, Volume and Issue: 91(3)

Published: April 30, 2021

Abstract Diatoms are the most recent major algal lineage added to geological record, appearing more than 200 million years ago. They stramenopile protists resulting from a secondary endosymbiotic event that yielded only photosynthetic protistan expressing external siliceous cell wall structures called frustules. Many diatoms also have large internal vacuoles, and common assumption in literature is success of largely attributable these two morphological inventions: frustule for defense vacuole luxury nutrient uptake. Here, we revisit evolution inventions, propose sequential steps development, replace uptake with predator buoyancy control as driver expansion, suggest perhaps greatest significance diatom consequence enhancing sexual reproduction. In this synthesis, emphasize distinction between “general” “bloom‐forming” species, physiological drivers successes differ. Importantly, bloom‐forming species responsible role aquatic biogeochemical cycles. The habit ascribe specific attributes that, at their core, revolve around influencing balance growth losses predators. We adaptations linked size‐dependent maximum division rates diatoms, because size scaling predator–prey interactions. existence yields an apparent allometric relationship has previously been interpreted terms acquisition. Our analysis insights into successions during blooms, considers fundamental benefit blooming (and subsequent sinking) reproductive standpoint, provides some reinterpretation over geologic time modern ocean.

Language: Английский

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