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{| class="model-ib" style="float:right; margin-left:1em; margin-bottom:1em;" ! Microzooplankton grazing, size-fractionated |- | '''Approach:''' dilution method with FCM or HPLC tracking of size-class phytoplankton |- | '''Context:''' incubation |- | '''Spatial scale:''' point..."

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Created page with "{{BreadcrumbsInteractions}} * Page authors: PRIMO * Responsible curator: Hagen Buck-Wiese ---- __TOC__ <div class="model-box"> {| class="model-ib" style="float:right; margin-left:1em; margin-bottom:1em;" ! Microzooplankton grazing, size-fractionated |- | '''Approach:''' dilution method with FCM or HPLC tracking of size-class phytoplankton |- | '''Context:''' incubation |- | '''Spatial scale:''' point..."

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* [[Page authors|Page authors]]: [[PRIMO]]
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{| class="model-ib" style="float:right; margin-left:1em; margin-bottom:1em;"
! Microzooplankton grazing, size-fractionated
|-
| '''Approach:''' dilution method with FCM or HPLC tracking of size-class phytoplankton
|-
| '''Context:''' incubation
|-
| '''Spatial scale:''' point sample
|-
| '''Temporal scale:''' hours (one diel cycle)
|-
| '''Units:''' d<sup>-1</sup>
|-
| '''Community captured:''' size-fractionated phytoplankton (FCM populations or HPLC pigment groups)
|-
| '''Co-measurements:''' temperature, simulated or ''in situ'' PAR, depth of collection
|}
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== Method Overview ==

This is the size-fractionated variant of the [[Incubation dilution experiments]] method, in which phytoplankton growth and grazing rates are resolved for distinct size classes or taxonomic groups rather than the bulk community. The dilution procedure is identical to the standard method: whole seawater is diluted with particle-free (0.2 µm) filtrate across a dilution series. Rather than tracking bulk chlorophyll-a, phytoplankton biomass in distinct populations is measured by flow cytometry (resolving Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes) or by HPLC pigment analysis<ref name="Morison2017">Morison, F., & Menden-Deuer, S. (2017). Doing more with less? Balancing sampling resolution and effort in measurements of protistan growth and grazing rates. ''Limnology and Oceanography: Methods'', 15, 794–809. https://doi.org/10.1002/lom3.10200</ref>. Separate µ and g values are derived for each resolvable population, revealing which phytoplankton groups are most heavily grazed.

=== Scale of measurement ===

Point sample; 24 h incubation. Multiple populations resolved within a single dilution series provide a more complete picture of community trophic dynamics than bulk Chl tracking alone.

=== Data generated ===

Population-specific phytoplankton growth rates (µ, d<sup>-1</sup>) and microzooplankton grazing rates (g, d<sup>-1</sup>) for each FCM-resolvable population or HPLC-derived taxon group.

=== Units & currency ===

Units are d<sup>-1</sup>. The currency is Chl-a or cell counts.

=== Sample size ===

Typical samples are 1–2 L per dilution treatment.

=== Repositories & databases ===

== Limitations ==

Same assumptions apply as for the bulk dilution method. FCM populations must be optically distinct; overlapping populations cannot be separated. HPLC pigment markers require taxon-specific pigment:Chl ratios for biomass conversion.

== Example Applications & Protocols ==

=== Classic examples ===
* Morison & Menden-Deuer (2017) ''Doing more with less? Balancing sampling resolution and effort in measurements of protistan growth and grazing rates'' <ref name="Morison2017" />

=== Recent applications ===
* Marrec & Menden-Deuer (2024) ''Changes in phytoplankton size-structure alter trophic transfer in a temperate, coastal planktonic food web'' <ref name="Marrec2024">Marrec, P., & Menden-Deuer, S. (2024). Changes in phytoplankton size-structure alter trophic transfer in a temperate, coastal planktonic food web. ''Limnology and Oceanography Letters'', 9(5), 624–633. https://doi.org/10.1002/lol2.10410</ref>

=== Common calculations/conversions ===
* As for the bulk dilution method, applied separately to each FCM population or pigment group.

== References ==

[[Category:Main Pages|Model types]]

Size-fractionated incubation dilution experiments - Revision history