Key players of the phytoplankton communities 5 µm 50 µm 0.5 µm50 µm.

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Key players of the phytoplankton communities 5 µm 5 µm 50 µm 50 µm 0.5 µm 50 µm

Transcript of Key players of the phytoplankton communities 5 µm 50 µm 0.5 µm50 µm.

Page 1: Key players of the phytoplankton communities 5 µm 50 µm 0.5 µm50 µm.

Key players of the phytoplankton communities

5 µm 5 µm

50 µm 50 µm

0.5 µm

50 µm

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Key players of the phytoplankton communities

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Key players of the phytoplankton communities

M2

D6

D5D4

D3D2

D1

A5

A1

A11 B11

C11

C1B1

KERFIX

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Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

2

8

6

4

To

tal

cell

Car

bo

n,

µg

L-1

M2

Kopczynska E.E., Fiala M., and Jeandel C., Annual and interannual variability in phytoplankton at a permanent station off Kerguelen Islands, Southern Ocean, Polar Biology, 20 (5), 342-351, 1998.

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Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

2

8

6

4

To

tal

cell

Car

bo

n,

µg

L-1

0

20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

Kopczynska et al., 1998

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Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

Diatoms

total Dinoflagellates

naked flagellates

picoplankton

Coccolithophorids

Kopczynska et al., 1998

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Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

Diatoms

Kopczynska et al., 1998

• low contribution• dominant species : Fragilariopsis kerguelensis,

Thalassionema nitzschioides

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• highest contribution

• dominant species : Prorocentrum spp., Gymnodinium spp., heterotrophic species of Protoperidium spp. and Gyrodinium spp. during summer.

total Dinoflagellates

Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

Kopczynska et al., 1998

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Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

0

20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

naked flagellates

Kopczynska et al., 1998

• low contribution during biomass peaks

• dominant groups : Prymnesiophyceae (Chrysochromulina spp.), Prasinophyceae (Pyramimonas spp.), and Cryptophyceae (Hillea fusiformis)

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• occasionally abundant• dominant species :

Coccolithophorids

Key players of the phytoplankton communities

N D J F M A M J Jt A S O N D J F M A M J Jt A S O N D J F

1992 1993 1994 1995

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20

40

60

80

100A

lgal

gro

up

sas

% o

f to

tal

cell

C

Emiliania huxleyi

Kopczynska et al., 1998

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Surface temperatures (> 2°C) are compatible with Emiliania huxleyi and Fragilariopsis kerguelensis

Key players of the phytoplankton communities

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Key players of the phytoplankton communities

M2

Blain S., Tréguer P., Belviso S., Bucciarellia E., Denis M., Desabre S., Fiala M., Martin Jézéquel V., Le Fèvre J., Mayzaud P., Marty J.-C., and Razouls S., A biogeochemical study of the island mass effect in the context of the iron hypothesis: Kerguelen Islands, Southern Ocean, Deep-Sea Research, 48 (1), 163-187, 2001.

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Key players of the phytoplankton communities

Blain et al., 2001 – 4-10 October 1995

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Objective 3 : Knowledge and quantification of biogeochemical processes and their responses to changes in the forcing parameters.

3.1) Structure of phytoplankton communities. KEOPS will address the question "what physical and chemical factors regulate phytoplankton growth and species composition?"

3.2) Shifts in the structure of the phytoplankton communities in response to changes in the forcing parameters. (KEOPS will focus on the following forcing parameters: iron, light (visible and UV), stratification.

3.3) Do biological activity compete with photochemical processes for the production of biogenic gases and iron speciation?

Key players of the phytoplankton communities

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3.1) Structure of phytoplankton communities. KEOPS will address the question "what physical and chemical factors regulate phytoplankton growth and species composition?" Detailed topics include:

3.1.1) Characterization of phytoplankton communities in contrasted environments. Special attention will be paid to the major biogeochemical players: diatoms, Phaeocystis, coccolithophorids, cryptophyceans and picoplankton.

3.1.2) Identification, hierarchisation, and parameterization of the processes that control the structure of the phytoplankton communities.

3.1.3) Impact of the structure of the phytoplankton community on the fluxes of chemical compounds that are relevant for climate.

3.1.4) Impact of the structure of the phytoplankton community on the flux of carbon exported below the depth of the mixed layer

Objective 3 : Knowledge and quantification of biogeochemical processes and their responses to changes in the forcing parameters.

Key players of the phytoplankton communities

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3.2) Shifts in the structure of the phytoplankton communities in response to changes in the forcing parameters. (KEOPS will focus on the following forcing parameters: iron, light (visible and UV), stratification. The processes will be investigated mainly in the surface layer.

3.2.1) How will the forcing parameters impact the processes controlling the production of chemical compounds that are relevant for climate?

3.2.2) How will the forcing parameters impact the processes controlling the export of carbon below the depth of the mixed layer?

3.2.3) What is the feedback of biological activity on iron speciation?

Objective 3 : Knowledge and quantification of biogeochemical processes and their responses to changes in the forcing parameters.

Key players of the phytoplankton communities