The role of marine plankton in the global climate

Bas KooijmanDept Theoretical Biologyhttp://www.bio.vu.nl/thb/

Climate Center Vrije Universiteit

Tuesday 15 Oct 2002

Biogeochemo- research by Theor Biol VUA

Past projects:Global Emiliania Modelling Initiative (GEM) Peter Westbroek (RUL) & Jan van Hinte (VUA)Mast II: European program NOP II: VUA: modelling nutrient limited growth (Kooijman, Zonneveld) RUL: molecular aspects (Westbroek, Corstjens) NIOZ: growth experiments (Riegman) RUG: DMS (Gieskes, van Rijssel)

Current projects:Stochiometric contraints in producer/consumer interactions Kuijper, Kooi, Kooijman, Andersen (Southampton)Time scale separation in producer/consumer interactions Kooi, Kooijman, Auger (Lyon), Poggiale (Marseille)Primary production in ocean circulation models Kooijman, Kooi, Dijkstra (IMAU)Self organisation of trophic structures in ecosystems Troost, Kooi, Kooijman, Metz (RUL), Loreau (Paris)

Dynamic Energy Budget theoryfor metabolic organisation of all life on earth• first principles• quantitative

Biological equivalent of Theoretical Physics• biogeochemical perspective

Primary target: the individual with consequences for• sub-organismal organization• supra-organismal organization

Relationships between levels of organisation

Practical applications: direct links with empiry• ecotoxicology• biotechnology• medicine/ health care

DEB info athttp://www.bio.vu.nl/thb/deb/

Climate affects marine plankton

• temperature affects all physiological rates• nutrient supply via erosion from terrestrial systems water cycle ocean circulation (wind forcing, plate tectonics) wind-induced primary production• light availability (albedo)

Climate change induces extinction and speciation in combination with biotic factors (competition)

Marine plankton affects climate

• organic carbon pump transport of atmospheric CO2 to deep ocean (1000 year memory) linked to nutrient cycling, terrestrial ecosystems• calcification (inorganic carbon pump) precipitation of CO2 in CaCO3 burial by plate tectonics

• albedo emission of DMS cloud formation, effects on radiation

Half rules:Half of evaporation is from land (plants compensate land/sea difference)Half of present primary production is from marine plankton Half of carbonate precipitation is by reefs (corals), the rest by plankton (forams and coccolithophores)

Rates depend on temperature

Arrhenius plot for the population growth rate of E. coliData Heredeen et al 1979

low and high temperature inactive state of catalysator

103/T, K-1

ln p

op. g

row

th r

ate,

h-1

Arrhenius temperatures Lower 20110 K Midrange 4370 K Upper 69490 K

Tolerance range 293 – 318 K

Rock cycle

SiO2 + CaCO3

CO2 + CaSiO3H4SiO4 + 2 HCO3

- + Ca++

2 CO2 + 3 H2O

weathering

burialsedimentation

out gassing

Photosynthesis: H2O + CO2 + light CH2O + O2

Fossilisation: CH2O C + H2OBurning: C + O2 CO2

Calcification: 2HCO3- + Ca++ CaCO3 + CO2 + H2O

Silification: H4SiO4 SiO2 + 2H2O

pH of seawater = 8.398 % DIC = HCO3

- not available to most org.

evaporationraining

After Peter Westbroek

CalcificationOriginal hypothesis:E.huxleyi uses bicarbonate assupplementary DIC source;CO2 might be growth limiting

However:non-calcifying strains have similar max growth rate

New hypothesis:carbonate is used for protection against grazing

Emiliania huxleyi

Nutrients from rocks to plankton by plants + micro’s

Plants started to explore the terrestrial environment in the Silurian closed vegetations during DevonianFilter-feeding reefs flourished during the Silurian and Devonian

Hypotheses:• reefs developed in presence of plankton • nutrients released by plants from rocks entered oceans and stimulated plankton growth• followed by a reduction due to the formation of Pangaea

landscape lower Devonian

reef upper Devonian

Growth on reserve

Opt

ical

Den

sity

at 5

40 n

m

Con

c. p

otas

sium

, mM

Potassium limited growth of E. coli at 30 CData Mulder 1988; DEB predictions fitted

OD increases by factor 4 during nutrient starvationinternal reserve fuels 9 hours of growth

time, h

Organic carbon pumpWind: weak moderate strong

light + CO2

“warm”no nutrients

coldnutrientsno light

readily degradable

poorly degradable

no growth growth poor growthbloom

producersbind CO2

from atmosphereand transport

organic carbonto deep ocean

recovery ofnutrients tophoto-zone

controls pump

Grazing accelerates exportcopepods tintinnids

appendicularians

Fecal pellets sink fast most nutrients remain in photo-zoneAppendicularians produce marine snow (1 feeding house/ 2 hours)Dead bodies decompose fast

Synthesizing Unit

dots: arrival and production events

gray areas: periods blocked for binding

11111 BABACmC jjjjjjFlux C:

transformation: 1 A + 1 B 1 C

Simultaneous nutrient limitation

Specific growth rate of Pavlova lutheri as function of intracellular phosphorus and vitamin B12 at 20 ºC

Data from Droop 1974; SU-based DEB model fitted

P content, fmol/cell

B12 content,

10 -21 mol/cell

Conclusions:• SU-based model fits well• biomass composition varies considerably

• no high P-high B12

due to damming up• uptake of abundant nutrient is not reduced by rare one• composition control by excretion• growth limiting reserve increases with growth rate, other reserves can decrease

C,N,P-limitation

Nannochloropsis gaditana (Eugstimatophyta) in sea waterData from Carmen Garrido PerezReductions by factor 1/3 starting from 24.7 mM NO3, 1.99 mM PO4

CO2 HCO3- CO2 ingestion only

No maintenance, full excretion

N,P reductions N reductions

P reductions

79.5 h-1

0.73 h-1

C,N,P-limitation

half-saturation parameters KC = 1.810 mM for uptake of CO2

KN = 3.186 mM for uptake of NO3

KP = 0.905 mM for uptake of PO4

max. specific uptake rate parameters jCm = 0.046 mM/OD.h, spec uptake of CO2

jNm = 0.080 mM/OD.h, spec uptake of NO3

jPm = 0.025 mM/OD.h, spec uptake of PO4

reserve turnover rate kE = 0.034 h-1

yield coefficients yCV = 0.218 mM/OD, from C-res. to structure yNV = 2.261 mM/OD, from N-res. to structure yPV = 0.159 mM/OD, from P-res. to structure

carbon species exchange rate (fixed) kBC = 0.729 h-1 from HCO3

- to CO2

kCB = 79.5 h-1 from CO2 to HCO3-

initial conditions (fixed) HCO3

- (0) = 1.89534 mM, initial HCO3- concentration

CO2(0) = 0.02038 mM, initial CO2 concentration

mC(0) = jCm/ kE mM/OD, initial C-reserve density mN(0) = jNm/ kE mM/OD, initial N-reserve density mP(0) = jPm/ kE mM/OD, initial P-reserve density

OD(0) = 0.210 initial biomass (free)

Nannochloropsis gaditana in sea water

Producer/consumer stoichiometry

CjPrPdt

dPAP

ChrCdt

dC )(

NNP

NNP my

mkr

PK

Pjj Pm

PA

1111 CNCPCNCPC rrrrr

MPPACPCP kjyr MNPANCNCN kjmyr

consumer producer reserve density of producer

total nutrient (constant)

no free nutrientno -maintenanceno -reserve

CPC rr

N

PC

Nm

no need for reserve need for reserve

PmnN NNP CnNC

CPC rr

CP

Bifurcation diagramsby Bob Kooi

Diauxic growth

time, h

biom

ass

conc

., O

D43

3 acetate

oxalate

Sub

stra

te c

onc.

, mM

Growth of acetate-adapted Pseudomonas oxalaticus OX1data from Dijkhuizen et al 1980

SU-based DEB curves fitted by Bernd Brandt

Adaptation todifferent substratesis controlled by:

enzyme turnover 0.15 h-1

preference ratio 0.5

cells

Diauxic growthbi

omas

s co

nc.,

OD

590

Growth of succinate-adapted Azospirillum brasilenseintracellular amounts followed with radio labels

data from Mukherjee & Ghosh 1987SU-based DEB curves fitted by Bernd Brandt

Adaptation todifferent substratesis controlled by:

enzyme turnover 0.7 h-1

preference ratio 0.8

time, h

fruc

tose

con

c, m

M

succ

inat

e co

nc, m

M

succinate

fructose cells

suc in cells

fruc in cells

1-species mixotroph communityMixotrophs areproducers, which live off light and nutrientsas well asdecomposers, which live off organic compounds which they produce by aging

Simplest community with full material cycling

1-species mixotroph communityCumulative amounts in a closed community as function of total C, N, light

E: reserveV: structureDE: reserve-detritusDV: structure-detritusrest: DIC or DIN

Note: absolute amountof detritus is constant

Canonical communityShort time scale:Mass recycling in a community closed for mass open for energy

Long time scale:Nutrients leaks and influxes

Memory is controlled by life span (links to body size)Spatial coherence is controlled by transport (links to body size)

Self organisation ofecosystems’ trophic structure

Aim:• understand ecosystem dynamics future application in planetary modelling of life’s actions• characterize functional aspects, and link to structure effects of total nutrient amounts and light

Method:• all organisms in closed ecosystem follow DEB rules constant parameters for each individual during life span• food preference parameters values diffuse across generations• extensive parameters co-diffuse across generations body size scaling relationships for life histories• start with one single mixotroph in well-mixed closed system• use theory for adaptive dynamics to understand speciation

Some conclusions• simultaneous nutrient limitations on producers’ growth is well captured by DEB theory based on SU’s• surface area/volume interactions dominate (transport) kinetics on all space/time scales and are basic to DEB theory• wind is in proximate control of primary production in oceans• rate of organic carbon pump is controlled by nutrient recycling factors: sinking, decomposition, grazing• need for clear time scale separation organic carbon pump is only of interest on time scale of ocean turnover calcification is important at longer time scales plants reduce erosion on short time scale, increase it on long time scale• long term behaviour of ecosystems is controlled by leaks and inputs of nutrients, with important roles for continental drift and vulcanism• climate-life interactions can only be understood in a holistic perspective coupling of biogeochemical cycles with climate (water, heat)

Further readingS. A. L. M. Kooijman 2002 Global aspects of metabolism; on the coevolution of life and its environment. In: J. Miller, P. J. Boston, S. H. Schneider and E. Crist, eds., Scientists on Gaia. MIT Press, , Cambridge, Mass., to appear.

Downloadable from: http://www.bio.vu.nl/thb/research/bib/Kooy2002a.htmlFrom which you can also download this slide collection

Thank you for your attention