What Can Tea Bags in Salt Marshes

Tell Us About Climate Change?

Jim Tang, Ph.D. Marine Biological Laboratory in Woods Hole

jtang@mbl.edu

Funding:

NOAA/National Estuarine Research Reserve

System Science Collaborative (BWM1 and BWM2)

Collaborators:

Faming Wang, Kevin Kroeger, Omar Abdul-Aziz,

Serena Moseman-Valtierra,, Meagan Gonneea, Kate

Morkeski, Jordan Mora, Joanna Carey, Tonna-Marie

Surgeon-Rogers, James Rassman, Chris Weidman

Acknowledgements

IPCC, 2001 IPCC, 2001

55 4 60 Pg 5.4

88

120

90

Global carbon cycling

?

2.4 Unit: Billion ton

G lobal m ean tem perature anom aly

(re la tive to 1961-1990 m ean)

Y ear

1840 1860 1880 1900 1920 1940 1960 1980 2000 2020

Te

mp

era

ture

(oC

)

-0 .6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

Atm ospheric CO2 record

from Mauna Loa

Y ear

1960 1970 1980 1990 2000 2010

Co

nc

en

tra

tio

n (

pp

m)

300

310

320

330

340

350

360

370

380

390

Carbon-climate-ecosystems-Earth system

Carbon

cycle

Climate

change:

warming,

sea level,

storms

Ecosystems

Earth system processes

and modeling

Coastal blue carbon

Tang et al. 2018.

Photosynthesis: 6CO2 + 6H2O + light → C6H12O6 + 6O2

Respiration： C6H12O6 + 6O2 → 6CO2 + 6H2O + heat

Calcification: Ca2+ + 2HCO3- ↔ CaCO3 + H2O + CO2

Therefore,

• to understand and predict climate change,

we need to understand the carbon cycle;

• to mitigate climate change, we need to

increase carbon uptake (the negative

carbon emissions), where coastal salt

marsh plays an important role.

Negative Emissions Technologies (NET)

Developing a Research Agenda for Carbon

Dioxide Removal and Reliable Sequestration

http://nas-sites.org/dels/studies/cdr/

US NAS 2018, Negative Emissions Technologies

CH4

GPP

C stocks

R

N

F(L)

Carbon cycling components

CH4

GPP

C stocks

R F(L)

restore

Tang et al. Unpublished

In-situ GHG

Chamber flux

measurement for

salt marsh

CO2/CH4 Analyzer

Flux measurement for

Phragmites

Blue carbon monitoring system

CO2 & CH4 Fluorescence

Camera

Weather system

Yang, Tang, et al. 2015 Geo. Res. Letter; Yang, Tang, et al. 2017, Global Change

Biology; Lu at al. 2018 Agri. For. Met.; Lu et al. 2018a,b, Remote Sensing

Use 210Pb to date sediment cores (Gonneea et al.)

Long sediment cores

Tea

decomposition

experiment:

to understand the

decomposition

rate of organic

carbon

Djukic et al. 2018

Djukic et al. 2018

Tang et al. 2016

Ecosphere

Using Cameras to record leaf phenology

Gre

en

ne

ss

Day of the year

Quiescence

Senescence

Bud-break

Full canopy

Leaf Abscission

October January April July

Summer Spring Winter Autumn

Courtesy of Jeremy Fisher

Leaf phenology vs. carbon (i.e. GPP)

GPP

Phenology

CO2 and CH4 fluxes

in the pristine site

0 50 100 150 200 250 300 350 400

Flu

x (

mol m

-2s-1

)

-20

-15

-10

-5

0

5

10

NEP

GPP

R

DOY

0 50 100 150 200 250 300 350 400

Flu

x (

nm

ol m

-2s-1

)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

CH4

CH4(4)

GPP

(773)

C stocks

R(394) F(L) (215)

NECB (160)

Tang et al. unpublished

(gC m-2y-1 )

Dike

Degraded marsh

Case study: Herring River wetland

restoration project

Natural

marsh

161

54

135

0

40

80

120

160

200

Saltmarsh PhragmitesBrackish TyphaMarsh

CBurialRate

(gCm

-2yr-1)

60.00

9,150.00

75.00

1

10

100

1000

10000

Saltmarsh PhragmitesBrackish TyphaMarsh

CO2-equavalentCH4emission

(gCO2-Cm

-1yr-1)

Net CO2 uptake

CH4 emissions

C from

different

ecosystems

Salt marsh:

100-200 gC

m-2y-1)

Wang et al. in review

Blue Carbon Credit

Carbon credit =

Carbon storage after human intervention -

Carbon storage baseline

• We use gas analyzers, cameras, and

tea bag experiments to understand the

carbon cycle.

• We found that the coastal wetland is a

significant carbon sink (blue carbon).

• Restoration increased carbon

sequestration and decreased CH4

fluxes.

Conclusions

IPCC, 2001 IPCC, 2001

55 4 60 Pg 5.4

88

120

90

Global carbon cycling 2.4

Unit: Billion ton