300 years of nep caused by land use, co 2 fertilization and climate change according to lm3...

300 Years of NEP Caused By Land Use, CO2 Fertilization and Climate Change According to

LM3

Shevliakova, Malyshev, Hurtt and Pacala

Can

opy

and

cano

py a

irS

oil/

snow

Atm

osph

ere

Pho

tosy

nthe

sis

Pla

nt a

nd s

oil r

espi

rati

on

En

ergy

an

d m

oist

ure

bal

ance

Car

bon

up

tak

e an

d r

elea

se

t~ 30 min

fine

ro

ots

Energy, water and carbon exchange

leav

essa

pwoo

dla

bile

woo

d

Car

bon

allo

cati

on a

nd g

row

th, t

~ 1

day

Phe

nolo

gy, t

~ 1

mon

th

Mor

tali

ty, n

atur

al a

nd f

ire

t ~ 1

yea

r

Bio

geog

raph

y, t

~ 1

year

{

Lan

d-us

e m

anag

emen

t, t ~

1 y

ear

Climate statistics

Carbon gain

Plant typeLAI, height,roots

Lan

d-us

etr

ansi

tion

s

Vegetation dynamics

Dynamic Land Model LM3V

Land use characterization

climate 1951-1970

Experimental Design

spin-up (300 y)

1700

no land-use

land-use

land-use, no secondary

CO2 historical

climate “recycled” 1951-1970

no land-use

CO2 286 ppm

CO2 historical

CO2 historical

CO2 286 ppmCO2 286 ppm

climate 1951-1970

climate 1951-1970

climate 1951-1970

climate 1951-1970

1971-2000

1971-2000

1971-2000

1971-2000

1971-2000

Global NEP

no land use land use

CO2=286 ppm

CO2=historic

1950

-196

9 R

ecyc

led

Clim

ate

1970

-199

9 T

rue

Clim

ate

CO2=286 ppm

CO2=historic

carb

on,

Gt

carb

on,

Gt

Historic CO2 No Secondary

Historic CO2 Real Land Use

286 ppm Real Land Use

CO2 Fertilization = 2 GtC / y

Global NEP

no land use land use

CO2=286 ppm

CO2=historic

1950

-196

9 R

ecyc

led

Clim

ate

1970

-199

9 T

rue

Clim

ate

CO2=286 ppm

CO2=historic

carb

on,

Gt

carb

on,

Gt

ENSO Matters

ENSO Matters

Historic CO2 No Secondary

Historic CO2 Real Land Use


Zonal distribution (1980-1999 ave.)

Recycled climate (1950-1969) True climate (1970-1999)

Model Stable With No Perturbation

Real CO2 No Land Use

Real CO2 No Secondary

Real CO2

Real Land Use


286 ppm No Land Use





Real CO2

Real Land Use


286 ppm No Land Use

Tropical Sources Caused By Harvest and Climate





Real CO2

Real Land Use


286 ppm No Land Use

Tropical and Northern Sinks Caused By Climate and CO2



Temperate Sink Sharpened by Land Use



Real CO2

Real Land Use


286 ppm No Land Use

Decadal zonal averages

“80s” “90s”

Rec

ycle

d cl

imat

eT

rue

clim

ate

Tropical Dipole Flips



Real CO2

Real Land Use


286 ppm No Land Use

Decadal zonal averages

“80s” “90s”

Rec

ycle

d cl

imat

eT

rue

clim

ate

Temperate Sink Stable



Real CO2

Real Land Use


286 ppm No Land Use

No land use

East US Regrowth

Land use

East US Regrowth

No land use

Amazonian Deforestation

Land use

Amazonian Deforestation

Land use

Africa Drying

Tru

e C

limat

eR

ecyc

led

Clim

ate

Wood Products Matter

Wood Products Sink

NEP

Message to modelers who want to diagnose the cause of the

terrestrial sink:

• Estimate dependencies on climate with forest inventory, eddy covariance and atmospheric trace gas measurements.

• Add land use with secondary harvest to solve the initial condition problem.

• Track agricultural and wood products.

300 years of nep caused by land use, co 2 fertilization and climate change according to lm3...

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