Soil organic matter dynamics in

mountainous environments under a changing climate -

Concepts and methodology

Frank Hagedorn

and Stephan Zimmermann

Swiss Federal Institute for Forest, Snow and Landscape Research (WSL)

Birmensdorf (CH)

outli

ne

1. Why to look at feedbacks climate change - SOM?

2. Experimental approaches

3. Case study: Treelines in the Ural mountains

4. Case study: Alpine treeline in Stillberg (Switzerland)

5. Learning from the global C distribution and past

outli

ne

Batjes, European Journal of Soil Science, 47, 151-163, 1996

back

grou

ndFeedbacks: Warming C storage

SOM-decay + _atmospheric

CO2

Warming

Growth

SOMincrease

C storage

Feed

back

s: S

OM

cl

imat

eWill changes in soil organic carbon act as a positive

or negative feedback on global warming?

Miko U.F. KirschbaumBiogeochemistry 48, 21-51, 2000

LGM: Last Glacial Maximum

Feed

back

s: S

OM

cl

imat

e

Tem

pera

ture

dep

ende

ncy

Growth

SOM

increase

Warming

SOM-decay+

_

atmospheric

CO2

C storage

)(2 )/( 12

10

110TTkkQ −=

Van't Hoff, 1898: Change of reaction rates across 10K

Exp

erim

enta

l app

roac

hes

1. Laboratory incubations

2. Soil warming studies

3. Altitudinal/latitudinal transects

Labo

rato

ry in

cuba

tion

CO2 -Production

DOC-leaching

Labo

rato

ry in

cuba

tion

From Reichstein et al. (2000): Soil Biol. Biochem. 32, 947-958

Temperature drives soil respiration

Labo

rato

ry in

cuba

tion

Q10 -

Temperature dependent

Ref.: Kirschbaum (1995): Soil Biol. Biochem. 27, 753-760Mikan et al. (2002): Soil Biol. Biochem. 34, 1785-1795

Sum

mar

y la

bora

tory

incu

batio

n

• Temperature sensitivity greater at lower T

Limitations

• More rapid losses of labile SOM at high T

• Disturbance, no input

Soi

l war

min

g st

udie

sExperimental Warming

Greenhouse-WarmingVal Bercla, Switzerland

Marion et al., Global Change Biology 3 (Suppl.1), 20-32, 1997Hollister and Webber, Global Change Biology 6, 835-842, 2000

Soi

l war

min

g st

udie

s

UV-Lamps

Problems: Decreasing air humidityNon-uniform heating

Soi

l war

min

g st

udie

s

Soil Disturbance

Non-uniform heating

Heating cables

Problems

Soi

l war

min

g st

udie

sWarming: increased C losses

Ref.: Melillo et al. (2002): Science 298, 2173-2176

Soi

l war

min

g st

udie

sWarming: increased C losses

Ref.: Melillo et al. (2002): Science 298, 2173-2176

Sum

mar

y so

il w

arm

ing

stud

ies Experimental warming

• Warming = Drying

• Uneven warming: C fluxes respond differently

• Response time dependent

Alti

tudi

nal t

rans

ects

Maly Iremel, Southern-Ural

Altitudinal transect

Alti

tudi

nal t

rans

ects

Where to look?

1.

Sensitive region

2.

Low anthropogenic influence

3.

Large areas

Alti

tudi

nal t

rans

ects

http://arctic.atmos.uiuc.edu/

Summer Winter

Global Warming -

Greater warming in winter

Alti

tudi

nal t

rans

ects

Treeline is limited by summer temperature

Ref.: Körner & Paulsen (2004): Journal of Biogeography 31, 713-732

Alti

tudi

nal t

rans

ects

Study Area -

Treeline in the Ural mountains

Alti

tudi

nal t

rans

ects

1999(Moiseev, Shiyatov, 2003)

1976

1929Rising treelines

Alti

tudi

nal t

rans

ects

1929

1999

Rising treelines

Alti

tudi

nal t

rans

ects

Northern treeline

Alti

tudi

nal t

rans

ects

-25

-20

-15

-10

-10

-5

0

5

10

5

10

15

20

1850 1900 1950 2000-10

-5

0

5

April

January

Mon

thly

Mea

n Te

mpe

ratu

re (°

C)

October

July

+3.6°C

+4.0°C

+1.4°C

+0°C

Year

South-UralTaganai,1100 mData from Fomin, Moiseev

Sum

mar

y al

titud

inal

tran

sect

s 1.

Treeline sensitive to temperature

2.

Large scale changes of treelines in remote regions

3.

Warming particular in winter (?)

Cas

e st

udy

Ura

lEarly Response Areas for Climate Change in Eurasia -

Spatio-Temporal Dynamics of the Upper Tree-line in the Ural

Mountains and Implications for Carbon Sequestration

IPAE, USFEU Ekaterinburg

SB RAS Krasnojarsk

ETH Zürich

Uni Halle

WSL Birmensdorf

EU-INTAS

Diploma thesis of Adrian Kammer under the supervision of Dr. Frank Hagedorn, WSL Birmensdorf

Cas

e st

udy

Ura

l

Maly Iremel, Southern-Ural

Altitudinal Gradient: ‚Space for time and climatic change‘

Cas

e st

udy

Ura

l

Treeline (1360m.a.s.l.)

3km

Forest (1260m.a.s.l.)

Mali Iremel (1449m.a.s.l)

Altitudinal Gradient

∂

0.3K

Cas

e st

udy

Ura

lC-pool estimates

Cas

e st

udy

Ura

l

Devy, Mazepa, Hagedorn, Rigling unpublished data

C-pool estimates: C-Allocation

Cas

e st

udy

Ura

l

Maly Iremel, Southern-Ural

Transect: ‚Space for time and climate change‘C-pools and productivity

Cas

e st

udy

Ura

l

1. Greater C-Input through more biomass

(above-ground: 180 vs. 60 g C m-2y-1)

2. Greater decomposition through warming ?

Rising treeline and soil carbon: mechanisms

Cas

e st

udy

Ura

l

01.01.2004 01.07.2004 01.01.2005 01.07.2005

-20

-15

-10

-5

0

5

10

15

Tundra 1350 m Forest 1250 m

Air

Tem

pera

ture

(°C

)

Micro climate: air temperature

Cas

e st

udy

Ura

l

01.01.2004 01.07.2004 01.01.2005 01.07.2005

-20

-15

-10

-5

0

5

10

15

-20

-15

-10

-5

0

5

10

15

Tundra 1350 m Forest 1250 m

Soil

Air

Tem

pera

ture

(°C

)

Micro climate: soil temperature

Cas

e st

udy

Ura

l

1360 m

1300 m

Winter climate

Cas

e st

udy

Ura

l

1200

1250

1300

1350

1400

1450

0 20 40 60 80 100 -8 -6 -4 -2 0 2Soil

Wintertemperature (°C)

Snow height (cm)

Alti

tude

(m.a

.s.l.

) Treeline

Winter climate: Snow height and temperature

Cas

e st

udy

Ura

l

Sampling: soil C pools

• 3 altitudes

•4 trees

•2 profiles under trees and

‚open‘ land

• L, F, H, 0-7cm, 7-25cm, 25-C

• additional topsoil sampling

• areal and volume based sampling

Cas

e st

udy

Ura

l

Soils: Cambisols

Tundra 1360 m a.s.l.

Forest 1260 m a.s.l.

Cas

e st

udy

Ura

lAltitudinal transect Ural: Soil profiles

Cas

e st

udy

Ura

lAltitudinal transect Ural: Soil C pools

Cas

e st

udy

Ura

lAltitudinal transect Ural: Soil C pools

Cas

e st

udy

Ura

l

Kammer, Hagedorn unpublished data

Altitudinal transect Ural: Soil C-Pools

Maly Iremel: Southern-Ural

Cas

e st

udy

Ura

l

Kammer, Hagedorn unpublished data

Altitudinal transect Ural: Soil C-Pools and producitivity

Maly Iremel: Southern-Ural

Cas

e st

udy

Ura

lAltitudinal transect Ural:SOM quality changes from tundra to forest

Cas

e st

udy

Ura

lAltitudinal transect Ural:SOM quality changes from tundra to forest

Cas

e st

udy

Ura

l

1. Increasing biomass: 15 tC/ha 75 tC/ha

2. Tripling of litter input

3. 20-40%-increase of soil C pool + 20-40 t C ha-1

4. SOM quality increases

Rising treelines and C pools

SOM <–> climate change

Cas

e st

udy

Ura

lC-Mineralisation (SOM CO2)

Cas

e st

udy

Ura

lC-Mineralisation (SOM CO2)

Cas

e st

udy

Ura

lIn situ decomposition (litter bags)

Cas

e st

udy

Ura

lAnnual C mineralization

Modelling with soil temperatures and SOM pools ICBM (Andrén & Kätterer, 1997)

Cas

e st

udy

Ura

lAnnual C in-

and outputs

Cas

e st

udy

Ura

l

Rising treelines

Greater decomposition

More biomass (15 75 t C ha-1)

Better Decomposability

Warmer microclimate

Greater litter input

Faster C-turnover compensated for greater C inputsHow does it affect N-cycling?

Summary

Cas

e st

udy

Ura

lN-Mineralisation

Cas

e st

udy

Ura

l

Warming

Precipitation1

Soil temperature

Snow cover

SOM turnover

Microbial activity

Plant (Tree)-

growth

N availability

Feedbacks: Winterwarming -

Rising Treeline

1Devi et al., Global Change Biology 14, 1581-1591, 2008

Cas

e st

udy

Ura

l

SOM <-> climate change: Summary

Climatic change likely affects C in-

and outputs in similar ways

Total SOM pool (=C sink) remains unchanged

SOM turnover increases

Cas

e st

udy

Ura

l

M. Bauer, P. Egli, T. Handa, S. Hättenschwiler, J. Hutzler, T. Hollmann, A. Kammer, R. Köchli,

Ch. Körner, W. Landolt, P. Moiseev, A. Rigling, M. Saurer, R. Siegwolf, D. Spinnler, D.

Tarjan, A. Zürcher,…Schweizer Nationalfonds, BAFU, EU-INTAS

Thanks!