Wetlands and GHG – exchange

Matthias Drösler

Vegetation Ecology

Estimates of C storage as peat globally / in Europe

• Great global C store270-450 Pg, equals 1/5 – 1/3 of the soil C pool of the earth,

and approximately half the amount of CO2-C as in the

atmospheremineral subsoil C store min ~ 10 Pg, Europe 1.6 Pglive vegetation ~ 1 – 2.5 % of the total C storage, ~ 7 Pg

European peat ~ 10-15% of the global C store in peat

Spatial variability matters:-water table -vegetation type-management -peat characteristics-…..

Peatland-Landscape composed by a small scale mosaic of parameter combinations => specific requirements for site

selection, measurement techniques and upscaling approaches

Temporal variability matters:-interannual variability -time since restoration-Management schemes

Multiyear measurement programmes to support modeling processes

Peatland GHG-fluxes - characteristics

undisturbed gas-exchange ++ +/- (cross-checks!) +/- (cross-checks!)

integration over spatial variability

++ - (quantity of chambers vs.

mosaic)

- (quantity of chambers vs.

mosaic)

direct measurement of the spatial variability

-- ++ ++

tracking temporal variablity ++ ++ - (campaigns as basis for modelling)

costs -- -- ++

workload ++ + --

performance under all climate conditions

+/- +/- ++

Measurement techniques

DGMTDeutsche Gesellschaft für

Moor- und Torfkunde e.V

Climate change mitigation viapeatland management?

Freising 5. – 6. Oktober 2007

Vegetation Ecology

Thematic sessions

• session 1: GHG-exchange and climatic relevance of peatlands – balances and processes

• session 2: scaling and inventories- requirements and methods

• session 3: management – economic and political aspects of peatland management and conservation

Thematic sessions

• session 1: GHG-exchange and climatic relevance of peatlands – balances and processes

• session 2: scaling and inventories- requirements and methods

• session 3: management – economic and political aspects of peatland management and conservation

1236

5

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Carbon balance: g C m-2 yr-1

-100 0 100 200 300 400 500 600-100

0

100

200

300

400

500

600fensbogs

Net

cli

mat

e ef

fect

: g

C-e

qu

iv.

m-2

yr-1

1 forest bog2 forest fen3 natural bog4 restoration fen

(but without NEE!)5 natural fen6 drainage fen7 restoration bog8 drainage bog9 peat cut bog10 grassland bog11 abandoned

after peat cut bog12 arable bog13 grassland fen14 arable fen

Climate change mitigation via peatland management

Drained

Restored

Carrot

Grass

Typha

C. acu.

C. pan.

-500

0

500

1000

-500 0 500 1000

C balance [g C m -2 yr-1]

Ne

t c

lim

ate

eff

ec

t

[C-e

qu

iv.

m-2

yr-1

] Forest

Cropland

Peatlands

Donauried fens

Peenetal fen

Fen mire Poland

Climate change mitigation via peatland management

-5000

0

5000

10000

15000

20000

25000

30000

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Phase 1 Phase 2 Phase 3

pristine reflooded

? ?

drained

Effect of drainage and reflooding on radiative forcing

present

Glo

bal w

arm

ing

pote

ntia

l (kg

CO

2 e

quiv

alen

ts *

ha-1*y

r-1)

Negative effect

Positive effect

Augustin, unpubl.

Thematic sessions

• session 1: GHG-exchange and climatic relevance of peatlands – balances and processes

• session 2: scaling and inventories- requirements and methods

• session 3: management – economic and political aspects of peatland management and conservation

Thematic sessions

• session 2: scaling and inventories- requirements and methods– soil C-inventories lacking (Germany)– remote sensing of landuse pattern o.k. but

no activity data for upscaling (landuse intensity, management)

– peatland-GHG to be reported in the NIR– Kyoto: Germany Art. 3.4 forest

management; Denmark Art 3.4, grassland corpland management on organic soisl

Thematic sessions

• session 1: GHG-exchange and climatic relevance of peatlands – balances and processes

• session 2: scaling and inventories- requirements and methods

• session 3: management – economic and political aspects of peatland management and conservation

Thematic sessions

• session 3: management – economic and political aspects of peatland management and conservation – conservation programmes in Germany include to

very different extend climate proteccion within the goals for peatland managment and conservation

– Mostly win-win situation (climate, water retention and species conservation) expected

– Wise use and climate friendly management of peatlands pays back (alder, reed …)

Obvious gaps in our knowledge

• Few year round GHG budgets based on continuous measurements exist for peatlands (EU-review in progress; will be submitted end of Nov.)

• Representation of different climate zones up to now only limited. • There is particular need for more data about GHG budgets of

peatlands under particular land uses and management: a) bog: grassland, cropland, land abandoned after peat cut, restoration, forest chronosequences, N2O fluxes in general. b) fen: abandoned after harvest, restoration, CO2 fluxes in general.

• There are insufficient data to characterize GHG-flux sensitivity from peatlands to weather variability, climate change and N-input.

• The assessment of restoration effects on GHG-fluxes needs more measurement programs and process studies, to cover variability in time and space (water table effects, management, vegetation)

• GHG-studies to be combined with policy and economy research to identify socioeconomic drivers of peatland management

German BMBF-funded project within the programme on climate mitigation:

GHG-exchange at 6 sites across german peatland regions

Partners: TUM (coordination)IÖWLBEGMPIZALF

associated via EU-TOK: University of PoznanRzecin-site

Map from Schopp-Guth (1999)

2006-10

2006-10

2004-10

2006-10

2006-10

2006-102006

1999/00

2005

2006-10

Climate change mitigation via peatland management

Climate change mitigation via peatland management

TG1 & TG2LBEGGHG-exchange

TG3 & TG4ZALF-AUGGHG-exchange

TG5 & TG6TUM-VegOekGHG-exchange

IÖW macro-economics

TUM-WDL farm level economy

ZALF-BLF upscaling

TUM-VegOek modeling

MPI GHG in the soil profile

MPI and TUM-VegOek policy advice

TUM-VegOek coordination

total-Carbon in German peatlands min. 400 - 1000 Mio t CBavaria min. 65 Mio t C (NIR 2004 and Byrne et al. 2004)

potential emission to CO2 equals min. 1.5-times the annual total emissions of Germany (2002) or 3-times the bavarian total emissions

estimates of the total GHG-balance of German peatlands are between 23 (Byrne et al. 2004) to 44 Mio t CO2-equiv. a-1 (Freibauer et al., in Vorb.).

Bavarian part around 6.8 Mio t CO2-Äquiv. a-1

anthropogenic GHG-emissions from peatlands represent 2.3-4.5% of German total emissionsor around 8 % for Bavaria

But still big uncertainties and data-gaps!

climatic relevance of the GHG-exchange of German and Bavarian Peatlands

Thanks for your attention

wetland

fen(minero-trophic)

bog(ombro-trophic)

usednaturalused

mire

swampnon-peatforming

fresh-water

marshnon-peatforming

salt-water influenced

peatland

Management in wetlands-Goals

-Agricultural Production-Forestry production-Bioernegy-Species conservation-Water retention-Carbon storage-Scenery, tourism-…

- Temporal aspectscutting: decreasing frequencies with decreasing intensity grazing: intensity gradient, speciesfertilization: water table: dynamics restoration works

-Intensity-Spatial

small scale mosaic of different landuse regimeManipulation of site conditionsWater table management (drainage, rewetting)Restoration

Klimaschutz - Moornutzungsstrategien

Fluctuating wt Flooded

CO2-C equivalents

(kg CO2-C*ha-1*a-1)

CO2-C equivalents

(kg CO2-C*ha-1*a-1)

2005 2006 2005 2006

CO2

CH4

N2O

19411

188

2500-1

492

-500015239

13

-236229351

13

Total global warming potential

2130 2991 10226 27002

Global warming potential in 2005 and 2006