Landscape Scale Investigation of Greenhouse Gas Exchange (LAGGE): presentation

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Seminar on Landscapes in a Carbon Focused World 26 October 2012 SIANI, Focali & Naturskyddsföreningen organized a one-day seminar in Gothenburg. Summary: Forests are discussed as important globally widespread carbon sinks in the terrestrial landscape and it has recently been postulated that this view is valid for forests of all ages. However, this approach is inadequate to assess the carbon and greenhouse has (GHG) balances from the total forested landscape since transport of carbon from land to water and subsequent GHG emissions from aquatic habitats are typically not considered. Inland waters contribute large amounts of carbon dioxide to the atmosphere, and are important for the global warming potential. These findings indicate a disproportionate aquatic impact on the overall terrestrial GHG balance relative to the small freshwater surface area.In order to challenge the current view of the continental carbon or GHG sink a national Formas project LAGGE was started, with its main field activities during 2012-2013. With the hypothesis that the GHG sink is smaller than currently believed, the main objective is to quantify GHG balances at the landscape scale in forested regions that include land-atmosphere, land-water, and water-atmosphere exchange. Leif Klemedtsson is heading the Gothenburg Greenhouse Gas Group (G4). G4 conducts flux measurements from tundra, peat, agriculture and forestlands, process studies, modelling followed by ecosystem analysis in order to find mitigation strategies. Hi is the coordinator for the LAGGE project. Link to the video of this presentation To read more about the seminar click here

Transcript

Landscape Scale Investigation of

Greenhouse Gas Exchange (LAGGE)

Leif Klemedtsson, Department of Earth Sciences

Gothenburg University Contact: leif.klemedtsson@gu.se

To quantify GHG balances, and matter transport at the

landscape scale in forested regions that include land-

atmosphere, land-water, and water-atmosphere exchange

of CO2, CH4 and N2O as well as DOC/DON.

To incorporate new measurements and technologies as

well as available data from ongoing environmental monitoring

to estimate the overall watershed net C and GHG balances

at different scales, by linking data with models.

The aims of this project are:

Large team within LAGGE and at

Skogaryd

L. Klemedtsson1, D, Allbrand1, D. Bastviken2, R.G. Björk1, A.-K.

Björsne1, P. Boeckx3, P. Crill4, A. Ekblad5, M. Ernfors1, H. He1, M.

Hellstöm6, J. Holst6 P-E. Jansson7, E. Julén1, C. Kalin6, A. Lindroth6, A.

Meyer1, S. Natchimuthu2, A. Nousratpour1, J. Nylinder1, E.

Podgrajsek8, A. Rutgersson8, T. Rütting1, M. Räntfors1, E. Sahlée9,

L.Shubhangi1, S. Sobek9, L. Tarvainen1, L. Tranvik8, J. Uddling1, G.

Wallin1, P. Weslien1, and G. Weyhenmeyer8 and more!

1University of Gothenburg, Sweden, 2Linköping University, Sweden, 3Ghent University,

Belgium, 4Stockholm University, Sweden, 5Örebro University, Sweden, 6Royal Institute of

Technology, Sweden, 7Lund University, Sweden, 8Uppsala University, Sweden.

Terrestrial ecosystems

are sinks for C

The global land sink is estimated to be 2.6 T 1.7 Pg

of C year−1 (variability T range, excluding C emissions

because of deforestation) (K. L. Denman et al., 2007)

The problem…

From Benoy et al. 2007

CO2 equivalents

Aquatic CH4

return 25 % of the

land CO2 eq.

sink!?

(CO2+CH4 = 79%) Bastviken et al. 2011

Tranvik et al. 2009

Lake organic matter is related to the soil

organic matter in the catchments

Weyhenmeyer et al., 2012 (GCB)

Skogaryd Research station (58°23’N, 12°09’E).

Ecosystems

“Catchment”

Lake Erssjön

Team Rutgersson et al. and Team Bastviken et al.

Mire systems

Mire Micrometeorological

station

Team Crill et al.,/Lindroth et al.

and UGOT

Mire systems

Mire stream station

NEE versus TOC

Degrö mire

• Of the annual net CO2-C uptake, 37% and 31% was lost

through runoff (with runoff TOC>DIC >> CH4).

• ….. the variability in runoff export of Total Organic

Carbon (TOC) from boreal continental mires originates

from variations in the annual specific discharge,

rather than TOC concentration.

Nilsson et al., 2008 (Global Change Biology)

Forest ecosystems

The global land sink is estimated to be 2.6 T 1.7 Pg

of C year−1 (variability T range, excluding C emissions

because of deforestation) (K. L. Denman et al., 2007)

But, is this true for all forest ecosystems?

No real net uptake of

CO2 in relation to

biomass production

on drained organic

soils

2.7 (±1.0)

+13.1 (±2.2)

-2.0 (±0.3a) -0.01 (±2.6b)

Decay of roots and mycelia

+8.2 (±1.9b)

Decay of plant litter

-8.2 (±1.7)

NEEmeas NEEcalc

Approach 1 Approach 2

+6.2

-

Measured soil efflux RSOM

Residual soil efflux Rres

2.2(±0.4)

a assuming 15% data uncertaintyb propagated error estimates are calculated by the Gaussian error propagation scheme

assuming that components are independent

CO2

(?)

N2O equal to about 1 ton C

Conclusion so far…

• The drained afforested organic soils, former under

agricultural use, are most likely a net source for GHG, -

the DOC contribution is still unknown.

• They represent abort 1/3 of drained forests. Ernfors et al.

(2008)

• Ernfors et al. (2008) estimated that afforested organic

soils contribute by 18% to the total Swedish

anthropogenic N2O emissions.

• The mineral sites are under investigation!

Question

• What are the implications for the

management of land, forests and water in

a changing climate?

Thank You

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