Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. CarboZALF - the carbon dynamics of arable landscapes in North-East Germany Jürgen Augustin Olomouc October 21th 2010

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. atmospheric CO 2 ocean land fossil fuel emissions deforestation PgC CO 2 flux (PgC y -1 ) Sink Source Time (y) 0.3 Residual 2.3 Global Carbon Project 2009; Le Quéré et al. 2009, Nature Geoscience Role of terrestrial biosphere in the anthropogenic carbon cycle is unclear (reduced sink efficiency?) PgC

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Erosion – mean reason for uncertainties? Erosion-induced net soil-atmosphere C exchange SINK SOURCE NEUTRAL +1.5 Pg/yr -1.5 Pg/yr 0 → Lal, 2004 → Stallard, 1998 → Jacinthe, 2001 → Berhe, 2007 → Smith, 2001 → Van Oost, 2007 → Ito, 2007 (Van Ost 2009)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Particularly unclear: Significance of agricultural landscapes for C sequestration and climate impact Influence of land management on soil and carbon dynamics (controversial discussion, e.g. in case of energy crop cultivation)?  Creation of the project „CarboZALF“ Photo: R.J. Michel Transfer: DOC, DIC, SOC solid CO 2 exchange Sink? CO 2 exchange Source? CO 2 exchange steady state Significance of agricultural landscape elements and/or landscape pattern on soil and carbon dynamics

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. CarboZALF – target results Multi-scale and multidisciplinary approach for the investigation of the C dynamics (process analysis + modeling) Procedure for the assessment of land use and climate change impact at the complete landscape C dynamics Methodical Effect of current land use systems, sites, and climate at the exchange of greenhouse gases and the C sequestration in agricultural landscapes Landscape use systems with reduced climate impact und long-term preservation of the C sequestration potential Answers

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Approach: Coupling of process analysis and the development of multi-scale models Development of landscape based indicators (structure- process coupled), inclusively of lateral processes model Quantification of C balance elements on site scale model + experiment, site Clearing up processes (mechanism) on micro scale experiment, lab

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. First step: Establishing of a multidisciplinary field experiment as a „seed crystal“ (CarboZALF-D) Objective Clearing up the influence of the energy crop cultivation and erosion on soil functions, greenhouse gas exchange, C dynamics, and the climate impact of the north-east German glacial landscape

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. experimental site Site selection based on landscape reference and process relevance (Uckermark - north-east German glacial landscape: hummocky moraines, peaty lowlands) All relevant C fluxes are included (gaseous, solid, liquid) Manipulation experiments for the erosion Long term field trial (> 10a) What is new at CarboZALF-D?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Crop rotation Rotation 1 winter rye/silage maize (monoculture) Rotation 2 winter rye/silage maize– winter rye/food millet– winter triticale/perennial ryegrass Fertilization only mineral fertilizer 50 % mineral fertilizer and 50 % biogas slurry (related to N) 100 % biogas slurry (related to N) Soils orthic luvisol eroded orthic luvisol eroded orthic luvisol, manipulated calcaric regosol colluvium colluvium, manipulated Experimental design and test factors

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Work packages Long term measurements of soil parameter and erosion Long term measurements gas fluxes and global warming potential (Net CO 2, N 2 O, CH 4 ) Crop production aspects of C dynamics Development/test of a C dynamics model of agricultural sites Characterization of soil organic matter fractions Influence of soil microbiological activities on C turnover

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. C balance approach (C gas fluxes, C export/import) SlurryHarv SOCp in SOCp out DOC/DIC in DOC/DIC out ∆ SOC = NEE + (slurry – harvest) + (SOCp in – SOCp out ) + (DOC in + DIC in ) – (DOC out + DIC out ) GPP R eco NEE (Net CO 2 exchange) = GPP - R eco

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Greenhouse gas exchange and global warming potential: chamber measurements Manual chambersBig automated chambers: 2.5 m

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Monitoring of water and matter dynamics in soils Soil water potential Soil moisture (FDR) leachate (suction cups): DOC, DIC, others Eh potentials

CarboZALF-D installations Manual chambers Automated chambers Erosion manipulation plots

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Chamber test I: Maize H 2 O and CO 2 concentration after closing Air temperature inside and outside after closing

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Chamber test II: Maize Vetilators turned off Ventilators switched on

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Chamber performance I: influence of herbicide application on NEE Maize, June 11th till -40 ppm -5 till +5 ppm Herbicide application

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Chamber performance II: CO 2 uptake influneced by crop and time Maize max ppm Winter rye max. -10 ppm

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Automated chambers for wetlands

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. > 95% of German peatlands drained/rewetted Succow 1988 Up to 5000 t C and 120 t N per ha Stronly increased net climate impact (N 2 O, net CO 2 ) Very uncertain estimates Already integrated: GHG exchange and C dynamics of fen peatlands (minerotrophic mires)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Changed situation Fen restoration (rewetting and reflooding) Unclear Is a strong reduction of net climate impact (net CO 2 sink, weak CH 4 source) feasible again?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Approach: Long term gas flux measurements by enclosure and eddy technique (net CO 2, CH 4, N 2 O) Cropland + grassland Alder swamp forestRewetted + flooded fen grassland Willow swamp forest

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. What is the effect of fen rewetting on trace gas exchange and global warming potential?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Zarnekow – a former fen grassland in the Peene river valley geoportal-mv.de

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Control (flooded in winter) Control (drained from spring till autumn)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Reflooded (06/2006) Reflooded (11/2005)Reflooded (7/2005)Reflooded (04/2005)Reflooded in future (2004)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. 07/ / / /2007

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Surprise: Much more CH 4 than expected!

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Methane emission : weak reduction on the reflooded site

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Methane emission : No reduction on the reflooded site! temporarily dry

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. 05/ / /2009 Net CO 2 exchange after flooding: sink function is suspended

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. GHG balance: flooded site is much worse than control site to this day

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Arising discussion: Does flooding make sense at all? Is increased methane emission after reflooding like a snapshot! Short-term measurements of only a site do not permit any generalization capable statements, especially about long term effects! Is the global warming potential permanently more negative than on the site with fluctuating water table?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. litter of reed canary grass? Which substrate is responsible for the methane formation? old peat +/- roots?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Gas exchange measurements from substrate colums in lab incubation studies* *together with M. Hahn-Schöfl, A. Freibauer, D. Zak, M. Minke

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Main CO 2 and CH 4 source: reed canary grass litter (OM) OM = Organic mud (Reed canary grass litter) WT = old peat + roots AT = old peat

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Flooding of degraded and eutrophic fens: temporarily increase of climate impact Intermediate conclusion How can I avoid increased climate impact after restoration? - Water table only up to the peat surface - Promotion of helophyte development Reason: permanent high CH 4 emission, caused by flooding in combination with a high C pool of easily decomposable plant litter The spreading of helophytes might cause a diminution of the climate impact in the long-term (net CO 2 uptake, reduced CH 4 emissions as a result of the shunt effect)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. In many cases restoration of drained peatlands is limited by water shortage and socio-economic reasons Problem Question Can a reduction of the climate impact be reached also with an adapted land use?

Rhin-Havelluch - a drained fen area with different land use variants near Berlin TG 3 Field research station Paulinenaue

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. Experimental Variants Meadow extensive (1 cut) Meadow middle (reed canary grass, 3 cuts) Pasture (extensive, middle, intensive, partly simulated) cattle tracks cropland (maize?) (the same spectrum parallel on histosols with lower C content)

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. „Drained“ fen site 2007: flooded, flooded, flooded…

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V – strongly swaying groundwater table September January

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. Annual CH 4 -C fluxes: influenced very strongly by the groundwater Threshold Mean groundwater table (cm)

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. Annual net CO 2 -C losses: In the dry year 2008 much higher than in the wet year 2007

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. N 2 O contri % GHG balances are influenced by ground water level, weather and land use at the same time

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. Reed canary grass has lower CO 2 losses (more favourable climate impact) than extensive meadow: higher GPP at the same Reco

Leibniz-Zentrum für Agrarlandschaftsforschung (ZALF) e. V. Negative climate impact (and heavy C losses) can be caused by quite different factor constellations Gas exchange, GHG and C balance are influenced by groundwater table, land use, and weather simultaneously Adapted land use (reed canary grass cultivation) could contribute to the reduction of the climate impact. However, this presupposes further check and well-considered procedure. This drained fen site shows very high climate impact (and strong C losses) Intermediate conclusion

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Summary fen peatlands Gas fluxes and GWP are influenced by ground-water level, land use, and weather at the same time A reduction of the climate effect seems possible; however, requires sound knowledge How can this be guaranteed?  Expanding of sites, long-term flux measurements, Upscaling  model studies for understanding and controlling reflooding process Drained and newly reflooded fens can be strong sources for greenhouse gases

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Photo: M. Sommer Next step: Clearing up the role of small waters for the carbon dynamics of agricultural landscapes (“CarboAqua”) Hot spots of C/N dynamics and gas fluxes in agricultural landscapes? ?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Pothole site/zonekg CH 4 -C ha -1 a -1 Breites Fenn terrestrial zone amphibic zone Krummer Pfuhl terrestrial zone amphibic zone aquatic zone arable soils (loamy sand) arable land without riparean area: weak methane sink CH 4 emission character of this region is dominated by the riperean areas! arable land with riparean area: weak methane source! Riparean areas of potholes: Important for the CH 4 emission of the arable landscape in NE-Germany?

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Outlook: from “CarboZALF” to “Carbo-Landscape” Separation and dynamics of the assimilate fluxes in the plant soil system (isotope studies) Modeling of the interactions between a lateral matter transfer and soil C dynamics (different scales, erosion specialists etc.) Including other landscape compartments: grassland, forest) Development of a landscape and regional model (+ urban rural relations) General: fund raising, integration into research networks

Leibniz-Centre for Agricultural Landscape Research (ZALF) e. V. Thank you for attention!