1. Horstermeerpolder ME1-WP3  Goal of the research  The Horstermeerpolder  Overview of measurement techniques  Preliminary results  Further research & planned papers  Collaboration

2. Research Goals This research aims to assess the effects of changing environment and management practices on the greenhouse gas fluxes from peat meadow areas. The research goals are: 1. To asses the possibility of water level manipulation as a management tool for GHG fluxes from peat meadow areas; 2. To understand the controlling mechanisms of GHG fluxes (CO2, CH4,N2O) emissions in natural fen meadows; 3. To improve the estimates of the contribution of the fen meadow areas to overall land use GHG emissions from the Netherlands.

3. The Horstermeerpolder

4.   Former agricultural land in drained natural lake   Taken out of agricultural production more than 10 years ago  semi-natural grassland   Ditch water table has been raised to 10 cm below surface   Peat meadow underlain by Pleistocene sands and overlain with organic-rich lake deposits.   Groundwater seepage The Horstermeerpolder

5. meteorology tower eddy-correlation tower fixed site flux chamber measurements planned fixed site flux- chamber measurements discharge measurements soil measurements hydrological measurements Measurement techniques

6. Other measurement techniques  Flux chamber measurements ( CO 2, CH 4 & N 2 O) at fixed sites, on ditchwater and in grid setup.  Additional measurements at fixed sites for flux chamber measurements  Water quality: TOC, dissolved CH4, pH, EC, cations and anions  Water quantity: groundwater, soil water, discharge, precipitation  Vegetation analysis  Soil analysis

7. Additional site: Ruwiel  Peat land reserve  Fen meadow  Hay pasture  High groundwater table  Never manured, mown once a year Interesting for comparisons:  Vegetation is different than at Horstermeer, while soil profiles are the same

8. Preliminary results

9. Eddy Correlation Energy Balance NEE and Cumulative NEE Yearly NEE = 576 gC/m2 uptake (5.76 ton/hectare) growing season 2005: 24 March to 16 October

10. Flux Chamber measurements: Horstermeerpolder

11. * N 2 O measurements not significant Flux data on land Flux data on water: CH4 very high

12.  Spatially variability over short distances  Groundwater table and CH4 flux are correlated  Temperature and CH4 flux are correlated

13. High CH4 fluxes do not always coincide with high water levels!!

14.  CH4 flux higher along the ditches  High porosity seems to correlate with low CH4 fluxes

15. Flux Chamber measurements: Ruwiel

16.   Continuous measurements of CH4 using eddy- covariance techniques with a tunable diode fast methane analyzer (DLT-100)   Measuring concentration profiles for CO2 (and CH4)   Measuring CH4 fluxes from water surfaces   Further analysis of the relation between CH4 fluxes and water level, water quality, soil temperature, vegetation and soil parameters The Next Years…

17. and…   Analysis of the relation of CH4 and CO2   Relating the eddy-covariance measurements to land use in the Horstermeerpolder, using footprint techniques and GIS   Modeling the data and improving the PEATLAND model

18.  Measurement campaigns  Discussion group  Measurement protocol  Exchange of useful data  Collaborative papers Collaboration with WUR, ECN and Alterra