Recommandé
Recommandé
Contenu connexe
Similaire à The role of non-growing season processes in CH4 and N2O budgets
Similaire à The role of non-growing season processes in CH4 and N2O budgets (20)
Dernier
Dernier (20)
The role of non-growing season processes in CH4 and N2O budgets
- 1. FluxWIN Lona van Delden The role of non-growing season processes in CH4 and N2O budgets in pristine northern ecosystems Lona van Delden (lona.van.delden@awi.de)1, Katharina Jentzsch1, Eeva-Stiina Tuittila2, Timo Vesala3, Claire Treat1 1 Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Potsdam, Germany 2 Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland 3 Institute for Atmospheric and Earth System Research, University of Helsinki, Helsinki, Finland
- 2. FluxWIN – Research Focus Lona van Delden • Non-growing and shoulder seasons • CH4 & N2O measurements are limited (Treat et al., 2018) • Boreal zone • Freeze-thaw dynamics (Pirk et al., 2015) • Annual greenhouse gas (GHG) budgets • Improve process-based models Finland
- 3. FluxWIN – Methods Lona van Delden • Automated static chamber system • 3 micro sites along moisture gradient • 12 chambers • 1 opaque chamber per micro site for ecosystem respiration • In-situ laser gas analysis (Picarro G2508) • 10 min closure time • Continuous CH4, N2O & CO2 in high frequency
- 4. FluxWIN – Methods Lona van Delden • Environmental monitoring in Near-Real-Time • Seasonal soil gas & water biogeochemistry • Plant Root Simulators all year around • Phenological cameras • In-situ vegetation removal experiments • Incubation experiments
- 5. FluxWIN – Site Lona van Delden • Boreal Zone • All year round, freeze- thaw dynamics • Ecosystem along a moisture gradient
- 6. FluxWIN – Upland Forest micro site Lona van Delden • Drained upland Scots Pine forest • Moss and lichen understory • Podzol • Profile depth ⁓60 cm until bedrock
- 7. FluxWIN – Dry Bog micro site Lona van Delden • Intermediate shrubby peat bog • Histosol • moderately to highly decomposed peat • Gap in peat about 20 cm depth due to strongly varying, deep water table • Water table: -25 cm
- 8. FluxWIN – Wet Bog Site Lona van Delden • Sphagnum moss dominated peat bog, slightly decomposed • Histosol • Water table range: + 1 cm to – 8 cm • ⁓ 4 m depth
- 9. FluxWIN – Spring thaw period 2022 Lona van Delden Forest thaw Wet bog thaw • Mean daily air temperatures above 0 C starting April 7th • 10 cm soil temperature: warmest at dry bog, coldest in forest, latest at wet bog
- 10. FluxWIN – CH4 flux, Spring 2022 Lona van Delden • Daily averages based on 4 closure periods per chamber • CH4 emissions from the wet bog after thaw (~May 5th) • Net CH4 oxidation from upland forest 2 cm 10 cm Thaw 10 cm Net release Net uptake Wet bog thaw
- 11. FluxWIN – N2O flux, Spring 2022 Lona van Delden • N2O within detection limit (near zero = no flux), closure time long enough?
- 12. FluxWIN – CO2 exchange, Spring 2022 Lona van Delden • CO2 flux from 3 light chambers • Ecosystem respiration (ER) from 1 opaque chamber per micro site • After thaw, wet bog mosses shorter lag time, resulting in some CO2 uptake while the other sites are releasing CO2 Net release Net uptake
- 13. FluxWIN – Temperature response of CH4, ER Lona van Delden • Sporadic emissions around 0 °C • Temperature response differs by micro-site
- 14. FluxWIN – Outlook Lona van Delden • Captured spring thaw in 2022 • CO2 & CH4 flux respond as soil temperature increases • Varies by micro-site • System fine tuning ongoing - e.g. N2O detection limit • Can detect CH4 oxidation in upland forest! • Further analysis of soil biogeochemistry & pore water soluble gases Conclusion – High-resolution automated chamber measurements are suitable to elucidate possible emission events
- 15. Thank you Lona van Delden AWI FluxWIN Website (https://www.awi.de/en/science/junior-groups/fluxwin.html) AWI Permafrost Region GHG Group https://www.awi.de/en/science/geosciences/permafrost- research/research-focus/permafrost-region-greenhouse- gases.html ERC grant number 851181