EGU General Assembly 2020
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Using N2O to detect if a tipping point has been crossed in tropical soils after droughts

Simone Kilian Salas1, Elisa Díaz García2, Alberto Andrino2, Katharina H. E. Meurer1,3, Diana Boy4, Marcus Horn4, Jens Boy2, and Hermann Jungkunst1
Simone Kilian Salas et al.
  • 1University of Koblenz-Landau, Institute for Enviromental Sciences, Dep. of Geoecology & Physical Geography, Landau, Germany (
  • 2Leibniz University Hannover, Institute of Soil Science, Hannover, Germany
  • 3Swedish University of Agricultural Sciences, Department of Ecology, Uppsala, Sweden
  • 4Leibniz University Hannover, Institute of Microbiology, Hannover, Germany

The western Amazon is particularly sensitive to drought since precipitation is common even during "dry season". The combination of increasing land use pressure and droughts due to climate change makes the scenario of this ecosystem likely to cross or having crossed tipping points. We argue that nitrous oxide (N2O) emissions can be used to identify the crossing of tipping points in soils, particularly those related to N-cycling. This hypothesis is being tested within the BMBF funded Project PRODIGY, which will show that under stress microbial functional diversity in soils are a safety-net for ecosystems. The survey area (MAP) spreads across three countries (Peru, Brazil and Bolivia). Lab and field experiments are used to test our hypothesis based on the observations that N2O emission under tropical pasture shift after 10 years in use. Pre-measurement modeling is used to optimize measurement designs. Replicated above-ground biodiversity levels (n=4) will be sampled in each country. The soil will also be used for lab drought manipulation experiments to unravel underlying mechanisms. Measured values have shown to be lower than expected and simulated rates. Maybe because tipping points at different spacial and temporal scales are crossed faster than in temperate regions and biogeochemistry is less understood? Results from this investigation will allow the improvement of N2O models for tropical soils.

How to cite: Kilian Salas, S., Díaz García, E., Andrino, A., Meurer, K. H. E., Boy, D., Horn, M., Boy, J., and Jungkunst, H.: Using N2O to detect if a tipping point has been crossed in tropical soils after droughts, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-18405,, 2020

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