EGU2020-9460
https://doi.org/10.5194/egusphere-egu2020-9460
EGU General Assembly 2020
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Drought effects on the carbon balance and VOC emissions of a tropical rainforest ecosystem

Ines Bamberger1, Lars Erik Daber1, Juliana Gil Loaiza2, Gemma Purser3, Jason De Leeuw2, S. Nemiah Ladd1, Laura Meredith2, Jürgen Kreuzwieser1, and Christiane Werner1
Ines Bamberger et al.
  • 1University of Freiburg, Ecosystem Physiology, Freiburg, Germany (ines.bamberger@cep.uni-freiburg.de)
  • 2School of Natural Resources and the Environment, University of Arizona, Tucson, AZ, USA
  • 3Centre for Ecology & Hydrology (CEH), Edinburgh, Scotland, UK

Trees contribute substantially to the carbon cycling between the biosphere and atmosphere. Tropical ecosystems in particular are known to exchange not only CO2 with the atmosphere, but also a wide variety of volatile organic compounds (VOCs). With their high reactivity and short life time, VOCs are known to play not only a crucial role in atmospheric chemistry but also in plant signaling and interactions. Due to climate change periods of sustained drought are thought to increase in future and have the potential to alter the carbon balance of tropical ecosystems drastically. However, combined VOC and CO2 flux measurements are rare and thus a quantitative understanding of carbon exchange fluxes in rainforest species during and after drought periods has not yet been reached.

Thus, we used the unique opportunity to study changes of VOC and CO2 flux patterns of the rainforest mesocosm of Biosphere 2 (University of Arizona) in response to an experimentally induced drought period and during the recovery (Biosphere 2 Water, Atmosphere, and Life Dynamics experiment; B2-WALD). This provides us novel information about stress responses of a rainforest ecosystem and its ability to recover, specifically to drought stress. Real-time fluxes of CO2 and VOC exchange were measured by means of 13CO2 laser spectroscopy and proton-transfer-reaction time-of-flight mass-spectrometry (PTR-TOF-MS) using leaf chambers on five different tree and understory species.

While photosynthesis decreased during the drought, changes in VOC flux patterns were more diverse. For example, isoprene emissions increased with dry conditions, whereas fluxes of acetone declined. Here we will present and discuss our first results on leaf gas exchange measurements of different VOCs and CO2 and their response to drought and recovery.

How to cite: Bamberger, I., Daber, L. E., Gil Loaiza, J., Purser, G., De Leeuw, J., Ladd, S. N., Meredith, L., Kreuzwieser, J., and Werner, C.: Drought effects on the carbon balance and VOC emissions of a tropical rainforest ecosystem, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9460, https://doi.org/10.5194/egusphere-egu2020-9460, 2020.

This abstract will not be presented.