Publication Details

Category Text Publication
Reference Category Journals
DOI 10.5194/bg-19-1979-2022
Licence creative commons licence
Title (Primary) The effects of varying drought-heat signatures on terrestrial carbon dynamics and vegetation composition
Author Tschumi, E.; Lienert, S.; van der Wiel, K.; Joos, F.; Zscheischler, J. ORCID logo
Source Titel Biogeosciences
Year 2022
Department CHS
Volume 19
Issue 7
Page From 1979
Page To 1993
Language englisch
Topic T5 Future Landscapes
Data and Software links
Abstract The frequency and severity of droughts and heatwaves are projected to increase under global warming. However, the differential impacts of climate extremes on the terrestrial biosphere and anthropogenic CO2 sink remain poorly understood. In this study, we analyse the effects of six hypothetical climate scenarios with differing drought-heat signatures, sampled from a long stationary climate model simulation, on vegetation distribution and land carbon dynamics, as modelled by a dynamic global vegetation model (LPX-Bern v1.4). The six forcing scenarios consist of a Control scenario representing a natural climate, a Noextremes scenario featuring few droughts and heatwaves, a Nocompound scenario which allows univariate hot or dry extremes but no co-occurring extremes, a Hot scenario with frequent heatwaves, a Dry scenario with frequent droughts, and a Hotdry scenario featuring frequent concurrent hot and dry extremes. We find that a climate with no extreme events increases tree coverage by up to 10 % compared to the Control scenario and also increases ecosystem productivity as well as the terrestrial carbon pools. A climate with many heatwaves leads to an overall increase in tree coverage primarily in higher latitudes, while the ecosystem productivity remains similar to the Control scenario. In the Dry and even more so in the Hotdry scenario, tree cover and ecosystem productivity are reduced by up to 4 % compared to the Control scenario. Regionally, this value can be much larger, for example up to 80 % in mid-western USA or up to 50 % in mid-Eurasia for Hotdry tree ecosystem productivity. Depending on the vegetation type, the effects of the Hotdry scenario are stronger than the effects of the Hot and Dry scenarios combined, illustrating the importance of correctly simulating compound extremes for future impact assessment. Overall, our study illustrates how factorial model experiments can be employed to disentangle the effects of single and compound extremes.
Persistent UFZ Identifier
Tschumi, E., Lienert, S., van der Wiel, K., Joos, F., Zscheischler, J. (2022):
The effects of varying drought-heat signatures on terrestrial carbon dynamics and vegetation composition
Biogeosciences 19 (7), 1979 - 1993 10.5194/bg-19-1979-2022