- 1Institute of Botany of the Czech Academy of Sciences, Průhonice, Czech Republic (Qi.Liu@ibot.cas.cz; Martin.Bouda@ibot.cas.cz)
- 2Silva Tarouca Research Institute for Landscape and Horticulture, Průhonice, Czechia (weger@vukoz.cz)
- 3Department of Botany, Faculty of Science, Charles University, Praha, Czechia (martin.weiser@natur.cuni.cz)
- 4Department of Water Resources, Institute of Hydrodynamics of the Czech Academy of Sciences, Praha, Czechia (sipek@ih.cas.cz)
- 5Department of Plant Ecophysiology, University of Hohenheim, Stuttgart, Germany (Martin.Bouda@ibot.cas.cz)
Increasing drought extremes represent a major stress on ecosystem function through direct impacts on critical plant physiological processes such as transpiration and growth. While the immediate effects of drought are well-documented, vegetation recovery processes and associated time lags in ecosystem function remain poorly understood due to the scarcity of the requisite plant physiological data time series.
This study relates transpiration to evaporative demand, soil moisture, and tree growth during the recovery period following a multiyear drought cluster, centred on the extreme in 2018. High-resolution time-series data were collected with dendrometers, stem sap flow, and soil water potential sensors in a Fagus sylvatica stand located in Pruhonice, Czech Republic.
We found unexpected evidence that transpiration may be xylem-limited during drought recovery by examining the different patterns in transpiration between 2021 (the first major drought recover year at our site) and 2022. During the 2022 (control) season, canopy transpiration achieved a balance between potential evapotranspiration and soil moisture, independent of seasonal stem growth. By contrast, in 2021, we observed an unexpected gradual increase in transpiration over the growing season corresponding to stem incremental growth but independent of soil moisture or potential transpiration. These results indicate that post-drought recovery may involve a feedback loop between growth and transpiration until plants overcome xylem-limitation following drought.
In sum, this study observed surprisingly strong plant carbon-hydraulic feedback during drought recovery. If confirmed, this feedback may prove key to predicting the pathways of plant and soil water status following drought events and their impacts on ecosystem function. The findings also suggest a possibility that plants’ ability to break out of the feedback loop may be a key trait to track when choosing suitable species for future forest management.
How to cite: Liu, Q., Weger, J., Weiser, M., Sipek, V., and Bouda, M.: Life after drought: breaking out of the transpiration-assimilation feedback loop , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16659, https://doi.org/10.5194/egusphere-egu25-16659, 2025.
