05 Sep 2023
 | 05 Sep 2023
Status: this preprint is currently under review for the journal BG.

Integration of tree hydraulic processes and functional impairment to capture the drought resilience of a semi-arid pine forest

Daniel Nadal-Sala, Rüdiger Grote, David Kraus, Uri Hochberg, Tamir Klein, Yael Wagner, Fedor Tatarinov, Dan Yakir, and Nadine Katrin Ruehr

Abstract. Drought stress is imposing multiple feedback responses in plants. These responses span from stomata closure and enzymatic downregulation of photosynthetic activity to structural adjustments in leaf area. Some of these processes are not easily reversible and may persist long after the stress ended. Unfortunately, simulation models widely lack an integrative mechanistic description on how this sequence of tree physiological to structural responses occur.

Here, we suggest an integrative approach to simulate drought stress responses. Firstly, a decreasing plant water potential triggers stomatal closure alongside a downregulation of photosynthetic performance. This is followed by a disconnection of roots and soil and the reliance on internal stem water storage or water uptake from deep soil layers. Consistently, loss in hydraulic functioning is reflected in sapwood loss of functionality and foliage senescence. This new model functionality has been used to investigate responses of tree hydraulics, carbon uptake and transpiration to soil- and atmospheric drought in an extremely dry Aleppo pine (Pinus halepensis L.) plantation.

Using the hypothesis of a sequential triggering of stress-mitigating responses, the model was able to reflect the carbon uptake and transpiration patterns under varying soil water supply and atmospheric demand – especially during summer – and responded realistically regarding medium-term responses such as leaf and sapwood senescence. In agreement with the high drought resistance observed at the site our model indicated little loss of hydraulic functioning in Aleppo pine, despite the intensive seasonal summer drought.

Daniel Nadal-Sala et al.

Status: open (until 17 Oct 2023)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse

Daniel Nadal-Sala et al.

Daniel Nadal-Sala et al.


Total article views: 186 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
133 46 7 186 9 5 6
  • HTML: 133
  • PDF: 46
  • XML: 7
  • Total: 186
  • Supplement: 9
  • BibTeX: 5
  • EndNote: 6
Views and downloads (calculated since 05 Sep 2023)
Cumulative views and downloads (calculated since 05 Sep 2023)

Viewed (geographical distribution)

Total article views: 190 (including HTML, PDF, and XML) Thereof 190 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 24 Sep 2023
Short summary
We present an integrative model approach that is based on plant water potential triggering stomatal closure, downregulation of photosynthesis, and sapwood as well as foliage senescence. This new model functionality that can be added to any physiologically based ecosystem model has been evaluated in an extremely dry Aleppo pine plantation. We were able to represent gas exchanges under varying soil water supply and atmospheric demand and the model responded realistically regarding leaf senescence.