Verdone et al. (2025) Topography Controls the Response of Beech Trees to Atmospheric Demand During Soil Moisture Droughts

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Ecohydrology
• Year: 2025
• Date: 2025-12-01
• Authors: Matteo Verdone, Christian Massari, Ilenia Murgia, Claudia Cocozza, Ilja van Meerveld, Daniele Penna
• DOI: 10.1002/eco.70139

Research Groups

Information not available in the provided abstract.

Short Summary

This study investigated how landscape position (topography and soil moisture) and atmospheric demand (VPD) influence tree transpiration (sap flow) across a forested hillslope in central Italy. It found that hillslope trees experienced decreased sap flow and moderate stress during summer droughts, primarily driven by soil moisture, while riparian trees maintained stable sap flow, primarily influenced by VPD and temperature, due to consistent water availability.

Objective

• To investigate the combined effects of landscape position (topography and related variability in soil moisture) and atmospheric demand (vapour pressure deficit, VPD) on tree sap flow velocities across a forested hillslope to better understand how droughts affect tree transpiration.

Study Configuration

• Spatial Scale: Forested hillslope scale (central Italy).
• Temporal Scale: Daily measurements over a summer period, focusing on the hottest period.

Methodology and Data

• Models used: No specific models were used in this study, but the findings inform the need for improved ecohydrological models.
• Data sources: In-situ measurements of sap flow velocities, soil moisture, vapour pressure deficit (VPD), and temperature.

Main Results

• Sap flow velocities for trees on the upper hillslope decreased during the hottest summer period, while remaining relatively stable for trees in the riparian zone.
• Variation in mean daily sap flow velocity for hillslope trees was best explained by soil moisture variation.
• Variation in mean daily sap flow velocity for riparian zone trees was best explained by variations in VPD and temperature.
• Analysis of the time lag between daily peak VPD and peak sap flow velocity indicated that hillslope trees experienced moderate water stress during periods of low water availability.
• The wet riparian zone effectively limited tree water stress and early stomatal closure in summer.

Contributions

• Highlights the critical need to account for topography and associated hillslope-scale differences in soil moisture when analyzing forest responses to droughts.
• Emphasizes the importance of incorporating these spatial variabilities into catchment- or landscape-scale ecohydrological models for simulating transpiration.
• Provides empirical evidence differentiating drought response mechanisms between hillslope and riparian zone trees within the same catchment.

Funding

Information not available in the provided abstract.

Citation

@article{Verdone2025Topography,
  author = {Verdone, Matteo and Massari, Christian and Murgia, Ilenia and Cocozza, Claudia and Meerveld, Ilja van and Penna, Daniele},
  title = {Topography Controls the Response of Beech Trees to Atmospheric Demand During Soil Moisture Droughts},
  journal = {Ecohydrology},
  year = {2025},
  doi = {10.1002/eco.70139},
  url = {https://doi.org/10.1002/eco.70139}
}