Stomatal sensitivity to VPD across 38 tree species reflects past drought responses but is little explained by stomatal and leaf economic traits
- 1German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Abstract
Climate change is exposing trees to rising atmospheric water demand. Because stomata regulate plant water loss, understanding stomatal behaviour is critical. However, few comparative studies examine species-specific stomatal responses to atmospheric demand. Here, we quantify stomatal behaviour in 38 temperate tree species (27 broadleaved, 11 conifers) in a German research arboretum during a warm summer without soil drought. We measured the diurnal stomatal conductance (gs) of 787 leaves and modelled gs species-specific responses to leaf-to-air vapour pressure deficit (VPDL). Four descriptors of the gs-VPDL relationship were derived: maximum stomatal conductance (gmax), the VPDL that maximises gs, the VPDL associated with a 50% reduction in gs, and the stomatal closure rate. We relate these metrics to drought-induced shifts of carbon isotope ratios and to leaf functional traits. Large variation in stomatal behaviour exists, ranging from early-closure to VPDL-tolerant strategies. Species maintaining gs at higher VPDL also show weaker physiological responses to past drought. gmax is partly explained by leaf economic traits; other gs-VPDL descriptors are not related to stomatal anatomy and leaf economy. Our interspecific comparison reveals substantial variation in stomatal responses to atmospheric demand that is relevant to drought responses, but cannot be readily inferred from commonly measured leaf traits.
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BibTeX
@misc{sachsenmaier2026stomatal,
title = {{Stomatal sensitivity to VPD across 38 tree species reflects past drought responses but is little explained by stomatal and leaf economic traits}},
author = {L. Sachsenmaier and R. Richter and C. Ahner and L. Kretz and A. Kahl and D. Schellenberger Costa and F. Schnabel and I. Staude and M. Sabot and C. Wirth},
howpublished = {bioRxiv},
year = {2026},
month = sep,
doi = {10.64898/2026.09.09.750341},
url = {https://www.biorxiv.org/content/10.64898/2026.09.09.750341v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Stomatal sensitivity to VPD across 38 tree species reflects past drought responses but is little explained by stomatal and leaf economic traits
AU - L. Sachsenmaier
AU - R. Richter
AU - C. Ahner
AU - L. Kretz
AU - A. Kahl
AU - D. Schellenberger Costa
AU - F. Schnabel
AU - I. Staude
AU - M. Sabot
AU - C. Wirth
PY - 2026
DA - 2026/09/09
PB - bioRxiv
DO - 10.64898/2026.09.09.750341
UR - https://www.biorxiv.org/content/10.64898/2026.09.09.750341v1
AB - Climate change is exposing trees to rising atmospheric water demand. Because stomata regulate plant water loss, understanding stomatal behaviour is critical. However, few comparative studies examine species-specific stomatal responses to atmospheric demand. Here, we quantify stomatal behaviour in 38 temperate tree species (27 broadleaved, 11 conifers) in a German research arboretum during a warm summer without soil drought. We measured the diurnal stomatal conductance (gs) of 787 leaves and modelled gs species-specific responses to leaf-to-air vapour pressure deficit (VPDL). Four descriptors of the gs-VPDL relationship were derived: maximum stomatal conductance (gmax), the VPDL that maximises gs, the VPDL associated with a 50% reduction in gs, and the stomatal closure rate. We relate these metrics to drought-induced shifts of carbon isotope ratios and to leaf functional traits. Large variation in stomatal behaviour exists, ranging from early-closure to VPDL-tolerant strategies. Species maintaining gs at higher VPDL also show weaker physiological responses to past drought. gmax is partly explained by leaf economic traits; other gs-VPDL descriptors are not related to stomatal anatomy and leaf economy. Our interspecific comparison reveals substantial variation in stomatal responses to atmospheric demand that is relevant to drought responses, but cannot be readily inferred from commonly measured leaf traits.
ER -