Stomatal responses of herbaceous plants to climate change since the 1800s: A case study using herbarium specimens
Abstract
Background and Aims: As climate change accelerates, plants are expected to respond in myriad ways, such as shifting phenology or altering the density or size of stomata. Nonetheless, most studies to date have focused on just a single facet at a time. Methods: Here, we used herbarium specimens to examine stomatal responses to climate change in two perennial herbaceous species that have not shifted flowering time across the past century, Oenothera macrocarpa (Onagraceae) and Viola sororia (Violaceae). These trends were evaluated across time and in relation to three major climate drivers: temperature, precipitation, and atmospheric CO2 concentrations. Key Results: Stomatal lengths in O. macrocarpa became smaller, significantly changing by -0.345 μm per decade (95% confidence intervals: -0.505 to -0.184), amounting to a ~17.5% reduction in size from the 1880s to the present. Otherwise, stomatal densities and lengths did not change significantly over time and were unrelated to temperature, precipitation, and atmospheric CO2, except for a marginally significant decline in O. macrocarpa stomatal length with CO2. Conclusions: Previous research on stomatal trends obtained from herbarium specimens across time have largely focused on trees, while the stomatal response of herbaceous plants to climate change has been relatively understudied. These findings demonstrate that species lacking a phenological response to climate change may exhibit other types of response, such as decreased stomatal size. Accordingly, this study underscores the importance of simultaneously investigating the response of multiple morphological and physiological facets for a more holistic understanding of how climate change influences species.
Related
- Molecular Data From Herbarium Specimens Reveal A Potential Extirpation of Azolla microphylla From California
- Towards understanding stomatal decoupling under extreme heat: integrating stomatal kinetics, leaf light responses, and the role of stomatal versus cuticular conductance
- Stomatal sensitivity to VPD across 38 tree species reflects past drought responses but is little explained by stomatal and leaf economic traits
- Contrasting responses to climate change in two Dianthus species of the Irano-Anatolian biodiversity hotspot
- Growth, Antioxidant, and Physiological Responses Associated with Tuber Yield in Cassava Under Irrigation and Late-Season Drought Conditions in a Tropical Savanna Climate
BibTeX
@misc{richardson2026stomatal,
title = {{Stomatal responses of herbaceous plants to climate change since the 1800s: A case study using herbarium specimens}},
author = {Nia Richardson and Léa Vilna-Santos and Axel Cortes and Mia Gaughan and Adam B. Smith and Matthew Austin},
howpublished = {EcoEvoRxiv},
year = {2026},
month = sep,
doi = {10.32942/x2mm6p},
url = {https://ecoevorxiv.org/repository/view/15084/},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - UNPB
TI - Stomatal responses of herbaceous plants to climate change since the 1800s: A case study using herbarium specimens
AU - Nia Richardson
AU - Léa Vilna-Santos
AU - Axel Cortes
AU - Mia Gaughan
AU - Adam B. Smith
AU - Matthew Austin
PY - 2026
DA - 2026/09/22
PB - EcoEvoRxiv
DO - 10.32942/x2mm6p
UR - https://ecoevorxiv.org/repository/view/15084/
AB - Background and Aims: As climate change accelerates, plants are expected to respond in myriad ways, such as shifting phenology or altering the density or size of stomata. Nonetheless, most studies to date have focused on just a single facet at a time. Methods: Here, we used herbarium specimens to examine stomatal responses to climate change in two perennial herbaceous species that have not shifted flowering time across the past century, Oenothera macrocarpa (Onagraceae) and Viola sororia (Violaceae). These trends were evaluated across time and in relation to three major climate drivers: temperature, precipitation, and atmospheric CO2 concentrations. Key Results: Stomatal lengths in O. macrocarpa became smaller, significantly changing by -0.345 μm per decade (95% confidence intervals: -0.505 to -0.184), amounting to a ~17.5% reduction in size from the 1880s to the present. Otherwise, stomatal densities and lengths did not change significantly over time and were unrelated to temperature, precipitation, and atmospheric CO2, except for a marginally significant decline in O. macrocarpa stomatal length with CO2. Conclusions: Previous research on stomatal trends obtained from herbarium specimens across time have largely focused on trees, while the stomatal response of herbaceous plants to climate change has been relatively understudied. These findings demonstrate that species lacking a phenological response to climate change may exhibit other types of response, such as decreased stomatal size. Accordingly, this study underscores the importance of simultaneously investigating the response of multiple morphological and physiological facets for a more holistic understanding of how climate change influences species.
ER -