Claim · model-written summary
Fossil Salix herbacea leaves showed lower stomatal density as CO2 rose over a glacial cycle covering 140,000 years.
- Taxon
- Salix herbacea
Salix herbaceae0 - Organ / stage
- leavese0
- Outcome
- stomatal densitye0
- Direction
- decreasee0
- Qualifier
- last 140 000 yearse0
Not reportedMaterialGeneCompoundInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorSettingValue
Organisms pictured · Representative pictures of the matched species, not figures from the paper.

Verbatim
e0“Measurements of stomatal density on fossil leaves of Salix herbacea through a glacial cycle covering the last 140 000 years have shown a decrease in stomatal density in response to the rising CO 2 levels of this period.”
Title
Evolutionary responses of stomatal density to global CO2 change
DAVID J. BEERLING; WILLIAM G. CHALONER Biological Journal of the Linnean Society 1993. doi:10.1111/j.1095-8312.1993.tb02096.x
Other claims from this paper (4)
- Association Herbarium tree leaves showed declining stomatal density as CO2 rose over the last 200 years.
- Mechanism The authors interpret long-term selection as possibly favoring a response similar to the shorter-term phenotypic response in trees.
- Mechanism The authors propose improved water use efficiency under elevated CO2 as the main selective force affecting genetic control of stomatal density.
- Recommendation The authors recommend considering natural selection when extrapolating short-term stomatal responses to long-term climatic and atmospheric change.