stomatal conductance
nounPronunciation: /stoʊˈmætəl kənˈdʌktəns/
Also written as: gs
A measure of the rate of CO₂ entering or water vapor leaving through stomata per unit area of leaf surface.
Full Definition
Stomatal conductance quantifies the ease with which carbon dioxide and water vapor move through leaf stomata, typically measured in mol m⁻² s⁻¹. It reflects the degree of stomatal opening and directly influences photosynthetic gas exchange and transpiration rates. This parameter is crucial for understanding plant water use efficiency and responses to environmental stress. Stomatal conductance varies with environmental conditions including light, humidity, CO₂ concentration, and water availability.
Plain English
How easily air and water vapor can move in and out of tiny pores on plant leaves, which affects how well plants can photosynthesize and manage water loss.
In Editorial Context
A key physiological parameter frequently reported in abiotic stress studies to demonstrate plant responses to drought, salinity, temperature, and other environmental stressors, requiring precise measurement protocols and standardized units.
Etymology & History
Term emerged with development of gas exchange measurement techniques in plant physiology research
Initially measured as resistance, later expressed as conductance with improved instrumentation
Usage
"The manuscript reported a 45% reduction in stomatal conductance under drought conditions, but the authors failed to specify measurement timing and environmental conditions."
Usage note: Always specify units (mol m⁻² s⁻¹) and measurement conditions in research reports
Context: plant physiology, ecophysiology, stress response studies, gas exchange research
Region: international
Style guide notes: Chicago Manual recommends hyphenating when used as compound modifier (stomatal-conductance measurements); AP style prefers no hyphen in noun form
In Context
- "The manuscript's methodology section failed to specify whether stomatal conductance was measured on adaxial or abaxial leaf surfaces."
- "Authors must clarify the units for stomatal conductance measurements before publication can proceed."
- "The reviewer questioned the correlation between stomatal conductance and water use efficiency in the drought treatment."
Also known as
Contrasted with
Don't confuse with
Often confused with transpiration rate, but conductance is the capacity for gas exchange while transpiration is the actual water loss rate
Common mistake: Often confused with stomatal aperture or incorrectly used interchangeably with transpiration rate; units frequently misreported as mol/s instead of mol m⁻² s⁻¹
Related Terms
Broader term: gas exchange
Frequently Asked Questions
What units should be used for stomatal conductance in manuscripts?
Standard units are mol m⁻² s⁻¹ for water vapor or mmol m⁻² s⁻¹, with leaf area as the basis for measurement.
How does stomatal conductance differ from transpiration rate?
Stomatal conductance measures the aperture of stomatal pores, while transpiration rate measures actual water loss from the plant.
Should stomatal conductance be measured on both leaf surfaces?
Yes, when significant stomata are present on both surfaces, or specify which surface was measured in the methodology.
Why Test Candidates on This?
Critical for evaluating candidate ability to review plant physiology manuscripts and ensure proper reporting of gas exchange parameters
Required skill level: Mid