Related Experiment Video
Updated: Jun 23, 2025

A CO2 Concentration Gradient Facility for Testing CO2 Enrichment and Soil Effects on Grassland Ecosystem Function
Published on: November 21, 2015
Enhanced decreases in rice evapotranspiration in response to elevated atmospheric carbon dioxide under warmer
Hiroki Ikawa1, Toshihiro Hasegawa2,3, Etsushi Kumagai2,3
1Hokkaido Agricultural Research Center, National Agriculture and Food Research Organization, Sapporo, Hokkaido, Japan.
Abstract:
A short period of exposure to elevated CO2 is known to decrease evapotranspiration via stomatal closure. Based on theoretical evaluation of a canopy transpiration model, we hypothesized that this decrease in the evapotranspiration of rice under elevated CO2 was greater under higher temperature conditions due to an increased sensitivity of transpiration to changes in CO2 induced by the greater vapour pressure deficit. In a temperature gradient chamber-based experiment, a 200 ppm increase in CO2 concentration led to 0.4 mm (-7%) and 1.5 mm (-15%) decreases in 12 h evapotranspiration under ambient temperature and high temperature (+3.7°C) conditions, respectively. Model simulations revealed that the greater vapour pressure deficit under higher temperature conditions explained the variations in the reduction of evapotranspiration observed under elevated CO2 levels between the temperature treatments. Our study suggests the utility of a simple modelling framework for mechanistic understanding of evapotranspiration and crop energy balance system under changing environmental conditions.
More Related Videos
Related Concept Videos
Responses to Drought and Flooding
Global Climate Change
Adaptations that Reduce Water Loss
The Calvin Benson Cycle
C4 Pathway and CAM
C4 Pathway
The C4 pathway is used by plants such as...
The Carbon Cycle

