EFFECTS OF ELEVATED ATMOSPHERIC CO{sub 2} ON CANOPY TRANSPIRATION IN SENESCENT SPRING WHEAT

PDF Version Also Available for Download.

Description

The seasonal course of canopy transpiration and the diurnal courses of latent heat flux of a spring wheat crop were simulated for atmospheric CO{sub 2} concentrations of 370 {micro}mol mol{sup {minus}1} and 550 {micro}mol mol{sup {minus}1}. The hourly weather data, soil parameters and the irrigation and fertilizer treatments of the Free-Air Carbon Dioxide Enrichment wheat experiment in Arizona (1992/93) were used to drive the model. The simulation results were tested against field measurements with special emphasis on the period between anthesis and maturity. A model integrating leaf photosynthesis and stomatal conductance was scaled to a canopy level in order to ... continued below

Physical Description

46 pages

Creation Information

GROSSMAN,S.; KIMBALL,B.A.; HUNSAKER,D.J.; LONG,S.P.; GARCIA,R.L.; KARTSCHALL,TH. et al. December 31, 1998.

Context

This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Description

The seasonal course of canopy transpiration and the diurnal courses of latent heat flux of a spring wheat crop were simulated for atmospheric CO{sub 2} concentrations of 370 {micro}mol mol{sup {minus}1} and 550 {micro}mol mol{sup {minus}1}. The hourly weather data, soil parameters and the irrigation and fertilizer treatments of the Free-Air Carbon Dioxide Enrichment wheat experiment in Arizona (1992/93) were used to drive the model. The simulation results were tested against field measurements with special emphasis on the period between anthesis and maturity. A model integrating leaf photosynthesis and stomatal conductance was scaled to a canopy level in order to be used in the wheat growth model. The simulated intercellular CO{sub 2} concentration, C{sub i} was determined from the ratio of C{sub i} to the CO{sub 2} concentration at the leaf surface, C{sub s} the leaf to air specific humidity deficit and a possibly unfulfilled transpiration demand. After anthesis, the measured assimilation rates of the flag leaves decreased more rapidly than their stomatal conductances, leading to a rise in the C{sub i}/C{sub s} ratio. In order to describe this observation, an empirical model approach was developed which took into account the leaf nitrogen content for the calculation of the C{sub i}/C{sub s} ratio. Simulation results obtained with the new model version were in good agreement with the measurements. If changes in the C{sub i}/C{sub s} ratio accorded to the decrease in leaf nitrogen content during leaf senescence were not considered in the model, simulations revealed an underestimation of the daily canopy transpiration of up to 20% and a decrease in simulated seasonal canopy transpiration by 10%. The measured reduction in the seasonal sum of canopy transpiration and soil evaporation owing to CO{sub 2} enrichment, in comparison, was only about 5%.

Physical Description

46 pages

Notes

OSTI as DE00758982

Source

  • Other Information: PBD: 31 Dec 1998

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • Report No.: BNL--66146
  • Report No.: KP120302
  • Grant Number: AC02-98CH10886
  • DOI: 10.2172/758982 | External Link
  • Office of Scientific & Technical Information Report Number: 758982
  • Archival Resource Key: ark:/67531/metadc708096

Collections

This report is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • December 31, 1998

Added to The UNT Digital Library

  • Sept. 12, 2015, 6:31 a.m.

Description Last Updated

  • Nov. 9, 2015, 7:51 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 3

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

GROSSMAN,S.; KIMBALL,B.A.; HUNSAKER,D.J.; LONG,S.P.; GARCIA,R.L.; KARTSCHALL,TH. et al. EFFECTS OF ELEVATED ATMOSPHERIC CO{sub 2} ON CANOPY TRANSPIRATION IN SENESCENT SPRING WHEAT, report, December 31, 1998; Upton, New York. (digital.library.unt.edu/ark:/67531/metadc708096/: accessed October 24, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.