Transpiration from an Amazonian rainforest calculated from stomatal conductance measurements

John Roberts, Osvaldo M R Cabral, G. Fisch, L. C B Molion, C. J. Moore, W. James Shuttleworth

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

A multi-layer combination equation has been used to calculate transpiration from a tropical rainforest in the central Amazon, Brazil. The five-layer formulation used through-canopy measurements of temperature and humidity deficit with leaf stomatal and boundary layer conductances scaled up to canopy layer values used a profile of canopy leaf area index derived from the literature. Net radiation input to each layer was estimated from an above canopy measurement using an extinction function and leaf area index. Transpiration calculated for hourly and daily periods in a range of seasonal conditions agreed well with those measured directly with an eddy correlation device. Four simplified forms of the transpiration calculation were also compared with the direct measurement. These simplified forms used the above-canopy or the average of the through-canopy values of weather variables and used either the average of leaf conductances multiplied by total leaf area index or the average of the layer conductances. These simplified forms of the transpiration calculation gave poorer agreement with measured transpiration.

Original languageEnglish (US)
Pages (from-to)175-196
Number of pages22
JournalAgricultural and Forest Meteorology
Volume65
Issue number3-4
DOIs
StatePublished - 1993
Externally publishedYes

Fingerprint

stomatal conductance
rainforest
transpiration
rain forests
canopy
leaf area index
leaf conductance
eddy covariance
net radiation
tropical rain forests
humidity
eddy
extinction
weather
boundary layer
Brazil
leaves
temperature

ASJC Scopus subject areas

  • Forestry
  • Atmospheric Science
  • Earth and Planetary Sciences(all)
  • Environmental Science(all)

Cite this

Transpiration from an Amazonian rainforest calculated from stomatal conductance measurements. / Roberts, John; Cabral, Osvaldo M R; Fisch, G.; Molion, L. C B; Moore, C. J.; Shuttleworth, W. James.

In: Agricultural and Forest Meteorology, Vol. 65, No. 3-4, 1993, p. 175-196.

Research output: Contribution to journalArticle

Roberts, John ; Cabral, Osvaldo M R ; Fisch, G. ; Molion, L. C B ; Moore, C. J. ; Shuttleworth, W. James. / Transpiration from an Amazonian rainforest calculated from stomatal conductance measurements. In: Agricultural and Forest Meteorology. 1993 ; Vol. 65, No. 3-4. pp. 175-196.
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