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Effect of variations of PAR on CO2 exchange estimation for Scots pine

Publication ,  Journal Article
Vesala, T; Markkanen, T; Palva, L; Siivola, E; Palmroth, S; Hari, P
Published in: Agricultural and Forest Meteorology
February 25, 2000

A set-up with 161 photosynthetically active radiation (PAR) sensors was used to investigate spatio-temporal variations of irradiance for five horizontal arrays within a Scots pine canopy. The measured PAR was converted to CO2 exchange using of a shoot-scale photosynthetic response curve and the vertical distribution of the needle area. The net ecosystem exchange was simultaneously measured by the eddy covariance technique. The effect of spatial and temporal averaging of the PAR values and the number of sensors were analysed under different conditions as regards cloudiness and the shading by the foliage. In 1/2 h CO2 exchange values for the entire canopy, a maximum overestimation of 30% resulted from a spatial averaging over horizontal arrays of 2-5 m and occurred under clear-sky conditions and significant foliage shading. Under partly cloudy conditions, the largest overestimation occurred for a case of little shading and the inaccuracy resulting from 1/2 h temporal averaging exceeded that of spatial averaging. (C) 2000 Elsevier Science B.V.

Duke Scholars

Published In

Agricultural and Forest Meteorology

DOI

ISSN

0168-1923

Publication Date

February 25, 2000

Volume

100

Issue

4

Start / End Page

337 / 347

Related Subject Headings

  • Meteorology & Atmospheric Sciences
  • 37 Earth sciences
  • 31 Biological sciences
  • 30 Agricultural, veterinary and food sciences
  • 07 Agricultural and Veterinary Sciences
  • 06 Biological Sciences
  • 04 Earth Sciences
 

Citation

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Vesala, T., Markkanen, T., Palva, L., Siivola, E., Palmroth, S., & Hari, P. (2000). Effect of variations of PAR on CO2 exchange estimation for Scots pine. Agricultural and Forest Meteorology, 100(4), 337–347. https://doi.org/10.1016/S0168-1923(99)00146-X
Vesala, T., T. Markkanen, L. Palva, E. Siivola, S. Palmroth, and P. Hari. “Effect of variations of PAR on CO2 exchange estimation for Scots pine.” Agricultural and Forest Meteorology 100, no. 4 (February 25, 2000): 337–47. https://doi.org/10.1016/S0168-1923(99)00146-X.
Vesala T, Markkanen T, Palva L, Siivola E, Palmroth S, Hari P. Effect of variations of PAR on CO2 exchange estimation for Scots pine. Agricultural and Forest Meteorology. 2000 Feb 25;100(4):337–47.
Vesala, T., et al. “Effect of variations of PAR on CO2 exchange estimation for Scots pine.” Agricultural and Forest Meteorology, vol. 100, no. 4, Feb. 2000, pp. 337–47. Scopus, doi:10.1016/S0168-1923(99)00146-X.
Vesala T, Markkanen T, Palva L, Siivola E, Palmroth S, Hari P. Effect of variations of PAR on CO2 exchange estimation for Scots pine. Agricultural and Forest Meteorology. 2000 Feb 25;100(4):337–347.
Journal cover image

Published In

Agricultural and Forest Meteorology

DOI

ISSN

0168-1923

Publication Date

February 25, 2000

Volume

100

Issue

4

Start / End Page

337 / 347

Related Subject Headings

  • Meteorology & Atmospheric Sciences
  • 37 Earth sciences
  • 31 Biological sciences
  • 30 Agricultural, veterinary and food sciences
  • 07 Agricultural and Veterinary Sciences
  • 06 Biological Sciences
  • 04 Earth Sciences