Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands

Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands The feasibility of detecting the seasonal variation in leaf area index (LAI) in boreal conifer forests is investigated using optical instruments. The LAI of six stands was measured. They include young and old jack pine ( Pinus banksiana ) and old black spruce ( Picea mariana ) located near the southern border (near Prince Albert, Saskatchewan) and near the northern border (near Thompson, Manitoba) of the Canadian boreal ecotone. LAI values of the stands are obtained by making several corrections to the effective LAI measured from the LI-COR LAI-2000 Plant Canopy Analyzer (PCA). The corrections include a foliage element (shoot) clumping index (for clumping at scales larger than the shoot) measured using the optical instrument TRAC (Tracing Radiation and Architecture of Canopies) developed by Chen and Cihlar (Chen, J.M. and Cihlar, J., 1995a, Plant canopy gap size analysis theory for improving optical measurements of leaf area index of plant canopies, Appl. Opt., 34: 6211–6222), a needle-to-shoot area ratio (for clumping within the shoot) obtained from shoot samples, and a woody-to-total area ratio obtained through destructive sampling of trees. It is found that the effective LAI varied about 5% to 10% in the growing season and the element clumping index remained almost unchanged. The needle-to-shoot area ratio varied the most, about 15% to 25%, which is of the same order of magnitude as the expected seasonal variability in LAI. This demonstrates that most of the seasonal variation information is contained in the needle-to-shoot area ratio, which can not be measured indirectly using in situ optical instruments and has to be obtained from a large quantity of shoot sample analysis which is laborious and error-prone. Based on our experience, an improved and convenient shoot sampling strategy is suggested for future studies. The optically-based LAI values were compared with destructive sampling results for three of the stands. Based on error analysis, we believe that optical measurements combined with shoot sample analysis can produce LAI values for conifer stands which are more accurate than destructive sampling results. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Agricultural and Forest Meteorology Elsevier

Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands

Chen, Jing M.
Agricultural and Forest Meteorology, Volume 80 (2) – Jul 1, 1996
29 pages
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Publisher
Elsevier
Copyright
Copyright © 1996 Elsevier Ltd
ISSN
0168-1923
DOI
10.1016/0168-1923(95)02291-0
Publisher site
See Article on Publisher Site

Abstract

The feasibility of detecting the seasonal variation in leaf area index (LAI) in boreal conifer forests is investigated using optical instruments. The LAI of six stands was measured. They include young and old jack pine ( Pinus banksiana ) and old black spruce ( Picea mariana ) located near the southern border (near Prince Albert, Saskatchewan) and near the northern border (near Thompson, Manitoba) of the Canadian boreal ecotone. LAI values of the stands are obtained by making several corrections to the effective LAI measured from the LI-COR LAI-2000 Plant Canopy Analyzer (PCA). The corrections include a foliage element (shoot) clumping index (for clumping at scales larger than the shoot) measured using the optical instrument TRAC (Tracing Radiation and Architecture of Canopies) developed by Chen and Cihlar (Chen, J.M. and Cihlar, J., 1995a, Plant canopy gap size analysis theory for improving optical measurements of leaf area index of plant canopies, Appl. Opt., 34: 6211–6222), a needle-to-shoot area ratio (for clumping within the shoot) obtained from shoot samples, and a woody-to-total area ratio obtained through destructive sampling of trees. It is found that the effective LAI varied about 5% to 10% in the growing season and the element clumping index remained almost unchanged. The needle-to-shoot area ratio varied the most, about 15% to 25%, which is of the same order of magnitude as the expected seasonal variability in LAI. This demonstrates that most of the seasonal variation information is contained in the needle-to-shoot area ratio, which can not be measured indirectly using in situ optical instruments and has to be obtained from a large quantity of shoot sample analysis which is laborious and error-prone. Based on our experience, an improved and convenient shoot sampling strategy is suggested for future studies. The optically-based LAI values were compared with destructive sampling results for three of the stands. Based on error analysis, we believe that optical measurements combined with shoot sample analysis can produce LAI values for conifer stands which are more accurate than destructive sampling results.

Journal

Agricultural and Forest Meteorology – Elsevier

Published: Jul 1, 1996

References

  • Canopy radiative transfer models for spherical and known leaf inclination distribution angles: a test in an oak hickory forest
    Baldocchi, D.D.; Hutchison, B.A.; Matt, D.R.; McMillen, R.T.
  • Importance of leaf area index and forest type when estimating photosynthesis in boreal forests
    Bonan, G.B.
  • Evaluation of hemispherical photography for determining plant area index and geometry of a forest stand
    Chen, J.M.; Black, T.A.; Adams, R.S.
  • Measuring leaf area index of plant canopies with branch architecture
    Chen, J.M.; Black, T.A.
  • Foliage area and architecture of plant canopies from sunfleck size distributions
    Chen, J.M.; Black, T.A.
  • Defining leaf area index for non-flat leaves
    Chen, J.M.; Black, T.A.
    Bookmark
  • Plant canopy gap size analysis theory for improving optical measurements of leaf area index of plant canopies
    Chen, J.M.; Cihlar, J.
  • Quantifying the effect of canopy architecture on optical measurements of leaf area index using two gap size analysis methods
    Chen, J.M.; Cihlar, J.
  • Retreiving leaf area index of boreal conifer forests using Landsat TM images
    Chen, J.M.; Cihlar, J.
  • Identification of contaminated pixels in AV14RR composite images for studies of land biosphere
    Cihlar, J.
  • Measuring leaf area index with the LI-COR LAI-2000 in pine stands
    Deblonde, G.; Penner, M.; Royer, A.
  • A comparison of optical and direct methods for estimating foliage surface area index in forests
    Fassnacht, K.; Gower, S.T.; Norman, J.M.; McMurtrie, R.E.
  • Rapid estimation of leaf area index in forests using the LI-COR LAI-2000
    Gower, S.T.; Norman, J.M.
  • Application of some of Cauchy's theorems to estimation of surface areas of leaves, needles and branches of plants, and light transmittance
    Lang, A.R.G.
  • Shoot structure, leaf area index and productivity of evergreen conifer stands
    Leverenz, J.W.; Hinckley, T.M.
  • A formula for average foliage density
    Miller, J.B.
  • A sunfleck theory for plant canopies. I. Lengths of sunlit segments along a transect
    Miller, E.E.; Norman, J.M.
  • A theoretical analysis of the frequency of gaps in plant stands
    Nilson, T.
  • Photosynthesis in Sitka spruce ( Picea sitchensis (Bong.) Carr.). Part III. Measurement of canopy structure and interception of radiation
    Norman, J.M.; Jarvis, P.G.
  • Photosynthetic radiation regime and canopy structure in modeled forest stands
    Oker-Blom, P.
  • Architecture of Scots pine crown: Phytometrical characteristics of needles and shoots
    Ross, J.; Kellomaki, S.; Oker-Blom, P.; Ross, V.; Vilikainen, L.
  • Generalization of a forest ecosystem process model for other biomes, BIOME-BGC, and an application of global scales
    Running, S.W.; Hunt, E.R.
  • A simple biosphere model (SiB) for use within general circulation models
    Sellers, P.J.; Mintz, Y.; Sud, Y.C.; Dalcher, A.
  • Effects of clumping on estimates of stand leaf area index using the LI-COR LAI-2000
    Smith, N.J.; Chen, J.M.; Black, T.A.
  • Performance of the LAI-2000 plant canopy analyzer in estimating leaf area index of some Scots pine stands
    Stenberg, P.; Linder, S.; Smolander, H.; Flower-Ellis, J.
  • The seasonal trends of AVHRR data of temperate coniferous forests: relationship with leaf area index
    Spanner, M.A.; Pierce, L.L.; Running, S.W.; Peterson, D.L.

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