Foliage randomness and light interception in 3-D digitized trees: an analysis from multiscale discretization of the canopy Export

@article{citeulike:297498, abstract = {Light models for vegetation canopies based on the turbid medium analogy are usually limited by the basic assumption of random foliage dispersion in the canopy space. The objective of this paper was to assess the effect of three possible sources of non-randomness in tree canopies on light interception properties. For this purpose, four three-dimensional (3-D) digitized trees and four theoretical canopies 2013 one random and three built from fractal rules 2013 were used to compute canopy structure parameters and light interception, namely the sky-vault averaged STAR (Silhouette to Total Area Ratio). STAR values were computed from (1) images of the 3-D plants, and (2) from a 3-D turbid medium model using space discretization at different scales. For all trees, departure from randomness was mainly due to the spatial variations in leaf area density within the canopy volume. Indeed STAR estimations, based on turbid medium assumption, using the finest space discretization were very close to STAR values computed from the plant images. At this finest scale, foliage dispersion was slightly clumped, except one theoretical fractal canopy, which showed a marked regular dispersion. Taking into account a non-infinitely small leaf size, whose effect is theoretically to shorten self-shading, had a minor effect on STAR computations. STAR values computed from the 3-D turbid medium were very sensitive to plant lacunarity, a parameter introduced in the context of fractal studies to characterize the distribution of gaps in porous media at different scales. This study shows that 3-D turbid medium models based on space discretization are able to give correct estimation of light interception by 3-D isolated trees, provided that the 3-D grid is properly defined, that is, discretization maximizes plant lacunarity.}, address = {UMR PIAF INRA-UBP, Site de Crouelle, 234 Avenue du Brzet, 63039 Clermont-Ferrand Cedex 2, France, ; Kasetsart University, Faculty of Science, Department of Botany, Bangkok, Thailand and ; INRIA, UMR AMAP, TA40PSII, Boulevard de la Lironde, 34398 Montpellier Cedex 5, France}, author = {Sinoquet, H. and Sonohat, G. and Phattaralerphong, J. and Godin, C.}, citeulike-article-id = {297498}, citeulike-linkout-0 = {http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-3040.2005.01353.x}, citeulike-linkout-1 = {http://dx.doi.org/10.1111/j.1365-3040.2005.01353.x}, citeulike-linkout-2 = {http://www.ingentaconnect.com/content/bsc/pce/2005/00000028/00000009/art00009}, citeulike-linkout-3 = {http://www3.interscience.wiley.com/cgi-bin/abstract/118693926/ABSTRACT}, doi = {10.1111/j.1365-3040.2005.01353.x}, issn = {1365-3040}, journal = {Plant, Cell \& Environment}, keywords = {canopy, gap-frequency, light-interception, multi-scale}, month = {September}, number = {9}, pages = {1158--1170}, posted-at = {2006-04-25 18:03:10}, priority = {0}, publisher = {Blackwell Publishing}, title = {Foliage randomness and light interception in 3-D digitized trees: an analysis from multiscale discretization of the canopy}, url = {http://dx.doi.org/10.1111/j.1365-3040.2005.01353.x}, volume = {28}, year = {2005} }

TY - JOUR ID - citeulike:297498 L3 - citeulike-article-id:297498 N2 - Light models for vegetation canopies based on the turbid medium analogy are usually limited by the basic assumption of random foliage dispersion in the canopy space. The objective of this paper was to assess the effect of three possible sources of non-randomness in tree canopies on light interception properties. For this purpose, four three-dimensional (3-D) digitized trees and four theoretical canopies 2013 one random and three built from fractal rules 2013 were used to compute canopy structure parameters and light interception, namely the sky-vault averaged STAR (Silhouette to Total Area Ratio). STAR values were computed from (1) images of the 3-D plants, and (2) from a 3-D turbid medium model using space discretization at different scales. For all trees, departure from randomness was mainly due to the spatial variations in leaf area density within the canopy volume. Indeed STAR estimations, based on turbid medium assumption, using the finest space discretization were very close to STAR values computed from the plant images. At this finest scale, foliage dispersion was slightly clumped, except one theoretical fractal canopy, which showed a marked regular dispersion. Taking into account a non-infinitely small leaf size, whose effect is theoretically to shorten self-shading, had a minor effect on STAR computations. STAR values computed from the 3-D turbid medium were very sensitive to plant lacunarity, a parameter introduced in the context of fractal studies to characterize the distribution of gaps in porous media at different scales. This study shows that 3-D turbid medium models based on space discretization are able to give correct estimation of light interception by 3-D isolated trees, provided that the 3-D grid is properly defined, that is, discretization maximizes plant lacunarity. IS - 9 JF - Plant, Cell & Environment SN - 1365-3040 AD - UMR PIAF INRA-UBP, Site de Crouelle, 234 Avenue du Brzet, 63039 Clermont-Ferrand Cedex 2, France, ; Kasetsart University, Faculty of Science, Department of Botany, Bangkok, Thailand and ; INRIA, UMR AMAP, TA40PSII, Boulevard de la Lironde, 34398 Montpellier Cedex 5, France EP - 1170 TI - Foliage randomness and light interception in 3-D digitized trees: an analysis from multiscale discretization of the canopy PB - Blackwell Publishing VL - 28 SP - 1158 KW - canopy KW - gap-frequency KW - light-interception KW - multi-scale AU - Sinoquet, H AU - Sonohat, G AU - Phattaralerphong, J AU - Godin, C PY - 2005/09// UR - http://dx.doi.org/10.1111/j.1365-3040.2005.01353.x ER -