Light interception efficiency explained by two simple variables: a test using a diversity of small- to medium-sized woody plants.

• Plant light interception efficiency is a crucial determinant of carbon uptake by individual plants and by vegetation. Our aim was to identify whole-plant variables that summarize complex crown architecture, which can be used to predict light interception efficiency. • We gathered the largest database of digitized plants to date (1831 plants of 124 species), and estimated a measure of light interception efficiency with a detailed three-dimensional model. Light interception efficiency was defined as the ratio of the hemispherically averaged displayed to total leaf area. A simple model was developed that uses only two variables, crown density (the ratio of leaf area to total crown surface area) and leaf dispersion (a measure of the degree of aggregation of leaves). • The model explained 85% of variation in the observed light interception efficiency across the digitized plants. Both whole-plant variables varied across species, with differences in leaf dispersion related to leaf size. Within species, light interception efficiency decreased with total leaf number. This was a result of changes in leaf dispersion, while crown density remained constant. • These results provide the basis for a more general understanding of the role of plant architecture in determining the efficiency of light harvesting.

[1]  Ontogeny, understorey light interception and simulated carbon gain of juvenile rainforest evergreens differing in shade tolerance. , 2011, Annals of botany.

[2]  A.R.G. Lang,et al.  Application of some of Cauchy's theorems to estimation of surface areas of leaves, needles and branches of plants, and light transmittance , 1991 .

[3]  F. Valladares,et al.  A functional analysis of the crown architecture of tropical forest Psychotria species: do species vary in light capture efficiency and consequently in carbon gain and growth? , 2004, Oecologia.

[4]  Daniel S. Falster,et al.  Leaf size and angle vary widely across species: what consequences for light interception? , 2003, The New phytologist.

[5]  A. Takenaka,et al.  Effects of leaf blade narrowness and petiole length on the light capture efficiency of a shoot , 1994, Ecological Research.

[6]  Robert W. Pearcy,et al.  A three-dimensional crown architecture model for assessment of light capture and carbon gain by understory plants , 1996, Oecologia.

[7]  Risto Sievänen,et al.  Height growth strategies in open-grown trees , 1992 .

[8]  David P. Dobkin,et al.  The quickhull algorithm for convex hulls , 1996, TOMS.

[9]  M. Monsi,et al.  On the factor light in plant communities and its importance for matter production. 1953. , 2004, Annals of botany.

[10]  S. Pacala,et al.  A METHOD FOR SCALING VEGETATION DYNAMICS: THE ECOSYSTEM DEMOGRAPHY MODEL (ED) , 2001 .

[11]  Pauline Stenberg,et al.  A note on the G-function for needle leaf canopies , 2006 .

[12]  Peng Gong,et al.  Modeling radiation and photosynthesis of a heterogeneous savanna woodland landscape with a hierarchy of model complexities , 2007 .

[13]  F. A. Bazzaz,et al.  SEEDLING CROWN ORIENTATION AND INTERCEPTION OF DIFFUSE RADIATION IN TROPICAL FOREST GAPS , 1995 .

[14]  P. Stenberg.  Correcting LAI-2000 estimates for the clumping of needles in shoots of conifers , 1996 .

[15]  F. Valladares,et al.  The geometry of light interception by shoots of Heteromeles arbutifolia: morphological and physiological consequences for individual leaves , 1999, Oecologia.

[16]  J. Monteith.  Climate and the efficiency of crop production in Britain , 1977 .

[17]  T. O. Kvålseth.  Cautionary Note about R 2 , 1985 .

[18]  Hervé Sinoquet,et al.  Does shade improve light interception efficiency? A comparison among seedlings from shade-tolerant and -intolerant temperate deciduous tree species. , 2006, The New phytologist.

[19]  Hervé Sinoquet,et al.  Foliage determinants of light interception in sunny and shaded branches of Fagus sylvatica (L.) , 1998 .

[20]  M. Küppers,et al.  Ecological significance of above-ground architectural patterns in woody plants: A question of cost-benefit relationships. , 1989, Trends in ecology & evolution.

[21]  H Sinoquet,et al.  Canopy structure and light interception in Quercus petraea seedlings in relation to light regime and plant density. , 2001, Tree physiology.

[22]  Robert W. Pearcy,et al.  Plastic Phenotypic Response to Light of 16 Congeneric Shrubs From a Panamanian Rainforest , 2000 .

[23]  T. Nilson.  A theoretical analysis of the frequency of gaps in plant stands , 1971 .

[24]  Tiit Nilson,et al.  Inversion of gap frequency data in forest stands , 1999 .

[25]  Dennis D. Baldocchi,et al.  Canopy radiative transfer models for spherical and known leaf inclination angle distributions: a test in an oak-hickory forest , 1985 .

[26]  M. Monsi.  Uber den Lichtfaktor in den Pflanzengesellschaften und seine Bedeutung fur die Stoffproduktion , 1953 .

[27]  A. Mäkelä,et al.  Self-shading affects allometric scaling in trees , 2010 .

[28]  Fernando Valladares,et al.  The Architecture of Plant Crowns , 2007 .

[29]  M. Cannell,et al.  Radiation Interception and Productivity of Willow , 1987 .

[30]  P. Reich,et al.  Controls on declining carbon balance with leaf age among 10 woody species in Australian woodland: do leaves have zero daily net carbon balances when they die? , 2009, The New phytologist.

[31]  John M. Norman,et al.  Characterization of radiation regimes in nonrandom forest canopies: theory, measurements, and a simplified modeling approach. , 1999, Tree physiology.

[32]  J. Phattaralerphong,et al.  Foliage randomness and light interception in 3-D digitized trees: an analysis from multiscale discretization of the canopy , 2005 .

[33]  A. Mäkelä,et al.  Summary models for light interception and light-use efficiency of non-homogeneous canopies. , 2007, Tree physiology.

[34]  B. Andrieu,et al.  Functional-structural plant modelling: a new versatile tool in crop science. , 2010, Journal of experimental botany.

[35]  J. Ross.  The radiation regime and architecture of plant stands , 1981, Tasks for vegetation sciences 3.

[36]  D. Whitehead,et al.  Architectural distribution of foliage in individual Pinus radiata D. Don crowns and the effects of clumping on radiation interception. , 1990, Tree physiology.

[37]  Fernando Valladares,et al.  Implications of opposite phyllotaxis for light interception efficiency of Mediterranean woody plants , 2005, Trees.

[38]  Feike Schieving,et al.  3-D GROWTH PATTERNS OF TREES: EFFECTS OF CARBON ECONOMY, MERISTEM ACTIVITY, AND SELECTION , 2007 .

[39]  Fernando Valladares,et al.  Convergence in light capture efficiencies among tropical forest understory plants with contrasting crown architectures: a case of morphological compensation. , 2002, American journal of botany.

[40]  Annikki Mäkelä,et al.  Bridging process-based and empirical approaches to modeling tree growth. , 2005, Tree physiology.

[41]  A. Rabinovitch,et al.  A simple model of light transmission through metachronally moving cilia , 1990 .

[42]  A. Kitchen,et al.  Cautionary Note , 2000, Vox sanguinis.

[43]  Alessandro Cescatti,et al.  Light capture efficiency decreases with increasing tree age and size in the southern hemisphere gymnosperm Agathis australis , 2005, Trees.

[44]  G. Campbell,et al.  An Introduction to Environmental Biophysics , 1977 .

[45]  R. Zorer,et al.  Structural acclimation and radiation regime of silver fir (Abies alba Mill.) shoots along a light gradient , 2003 .

[46]  D. Barthélémy,et al.  Plant architecture: a dynamic, multilevel and comprehensive approach to plant form, structure and ontogeny. , 2007, Annals of botany.

[47]  Annikki Mäkelä,et al.  A carbon balance model of growth and self-pruning in trees based on structural relationships , 1997 .

[48]  F. Valladares,et al.  Functional and evolutionary correlations of steep leaf angles in the mexical shrubland , 2010, Oecologia.

[49]  N. Kiang,et al.  A clumped-foliage canopy radiative transfer model for a global dynamic terrestrial ecosystem model. I: Theory , 2010 .

[50]  Ontogenetic variation in light interception, self-shading and biomass distribution of seedlings of the conifer Araucaria araucana (Molina) K. Koch , 2006 .

[51]  K. Nakaseko,et al.  Canopy structure and light interception in potato plant , 1984 .

[52]  Heikki Smolander,et al.  The Ratio of Shoot Silhouette Area to Total Needle Area in Scots Pine , 1988, Forest Science.

[53]  F. Pugnaire,et al.  Functional Plant Ecology , 2007 .

[54]  P. Stenberg.  Implications of shoot structure on the rate of photosynthesis at different levels in a coniferous canopy using a model incorporating grouping and penumbra , 1998 .

[55]  M. Westoby,et al.  Bivariate line‐fitting methods for allometry , 2006, Biological reviews of the Cambridge Philosophical Society.

[56]  H. Sinoquet,et al.  Simple equations to estimate light interception by isolated trees from canopy structure features: assessment with three-dimensional digitized apple trees. , 2007, The New phytologist.

[57]  Hiroyuki Muraoka,et al.  Crown architecture in sun and shade environments: assessing function and trade-offs with a three-dimensional simulation model. , 2005, The New phytologist.

[58]  J. W. Palmer,et al.  A Simple Model of Light Transmission and Interception by Discontinuous Canopies , 1979 .

[59]  Fernando Valladares,et al.  Photoinhibition and drought in Mediterranean woody saplings: scaling effects and interactions in sun and shade phenotypes. , 2004, Journal of experimental botany.

[60]  P. Tomlinson,et al.  Tropical Trees and Forests: An Architectural Analysis , 1978 .

[61]  Prof. Dr. Francis Hallé,et al.  Tropical Trees and Forests , 1978, Springer Berlin Heidelberg.

[62]  Robert W. Pearcy,et al.  The functional ecology of shoot architecture in sun and shade plants of Heteromeles arbutifolia M. Roem., a Californian chaparral shrub , 1998, Oecologia.

[63]  Alessandro Cescatti,et al.  Effects of needle clumping in shoots and crowns on the radiative regime of a Norway spruce canopy , 1998 .

[64]  H Sinoquet,et al.  Contributions of foliage distribution and leaf functions to light interception, transpiration and photosynthetic capacities in two apple cultivars at branch and tree scales. , 2008, Tree physiology.

[65]  R. W. Pearcy,et al.  Petiole twisting in the crowns of Psychotria limonensis: implications for light interception and daily carbon gain , 2003, Oecologia.