Physiological basis of the light use efficiency model.

The observation that, for unstressed plants, light use efficiency of a plant canopy, defined as the ratio of net primary productivity (NPP) to absorbed photosynthetically active radiation (APAR), is approximately constant with respect to changes in APAR, implies that NPP can be modeled using a linear relationship with APAR. However, such a linear relationship is counter-intuitive because the relationship between leaf photosynthesis and absorbed light is strongly nonlinear. Three arguments have been advanced to explain the observed linear relationship between NPP and APAR. In this paper, a detailed, physiologically based model of canopy radiation absorption and photosynthesis (MAESTRO) was used to analyze these arguments. The first argument is that the canopy is structured so that radiation is distributed throughout the canopy such that most leaves are exposed to non-saturating quantum flux density, resulting in a linear response of canopy photosynthesis to APAR. Simulations of MAESTRO indicated that this explanation is inadequate, because daily values of canopy photosynthetic light use efficiency calculated with MAESTRO were highly variable regardless of canopy structure. The second argument is that variability in light use efficiency decreases with increasing time scale. The simulations showed that this is true to some extent, although simulated annual canopy photosynthetic light use efficiency still varies across sites with different LAI or light climate. The third argument is that changes in canopy nitrogen content act both to maximize net canopy photosynthesis and to keep light use efficiency constant. This argument could not be tested with the model, but the failure of the first two explanations suggests that this third explanation deserves closer attention.

[1]  J. Monteith.  SOLAR RADIATION AND PRODUCTIVITY IN TROPICAL ECOSYSTEMS , 1972 .

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

[3]  A. Moore.  Encyclopaedia of plant physiology - new series: Volume 3 Edited by C. R. Stocking and U. Heber Springer; Berlin, 1976 xvii + 517 pages. DM 145, $59.50 , 1978 .

[4]  P. Biscoe,et al.  Radiation absorption, growth and yield of cereals , 1978, The Journal of Agricultural Science.

[5]  D. Lawlor,et al.  The effects of drought on barley growth: models and measurements showing the relative importance of leaf area and photosynthetic rate , 1979, The Journal of Agricultural Science.

[6]  P. G. Jarvis,et al.  Productivity of temperate de-ciduous and evergreen forests , 1983 .

[7]  J. Norman,et al.  Radiative Transfer in an Array of Canopies1 , 1983 .

[8]  J. Goudriaan,et al.  SEPARATING THE DIFFUSE AND DIRECT COMPONENT OF GLOBAL RADIATION AND ITS IMPLICATIONS FOR MODELING CANOPY PHOTOSYNTHESIS PART I. COMPONENTS OF INCOMING RADIATION , 1986 .

[9]  G. Campbell.  Extinction coefficients for radiation in plant canopies calculated using an ellipsoidal inclination angle distribution , 1986 .

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

[11]  Paul G. Jarvis,et al.  Mean leaf angles for the ellipsoidal inclination angle distribution , 1988 .

[12]  M. Cannell,et al.  Light Use Efficiency and Woody Biomass Production of Poplar and Willow , 1988 .

[13]  P. Jarvis,et al.  Simulation of the Role of Stress on Radiation Absorption, Assimilation, Transpiration and Water Use Efficiency of Stands of Eucalyptus Globulus , 1989 .

[14]  S. Linder,et al.  Optimization of Biomass Production in Eucalyptus Globulus Plantations. — A Case Study , 1989 .

[15]  J. J. Landsberg,et al.  Biomass production by fast-growing trees. , 1989 .

[16]  Sune Linder,et al.  Research Priorities in Field Experiments on Fast-Growing Tree Plantations: Implications of a Mathematical Production Model , 1989 .

[17]  G. Russell,et al.  Plant Canopies: Their Growth, Form and Function: Absorption of radiation by canopies and stand growth , 1989 .

[18]  Takeshi Horie,et al.  Leaf Nitrogen, Photosynthesis, and Crop Radiation Use Efficiency: A Review , 1989 .

[19]  Ross E. McMurtrie,et al.  Modelling the yield of Pinus radiata on a site limited by water and nitrogen , 1990 .

[20]  Y. P. Wang,et al.  Two-dimensional needle-area density distribution within the crowns of Pinus radiata. , 1990 .

[21]  Paul G. Jarvis,et al.  Description and validation of an array model - MAESTRO. , 1990 .

[22]  C. Spitters,et al.  Crop growth models: their usefulness and limitations. , 1990 .

[23]  Paul J. Curran,et al.  Dynamics of Canopy Structure and Light Interception in Pinus Elliottii Stands, North Florida , 1991 .

[24]  E. Jokela,et al.  Needlefall, canopy light interception, and productivity of young intensively managed slash and loblolly pine stands , 1991 .

[25]  S. Prince.  A model of regional primary production for use with coarse resolution satellite data , 1991 .

[26]  M. Benson,et al.  The biology of forest growth experiment: An introduction , 1992 .

[27]  M. Benson,et al.  Effects of combinations of irrigation and fertilisation on the growth and above-ground biomass production of Pinus radiata , 1992 .

[28]  S. Running,et al.  Effects of Climate and Lifeporm on Dry Matter Yield (E) from Simulations Using Biome-BGC , 1992, [Proceedings] IGARSS '92 International Geoscience and Remote Sensing Symposium.

[29]  Ross E. McMurtrie,et al.  Mathematical models of the photosynthetic response of tree stands to rising CO2 concentrations and temperatures , 1993 .

[30]  Influence of Shoot Structure on the Photosynthesis of Sitka Spruce (Picea sitchensis) , 1993 .

[31]  R. McMurtrie,et al.  Long-Term Response of Nutrient-Limited Forests to CO"2 Enrichment; Equilibrium Behavior of Plant-Soil Models. , 1993, Ecological applications : a publication of the Ecological Society of America.

[32]  Leaf Nitrogen Content and Minimum Temperature Interactions Affect Radiation‐Use Efficiency in Peanut , 1993 .

[33]  J. Randerson,et al.  Terrestrial ecosystem production: A process model based on global satellite and surface data , 1993 .

[34]  Soybean Radiation-Use Efficiency as Influenced by Nonuniform Specific Leaf Nitrogen Distribution and Diffuse Radiation , 1993 .

[35]  Gérard Dedieu,et al.  Methodology for the estimation of terrestrial net primary production from remotely sensed data , 1994 .

[36]  Ruiliang Pu,et al.  Seasonal Patterns and Remote Spectral Estimation of Canopy Chemistry Across the Oregon Transect , 1994 .

[37]  Henry L. Gholz,et al.  Climatic factors controlling the productivity of pine stands: a model-based analysis , 1994 .

[38]  D. A. King,et al.  Modelling forest response to increasing CO2 concentration under nutrient-limited conditions , 1994 .

[39]  J. L. Monteith,et al.  Validity of the correlation between intercepted radiation and biomass , 1994 .

[40]  Richard H. Waring,et al.  Environmental Limits on Net Primary Production and Light‐Use Efficiency Across the Oregon Transect , 1994 .

[41]  J. Moncrieff,et al.  Fluxes of carbon dioxide and water vapour over an undisturbed tropical forest in south‐west Amazonia , 1995 .

[42]  R. Leuning.  A critical appraisal of a combined stomatal‐photosynthesis model for C3 plants , 1995 .

[43]  D. Baldocchi,et al.  CO2 fluxes over plant canopies and solar radiation: a review , 1995 .

[44]  P. Jarvis.  The role of temperate trees and forests in CO2 fixation , 1995, Vegetatio.

[45]  R. Harrington,et al.  Radiation Interception and Growth of Planted and Coppice Stands of Four Fast-Growing Tropical Trees , 1995 .

[46]  R. Dewar.  The Correlation between Plant Growth and Intercepted Radiation: An Interpretation in Terms of Optimal Plant Nitrogen Content , 1996 .

[47]  I. Prentice,et al.  A general model for the light-use efficiency of primary production , 1996 .

[48]  Henry L. Gholz,et al.  The Use of Remote Sensing in the Modeling of Forest Productivity , 1997, Forestry Sciences.