Estimation of the directional and whole apparent clumping index (ACI) from indirect optical measurements

Abstract Canopy clumping index (CI) indicates the non-random distribution of foliage components in space, and is an important structural parameter for better understanding the radiative transfer process in a canopy. The apparent clumping index (ACI), calculated using the logarithmic gap fraction averaging method, is reported by the LAI-2200 Plant Canopy Analyzer. While LAI-2200 calculates the gap fraction and ACI from different conical rings, calculation of ACI for other geometric units (e.g., an angular cell or an azimuth sector) and instruments has been lacked. Building upon the LAI-2200 ACI, this study compares the ACIs calculated for different geometric spaces from different optical instruments. The field data obtained from seasonal continuous measurements with LAI-2200, digital hemispheric photography (DHP), and AccuPAR at a paddy rice field in northeast China were used to calculate the directional ACIs at different levels—a directional cell (ΩA(θ, ϕ)), a concentric ring (ΩA(θ)), an azimuth sector (ΩA(ϕ)), and over the horizontal landscape (ΩA(ν)). The whole ACIs were calculated from the directional ACIs with an angular integration method, a simple averaging method, a non-linear correction method, and a variance-to-mean ratio method. The directional ACIs for paddy rice generally follow the order of ΩA(θ, ϕ)

[1]  João Santos Pereira,et al.  Influence of woody tissue and leaf clumping on vertically resolved leaf area index and angular gap probability estimates. , 2015 .

[2]  J. Lovell,et al.  The Canopy Semi-analytic Pgap And Radiative Transfer (CanSPART) model: Validation using ground based lidar , 2012 .

[3]  A. Strahler,et al.  Global clumping index map derived from the MODIS BRDF product , 2012 .

[4]  K. Nackaerts,et al.  A fractal dimension-based modelling approach for studying the effect of leaf distribution on LAI retrieval in forest canopies , 2006 .

[5]  J. Pisek,et al.  Comparison of methods for measuring gap size distribution and canopy nonrandomness at Järvselja RAMI (RAdiation transfer Model Intercomparison) test sites , 2011 .

[6]  Gérard Dedieu,et al.  Estimation of leaf area and clumping indexes of crops with hemispherical photographs , 2008 .

[7]  A. Gonsamo,et al.  The computation of foliage clumping index using hemispherical photography , 2009 .

[8]  Frédéric Baret,et al.  Review of methods for in situ leaf area index determination Part I. Theories, sensors and hemispherical photography , 2004 .

[9]  Hideki Kobayashi,et al.  How to quantify tree leaf area index in an open savanna ecosystem: A multi-instrument and multi-model approach , 2010 .

[10]  R. McMurtrie,et al.  Estimation of leaf area index in eucalypt forest using digital photography , 2007 .

[11]  Rong Wang,et al.  Inter- and intra-annual variations of clumping index derived from the MODIS BRDF product , 2016, Int. J. Appl. Earth Obs. Geoinformation.

[12]  Jb Miller,et al.  A formula for average foliage density , 1967 .

[13]  R. Lacaze,et al.  Canada-wide foliage clumping index mapping from multiangular POLDER measurements , 2005 .

[14]  E. Mcpherson,et al.  Comparison of Five Methods for Estimating Leaf Area Index of Open-Grown Deciduous Trees , 1998, Arboriculture & Urban Forestry.

[15]  Jindi Wang,et al.  MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement , 2014, Sensors.

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

[17]  L. Hutley,et al.  Documenting improvement in leaf area index estimates from MODIS using hemispherical photos for Australian savannas , 2011 .

[18]  Danny Lo Seen,et al.  PAR extinction in shortgrass ecosystems: effects of clumping, sky conditions and soil albedo , 2000 .

[19]  Hongliang Fang,et al.  Seasonal variation of leaf area index (LAI) over paddy rice fields in NE China: Intercomparison of destructive sampling, LAI-2200, digital hemispherical photography (DHP), and AccuPAR methods , 2014 .

[20]  Pingheng Li,et al.  Canopy vertical heterogeneity plays a critical role in reflectance simulation , 2013 .

[21]  H. Fang,et al.  Estimation of canopy clumping index from MISR and MODIS sensors using the normalized difference hotspot and darkspot (NDHD) method: The influence of BRDF models and solar zenith angle , 2016 .

[22]  Sylvie Duthoit,et al.  Assessing the effects of the clumping phenomenon on BRDF of a maize crop based on 3D numerical scenes using DART model , 2008 .

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

[24]  J. Cihlar,et al.  Plant canopy gap-size analysis theory for improving optical measurements of leaf-area index. , 1995, Applied optics.

[25]  F. Baret,et al.  GAI estimates of row crops from downward looking digital photos taken perpendicular to rows at 57.5° zenith angle: Theoretical considerations based on 3D architecture models and application to wheat crops , 2010 .

[26]  Richard A. Fournier,et al.  Hemispherical photography simulations with an architectural model to assess retrieval of leaf area index , 2014 .

[27]  Markus Reichstein,et al.  Drought controls over conductance and assimilation of a Mediterranean evergreen ecosystem: scaling from leaf to canopy , 2003 .

[28]  Sindy Sterckx,et al.  Fractal dimension as correction factor for stand-level indirect leaf area index measurements , 1999, Remote Sensing.

[29]  R. Dickinson,et al.  Simplifying the Interaction of Land Surfaces with Radiation for Relating Remote Sensing Products to Climate Models , 2006 .

[30]  Hongliang Fang,et al.  Continuous estimation of canopy leaf area index (LAI) and clumping index over broadleaf crop fields: An investigation of the PASTIS-57 instrument and smartphone applications , 2018 .

[31]  Jan Pisek,et al.  Estimation of foliage clumping from the LAI-2000 Plant Canopy Analyzer: effect of view caps , 2014, Trees.

[32]  Sylvain G. Leblanc,et al.  Methodology comparison for canopy structure parameters extraction from digital hemispherical photography in boreal forests , 2005 .

[33]  Hideki Kobayashi,et al.  On the correct estimation of effective leaf area index: does it reveal information on clumping effects? , 2010 .

[34]  A. Lang,et al.  Leaf area and average leaf angle from transmission of direct sunlight , 1986 .

[35]  M. Rautiainen,et al.  Quantitative characterization of clumping in Scots pine crowns. , 2013, Annals of botany.

[36]  Andres Kuusk,et al.  Simulation of statistical characteristics of gap distribution in forest stands , 2011 .

[37]  Bin Chen,et al.  Assessment of foliage clumping effects on evapotranspiration estimates in forested ecosystems , 2016 .

[38]  A. Strahler,et al.  A clumped-foliage canopy radiative transfer model for a Global Dynamic Terrestrial Ecosystem Model II: Comparison to measurements. , 2010 .

[39]  A. Kuusk,et al.  Retrieving vegetation clumping index from Multi-angle Imaging SpectroRadiometer (MISR) data at 275 m resolution , 2013 .

[40]  J. M. Norman,et al.  Photosynthesis in Sitka Spruce (Picea sitchensis (Bong.) Carr.). III. Measurements of Canopy Structure and Interception of Radiation , 1974 .

[41]  Qiang Liu,et al.  The Design and Implementation of the Leaf Area Index Sensor , 2015, Sensors.

[42]  Pierre Dutilleul,et al.  Soybean canopy development as affected by population density and intercropping with corn : Fractal analysis in comparison with other quantitative approaches , 1999 .

[43]  Vanni Nardino,et al.  Estimation of canopy attributes in beech forests using true colour digital images from a small fixed-wing UAV , 2016, Int. J. Appl. Earth Obs. Geoinformation.

[44]  J. Norman,et al.  Photosynthesis in Sitka spruce (Picea sitchensis (Bong.) Carr.). V. Radiation penetration theory and a test case , 1975 .

[45]  G. Russell,et al.  Leaf area index estimates obtained for clumped canopies using hemispherical photography , 1999 .

[46]  Richard A. Fournier,et al.  Integrating clumping effects in forest canopy structure: an assessment through hemispherical photographs , 2003 .

[47]  J. Chen.  Optically-based methods for measuring seasonal variation of leaf area index in boreal conifer stands , 1996 .

[48]  B. Moulia,et al.  Spatial re-orientation of maize leaves affected by initial plant orientation and density , 1997 .

[49]  Hideki Kobayashi,et al.  Continuous observation of tree leaf area index at ecosystem scale using upward-pointing digital cameras , 2012 .

[50]  R. Myneni,et al.  Intercomparison and sensitivity analysis of Leaf Area Index retrievals from LAI-2000, AccuPAR, and digital hemispherical photography over croplands , 2008 .

[51]  J. Lovell,et al.  The Canopy Semi-analytic Pgap And Radiative Transfer (CanSPART) model: Formulation and application , 2012 .

[52]  J. Chen,et al.  Global mapping of foliage clumping index using multi-angular satellite data , 2005 .

[53]  J. Pisek,et al.  Effects of foliage clumping on the estimation of global terrestrial gross primary productivity , 2012 .

[54]  Simon D. Jones,et al.  Quantifying the impact of woody material on leaf area index estimation from hemispherical photography using 3D canopy simulations , 2016 .

[55]  Andrea Cutini,et al.  Estimation of canopy properties in deciduous forests with digital hemispherical and cover photography , 2013 .

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

[57]  John M. Norman,et al.  On the correct estimation of gap fraction: How to remove scattered radiation in gap fraction measurements? , 2013 .

[58]  A. Lang.  Estimation of leaf area index from transmission of direct sunlight in discontinuous canopies , 1986 .

[59]  Alemu Gonsamo,et al.  Sampling gap fraction and size for estimating leaf area and clumping indices from hemispherical photographs , 2010 .

[60]  S. Ustin,et al.  Canopy clumping appraisal using terrestrial and airborne laser scanning , 2015 .

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

[62]  Marcel Fuchs,et al.  The distribution of leaf area, radiation, photosynthesis and transpiration in a Shamouti orange hedgerow orchard. Part I. Leaf area and radiation☆ , 1987 .