Scaling PAR absorption from the leaf to landscape level in spatially heterogeneous ecosystems

Gregory P. Asner, Carol A. Wessman

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

Realistic and efficient photon transport modeling at the landscape level is vital to understanding material and energy exchange processes that occur between the biosphere and atmosphere. Our knowledge of the magnitude and dynamics of chemical fluxes in spatially heterogeneous areas is constrained by an insufficient understanding of photon transport at scales larger than a single homogeneous canopy. To address this problem, we examine factors controlling the absorption of photosynthetically active radiation (PAR) at the leaf, canopy, and landscape levels. A description of a landscape PAR simulation model based on canopy radiative transfer theory and geometric-optical modeling is provided from a biophysical scaling perspective. Using this model, some of the scaled factors controlling fractional PAR absorption by plants and plant assemblages are discussed. Landscape characteristics influence PAR absorption beyond that which is exerted at the leaf level, but are not divorced from leaf and canopy characteristics. For instance, the spatial distribution of canopies can have a greater effect on PAR absorption than the leaf area index of those canopies, but at the same time, this sensitivity is integrally dependent on canopy leaf area index. Leaf area index has a greater effect on canopy-level PAR absorption than either leaf orientation or leaf optical properties. While some of these relationships can be elucidated through field studies, a comprehensive analysis requires a model that accurately accounts for each interaction based on physical scattering principles.

Original languageEnglish (US)
Pages (from-to)81-97
Number of pages17
JournalEcological Modelling
Volume103
Issue number1
DOIs
StatePublished - Nov 1 1997
Externally publishedYes

Fingerprint

photosynthetically active radiation
canopy
ecosystem
leaf area index
optical property
biosphere
modeling
radiative transfer
scattering
spatial distribution
atmosphere
simulation
energy

Keywords

  • Canopy structure
  • Landscape ecology
  • Leaf optical properties
  • Photosynthetically active radiation
  • Radiative transfer
  • Remote sensing

ASJC Scopus subject areas

  • Ecological Modeling

Cite this

Scaling PAR absorption from the leaf to landscape level in spatially heterogeneous ecosystems. / Asner, Gregory P.; Wessman, Carol A.

In: Ecological Modelling, Vol. 103, No. 1, 01.11.1997, p. 81-97.

Research output: Contribution to journalArticle

@article{e2797582f0394a7baeba84d434f56635,
title = "Scaling PAR absorption from the leaf to landscape level in spatially heterogeneous ecosystems",
abstract = "Realistic and efficient photon transport modeling at the landscape level is vital to understanding material and energy exchange processes that occur between the biosphere and atmosphere. Our knowledge of the magnitude and dynamics of chemical fluxes in spatially heterogeneous areas is constrained by an insufficient understanding of photon transport at scales larger than a single homogeneous canopy. To address this problem, we examine factors controlling the absorption of photosynthetically active radiation (PAR) at the leaf, canopy, and landscape levels. A description of a landscape PAR simulation model based on canopy radiative transfer theory and geometric-optical modeling is provided from a biophysical scaling perspective. Using this model, some of the scaled factors controlling fractional PAR absorption by plants and plant assemblages are discussed. Landscape characteristics influence PAR absorption beyond that which is exerted at the leaf level, but are not divorced from leaf and canopy characteristics. For instance, the spatial distribution of canopies can have a greater effect on PAR absorption than the leaf area index of those canopies, but at the same time, this sensitivity is integrally dependent on canopy leaf area index. Leaf area index has a greater effect on canopy-level PAR absorption than either leaf orientation or leaf optical properties. While some of these relationships can be elucidated through field studies, a comprehensive analysis requires a model that accurately accounts for each interaction based on physical scattering principles.",
keywords = "Canopy structure, Landscape ecology, Leaf optical properties, Photosynthetically active radiation, Radiative transfer, Remote sensing",
author = "Asner, {Gregory P.} and Wessman, {Carol A.}",
year = "1997",
month = "11",
day = "1",
doi = "10.1016/S0304-3800(97)00080-X",
language = "English (US)",
volume = "103",
pages = "81--97",
journal = "Ecological Modelling",
issn = "0304-3800",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Scaling PAR absorption from the leaf to landscape level in spatially heterogeneous ecosystems

AU - Asner, Gregory P.

AU - Wessman, Carol A.

PY - 1997/11/1

Y1 - 1997/11/1

N2 - Realistic and efficient photon transport modeling at the landscape level is vital to understanding material and energy exchange processes that occur between the biosphere and atmosphere. Our knowledge of the magnitude and dynamics of chemical fluxes in spatially heterogeneous areas is constrained by an insufficient understanding of photon transport at scales larger than a single homogeneous canopy. To address this problem, we examine factors controlling the absorption of photosynthetically active radiation (PAR) at the leaf, canopy, and landscape levels. A description of a landscape PAR simulation model based on canopy radiative transfer theory and geometric-optical modeling is provided from a biophysical scaling perspective. Using this model, some of the scaled factors controlling fractional PAR absorption by plants and plant assemblages are discussed. Landscape characteristics influence PAR absorption beyond that which is exerted at the leaf level, but are not divorced from leaf and canopy characteristics. For instance, the spatial distribution of canopies can have a greater effect on PAR absorption than the leaf area index of those canopies, but at the same time, this sensitivity is integrally dependent on canopy leaf area index. Leaf area index has a greater effect on canopy-level PAR absorption than either leaf orientation or leaf optical properties. While some of these relationships can be elucidated through field studies, a comprehensive analysis requires a model that accurately accounts for each interaction based on physical scattering principles.

AB - Realistic and efficient photon transport modeling at the landscape level is vital to understanding material and energy exchange processes that occur between the biosphere and atmosphere. Our knowledge of the magnitude and dynamics of chemical fluxes in spatially heterogeneous areas is constrained by an insufficient understanding of photon transport at scales larger than a single homogeneous canopy. To address this problem, we examine factors controlling the absorption of photosynthetically active radiation (PAR) at the leaf, canopy, and landscape levels. A description of a landscape PAR simulation model based on canopy radiative transfer theory and geometric-optical modeling is provided from a biophysical scaling perspective. Using this model, some of the scaled factors controlling fractional PAR absorption by plants and plant assemblages are discussed. Landscape characteristics influence PAR absorption beyond that which is exerted at the leaf level, but are not divorced from leaf and canopy characteristics. For instance, the spatial distribution of canopies can have a greater effect on PAR absorption than the leaf area index of those canopies, but at the same time, this sensitivity is integrally dependent on canopy leaf area index. Leaf area index has a greater effect on canopy-level PAR absorption than either leaf orientation or leaf optical properties. While some of these relationships can be elucidated through field studies, a comprehensive analysis requires a model that accurately accounts for each interaction based on physical scattering principles.

KW - Canopy structure

KW - Landscape ecology

KW - Leaf optical properties

KW - Photosynthetically active radiation

KW - Radiative transfer

KW - Remote sensing

UR - http://www.scopus.com/inward/record.url?scp=0030813170&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030813170&partnerID=8YFLogxK

U2 - 10.1016/S0304-3800(97)00080-X

DO - 10.1016/S0304-3800(97)00080-X

M3 - Article

AN - SCOPUS:0030813170

VL - 103

SP - 81

EP - 97

JO - Ecological Modelling

JF - Ecological Modelling

SN - 0304-3800

IS - 1

ER -