Book contents
- Frontmatter
- Contents
- Foreword
- Preface
- Acknowledgments
- List of notation
- List of units
- List of common and scientific names
- 1 Introduction and overview
- Part I Biophysics
- Part II Darwinian ecology
- Appendices
- A Effect of crown shape on flow in canopy
- B Estimation of potential evaporation from wet simple surfaces
- C Water balance equations
- D Characterization of exponential decay
- E Transpiration as a productivity surrogate
- F Climatology of station storm rainfall in the U.S.: Parameters of the Poisson rectangular pulses model
- G Derivation of the G-function
- H The canopy absorption index and compensation ratio as species
- Glossary
- References
- Author index
- Subject index
A - Effect of crown shape on flow in canopy
Published online by Cambridge University Press: 22 September 2009
- Frontmatter
- Contents
- Foreword
- Preface
- Acknowledgments
- List of notation
- List of units
- List of common and scientific names
- 1 Introduction and overview
- Part I Biophysics
- Part II Darwinian ecology
- Appendices
- A Effect of crown shape on flow in canopy
- B Estimation of potential evaporation from wet simple surfaces
- C Water balance equations
- D Characterization of exponential decay
- E Transpiration as a productivity surrogate
- F Climatology of station storm rainfall in the U.S.: Parameters of the Poisson rectangular pulses model
- G Derivation of the G-function
- H The canopy absorption index and compensation ratio as species
- Glossary
- References
- Author index
- Subject index
Summary
EDDY VISCOSITY FOR MULTILAYER FOLIAGE (M = 1)
Introduction
In Chapter 4 we derived the vertical distribution of atmospheric eddy viscosity within the crown of leafy plants for closed canopies (i.e., M =1) of homogeneous circular cylinders (Eq. 4.40, m = 1/2), and for a nearly conical spruce (Eq. 4.102, m = 1/2, Ψ = 1). These crowns were assumed to have homogeneous foliage density which is high areally and low volumetrically. Using the terminology of Horn (1971), such crowns are often referred to as being multilayer. To compare the effect of multilayer crown geometry on the turbulent mixing we first derive the equations for a hemispherical crown and for a pure conical crown, both again at M = 1.
Keeping in mind the requirement for compensation light intensity at the lowest leaf level at all radii, any crown which does not fill its circumscribing cylinder must be non-homogeneous in leaf area density, that is at = at (ξ, r). We will deal with this variation in an approximate fashion by first averaging radially. In other words, we assume at(ξ) to be homogeneous and isotropic in the radial direction and deal with slices, Δξ of the circumscribing cylinder which are each homogeneous over the full cylindrical crossection (cf. Fig. A.1b).
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- Information
- EcohydrologyDarwinian Expression of Vegetation Form and Function, pp. 329 - 345Publisher: Cambridge University PressPrint publication year: 2002