Geoscience Reference
In-Depth Information
Shelter factors : mutual sheltering of leaves in a canopy raises the effective
value of boundary-layer resistances by empirical shelter factors of the order
of 2 to 3.
Stomatal resistance : in dry canopies water mainly evaporates inside the
leaves so, in addition to boundary-layer resistance, latent heat (and CO 2 ) flux
also has to pass through a stomatal resistance associated molecular diffusion
through the plants' stomata.
Single leaf Penman-Monteith equation : simultaneously solving the energy
balance equation for a single leaf and equations that control the rate of diffu-
sion of heat fluxes through boundary-layer resistances and stomatal resistance
gives the Penman-Monteith equation for a single leaf, see Equation (21.29).
Whole-canopy Penman-Monteith equation : the single source or 'big leaf '
representation of energy balance for a canopy (with surface resistance taken
as the canopy average of all stomatal resistances acting in parallel, and
aerodynamic resistance as the sum of turbulent transfer resistance and canopy
average boundary-layer resistance acting in series) gives the whole-canopy
Penman-Monteith Equation using a derivation analogous to that for a single
leaf, see Equation (21.33).
References
Monteith, J.L. (1965) Evaporation and environment. Symposium of the Society for
Experimental Biology
, 205-234; republished in Gash, J.H.C. and Shuttleworth, W.J.,
(2007) Benchmark Papers in Hydrology: Evaporation . IAHS Press, Wallingford, 521p.
Monteith, J.L. and Unsworth, M.H. (1990) Principles of Environmental Physics . Edward
Arnold, London, p. 291.
Thom, A.S. (1968) The exchange of momentum, mass, and heat between an artificial leaf
and the airflow in a wind-tunnel. Quarterly Journal of the Royal Meteorological Society ,
94
19
, 44-55.
Waggoner, P.E. and Reifsnyder, W.E. (1968) Simulation of the temperature, humidity, and
evaporation profiles in a leaf canopy. Journal of Applied Meteorology ,
, 400-409.
Waggoner, P.E. and Reifsnyder, W.E. (1969) Simulation of the microclimate in a forest.
Forest Science ,
7
, 37-40.
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