The concept of canopy spectral invariants expresses the observation that simple algebraic combinations of leaf and canopy spectral reflectance become wavelength independent and determine two canopy structure specific variables – the recollision and escape probabilities. These variables specify an accurate relationship between the spectral response of a vegetation canopy to incident solar radiat...

Improving canopy photosynthetic light use efficiency instead of leaf photosynthesis holds great potential to catalyze the next "green revolution". However, leaves in a canopy experience different biochemical limitations due to the heterogeneities of microclimates and also physiological parameters. Mechanistic dynamic systems models of canopy photosynthesis are now available which can be used to...

We have developed a spatially inexplicit model of canopy photosynthesis for balsam fir (Abies balsamea (L.) Mill.) that accounts for key processes of light-shoot interaction including irradiance interception by the shoot, spatial aggregation of shoots into branches and crowns, the differential propagation of diffuse and direct light within the canopy, and an ideal representation of penumbra. Al...

The present work has explored for the first time acclimation of upper versus lower canopy leaves along an altitudinal gradient. We tested the hypothesis that restrictive climatic conditions associated with high altitudes reduce within-canopy variations of leaf traits. The investigated beech (Fagus sylvatica L.) forest is located on the southern slope of the Hrubý Jeseník Mountains (Czech Republ...

A detailed 3D structural model of a conifer forest canopy was developed in order to simulate the reflectance (optical) and backscatter (microwave) signals measured remotely. We show it is feasible to model forest canopy scattering using detailed 3D models of tree structure including the location and orientation of individual needles. An existing structural growth model of Scots pine (Pinus sylv...

Both canopy flow and porous media theories have been developed independent of one another to predict flow through submerged porous structures. These approaches are very similar, albeit with some key differences in how canopy resistance forces are parameterized. Canopy models provide a means of parameterizing the shear stresses that occur at the top of the canopy, whereas porous media models can...

− Adjoint formulation of three−dimensional radiative transfer and the Green's function concept have been developed in neutron transport several decades ago. This is not merely yet another method of simulating the radiative transfer process, but a method of reformulating the problem to better incorporate existing radiation models into a particular research. In the case of photon transport in veg...

The thermally driven wind over mountainous terrains challenges the estimation of CO2 exchange between forests and the atmosphere when using the eddy covariance technique. In this study, the wind regimes were investigated in a temperate deciduous forested valley at the Maoershan site, Northeast China. The wind direction above the canopy was preferentially up-valley in the daytime and down-valley...