This paper reviews the development of the stochastic interception model from the original, single-layer, drop-size-dependent model to the two-layer model that recognizes that vegetation canopies are wetted through both the primary impact of raindrops to the top layer of the canopy and secondary impacts from drops falling from the vegetation to lower layers of the canopy. It is shown that drop v...

Stable isotopes provide insight into ecosystem carbon cycling, plant physiological processes, atmospheric boundary-layer dynamics, and are useful for the integration of processes over multiple scales. Of particular interest is the carbon isotope content (dC) of nocturnal ecosystem-respired CO2 (dR). Recent advances in technology have made it possible to continuously examine the variation in dR ...

Nitrogen (N) addition typically increases overall plant growth, but the nature of this response depends upon patterns of plant nitrogen allocation that vary throughout the growing season and depend upon canopy position. In this study seasonal variations in leaf traits were investigated across a canopy profile in Miscanthus (Miscanthus 9 giganteus) under two N treatments (0 and 224 kg ha ) to de...

A one-dimensional multi-layer scheme describing the coupled exchange of energy and CO2, the emission of isoprene and the dry deposition of ozone is applied to a rain forest canopy in southwest Amazonia. The model was constrained using mean diel cycles of micrometeorological quantities observed during two periods in the wet and dry season 1999. Calculated net fluxes and concentration profiles fo...

Mature potato (Solanum tuberosum L. cv. Kennebec) canopies are composed of leaves originating frommainand axillary-stem branches. Canopy leaf distribution and its corresponding contribution to wholecanopy photosynthetic rates have not been quantified. An experiment using SPAR (Soil–Plant–Atmosphere–Research) chambers maintained at 16-h day/night thermoperiods of 14/10, 17/12, 20/15, 23/18, 28/2...

uA microwave scattering model has been developed for layered vegetation based on an iteratlve solution of the radiative transfer equation up to the second order to account for multiple scattering within the canopy and between the ground and the canopy'. The model is designed to operate over a wide frequency range for both deciduous and coniferous forest and to account for th_ branch size distri...

Momentum and scalar (heat and water vapor) transfer between a walnut canopy and the overlying atmosphere are investigated for two seasonal periods (before and after leaf-out), and for five thermal stability regimes (free and forced convection, near-neutral condition, transition to stable, and stable). Quadrant and octant analyses of momentum and scalar fluxes followed by space-time autocorrelat...

In this paper, a new method for estimation of vertical leaf area density (LAD) profile of tree canopy using portable scanning lidar is proposed. In this method, which we refer to as the voxel-based canopy profiling (VCP) method, several measurement points surrounding the canopy and optimally inclined laser beams are adopted to facilitate full laser beam illumination of whole canopy up to the in...

Light is the key energy input for all vegetated systems. Forest light regimes are complex, with the vertical pattern of light within canopies influenced by forest structure. Human disturbances in tropical forests impact forest structure and hence may influence the light environment and thus competitiveness of different trees. In this study, we measured vertical diffuse light profiles along a gr...

In the southeastern United States, many forest managers are interested in restoring longleaf pine (Pinus palustrisMill.) to upland sites that currently support loblolly pine (Pinus taeda L.). We quantified the effects of four canopy treatments (uncut Control; MedBA, harvest to 9 m2·ha−1; LowBA, harvest to 5 m2·ha−1; and Clearcut) and three cultural treatments (NT, no treatment; H, herbicide rel...