This paper reports the application to vegetation canopies of a coherent model for the propagation of electromagnetic radiation through a stratified medium. The resulting multi-layer vegetation model is plausibly realistic in that it recognises the dielectric permittivity of the vegetation matter, the mixing of the dielectric permittivities for vegetation and air within the canopy and, in simpli...

The use of lidar and radar instruments to measure forest structure attributes such as height and biomass are being considered for future Earth Observation satellite missions. Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield information about the vertical profile of the canopy. Synthetic Aperture Radar (SAR) is known to sens...

Forest pathogens and insects can accelerate tree mortality, increase stand structural heterogeneity, and alter tree community composition. In northern California, the canopy trees Abies concolor var. lowiana (Gord. & Glend.) Lemmon (white fir) and Pseudotsuga menziesii var. menziesii (Mirbel) Franco (Douglas-fir) co-occur but vary in shade tolerance and regenerative abilities following disturba...

Perennial species with the C(4) pathway hold promise for biomass-based energy sources. We have explored the extent that CO(2) uptake of such species may be limited by light in a temperate climate. One energetic cost of the C(4) pathway is the leakiness () of bundle sheath tissues, whereby a variable proportion of the CO(2), concentrated in bundle sheath cells, retrodiffuses back to the mesophyl...

The CORSAR project (Carbon Observation and Retrieval from SAR), which is supported by the UK Natural Environment Research Council (NERC), has the objective to examine polarimetric decomposition and polarimetric SAR interferometry methods for estimating the effects of canopy structure in biomass-backscatter relationships. Forest canopy height is a useful input parameter to yield models, carbon c...

The flow about, and drag of, two types of parachute canopy have been examined at supersonic speeds at zero incidence, in isolation and in the presence of rigging lines,and behind bodies of revolution. The investigation has shown that the presence of rigging lines reduces the canopy drag by an extent dependent upon the length of the lines. Several different flom regimes are encountered similar t...

Culex pipiens was the dominant mosquito captured in a West Nile virus (WNV) focus in Stratford, Connecticut. More Cx. pipiens were captured in Centers for Disease Control miniature light traps baited with CO(2), quail/hamster traps, and mosquito magnet experimental (MMX) traps placed in the tree canopy than in similar traps placed near the ground. Significantly more Cx. pipiens were captured in...

Ground-based proximal sensing of vineyard features is gaining interest due to its ability to serve in even quite small plots with the advantage of being conducted concurrently with normal vineyard practices (i.e., spraying, pruning or soil tilling) with no dependence upon weather conditions, external services or law-imposed limitations. The purpose of the present work was to test performance of...

Japanese black bears often break branches when climbing trees and feeding on fruit in canopies, thereby creating small canopy gaps. However, the role of black bear-created canopy gaps has not been evaluated in the context of multiple forest dynamics. Our hypothesis was that small canopy gaps created by black bears improve light conditions, which facilitates fruiting of adult fleshy-fruited plan...

Intermittent coherent structures can be responsible for a large fraction of the exchange between a forest canopy and the atmosphere. Quantifying their contribution to momentum and heat fluxes is necessary to interpret measurements of trace gases and aerosols within and above forest canopies. The primary objective of the Community Atmosphere-Biosphere Interactions Experiment (CABINEX) field camp...