The spectral signatures of crop canopies in the field provide much information relating morphological or quality characteristics of crops to their optical properties. This experiment was conducted using two winter-wheat (Triticum aestivum) cultivars, Jingdong8 (with erect leaves) and Zhongyou9507 (with horizontal leaves). We analysiced the relation between the direction spectral characteristics...

We used field measurements and Monte Carlo simulations of canopy gap-size distribution and gap fraction to examine how beam radiation interacts with clumped boreal forest canopies of aspen (Populus tremuloides Michx.), black spruce (Picea mariana (Mill.) B.S.P.) and jack pine (Pinus banksiana Lamb.). We demonstrate that the Beer-Lambert law can be modified to accommodate transmission of radiati...

The thermal radiation distribution within and above the canopy is explored. CUPID model is chosen to simulate the canopy component temperatures. TRGM model, based on 3D realistic structure and radiosity solution, is used to simulate the component brightness temperature distribution within canopy and thermal radiation emission directionality distribution TB (θ) above canopy. It is noted that the...

There is increasing interest in evaluating the environmental effects on crop architectural traits and yield improvement. However, crop models describing the dynamic changes in canopy structure with environmental conditions and the complex interactions between canopy structure, light interception, and dry mass production are only gradually emerging. Using tomato (Solanum lycopersicum L.) as a mo...

Sugar beet varieties differ greatly in their canopy architecture and can be classified into types according to petiole angle. Leaf angle is one of the key factors which determines efficiency with plant canopies utilise incident absorbed light for photosynthesis. yield strongly correlated accumulated intercepted but impact on interception, biomass accumulation sugar has not been explored. This s...

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...

We investigate anisotropy in 1.4-GHz brightness induced by a field corn vegetation canopy. We find that both polarizations of brightness are isotropic in azimuth during most of the growing season. When the canopy is senescent, the brightness is a strong function of row direction. On the other hand, the 1.4-GHz brightness is anisotropic in elevation: an isotropic zero-order radiative transfer mo...

Gap characteristics and effects of gaps on plasticity of Fargesia qinlingensis and tree regeneration were studied under canopy, and in small, medium, and large gaps in a mixed hardwood-conifer forest in the Qinling Mountains, China. Gap formation was mainly tree snapping (40%). Gapmakers were dominated by Betula albosinensis and Abies fargesii (85%). Gap area ranged from 23.8 to 594.2 m and ave...

A rapid canopy reflectance model inversion experiment was performed using multi-angle reflectance data from the NASA Multi-angle Imaging Spectro-Radiometer (MISR) on the Earth Observing SystemTerra satellite, with the goal of obtainingmeasures of forest fractional crown cover, mean canopy height, and aboveground woody biomass for large parts of south-eastern Arizona and southern New Mexico (N20...

A decrease in stratospheric ozone may result in a serious threat to plants, since biologically active short-wavelength ultraviolet-B (UV-B 280–320 nm) radiation will increase even with a relatively small decrease in ozone. Numerous investigations have demonstrated that the effect of UV-B enhancements on plants includes reduction in grain yield, alteration in species competition, susceptibility ...