D oes genotypic variation in leaf form and function among tree species reflect adult height or only the seedling regeneration niche? For trees in closed canopy forests, typical adult tree height directly indicates the position of the species in the light hierarchy of the canopy. However, it is unknown whether trees that characteristically differ in mature height have similar or different canopy...

Growth at elevated CO2 often decreases photosynthetic capacity (acclimation) and leaf N concentrations. Lower-shaded canopy leaves may undergo both CO2 and shade acclimation. The relationship of acclimatory responses of flag and lower-shaded canopy leaves of wheat (Triticum aestivum L.) to the N content, and possible factors affecting N gain and distribution within the plant were investigated i...

Most studies assessing chlorophyll fluorescence (ChlF) have examined leaf responses to environmental stress conditions using active techniques. Alternatively, passive techniques are able to measure ChlF at both leaf and canopy scales. However, the measurement principles of both techniques are different, and only a few datasets concerning the relationships between them are reported in the litera...

Although extremely vulnerable to coastal eutrophication, seagrasses represent important structuring elements and sources of primary production in shallow waters. They also generate an optical signature that can be tracked remotely. Accurate knowledge of light absorption and scattering by submerged plant canopies permits the calculation of important plantand ecosystem-level properties, including...

1 h e theoretwal analyses of Sellers (1985, 1987), which hnked canopy spectral reflectance properties to (unstressed) photosynthetw rates and conductances, are cmtwally remewed and significant shortcomings are ~dent~fied These are addressed m thin article principally through the incorporation of a more sophmtwated and reahstw treatment of leaf phystological processes within a new canopy integra...

One of the main factors affecting vegetation productivity is absorbed light, which is largely governed by chlorophyll. In this paper, we introduce the concept of chlorophyll efficiency, representing the amount of gross primary production per unit of canopy chlorophyll content (Chl) and incident PAR. We analyzed chlorophyll efficiency in two contrasting crops (soybean and maize). Given that they...

to nadir-viewed vegetation reflectance data. Variability INTRODUCTION in tissue optical properties was wavelength-dependent. During the past several decades, the tools for vegetation For green foliage, the lowest variation was in the visible remote sensing have evolved significantly. Optical remote (VIS) spectral region and the highest in the near-infrared sensing has expanded from the use of p...

Radiative transfer models have seldom been applied for studying heterogeneous grassland canopies. Here, the potential of radiative transfer modeling to predict LAI and leaf and canopy chlorophyll contents in a heterogeneous Mediterranean grassland is investigated. The widely used PROSAIL model was inverted with canopy spectral reflectance measurements by means of a look-up table (LUT). Canopy s...

To test the prediction that elevated CO2 increases the maximum leaf area index (LAI) through a stimulation of photosynthesis, we exposed model herbaceous communities to two levels of CO2 crossed with two levels of soil fertility. Elevated CO2 stimulated the initial rate of canopy development and increased cumulative LAI integrated over the growth period, but it had no effect on the maximum LAI....

Several methods for extracting the chlorophyll sensitive red-edge position (REP) from hyperspectral data are reported in literature. This study is a continuation of a recent paper published as ‘A new technique for extracting the red edge position from hyperspectral data: the linear extrapolation method’. The method was validated experimentally for estimation of foliar nitrogen concentrations of...