Leaf area index (LAI) is an important ecological parameter that characterizes the interface between a vegetation canopy and the atmosphere. Indirect measurements of LAI using optical techniques such as the LAI-2000 plant canopy analyzer have been routinely conducted for different vegetation canopies including forests and agricultural crops. However, little attention has been paid to shrub canop...

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...

Four methods of estimating daily light interception (fisheye photography with image analysis, multiple-light sensors, ceptometer, and point grid) were compared using various apple (Malus domestica Borkh.) tree forms: slender spindle, Yand T-trellises, and vertical palmette. Interactions of tree form, time of day, and atmospheric conditions with light interception estimates were examined. All me...

Forest production depends on CO2 assimilation, but is rarely solely a function of leaf-level photosynthesis. Crown characteristics may affect tree growth by altering light interception and photosynthesis at canopy level. Strong light gradients are present in forest canopies, which often result in parallel changes in leaf morphology and leaf nitrogen for efficient use of light in photosynthetic ...

In biodiversity experiments based on seeded experimental communities, species richness and species composition exert a strong influence on canopy structure and can lead to an improved use of aboveground resources. In this study, we want to explore whether these findings are applicable to agriculturally managed permanent grassland. Vertical layered profiles of biomass, leaf area (LA) and light i...

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and super (SHD) or hedgerow olive system, by measuring PAR transmitted under canopy along transects at increasing distance from tree rows. Transmitted was measured every minute, then cumulated over day season. The frequencies of different levels occurring during were calculated. SHD intercepted signi...