18 Background and aims: Most optical devices for indirect measurement of leaf area 19 index (LAI) from canopy-transmitted light are tailored for homogeneous canopies, thus 20 limiting their application to discontinuous canopies such as vertically trained vineyards. 21 This study evaluates the influence of sun position on the reliability of LAI estimates 22 provided by a ceptometer and proposes ...

A considerable portion of Canada’s landmass is covered by grassland ecosystems. Insight into the grassland spatial heterogeneity will not only contribute to better understanding of the scale dependent ecological processes but will also help in management and monitoring. Leaf area index (LAI) is a key structural attribute of grassland that reflects primary production. It is well-known that topog...

Characterizing Leaf Area Index (LAI) and Vertical Foliage Profile (VFP) over the United States H. Tang, S. Ganguly, G. Zhang, M. A. Hofton, R. F. Nelson, and R. Dubayah Department of Geographical Sciences, University of Maryland, College Park, Maryland, USA Bay Area Environmental Research Institute (BAERI)/NASA Ames Research Center, Moffett Field, California, USA Biospheric Sciences Branch, Cod...

Taro, Colocasia esculenta (L.) Schott, is the most important species from the Araceae family. The leaf area (LA) is important for the interception of solar radiation and for the biomass production. The light extinction coefficient (k) is related to the leaf inclination angle, leaf arrangement, regarding the Leaf Area Index (LAI), providing an indication of the plants efficiency on intercepting ...

T h e PROSPECT leaf optical properties and SAIL canopy reflectance models were coupled and inverted using a set of 96 AVIRIS (Airborne Visible~Infrared Imaging Spectrometer) equivalent spectra gathered in afield experiment on sugar beet plots expressing a large range in leaf area index, chlorophyll concentration, and soil color. In a first attempt, the model accurately reproduced the spectral r...

The validation process for a moderate resolution leaf area index (LAI) product (i.e., MODIS) involves the creation of a high spatial resolution LAI reference map (LaiRM), which when scaled to the moderate LAI resolution (i.e., >1 km) allows for comparison and analysis with this LAI product. This research addresses two major sources of uncertainty in the creation of the LAI-RM: (1) the uncertain...

Leaf area index (LAI) is an important biophysical descriptor of crop canopies. Accurate measurements of LAI are laborious and time-consuming. Many methods of measuring LAI of corn (Zea mays L.) have been reported and vary greatly in their accuracy, preclslon, bias, and ease of measurement. We examined the magnitude of plant-to-plant variability of leaf area of corn plants selected from uniform ...

Leaf area index (LAI) is an important biophysical descriptor of crop canopies. Accurate measurements of LAI are laborious and time-consuming. Many methods of measuring LAI of corn (Zea mays L.) have been reported and vary greatly in their accuracy, precision, bias, and ease of measurement. We examined the magnitude of plant-to-plant variability of leaf area of corn plants selected from uniform ...

As a parameter of researching plant groups and cluster analysis, leaf area index (LAI) is closely related to a variety of biological processes, such as transpiration, photosynthesis and respiration. Now LAI has become a key parameter in researching the eco-system. There are two ways to get the LAI data, one is from the ground-based measurement, the other way is based on retrieval from remote se...

The objective of this research was to determine the effects of elevated concentrations of carbon dioxide (CO2) and sulfur dioxide (SO2) on field-grown soybean. Soybeans (Glycine max L. Merr. cv. "Essex) were grown a full-season in open-top field chambers exposed to either ambient (350 #l L -j) or elevated CO2 (500 #l L -j) levels under two levels of SO2 (0.00 and 0.12 #l L-t). Enriched CO2, wit...