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Leaf area index

USDA Forest Service / UNL Faculty Publications

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Full-Text Articles in Life Sciences

Evaluation Of The Modis Lai Product Using Independent Lidar-Derived Lai: A Case Study In Mixed Conifer Forest, Jennifer L.R. Jensen, Karen S. Humes, Andrew T. Hudak, Lee A. Vierling, Eric Delmelle Jan 2011

Evaluation Of The Modis Lai Product Using Independent Lidar-Derived Lai: A Case Study In Mixed Conifer Forest, Jennifer L.R. Jensen, Karen S. Humes, Andrew T. Hudak, Lee A. Vierling, Eric Delmelle

USDA Forest Service / UNL Faculty Publications

This study presents an alternative assessment of the MODIS LAI product for a 58,000 ha evergreen needleleaf forest located in the western Rocky Mountain range in northern Idaho by using lidar data to model (R2=0.86, RMSE=0.76) and map LAI at higher resolution across a large number of MODIS pixels in their entirety. Moderate resolution (30 m) lidar-based LAI estimates were aggregated to the resolution of the 1-km MODIS LAI product and compared to temporally-coincident MODIS retrievals. Differences in the MODIS and lidar-derived values of LAI were grouped and analyzed by several different factors, including MODIS retrieval algorithm, sun/sensor …


Seasonal Leaf Dynamics Across A Tree Density Gradient In A Brazilian Savanna, William A. Hoffman, Edson Rangel Da Silva Jr., Gustavo C. Machado, Sandra J. Bucci, Fabian G. Scholz, Guillermo Goldstein, Frederick C. Meinzer Jan 2005

Seasonal Leaf Dynamics Across A Tree Density Gradient In A Brazilian Savanna, William A. Hoffman, Edson Rangel Da Silva Jr., Gustavo C. Machado, Sandra J. Bucci, Fabian G. Scholz, Guillermo Goldstein, Frederick C. Meinzer

USDA Forest Service / UNL Faculty Publications

Interactions between trees and grasses that influence leaf area index (LAI) have important consequences for savanna ecosystem processes through their controls on water, carbon, and energy fluxes as well as fire regimes. We measured LAI, of the groundlayer (herbaceous and woody plants <1-m tall) and shrub and tree layer (woody plants >1-m tall), in the Brazilian cerrado over a range of tree densities from open shrub savanna to closed woodland through the annual cycle. During the dry season, soil water potential was strongly and positively correlated with grass LAI, and less strongly with tree and shrub LAI. By the end of the dry season, LAI of grasses, groundlayer dicots …