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Showing 1 to 20 of 53 for “"leaf area index (lai)"”.

  1. Validating Leaf Area Index (LAI) and canopy cover estimated from satellite imagery products with ground measurements in plum orchards, Western Cape

    Nqumkana, Sinathi YolandaUniversity of the Western Cape2025

    … performance, where accurate estimation of the Leaf Area Index (LAI) plays a central role in linking canopy structure to productivity. LAI is not only a key indicator of crop development and yield potential but also a critical input in biophysical and climatic models. However, direct measurement …

    western-cape Repository record

  2. Intra-field Nitrogen Estimation for Wheat and Corn using Unmanned Aerial Vehicle-based and Satellite Multispectral Imagery, Plant Biophysical Variables, Field Properties, and Machine Learning Methods

    Yu, Jody SeymonThe University of Western Ontario2021

    … imagery, vegetation indices (VI), crop height, leaf area index (LAI), field topographic metrics, and soil properties to predict canopy nitrogen weight (g/m2) of corn and wheat fields in southwestern Ontario, Canada. Random Forests (RF) and Support Vector Regression (SVR) machine learning models …

    uwo Repository record

  3. Characterizing spatiotemporal variation in LAI of Virginia Pine Plantations

    McCurdy, Wyatt ConnerVirginia Tech2020

    … and empirical relationships predicting pine LAI from the Landsat satellite, we conducted a statewide analysis of temporal patterns in stand-level southern pine leaf area index (LAI) following clear-cut and planting. Here, using 28 years of Landsat time-series data for 13,140 stands that were …

    vt Repository record

  4. Environmental And Stand Variables Influencing Soil CO2 Efflux Across The Managed Range Of Loblolly Pine

    Templeton, Benjamin SeanVirginia Tech2009

    … of that total efflux, heterotrophic respiration index (Rh), from data collected across the managed range of loblolly pine in the Southeastern U.S. We also performed tests of significance on controlled subsets of these data for the effects of fertilization and of thinning. Finally, we sought a …

    vt Repository record

  5. Stand Strucuture of Planted Stands in Storm-Water Retention Basins

    Lanza, Jason2025

    … removal, and determining stand structure and leaf area of forests can be a measure of their effectiveness. The structure of forest stands on these basins managed for runoff mitigation has received little attention. We investigated the structure and species composition/diversity (tree and …

    sfasu Repository record

  6. Reducing Corn Yield Variability and Enhancing Yield Increases Through the Use of Corn-Specific Growth Models

    Raymond, Fred DouglasVirginia Tech2007

    … biomass production was highly accurate. Greater leaf area index (LAI) and biomass production were measured than was predicted by the CERES-Maize CSM. Both CSMs were modified based on calibration data sets and validated. Validation results of the calibrated CSMs showed improved accuracy in …

    vt Repository record

  7. Influence of Several Herbicides on Visual Injury, Leaf Area Index, and Yield of Glyphosate-Tolerant Soybean <I>(Glycine max)</I>

    Johnson, Bryan FisherVirginia Tech2001

    … date, and herbicide treatment on soybean injury, leaf area index (LAI), and yield. Three glyphosate-tolerant soybean cultivars representing maturity groups III, IV and V were planted at dates representing the full-season and double-crop soybean production systems used in Virginia. Within each …

    vt Repository record

  8. Seasonal and Spatial Variation in Leaf Area Index, Litter Production, and Light Levels in Myrica Cerifera,Shrub Thickets Across a Barrier Island Chronsequence

    Brantley, Steven T.2014

    Leaf area index (LAI), litter production and understory light levels of Myrica cergera shrub thickets were assessed on Hog Island, Virginia to quantify spatial and seasonal variations in leaf area and light attenuation among four thickets representing a successional chronosequence and compare …

    vcu Repository record

  9. Evaluation and Application of the Community Land Model for Simulating Energy and Carbon Exchange in Agricultural Ecosystems

    Chen, Ming2016

    … production (GPP), ecosystem respiration (ER) and leaf area index (LAI). The key parameters include the maximum carboxylation rate at 25 oC (Vcmax25), specific leaf area at the top of the canopy (slatop) and a parameter determining the initial carbon allocation to leaves (fleafi). CLM4-CropM …

    umn Repository record

  10. Direct and Indirect Effects of Elevated Carbon Dioxide and Ozone on the Canopy of a Soybean Agroecosystem

    Dermody, Orla C.University of Illinois at Urbana-Champaign2015

    … and scale to affect ecosystems. I determined how leaf area index (LAI) was directly affected by elevated [CO 2] and [O3]. By increasing photosynthetic efficiency, elevated [CO2] may increase maximum LAI. However, [O3] accelerates senescence and may reduce LAI. My second objective was to determine …

    uiuc Repository record

  11. Management of summer grazed alfalfa

    Hamilton, Laurie AnneVirginia Polytechnic Institute and State University1983

    … (hay removed at 1/10 bloom). Forage yields, leaf area index (LAI), tiller numbers, crude protein (CP), and in vitro dry matter digestibility ( IVDMD) generally declined during grazing. Neutral detergent fiber (NDF), lignin, and cellulose content generally increased on all grazing systems. …

    vt Repository record

  12. Assessing the accuracy of the MODIS LAI 1-km product in southeastern United States loblolly pine plantations: Accounting for measurement variance from ground to satellite

    Iiames, John Shepherd, Jr.

    <p>Leaf area index (LAI), defined here as one-half of the total leaf area per unit ground surface area (Chen, 1996), has been estimated at a global scale from spectral data processed from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor aboard two NASA EOS-AM spacecraft, Terra …

    unh-thes Repository record

  13. ENHANCEMENT OF A CANOPY REFLECTANCE MODEL FOR UNDERSTANDING THE SPECULAR AND SPECTRAL EFFECTS OF AN AQUATIC BACKGROUND IN AN INUNDATED TIDAL MARSH

    Turpie, Kevin Ross2012

    … as structure information (e.g., canopy height, leaf area index, etc.) or plant species composition. The background reflectance can also influence spectral analysis of plant characteristics based on hyperspectral data. A model to account for the aquatic substrate would be useful to understanding …

    maryland Repository record

  14. Modeling Forest Canopy Distribution from Ground-Based Laser Scanner Data

    Henning, Jason GregoryVirginia Tech2005

    … with 41 and 45 scans gathered during periods of leaf-on and leaf-off, respectively. Data management and summary needs were addressed, focusing on the development of registration methods to align point clouds collected from multiple vantage points and minimize the volume of the plot canopy …

    vt Repository record

  15. The discrete wavelet transform as a precursor to leaf area index estimation and species classification using airborne hyperspectral data

    Banskota, AsimVirginia Tech2011

    … pine species (Pinus spp.), (2) estimation of leaf area index (LAI) using an empirically-based model, and (3) estimation of LAI using a physically-based model. For pine species classification, different sets of Haar wavelet features were compared to each other and to calibrated radiance. The …

    vt Repository record

  16. Testing the Limits of Hyperspectral Airborne Remote Sensing by Mapping Eelgrass in Elkhorn Slough

    Bostrom, Kelley J2011

    … containing dark gray sediment or eelgrass with Leaf Area Index (LAI) up to 8 could not be accurately modeled. A second set of spectral libraries was created by selecting endmembers from the HSI data with known depth and benthic coverage ranging from sediment to dense eelgrass. Different …

    uconn-diss Repository record

  17. Biology of the Rare Woodland Perennial Trillium Pusillum Micheaux (Liliaceae) in Southwest Missouri

    Andre, Cynthia S.

    … 5.9 at Heckmaster and 6.5 at Hoover Woods. Mean leaf area index (LAI), a measure of light penetration through the canopy where the higher the LAI the shadier the understory, was 0.69 in April and 6.49 in June at Baker, 0.94 in April and 6.11 in June at Heckmaster and 1.39 in April and 8.18 in …

    mo-state Repository record

  18. Validation and application of the MERIS Terrestrial Chlorophyll Index.

    Almond, Samuel FrancisBournemouth2009

    … product called the MERlS Terrestrial Chlorophyll Index (MTCI). The MTCI is related to the position of the red edge in vegetation spectra and can be used to estimate the chlorophyll content of vegetation. The MTCI therefore provides a powerful product to monitor phenology, stress and productivity. …

    bournemouth Repository record

  19. Quantifying genotypic and environmental factors affecting potato canopy growth

    Roberts, SarahUniversity of Cambridge2019

    … growth was less sensitive to temperature. Leaf production and canopy duration varied with cultivar determinacy. Cultivar and nitrogen fertilizer rate determined the potential for branch and branch leaf production (and therefore canopy longevity), altering distribution of leaf area index …

    cambridge Repository record

  20. Leaf area index, light penetration, and carbohydrate reserves during growth of Kentucky 31 tall fescue (Festuca arundinacea Schreb.)

    Alburquerque, Hector EugenioVirginia Polytechnic Institute1967

    … interrelationship between dry matter production, leaf area index (LAI), light penetration through the canopy and carbohydrate reserve fluctuations during regrowth under different growth stages and cutting managements of Kentucky 31 tall fescue were studied in three field experiments during spring …

    vt Repository record

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