Partial Least Squares Regression

Knowledge graph centered on Partial Least Squares Regression with 74 nodes and 171 connections. Top connected: Hummingbird, Ipomopsis, Delphinium, I. aggregata, Ipomopsis aggregata.

Method synopsis

Uses hyperspectral imaging (400-1000 nm) combined with Partial Least Squares Regression to correlate spectral signatures with measured leaf traits like LMA and LWC. Enables non-destructive remote measurement of plant traits.

Synthesized from method descriptions across 5 papers using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Can flowers affect land surface albedo and soil microclimates? (2021), International Journal of Biometeorology. The protocol was originally introduced by Correlation of leaf and community traits and various spectra in meadows along an elevation gradient (2016). Implementations in other papers (listed below) may differ.

1. Measure reflectance in laboratory
   Ten leaf samples and ten flower ray floret samples were collected from ten different plants and immediately brought to lab. One individual was haphazardly chosen near each control plot. Ray florets were clipped at base, arranged side by side without overlap, and taped at petal edges to white paper sheet. Three measurements per sample were taken with mean reflectance calculated for each wavelength.
   Quantities: 10 leaf samples, 10 flower samples, 3 measurements per sample across 325-1,075 nm spectrumDuration: Single sampling event in 2017Conditions: Laboratory conditions with controlled lighting
   Equipment: ASD HandHeld 2 Malvern Panalytical spectroradiometer
2. Measure reflectance in field
   Field reflectance measured with hand-held spectrometer held ca. 1m above ground surface taking measurements for which each view is a circle with 0.5m diameter. 20 measurements per plot (4 along each side and 4 in plot center) under full sun conditions near solar noon, calibrated against white reference every 5-7 minutes.
   Quantities: 20 measurements per plot, 0.5m diameter view circle, 1m height, 13 plots total measuredDuration: Single measurement campaign during peak flowering in 2019Conditions: Full sun conditions near solar noon, 10:00-14:00 hours
   Spectra Vista Corporation model HR-1024-i spectrometer, Spectralon 99% reflectance white reference

Typical Equipment

• SOC 710 hyperspectral camera
• digital camera
• weighing equipment
• 50% reflective standard
• ENVI software
• MATLAB

Output Measurements

• leaf mass per area (LMA)
• leaf water content (LWC)
• spectral reflectance

Papers Using This Protocol (5)

Species Studied With This Protocol