NDVI can provide optical estimates of kelp abundance
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Transcript of NDVI can provide optical estimates of kelp abundance
November 5 2007ERF 2007 International ConferenceProvidence, RI
• Spectra obtained from airborne inaging spectrometers are similar to lab measures of individual kelp blade reflectances:
• Spectra obtained from airborne inaging spectrometers are similar to lab measures of individual kelp blade reflectances:
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Wavelength (nm)R
rs (
sr-1
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Mature
Immature
Senescent
PHILLS Canopy
NDVI can provide optical estimates of kelp abundance
November 5 2007ERF 2007 International ConferenceProvidence, RI
• Converting NDVI into absolute kelp abundance and productivity:
• Optical BAI = NDVI/0.71• True BAI = Optical BAI * 9.04• Biomass = True BAI/13.3• Productivity = Biomass * 14.7
y = 0.1105x
R2 = 0.7823
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Diver Measured BAI
Op
tica
lly D
ete
rmin
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BA
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y = 13.303x
R2 = 0.9829
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Frond mass (kg DW)
Fro
nd B
lade
Are
a (m
2 fro
nd-1
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Standing crop (kg m-2)0.0 0.5 1.0 1.5 2.0
NP
P (
g d
ry m
ass m-2d-1
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a.
Macrocystis pyrifera (giant kelp) NPP = 14.7 x Standing Crop
November 5 2007ERF 2007 International ConferenceProvidence, RI
Carmel Bay
Santa Barbara Coastal LTER
November 5 2007ERF 2007 International ConferenceProvidence, RI
NDVI Derived Density and Productivity of Giant Kelp: Carmel Bay November 2004
NDVI Derived Density and Productivity of Giant Kelp: Carmel Bay November 2004
• 15 Km of irregular coastline
• 1.7 Km2 of kelp canopy
• Biomass: 1400 metric tons dry kelp biomass
• NPP: 19 metric tons dry biomass d-1
• 15 Km of irregular coastline
• 1.7 Km2 of kelp canopy
• Biomass: 1400 metric tons dry kelp biomass
• NPP: 19 metric tons dry biomass d-1
Kelp Density(Kg DW m-2)0.54 – 0.610.62 - 0.680.69 – 0.750.75 – 0.820.83 – 0.880.89 – 0.95
Kelp Productivity(g DW m-2 d-1)
8 – 99.1 – 10
10.1 – 1111.1 – 1212.1 – 1313.1 - 14