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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0.1

400 500 600 700 800 900

Wavelength (nm)R

rs (

sr-1

)

Mature

Immature

Senescent

PHILLS Canopy

NDVI can provide optical estimates of kelp abundance


• 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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2.5

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Diver Measured BAI

Op

tica

lly D

ete

rmin

ed

BA

I

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

)

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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40R2 = 0.623P < 0.0001

a.

Macrocystis pyrifera (giant kelp) NPP = 14.7 x Standing Crop


Carmel Bay

Santa Barbara Coastal LTER


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

NDVI can provide optical estimates of kelp abundance

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