Tabic 1 
Chlorophyll 
Fresh Biomass 
Fresh Biomass 
.86 * 
Wet% 
.66 ** 
.75 * 
Significance level: * = .0001, ** = .001 
4.2. Correlation between biophysical variables and first derivative of reflectance 
Figure 2 shows the correlation coefficients between the first derivative of the resampled and smoothed 
spectral reflectance and each of the three biophysical variables. The strongest correlations and their 
wavelength position are summarised in Table 2. Because of the interdependence between fresh biomass, leaf 
chlorophyll and water content, it is difficult establish the relationship between the spectral data and each of 
those variables separately. 
Wet % 
Figure 2. Product Moment Correlation Coefficients between the first derivative of 
reflectance and three biophysical variables. 
Table 2 
Chlorophyll 
Fresh Biomass 
Wet% 
.80 * (748) 
.74 * (748) 
.64 ** (749) 
.66 ** (943) 
-.70 * (945) 
-.71 * (951) 
-.61 ** (1124) 
-.66 ** (1122) 
-.71 * (1142) 
Strongest correlation coefficients between first derivative of reflectance and biophysical 
variables. Figures in brackets indicate wavelength position. 
Significance level: * = .0001, ** = .001 
For the 1150nm water absorption feature, the strongest correlation with first derivative of reflectance 
(-0.710 at 1142nm) is towards the lower section of the left limb of the water absorption feature. This 
correlation compares with a value of -0.92 (at 1150nm) reported by Danson et al, (1992) for laboratory data 
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