3.2 Near Infra-red — NIR (700-1,300nm) 
The evolution over time of the reflectance between the clones 
indicates, in contrast to VIS, a relation that is less associated 
with genetics than with environmental factors, restricted here to 
the sun exposure differences (Figure 10 and 11). The major 
reflectance values for the PB235-NW in both studied periods 
suggest a greater cutinization of the leaves and bigger thickness 
of their parenchyma (Jensen, 2009), considering their greater 
sun exposure and the tendency to leaf water loss when 
compared to other stands (GT1 and PB235-SE), which are more 
shaded. The reflectance values indicate an even greater presence 
of structural compounds (as lignin and cellulose) in GTI clone, 
what naturally indicates genetic origin. 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
  
  
  
  
mere GTI MAY 
~~ GT1 JUNE 
ses PBI3SSE MAY 
sve PRISE JUNE 
ve PBISENW MAY 
stes PRIS-NW JUNE 
Reflectance (%) 
  
  
  
Hay Ty May Bag Meg Bg Wo Oey Cy Pe Wag Tong Tos Top LI, Hy Hag any Ray 0s 
Wavelength (nm) 
  
  
  
Figure 10. Spectral behaviour in canopy scale from 740 to 
1,300nm, for May and June, of the Rubber trees stands: GT1, 
PB235-SE and PB235-NW 
  
  
  
  
T GTI MAY 
== GT1 JUNE 
  
Reflectance (Ya) 
  
  
  
cse PB23S-SE MAY 
oro PRAISE JUNE 
oem PB2SSNW MAY 
bes PRIMCNW JUNE 
EY à bad 
Muy Tag My, Vig ^7. tm nz Mug zz Pee, Tone, long, Magy Ming, Rng, Rp, Gus, 
  
  
Wavelength (am) 
  
Figure 11. Spectral behaviour in leaf scale from 740 to 
1,300nm, for May and June, of the Rubber trees stands: GT1, 
PB235-SE and PB235-NW 
One of the lignin and protein absorption peak happens around 
800nm. In this region, it was possible to observe that even 
though GT1 presents the greatest index of these compounds, 
mainly in June, the variation over the time showed a similarity 
of the shaded stands GT1 and PB235-SE (Figures 12 and 13). 
"Shade leaves" are thinnest and present smallest foliar area, if 
compared to “Sun leaves” (Fitter & Hay, 2002). Those factors 
reduce the gaseous spaces in the interior of the leaf, evidencing 
the response from the structural compounds, as lignin. 
  
eve GT) MAY. 
<< GTI JUNE 
vov PRIIS-SE MAY 
c P8235-SE JUNE 
cv PRIMONW MAY. 
voe PB135-NW JUNE 
Reflectance (%) 
8 2B UR RE NBY ESE 
    
May Wr M, + 72, 9 2 A» 1 LA LM 2; 5 2 e Etre 
  
Wavelength (nm) 
Figura 12. Spectral behaviour in canopy scale, for May and 
June, in the region of 800nm of Rubber trees stands: GT1, 
PB235-SE and PB235-NW 
  
  
    
   
   
    
   
   
    
    
    
     
   
  
     
   
   
     
  
  
   
    
   
    
  
  
  
  
  
  
  
  
   
    
   
    
    
    
  
    
  
"m GILMAY 
“= GT JUNE 
woo PRUS-SE AY 
PRISE JUR. 
con PRIENW MAY 
sob PBISENN JUNE 
Reflectance (%) 
  
727 Hn, 91 m 9, 52, id Hay 24; Reg eg 
‘Wavelength (nm) 
Figura 13. Spectral behaviour in leaf scale, for May and June, in 
the region of 800nm of the Rubber trees stands: GT1, PB235- 
SE and PB235-NW 
  
As observed in Figure 14, for the May data the spectral 
behaviour is unclear. As for June data, when the late autumn is 
more characteristic, the environmental similarity is imposed 
against the genetics. In the scale leaf (Figure 15) the 
environmental importance is more evident and happens 
indiscriminately in May and June. 
  
GT MPB23S-SE MAY 
tmm GTVPBIIS-NW MAY 
nares PBISE-SFPBISNY MAY 
Ratio value 
  
Tug Ty Wr, Uno, Seng Mag Paz Sig Pap, ergy Magy org Ting (ng sg sr, 
Wavelength (um) 
  
vo GTUPB1M-SE JUNE 
—— TLIPRIMCNW JUNE 
sev BBIM.SEPRIS-NW JUNE 
Ratío value 
  
Mey ry Wy Ch, ng Py Tay P, Pr, Is Tg, Toy Hy IP Mie, Pi Fg 
Wavelength (am) 
Figure 14. Ratios among spectra of the Rubber trees stands 
(GT1, PB235-SE and PB235-NW) from 740 to 1,300nm for 
May and June, in canopy scale 
  
  
  
  
  
  
  
  
  
  
  
  
1.004 pa ; I —— 
JE 
I i 
"E 
$ 099 +: 33S MAY 
à wis 3 NW MAY 
82. au - e YBI3SEBIM-NW MAY 
axe Es ss 
rr Er vm IS 
2.965 
Ting hg Wry Nag Yes, My, Ry, Bag Yay 7024 4 "064 7 upg Higg ng fus, EUM Ay. 
Wavelength (am) 
  
OBITS gui 
ve GEUPBIM-SE JUNE 
Fn GTUPB2IE-NW JUNE 
soos PRIIS-SEPBIIENW JUNE 
  
Ratio value 
  
  
ee 
  
  
Ms Ty, Mvp Ny Mess Muy az 7535 761 1026 a Oss) Toy, Thy, Moy, Ps, Psa, 94 
  
  
Wavelength (am) a) 
Figure 15. Ratios among spectra of the Rubber trees stands 
(GT1, PB235-SE and PB235-NW) from 740 to 1,300nm for 
May and June, in leaf scale 
3.3 Shortwave Infra-red — SWIR (1,400 a 2,500nm) 
A cellulose absorption peak happens around 1,420nm. The data 
from this spectral region were obtained only in the leaf scale, 
once there is coincidence with the radiation absorption by the 
atmospheric water. It was noted that GT1 clone presents the 
greatest index of this compound, exceeding for May in leaf 
scale, when the reflectance values of the PB235-SE stands are a 
little lower (Figure 16). The low variation of the reflectance 
values of the PB235-SE stand may be explained by the fact that, 
as it’s the most shaded stand, over the time the lighting intensity 
  
  
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