Land Cover and Forest Type Classification by Values of Vegetation Indices and Forest Structure of Tropical Lowland Forests in Central Vietnam

Table 3

Mean vegetation indices of forest types in ground-truth and training sample plots extracted from Sentinel-2 imagery dated on 22 march 2017.

Vegetation indices	Ground-truth plots (GTVIs)			Training sample plots (LCVIs)
	UF (N = 30)	LF (N = 30)	DF (N = 30)	UF (N = 611)	LF (N = 487)	DF (N = 600)
NDVI	0.84 ± 0.02^aA	0.85 ± 0.01^bA	0.86 ± 0.02^cA	0.83 ± 0.02^aA	0.85 ± 0.02^bB	0.87 ± 0.01^cB
IPVI	0.92 ± 0.01^aA	0.93 ± 0.01^bA	0.93 ± 0.01^cA	0.91 ± 0.01^aA	0.92 ± 0.01^bB	0.94 ± 0.01^cB
GNDVI	0.73 ± 0.03^aA	0.74 ± 0.02^aA	0.74 ± 0.02^aA	0.72 ± 0.03^aB	0.73 ± 0.02^bB	0.74 ± 0.02^cA
ARVI	0.85 ± 0.03^aA	0.84 ± 0.02^aA	0.85 ± 0.02^aA	0.83 ± 0.03^aA	0.84 ± 0.03^abB	0.85 ± 0.02^cB
EVI	0.22 ± 0.04^aA	0.33 ± 0.05^bA	0.40 ± 0.08^cA	0.21 ± 0.04^aA	0.32 ± 0.04^bB	0.49 ± 0.07^cB
NDI45	0.54 ± 0.07^aA	0.53 ± 0.04^aA	0.55 ± 0.05^aA	0.49 ± 0.06^aA	0.53 ± 0.04^bA	0.59 ± 0.03^cB
RVI	12.1 ± 1.9^aA	12.8 ± 1.2^abA	13.7 ± 1.9^cA	11.1 ± 1.7^aA	12.2 ± 1.5^bB	15.1 ± 1.9^cB
DVI	0.07 ± 0.02^aA	0.11 ± 0.02^bA	0.15 ± 0.04^cA	0.12 ± 0.02^aB	0.19 ± 0.03^bB	0.33 ± 0.06^cB
PVI	0.12 ± 0.03^aA	0.20 ± 0.03^bA	0.25 ± 0.06^cA	0.07 ± 0.01^aB	0.12 ± 0.02^bB	0.19 ± 0.04^cA
TNDVI	1.07 ± 0.02^aA	1.10 ± 0.01^bA	1.11 ± 0.02^cA	1.06 ± 0.02^aB	1.10 ± 0.01^bB	1.17 ± 0.01^cB

Within rows, values followed by the same lowercase letter (a, b) are not significantly different () between forest types; Within rows, values followed by the same capital letter (A, B) are not significantly different () of forest types between ground-truth and training sample plots.