Spectral Estimation of Soil Properties in Siberian Tundra Soils and Relations with Plant Species Composition

Table 2

Performance of model fits using lab spectra of dried samples, evaluated with leave-one-out cross-validation.

	pH	Total P (mg/100 g)	Total K (mg/100 g)	Total N (%)	Total N (%)	Total C (%)	Total C (%)	Moisture (%)
Method	PLSR	PLSR	PLSR	PLSR	SMLR	PLSR	SMLR	PLSR
No. of factors	5	2	2	8	2	2	9	2
𝑅^2	0.50	0.38	0.79	0.73	0.80	0.79	0.95	0.42
RMSE CV	0.47	29.77	193.92	0.26	0.23	5.17	2.59	10.09
RPD CV	1.42	1.28	2.20	1.93	2.18	2.22	4.43	1.33

RMSE CV: root mean square error of cross-validation, RPD CV: ratio of performance to deviation of cross-validation, PLSR: partial least squares regression, SMLR: stepwise multiple linear regression.