. 2021 Aug 17;16(8):e0247893. doi: 10.1371/journal.pone.0247893

Table 2. Linear (lm) and polynomial regressions (poly) between the different parameters tested and elevation.

Parameters	Elevation
	Significance		Multiple R²		AIC
	lm	Poly	lm	Poly-lm	lm	Poly-lm
SOC stock (kg C m^-2)	^***	^***	0.28	0.40	764	758
Soil N stock (g N m^-2)	^*	^*	0.15	0.20	510	509
Soil respiration (kg C m^-2 yr^-1)	^***	^***	0.33	0.36	34	34
Temperature sensitivity of soil respiration (Q10)	^***	^**	0.28	0.41	77	67
Respiration at the 10°C reference temperature (SR_ref) (kg C m^-2 yr^-1)	n.s.	n.s.	<0.01	0.08	139	139
Fine root dry weight (kg m^-2)	^*	^**	0.10	0.24	717	712
Fine root C stock (kg C m^-2)	^*	^***	0.39	0.80	199	186
Fine root N stock (g N m^-2)	n.s.	^***	0.28	0.80	102	88
Litter dry weight stock (g m^-2)	n.s.	^*	0.07	0.12	774	772
Litter C stock (kg C m^-2)	n.s.	n.s.	< 0.01	0.04	222	223
Litter N stock (g N m^-2)	n.s.	n.s.	< 0.01	< 0.01	112	114
pH	^**	^***	0.63	0.88	22	8
Soil bulk density (kg dm^-3)	^***	^***	0.32	0.29	9	11

*—p ≤ 0.05;

**- p ≤ 0.01;

***—p ≤ 0.001; n.s.–not significant. BD–soil bulk density; Q10 –temperature sensitivity of soil respiration; SR -–cumulative soil respiration; SRref–respiration at the 10°C reference temperature; AIC–Akaike information criterion.