Table 1.

MIMICS parameters included in the Monte Carlo (MC) optimization and the subsequent best-fit values found for the Reynolds Creek Experimental Watershed and Critical Zone Observatory (RCEW-CZO) calibration data.

Parameter	Description	Default priora	Best-fit scaling factorb	Scaling factor proposal rangec	Units
Vslope	Decomposition max rate coefficient	0.063	3.85 ± 0.8	0.4–4	ln(mg Cs (mg MIC)−1 h−1) °C−1
Vint	Decomposition max rate coefficient	5.47	1.16 ± 0.4	0.3–3	ln(mg Cs (mg MIC)−1 h−1)
Kslope	Decomposition half saturation coefficient	0.017, 0.027, 0.017	0.84 ± 1.0	0.4–4	ln(mg C cm−3) °C−1
Kint	Decomposition half saturation coefficient	3.19	1.55 ± 0.7	0.3–3	ln(mg C cm−3)
τ	Microbial biomass turnover rate	0.30 × e1.3(fclay), 0.20 × e0.8(fclay)	0.46 ± 0.5	0.3–3	h−1
MGE	Microbial growth efficiency	0.55, 0.25, 0.75, 0.35	0.54 ± 0.3	0.2–2	mg mg−1
D	Desorption rate from SOMp to SOMa	1.5 × 10–5 × e-1.5(fclay)	0.08 ± 0.03	0.001–0.3	h−1
fp	Fraction of τ partitioned to SOMp	0.015 × e1.3(fclay), 0.01 × e0.8(fclay)	0.34 ± 0.3	0.01–4	–

^aFurther information regarding MIMICS parameters and default initial values provided in²⁶

^bParameter proposals in the MC algorithm were conveyed as a factor of the initial prior value(s). Presented standard deviation is derived from the parameter ensemble (n = 30) with RMSE 1.8–2.0

^cFactor proposals for each parameter were confined to agree with natural analogs and to reduce computational demands.

See Methods for further details.