In:
Biogeosciences, Copernicus GmbH, Vol. 18, No. 10 ( 2021-05-26), p. 3147-3171
Abstract:
Abstract. For decades, predominant soil biogeochemical models have used conceptual soil organic matter (SOM) pools and only simulated them to a shallow depth
in soil. Efforts to overcome these limitations have prompted the development of the new generation SOM models, including MEMS 1.0, which represents
measurable biophysical SOM fractions, over the entire root zone, and embodies recent understanding of the processes that govern SOM dynamics. Here
we present the result of continued development of the MEMS model, version 2.0. MEMS 2.0 is a full ecosystem model with modules simulating plant
growth with above- and belowground inputs, soil water and temperature by layer, decomposition of plant inputs and SOM, and mineralization and
immobilization of nitrogen (N). The model simulates two commonly measured SOM pools – particulate and mineral-associated organic matter (POM and
MAOM, respectively). We present results of calibration and validation of the model with several grassland sites in the US. MEMS 2.0 generally
captured the soil carbon (C) stocks (R2 of 0.89 and 0.6 for calibration and validation, respectively) and their distributions between POM and
MAOM throughout the entire soil profile. The simulated soil N matches measurements but with lower accuracy (R2 of 0.73 and 0.31 for calibration
and validation of total N in SOM, respectively) than for soil C. Simulated soil water and temperature were compared with measurements, and the
accuracy is comparable to the other commonly used models. The seasonal variation in gross primary production (GPP; R2 = 0.83), ecosystem
respiration (ER; R2 = 0.89), net ecosystem exchange (NEE; R2 = 0.67), and evapotranspiration (ET; R2 = 0.71) was well
captured by the model. We will further develop the model to represent forest and agricultural systems and improve it to incorporate new
understanding of SOM decomposition.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-18-3147-2021
DOI:
10.5194/bg-18-3147-2021-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2021
detail.hit.zdb_id:
2158181-2
Permalink
