Input database related uncertainty of Biome-BGCMuSo agro-environmental model outputs

Abstract

Gridded model assessments require at least one climatic and one soil database for carrying out the simulations. There are several parallel soil and climate database development projects that provide sufficient, albeit considerably different, observation based input data for crop model based impact studies. The input database related uncertainty of the Biome-BGCMuSo agro-environmental model outputs was investigated using three and four different gridded climatic and soil databases, respectively covering an area of nearly 100.000 km 2 with 1104 grid cells. Spatial, temporal, climate and soil database selection related variances were calculated and compared for four model outputs obtained from 30-year-long simulations. The choice of the input database introduced model output variability that was comparable to the variability the year-to-year change of the weather or the spatial heterogeneity of the soil causes. Input database selection could be a decisive factor in carbon sequestration related studies as the soil carbon stock change estimates may either suggest that the simulated ecosystem is a carbon sink or to the contrary a carbon source on the long run. Careful evaluation of the input database quality seems to be an inevitable and highly relevant step towards more realistic plant production and carbon balance simulations.

Evaluation of the Terrestrial Ecosystem Model Biome-BGCMuSo for Modelling Soil Organic Carbon under Different Land Uses

“…Currently it is not the case in our study; therefore, it was not performed. Nevertheless, a recent study with Biome-BGCMuSo showed that the spatial variation in the SOC change rate is much larger than the variance in the SOC change rate originating from changes in model inputs (e.g., climate and soil data), for all investigated land uses (i.e., croplands, grasslands and forests) [92]. Accordingly, we can assume that the introduction of input data-related uncertainty at the plot level would not provide us with more information than we already obtained.…”

“…Uncertainty analysis implies estimating the model result uncertainty originating from different model inputs and/or different model parameters [91]. Estimating the uncertainty originating from model inputs for Biome-BGCMuSo would assume possessing more than one climate and soil database covering the entire area of the investigation (i.e., the whole national territory) [92]. Currently it is not the case in our study; therefore, it was not performed.…”

Soil-related developments of the Biome-BGCMuSo v6.2 terrestrial ecosystem model

“…The second, normal simulation uses the results of the spinup simulation as initial conditions and runs for a given, predefined time period (Running and Gower 1991). Socalled transient simulation option (which is the extension of the spinup routine) is a novel feature in Biome-BGCMuSo in order to ensure smooth transition between the spinup and normal phase (Hidy et al, 2021).…”

“…Below, we provide detailed description of the new developments that are included in Biome-BGCMuSo v6.2 which is the latest version released in September, 2021. A comprehensive review of the input data requirement of the model together with explanation on the input data structure is available in the User's Guide (Hidy et al, 2021). In this paper we refer to some input files (e.g.…”

“…But this might be of course a challenging task to define all of the input parameters. In order to support practical application of the model, the User's Guide contains proposed values for most of the new parameters (Hidy et al, 2021).…”