O. Andren et T. Katterer, ICBM - THE INTRODUCTORY CARBON BALANCE MODEL FOR EXPLORATION OF SOIL CARBON BALANCES, Ecological applications, 7(4), 1997, pp. 1226-1236
A two-component model was devised, comprising young and old soil C, tw
o decay constants, and parameters for litter input, ''humification,''
and external influences. Due to the model's simplicity, the differenti
al equations were solved analytically, and parameter optimizations can
be made using generally available nonlinear regression programs. The
calibration parameter values were derived from a 35-yr experiment with
arable crops on a clay soil in central Sweden. We show how the model
can be used for medium-term (30 yr) predictions of the effects of chan
ged inputs, climate, initial pools, litter quality, etc., on soil carb
on pools. Equations are provided for calculating steady-state pool siz
es as well as model parameters from litter bag or C-14-labeled litter
decomposition data. Strategies for model parameterization to different
inputs, climatic regions, and soils, as well as the model's relations
to other model families, are briefly discussed.