『Abstract
During the last decades,decision makers and policy have increasingly
demanded for regional and national inventories of greenhouse gas
emission, such as nitrous oxide (N2O), to
develop appropriate strategies and mitigation options. A potential
way to derive large-scale estimates of N2O
emission is the use of process-based models, such as PnET-N-DNDC
or Wetland-DNDC. While PnET-N-DNDC has been effectively applied
for various upland forest ecosystems, the wetland-DNDC model has
not yet been validated with regard to N2O
emission. We calibrated and validated the Wetland-DNDC model on
the basis of a 4-year field data set of two water-logged soils
(Humic Gleysol and Histic Gleysol) of of a spruce
forest ecosystem. Model calibration by means of the Levenberg-Marquardt
algorithm considerably improved the model performance for the
period of calibration (2001-2002). The error variance was reduced
by up to a factor of two and the modelling efficiency was increased
from -1.24 to -0.15(Humic Gleysol) and from -0.42 to 0.1
(Histic Gleysol). However, the model performance for the
period of validation (2003-2004) and particularly for the extreme
dry period in summer 2003 was not fully satisfying, notably with
regard to the temporal pattern of the N2O
emission.
Keywords: Biogeochemical modeling; Nitrous oxide emission; Spruce
forest ecosystem; Water-logged soils』
Introduction
Minerals and methods
Study area
The Wetland-DNDC model
Model input data
Model optimization and sensitivity analysis
Results and discussion
Sensitivity analysis
Modelling results
Cold simulations
Calibrated simulation
Summary and conclusion
References