SOFUN

Model documentation

SOFUN is a modelling framework (Stocker et al., in prep.) that combines modules for simulating light use efficiency, leaf N, growth and allocation, litter and soil decomposition, N mineralisation and inorganic soil N dynamics. SOFUN is designed in a modular fashion that allows for alternative process representations and levels of integration (see here) to be implemented within the same modelling framework.

Its two main development directions are:

• P-model: Application as a light use efficiency model with presribed vegetation greenness and an optimality-based prediction of light use efficiency to simulate global GPP. This is based on Prentice et al. (2014) and Wang Han et al. (2017).
• CN-model: A fully integrated and coupled model for the cycling of carbon and nitrogen in terrestrial ecosystems (so far only grasslands). At the current stage, this is formulated for point-scale applications and designed to provide the basis for simulating flexible carbon allocation for a next-generation Dynamic Global Vegetation Model. The CN-model accounts for feedbacks between plants and soil processes, including N losses. It is formulated based on costs of N acquisition. Above versus belowground C allocation is determined based on a functional balance approach, whereby CO\(_2\) fixation from photosynthesis (determined by leaf area) is in balance with N acquisition through roots (determined by root surface area) under the constraint of a C:N ratio required for new growth. Preliminary results are on my website.

The model is under development and no open access for its most recent version is provided before publication. Older code is available on github.