The abiotics can optionally be used as driving variables for nitrogen and carbon. This means that there will be no dynamic interaction between abiotics and biotics. There are several switches that regulate if a certain variable should be a driving or not (see below). The default option is “simulated”, which means that the abiotic variable in question will not be a driving variable in the simulation. On the other hand chosing “generated by parameters” or “read from pg-file” makes the abiotic variable a driving, either estimated from parameter values or directly read from a PG bin-file. If all possible abiotic variables are used as drivings the general switch “Nitrogen and Carbon” can be switched to “abiotic driving variables”, which disables a lot of options and parameter settings concerning abiotics that become unnecessary to select or determine when the variables are given elsewhere.