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## Annual Transient Land Use and Land Cover Data

The article discusses the "landuse.timeseries" dataset, which prescribes changes in the area of natural and crop vegetation over time. This dataset consists of an annual time series of global grids that describe the fractional area occupied by different plant functional types (PFTs) and crop functional types (CFTs), as well as the nitrogen fertilizer and irrigation fractions for each crop CFT, and the annual wood harvest for tree PFTs.

These changes in PFT and CFT areas are implemented on the first time step of January 1 each year. Fertilizer application and irrigation for each CFT are performed at each model time step based on rules from the crop model, with fertilizer application rates set annually and irrigation fractions also set annually.

As a special case, when the time dimension of the "landuse.timeseries" dataset starts or stops at a different year than the current model time step, the first or last time slice from the dataset is used to represent the current time step's PFT and CFT fractional area distributions. This ensures that the simulation has transient PFT and CFT distributions during the period covered by the "landuse.timeseries" dataset, with invariant representations before and after that period.