Land Use and Harvest

General description

FATES provides a namelist option, fates_harvest_modes, to allow the user to engage a variety of different harvest modes, which are set by passing one of five string options:

• 'no_harvest'

• 'event_code'

• 'landuse_timeseries'

• 'luhdata_area'

• 'luhdata_mass'

FATES also provides Land use transition logic options via fates_lu_transition_logic. The logic follows the rulesets as defined in Table 1 of Ma et al. 2020. The table is replacted here for convienence:

Translation rule	Rule 1	Rule 2	Rule 3	Rule 4	Rule 5	Rule 6	Rule 7	Rule 8	Rule 9
Cropland	X	X	X	X	X	X	O	O	O
Managed Pasture	X	F	X	X	O	O	X	X	O
Rangeland	F	F	X	O	X	O	X	O	X

Rules for vegetation clearance during cropland, pasture and rangeland expansion. “X” indicates complete removal of vegetation if the primary and secondary land state is altered. “O” indicates no vegetation removal when land-use change occurs. “F” indicates that vegetation is only removed if the preceding land cover is forested primary or forested secondary land.

FATES does not make the distinction between forested and non-forested lands from a land use/land cover perspective and therefore cannot exactly reproduce the table above. Instead in rulesets 1 and 2, F means primary or secondary land is cleared.

In addition, FATES has the parameter fates_landuse_clearing_mortality which determines the fraction of each PFT that is killed during transition to rangeland, if the given ruleset allows vegetation clearing during creation of rangeland.

Harvest mode descriptions

'no_harvest'

This turns off the land use and harvest modes. This is the default setting.

'event_code'

This mode is uses the FATES parameter file exclusively through the use of the fates_landuse_logging_event_code parameter file variable to define the time at which harvesting occurs.

'landuse_timeseries'

This mode makes use of the landuse timeseries harvest data provided by the host land model, which is discussed in more detail in the HLM documentation. While the host land model can provide a default landuse timeseries file based on the compset name option, the file can be directly set as in the namelist with the flanduse_timeseries option by providing it with a string formatted path to the file. Note: this option will likely be superseded by the luhdata_ options noted below in the future.

'luhdata_area'

This mode enables the use of a minimally processed Land Use Harmonization (LUH) dataset. The file must be set via the fluh_timeseries namelist option.

This option uses the area-based harvest data. Note that this mode automatically engages the FATES landuse x pft static mapping namelist option, use_fates_lupft as well as fixed biogeography and no competition options, use_fates_fixed_biogeog and use_fates_nocomp, respectively.

'luhdata_mass'

This modes uses the same dataset and automtically sets dependent namelist options as noted in the 'luhdata_area' option noted above. This option uses the mass-based harvest data.