sit does not currently support default last pass and historic disturbance types

[smorken]

attempting to run an inventory record with values:

columns: classifier1, using_age_class, age, area, delay, landclass

"c", False, 100, 1, 0, 0

will currently result in error, since there is no mechanism to set a default historic/last pass disturbance types as there is in CBM-CFS3 (the default there is wildfire)

For example:

"c", False, 100, 1, 0, 0, Fire, Fire

The workaround is to set the historical and last pass disturbance type columns explicitly