The impacts file contains a colon-delimited list of parameters for each impact module in LUCAS. For each module the following information is specified: the watershed to which it belongs, the module number, the name of the module and the name of the output file associated with the module. Currently only the impact of land cover change on the habitats of certain species is modeled.
littlet:0:Catawba Rhododendron:rhodo littlet:1:Cranefly Orchid:orchid ... hoh:8:Twinflower:flower hoh:9:Horsetail:tail ...
Module numbers are necessary to indicate which hard-coded routine should be used to simulate the desired impact. While it would be much more desirable to have the impacts file itself define the impact routine, the predefined routines are necessary because of performance considerations.