Why two different land covers The land cover was continually evolving, so version numbers were assigned to
each new set of modifications. For each new version, the vertebrate models
had to be rerun, a process that was very time-consuming. The last version
of the vertebrate models was run on Version 5 of the land cover, but a few
changes were made to the land cover after the last vertebrate models were
run. For more information see lcversions.txt.