Taxonomic reference lists are not included in vegdata to keep the package small. 
For taxonomic harmonization a Turboveg list with additional column ParentID must be available in the search path.

The reference list "GermanSL" will be automatically downloaded 
from http://geobot.botanik.uni-greifswald.de/reflist
into the tv_home directory, if needed.
In the future additional lists might be available.
