don't raise exception if harvest system is unknown, assume no harvest and don't count it
don't raise exception if harvest system is unknown, assume no harvest and don't count it

Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner,Ecotrust/forestplanner