The World Conservation Union (IUCN) Conifer Specialist Group maintains a database tracking conservation status of all conifer species and many subspecies and varieties. The most current version of this database is available online at the IUCN Red List Database. This information, in a somewhat dated form, is also available in print form as Farjon and Page (1999). IUCN categories and species numbers as cataloged in that publication are here summarized:
Fully detailed definition of these categories is available HERE.
This page is from the Gymnosperm Database