Wet climates produce many more species and numbers of epiphytes.
BRBR

Iris Cohen schreef
There is one more condition you forgot to mention; it has to be warm
enough. Few of the HIGHER plants thrive as epiphytes where it consistently
goes much below freezing. Even in the Pacific Northwest rain forest, there
are no HIGHER plant epiphytes (that I know of), because they are in Zone 8.
The northernmost epiphytic orchid in the Western Hemisphere, Epidendrum
conopseum, is found as far north as South Carolina.

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Still, epiphytes in Canadian rain forests are abundant:
http://www.pc.gc.ca/pn-np/bc/revelst.../natcul9_e.asp
PvR