Hi!
       I collected "nemoralis"  near the married students quarters
(this housing was on Acacia, or possible Acadia Road and may have been torn down) on the campus of the University of British Columbia, in approximately 1969; Frieda Schilling later confirmd my identification.  Someone with whom I corresponded visited the site, which, I think was on the north  side of the road, and found the clearing had a large amount of secondary growth and did not mention whether he found any  snails.  Unfortunately, I had to leave Vancouver rather suddenly, and I only came away with two or three shells.  It is a very variable and pretty species.   But I wonder if any effecrt on the environment where it has been seen has been documented.
      Also, I seem to recall that Tucker Abbott was involved in trying to control the effects on crops of some "Achatina" that had been introduced I think unwittingly.
                        My two cents,
                                Linda W. B.