Carl,
I agree there are definitional difficulties here. For some reason, when I think of "parkland" courses, I tend to think of deciduous rather than coniferous trees. Maybe that goes back to some of the first parkland courses in the UK which I understand were built on old hunting grounds, estates, etc. Courses in the UK do tend to be links, heathland, downland or parkland--maybe clifftop is another category. In the US, those categories breakdown--we don't have many links and we have other types of typography and soils--prairie, for instance.
I'm not sure I'm advancing the discussion, but I don't consider Bandon Trails a parkland course. To me, even though it's not on heathland (what course in the U.S. is?), it's more analogous to a heathland course. It's built on at least some sandy soil, the conditions are firm enough to allow for the ground game and trees are present but not much in play. I'd call Bandon Trails a links before I'd call it parkland.