There's an interesting article in the Globe and Mail about fiddlehead ferns and wild ramps. The article says that increased interest in these wild foods is endangering them. For example, eating a mature ramp bulb is eating 18 to 20 years of growth. If too many people eat too many of them, there won't be any more. Likewise, so many people are eating so many fiddleheads from ferns, they are damaging the plants.
In my opinion, this isn't because of a growing interest in wild food, but because of greed. (Like the changing meaning of organic and local, as it becomes corporate lingo.)
As with everything else, in wild food we need to take a little and leave a lot to enjoy later.