leaving what you find or choosing carefully what you take

On a trip into the forest in Switzerland with some kids in the middle of mushroom season, we took some time to look at some examples.  It was tricky working out which ones were edible and I decided not to take any home.  It seemed better to leave it and not take the chance rather than risk dying horribly. 
While the consequences for us aren't usually so extreme, it is the cumulative taking beyond the capacity of nature to regenerate that causes problems.  The population of humans is great and it only takes a small proportion of people to take more to cause a collapse in some plant, animal or fungus. 
In Switzerland where we live, there is a ban on taking mushrooms in the first 10 days of each month.  A bit like a rahui, that helps protect food crops for future generations. 
I still think that if in doubt, leave it.  There are enough places that are overused and I think there should be places where we show some self restraint. 
Chris LNTNZ chair