Last Sunday when we were near the villages of Westerbork/Hooghalen we passed this square area where -apparently- all trees had been cut, and thought nothing special about it until we saw the sign saying 'Mislukt bos' or 'The Forest that failed'. Staatsbosbeheer (a Dutch government organisation for forestry and the management of nature reserves) explains and tells about the planting of the lodgepole pine (Pinus Contorta) 50 years ago on this spot.
Common to the US and Canada, the pines unfortunately didn't do well here in the Netherlands. When some ditches in the area were closed in order to save a nearby vulnerable wet heather field, the forest became wetter. The trees were cut down then and now all is left to nature to 'spontaneously' create an area with whatever else will grow.