The Don of the fabulous Green Hermeticism blog pointed me to research on 'Wild urban woodlands' ages ago but only now have I managed to have a proper look. I think most of it deals with the controlled reforesting of abandoned landscapes (empty cities, decommissioned coal mines, etc). In a section on 'industrial fallow lands' as pedagogic challenges (the cryptoforest as a free school?) the following table is given.
Dog walkers as an unrecognized class of urban explorers? 100 Lingerers? 152 Acts of adolescent activity (sex?)?? 33 Foraging acts (berries plus mushrooms)??? Seven arsonists???? One hunter, hunting for what????? & who can tell what somebody is up to?