>there really is no other plant and animal habitat like it around.

Given that the ecosystem in the park is a disaster built on landfill, I think this is the weakest argument. Yes there are plants and animals there, but it is in no way natural or even close. What would be nice as part of a master plan for the park is if the 'forbidden zone' could be turned into both sports fields and actual natural lands of native species and an ecosystem helped by landscaping to be more like a natural setting. It could eventually look more like Central Park instead of a landfilled rail yard let gone to seed.