Fences at Mirrlees Fields now line the two main footpaths as an attempt to curtail access to the full area. They’re shown on the updated map. Rumours suggests the area is for sale, and that planning permission has been denied. As you can see in the photo, the fences are hip-height and not barbed-wire so are more indicative than enforcing.
Wythenshawe is not the only one of our parks with increasing areas for memorial trees. However, at Wythenshawe post Q is now inside the extended enclosure.