When this enclosure was refurbished some time ago I was sceptical that any of the new plantings would last with the chimps, but they have established very well and the enclosure is looking pretty lush now. It is hard to see in photos because most of the vegetation is on the far side of the enclosure.
@Chlidonias I thought the same, but from what I’ve seen on my visits, the size of their chimpanzee troop provides them with stimulation as opposed to a smaller troop (with less interactions) where they rely more on the environment to provide that same stimulation.