@blospz I believe they have access to the pine tree that is only partially in view in the front on the left side (notice the branches for climbing into it), the smaller pines trees in the back right and the pine tree behind the Chinese gate (I believe I see a nesting log up in there too) but not the big pine trees in the background, behind the red back wall of the exhibit.
The tree on the left-hand side is extremely high, at least 3 stories in height, and the animals have full access to it with zero hotwire anywhere. There are also a few much shorter trees that the Red Pandas have access to, but some at the very back are outside the exhibit.