I think any above-ground vegetation should count toward varying degrees of forest. On desert maps it's so pleasant to not worry about forests... but then on the others you realize even with the humble trait, only one, MAYBE two sauropods can fit into an enclosure unless you vastly expand the space. While huge enclosures are sometimes nice, it doesn't make sense that adding 'tall leaf' sacrifices forest when it is, quite literally, a forest. Even the fruit trees should count as perhaps the lowest amount of forest, as the goal of forest would theoretically be to give protection, shade, etc. Yes, you could on Sandbox remove the dinosaur comfort, but that wouldn't be quite as fun. An option or change where each above ground vegetation counts as some degree of forest would be very welcome! 