 Re: Please check if the sentences are correct and natural
Re "this" and why the general situation is unimportant: This is more emphatic than "the". So using it here emphasises that we really are talking about this forest rather than forests in general. The speaker is saying "It's only this one that's important. Although I know that, in general wolves aren't an "unsurprising" component of forests, you can forget about that. because in this one they are "integral and unsurprising" The meaning is the same with "the" of course, - it's just emphasis.
As for the other sentences you propose, as we've seen above, if you think of a specific context, almost any sentence can be possible. But with all of the sentences you suggest, there is/are would be more likely in any ordinary context. |