I am confused about the sentence below. Which structure is used: importance of + Ving or the importance of + ADJ + Noun ?
In recently years, there has been growing awareness of the importance of preserving the world's biological diversity.
The object of the preposition of here is the entire gerund phrase “preserving the world’s biological diversity”, and “the world’s biological diversity” is the direct object of preserving.
We can’t have adjectives working as prepositional objects. Since that makes preserving is a gerund, it is here functioning as a noun, although it still has verbal properties like having its own object.
There is nothing that preserving is acting as a modifier for, either. It’s the head of its own VP (verb phrase). Here’s the full parse:
Oh, and notice that you cannot say “in recently years”: it must be “in recent years”, because you need recent to be an adjective modifying years, and recently is an adverb.