1. There are many needle-leaved trees in the mountain.

2. There are many needle-leafed trees in the mountain.

3. There are many needle leaf trees in the mountain.

4. There are many broad-leafed trees in the mountain.

5. There are many broad-leaved trees in the mountain.

6. There are many broad leaf trees in the mountain.

(Would you let me know correct English expressions?)

2 and 4 are correct.