How could buffer zones mitigate the problems of overcrowding, development, pollution, and invasive species in national parks?

These buffer zones act as separators

Explanation:

Buffer zone is basically an area that is left intentionally between two land that have different land uses. Therefore, different land parcels with in a national park having different usages are kept separated from each other so that the activities happening in one land parcel shall not affect the activities of other land parcel

Hence, in this way problems such as overcrowding , development, pollution etc. in one land parcel does not reach /affect /or deteriorate the land or environment of other land parcel.