Any potential natural area recommended for inclusion in the State Register shall possess one or more of the following characteristics:
1. Rare, threatened, or endangered plant or animal species habitat;
2. Outstanding plant community type which is representative of the natural diversity of this state;
3. Outstanding geological element which is representative of the geological history or processes of this state;
4. Outstanding aquatic elements which are representative of the aquatic diversity of this state; or 5. Unusual natural features, such as vegetation types, virgin stands, or other unique biological or ecological phenomena.