I just wrote a long post about archetypal dreams and ecopsychology over at my dream studies site. Check it out; this is an important meeting grounds of ecology and dreams.
In the past, most communities listened to the dreams that bubbled up, especially during hard times. One of the interesting elements of human leadership is the dream-vision that speaks for the community at large. For better or worse, charistmatic leaders often used these emotionally powerful visions to stir up action, or face something that they could no longer afford to ignore.
That's where archetypal dreams come into play, socialized and legitimized by their authenticity.