what are good sites to look up stuff on earth science such as ecosystems and different geographic land types?

Question

i just need to know about sand dunes in florida.How their ecosystem works. Its for a research paper and i cant seem to find much but how they are made, and what plants are living there.

Answer 1

http://www.miamidade.gov/derm/Ecosystems/coastal_ecosystem.asp
http://sofia.usgs.gov/virtual_tour/ecosystems/index.html

also:
http://www.fi.edu/tfi/units/life/habitat/habitat.html