this SF/Fantasy forum they have tags, which is pretty much like tags on blogs, and you can search by them. It has been a pretty convenient searching format. Scroll down to the bottom of this page and you'll see the tags (at that forum, typically author, title, series, theme, genre, etc.). I could see it being very helpful in a future update (search for genus, species, things like "soil composition," "water," etc.). Something to think about for a future update (of course I have no idea how updates work and if this stuff costs money, lol.
Time to go mess with my profile! Time to make some friends!