How have humans influenced our native landscapes and native species?

Question

Discuss both negative and positive influences on native North American grasslands and the American bald eagle.

Answer 1

Humans have converted  great deal of those grasslands to farmland displacing many native species.  The use of DDT, a pesticide, is blamed for weakening the shells of the bald eagle causing them to break before hatching.  DDT breaks down slowly and accumulates in the food chain.  The bald eagle is at  the top of the food chain and received the DDT in concentrated amounts.

DDT is now banned in the US and the bald eagle is recovering.

Answer 2

I do not know the positive influences but these are a few influences -

http://www.jstor.org/pss/3809151

http://cat.inist.fr/?aModele=afficheN&cp...

http://www.esajournals.org/perlserv/?req...

http://www.fws.gov/midwest/eagle/guideli...

http://elibrary.unm.edu/sora/jrr/v016n04...

Grasslands -

http://www.cec.org/files/PDF/BIODIVERSIT...

http://www.ibiblio.org/london/permacultu...

http://www.npwrc.usgs.gov/resource/habit...