Grazing by abundant elk and bison in the riparian areas of Yellowstone National Park has been suggested to damage the vegetation. This, however is controversial. See:


Frank, DA 1998 WILDLIFE SOCIETY BULLETIN 26: 410-418


Frederick H. Wagner. 2006. Yellowstone's Destabilized Ecosystem: Elk Effects, Science, and Policy Conflict. Oxford, 2006.


Limnology - the study of inland waters
Photo: 20 October 2012