The Policy of Border Fencing between the United States and Mexico: Permeability and Shifting Functions

Curt McCasland, a biologist and the assistant manager of CPNWR since 2005, fears destruction of native plant cover, both from the direct clearing of the plants and from the illegal roads that function as canals, changing water flows during storms and bringing in aggressive invasive species (Ingley 2005; McCasland, e-mail to the author, May 30, 2007). The list of boundary functions described by Morehouse (1995) provides a spectrum of broad, primary functional categories of borders.\n The U.S. Fish and Wildlife and U.S. Border Patrol officials suggested this proposal would both minimize the amounts of illegal goods that could be transported into the United States and improve environmental conditions by, among other things, stopping the creation of illegal roads, while still allowing wildlife to pass above and below the barrier.