Plant invasion study in Californian grasslands investigates the likelihood of extinction of native species
by University of Toronto Professor Benjamin Gilbert, and Jonathan M. Levine, (Institute for Integrative Biology, Eidgenössiche Technische Hochschule Zurich, Switzerland)
Invasive plants lower native seed production and habitat connectivity, both of which increase native extinction rates. However, the time to extinction can be on the order of hundreds of years.
See article in U of T News article (Jan 11, 2013) or view the full paper plus supplimemntary materials on the PNAS web site.
Title: Plant invasions and extinction debts
for full pdf plus supporting information http://www.pnas.org/content/early/2013/01/04/1212375110.full.pdf+html?with-ds=yes