412009 ; Augustine 2010 ), northern mixed-grass prairie (Whisenant and Uresk 1990 ;
Vermeire et al. 2011 ), and southern mixed-grass prairie (Whisenant et al. 1984 ;
Ford and White 2007 ; Teague et al. 2008 , 2010 ; Vermeire et al. 2014 ) may be unaf-
fected by fi re or can recover productivity and species composition within 6 months
to 2 years of burning, depending on precipitation amounts during the recovery
period (Teague et al. 2008 ; Augustine and Milchunas 2009 ). Grazing is often
reported not to alter the effects of fi re (Augustine et al. 2010 ; Vermeire et al. 2014 ).
Not only do these ecosystems have high resilience to fi re, but fi re either reduces
(Whisenant and Uresk 1990 ; Scheintaub et al. 2009 ; Teague et al. 2010 ; Vermeire
et al. 2011 , 2014 ) or does not affect (Teague and Dowhower 2003 ; Augustine and
Milchunas 2009 ; Augustine et al. 2014 ) abundance of Bromus. However, in some
cases when Bromus were initially reduced by spring burning, they increased in
abundance the second year after the burn (Whisenant et al. 1984 ).
Fig. 2.14 In southern Northern Great Plains Network prairie parks, plots with high cover of
Bromus have lower native plant species richness than plots with little Bromus cover. NM = National
Monument; NP = National Park; NHS = National Historic Site; NMem = National Memorial.
(Courtesy of the National Park Service, Northern Great Plains Network Inventory and Monitoring
Program)
2 Exotic Annual Bromus Invasions: Comparisons Among Species and Ecoregions...