35312.4.3 Analysis Results
12.4.3.1 Burning
Our analysis revealed that burning reduced percentage cover of B. tectorum in the
early phases of studies, yet after a few years, this effect was not significant
(Fig. 12.3 ). In contrast, burning clearly increased biomass production of B. tectorum
on a per area basis in both the short and long term. The ability of B. tectorum to
recover after being signifi cantly reduced by wildfi re has been attributed to survival
of seeds on the soil surface that are not consumed by fi re (Diamond et al. 2012 ). In
addition, B. tectorum seedlings that emerge after burning experience lower intraspe-
cifi c competition and produce plants with greater seed production (Evans and Young
1978 ), which explains why biomass production increased more than cover over
time. Consequently, even though burning can reduce litter, increase bare ground,
and temporarily reduce B. tectorum competition with seeded desirable perennial
grasses (Young et al. 1969 ; Evans and Young 1970 ), these conditions appear to be
transitory. In fact, recent research illustrates that a very short time period exists after
wildfi re when conditions are favorable for the establishment of perennial species
(Pyke et al. 2013 ). Applying this knowledge to adaptive management would entail
prioritizing seeding events as closely as possible after burning and incorporating an
understanding of how burning interacts with site-specifi c differences in litter pro-
duction and temperature/precipitation regimes (Bansal et al. 2014 ; Chambers et al.
2014a ; Jones et al. 2015 ).
Fig. 12.3 Results of analysis comparing different Bromus tectorum control methods. Symbols
represent mean lnRR effect sizes (±95 % confi dence intervals) for percentage cover and biomass
production for B. tectorum 1 year after treatment ( closed symbol ) and 2 or more years after treat-
ment application ( open symbol ). Mean effects are considered signifi cant when confi dence intervals
do not overlap the vertical zero line. Values in parentheses indicate number of articles (e.g., Table
12.1 ) used to calculate effect sizes for early and late responses, respectively
12 Assessing Restoration and Management Needs for Ecosystems...