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negative ecosystem impacts in that aggressive grass growth will diminish native
recovery and diversity (Keeley 2004 ). Since this cereal is a sterile annual, there is
no second-year establishment and where there is abundant first-year growth there
is a vacuum created in the second year that could attract alien invasions. Regardless
of the attributes of seeded species, there is always the potential for contaminants in
the seed lot. For example, following the 2000 Cerro Grande Fire in New Mexico,
USA, it is estimated that aerial seeding inadvertently sowed over a billion seeds of the
highly aggressive alien Bromus tectorum (Keeley et al. 2006a ). Physical barriers
created by mulch and hay bales also have the potential for introducing exotic species
and as a consequence more and more such projects are requiring weed-free hay.
It is sometimes proposed that seeding of native species is more in line with
ecological management objectives and in the Mediterranean Basin natives are
routinely used for postfire seeding. However, even this has the potential for
impacting communities by upsetting aspect-specific community assemblages. In
addition, seeding natives, as with non-natives, tends to result in a dominance of
one or a few species and reduce native plant diversity (Dodson et al. 2010 ).
Postfire responses to ecosystem losses such as tree mortality involve replanting
seedlings. In crown fire ecosystems this may not be warranted, but in forests with
surface fire regimes, where forest regeneration requires survival of parent seed
trees, crown fires can greatly set back recovery without active replanting. Many
fires in the Mediterranean Basin occur in old-fields, which are dominated by early
succession flammable species (see Chapter 4 ) . In such situations, one of the post-
fire management actions includes planting seedlings of less flammable resprouting
species. The objectives of such an option are to increase the resilience to new fires,
as well as to increase soil stabilization in the midterm (Pausas et al. 2004a ; Vallejo
et al. 2006 ).
Future Fire Management
Future global changes in MTC regions and associated landscapes with MTV will
undoubtedly stress our ability to maintain community safety and sustainable
ecosystem structure and processes. Increasing population growth coupled with
continued urban sprawl and potential changes in fire regime due to climate change
will be some of the most critical factors.
Climate change impacts are intimately tied to fuel structure, both because fuel
structure affects how climate changes will alter fire regimes and because climate
change impacts will potentially alter fuel structure. Forests where fuels largely
comprise understory litter respond differently to climate than forests with herb-
aceous surface fuels (e.g. see Fig. 2.8) and both respond differently than crown fire
shrubland fuels.
There are numerous predictions that in most fire-prone landscapes in western
North America, Australia and the Mediterranean Basin fire activity will increase
with global change due to expected climatic changes (e.g. Pitman et al. 2007 ;
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