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dense woody growth and herbaceous vegetation will differ relative to resources as
a function of fire frequency. Functional responses of resprouting and seeding will
vary depending on growth form and fire regime.
The most resource limited conditions will limit options and favor annual species
that only seed and may not produce sufficient fuels to support fire. As resources
increase, fuels will increase and then the potential for fire is dependent on igni-
tions. When ignitions are not limiting, the seasonal distribution of precipitation
will play a key role in determining postfire response. Under MTC summer drought
and high fire frequency, annual grasses and forbs will dominate with a mixture of
resprouting geophytes that increase with decreasing drought stress. Under warm
growing season conditions such as tropical C 4 grasslands there is increasing
dominance by resprouting grasses with a minor component of annuals. As fire
frequency declines in both systems there will be increasing dominance by resprout-
ing woody species, with the exceptions of MTC obligate seeders discussed above.
As resources are added, functional type options increase but the combination of
temperature, precipitation and soil nutrients will lead to very different growth
form options and productivity, all of which will provide the fuel base for driving
different fire regimes (Pausas & Bradstock 2007 ). For a given fire regime one
can make broad generalizations about resprouting and seeding responses (see
Chapter 3 ) and one can make very useful generalizations across resource and
disturbance gradients (Clarke & Knox 2002 ). Indeed, there is even the possibility
of drawing parallels with other organisms; for example, the persistence strategy of
marine annelids to catastrophic winter storms has been likened to the resprouting
mode of fire adaptations (Barry 1989 ). However, it stands as a major challenge
to produce broad geographical generalizations. Several reviews have provided
additional perspectives on these patterns (Bond & Midgley 2001 , 2003 ; Vesk &
Westoby 2004 ).
Life History and Diversification
MTC ecosystems are among the most remarkable plant biodiversity hotspots on
Earth with many species-rich genera (Cowling et al. 1996 ; Myers et al. 2000 ). The
greatest concentration is in MTC South Africa and Australia, but with some large
woody genera also in California. These are all fire recruiter genera and most are
dominated by obligate seeding species; and it has been suggested that the evolu-
tion of this life history mode was key to their diversification (Wells 1969 ; Raven
1973 ; Cowling 1987 ).
Although both resprouters and seeder life histories are resilient to fire, life
history confers somewhat different population dynamics (Keeley 1986 ; Bond &
van Wilgen 1996 ; Pausas 1999 ) with potential impacts on rates of evolution
(Segarra-Moragues & Ojeda 2010 ). Because fire kills the entire population of
obligate seeders, this life history mode results in a shorter generation time
than is the case with resprouters, thus potentially increasing their molecular
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