Fires regularly affect many of the world's terrestrial ecosystems, and, as a result, fires mediate
the exchange of greenhouse gases (GHG) between the land and the atmosphere at a global scale
and affect the capacity of terrestrial ecosystems to store carbon (Bowman et al. 2009). Variations
in fire -regimes can therefore potentially affect the global, regional and local carbon
balance and, potentially, climate change itself (Bonan 2008). Here we examine how variation in
fire regimes (Gill 1975; Bradstock et al. 2002) will potentially affect carbon in fire-prone Australian
ecosystems via interactions with the stocks and transfers of carbon that are inherent to
all terrestrial ecosystems.
There are two key reasons why an appreciation of fire regimes is needed to comprehend the
fate of terrestrial carbon. First, the status of terrestrial carbon over time will be a function of
the balance between losses (emissions) from individual fires (of differing type, season and
intensity), which occur as a result of immediate combustion as well as mortality and longerterm
decomposition of dead biomass, and carbon that accumulates during regeneration in the
intervals between fires. The length of the interval between fires will determine the amount of
biomass that accumulates. Second, fire regimes influence the composition and structure of
ecosystems and key processes such as plant mortality and recruitment. Hence, alternative trajectories
of vegetation composition and structure that result from differing fire regimes will
affect carbon dynamics.
We explore these themes and summarise the dynamic aspects of carbon stocks and transfers
in relation to fire, present conceptual models of carbon dynamics and fire regimes, and
review how variation in fire regimes may affect overall storage potential as a function of fireinduced
losses and post-fire uptake in two widespread Australian vegetation types. We then
appraise future trends under global change and the likely potential for managing fire regimes
for carbon 'benefits', especially with respect to emissions.