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The use of fire as a management tool in African savannas
has long been a controversial topic. When the Kruger National
Park was first established, fire was viewed as a destructive
entity and was actively excluded. Fortunately scientists
soon realised that fire was a key determinant of savanna
ecosystems by releasing nutrients held in old, dry plant
material, by influencing herbivore distributions and feeding
patterns, by being necessary for certain seeds to germinate
and by influencing the grass/tree balance that defines savanna
ecosystems.
However, the original interpretation of this influence
resulted in managers applying very rigid and fixed burning
regimes, with areas being burnt at the same time of the
year at the same return interval. Recent research has shown
this to have a very negative influence on biodiversity by
favouring those species with a life cycle better adapted
to the specific burning regime. Contemporary ecological
theory emphasizes the importance of disturbance processes
in maintaining the composition and structure of savanna
ecosystems by continuously “resetting the clock”, and fire
is recognised as the most important disturbance process
of all. Central to this is the increasing appreciation of
the historical importance that pastoralist fires and ad
hoc lightning fires played in the maintenance of savannas.
Although the Waterberg is an area with limited potential
for secondary production (i.e. conversion of latent energy
in plants into animal body mass) due to nutrient constraints,
there are no such limitations for primary production (i.e.
conversion of solar energy through photosynthesis into plant
matter). As such, there is considerable vegetation growth
each year during the wet season, and the resulting fuel
loads for fires are therefore very high. Given that the
Waterberg is also an area prone to numerous lightning strikes,
it is reasonable to assume that, historically, fire was
a very important factor in maintaining ecosystem function
in the region. Lightning fires spread outward from a single
point of ignition and therefore have a very different behaviour
to controlled perimeter burns applied by management and
evidence suggests that fires with point ignition that occur
at differing intervals are far more effective in maintaining
habitat diversity across a landscape by preventing bush
encroachment and by creating an optimal patch-like mosaic.
As such, Welgevonden has moved away from a fixed management
burning regime to a more ad hoc point ignition policy whereby
lightning fires are closely monitored but allowed to burn.
However, in doing so, fire behavior is less predictable
and thus manageable and it is therefore necessary for every
lodge on the reserve to have a suitable fire break and to
be suitably equipped to prevent and fight fires. However,
given the distribution of infrastructure on the reserve
and also the fact that the reserve is confined, it is occasionally
necessary for management to intervene to prevent fires from
burning too large a proportion of the reserve at any one
time and/or to assist with preventing damage to infrastructure
and/or to prevent fires from spreading onto neighboring
properties that do not subscribe to the same fire policy.
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