Grasslands of
Cape York Peninsula—
a fire-dependent habitat
The processes involved in loss of habitat include
changes in vegetation structure.This has led to more
successful predation by birds such as pied
butcherbirds and loss of perennial grasses such as
cockatoo grass (Alloteropsis semialata), which seedeating birds rely upon for food at critical periods of
the year (especially the early wet season).
Grasslands in CapeYork are being invaded by woody
plants, particularly tea-tree (Melaleuca spp.), in the
absence of fires or under limited burning. The
diagram below illustrates the effects of fires at
different seasons on development of woody suckers.
Vegetation thickening also results in loss of termite
mounds in which the golden-shouldered parrots nest.
Grasses compete with tea-trees through the wet
season, but die off earlier in the dry season than
the deeper-rooted trees. Fires cut back tea-trees,
but also stimulate growth. The small amount of
grass regrowth following an early dry season fire
is soon grazed out or dies, while the tea-trees
continue to grow.
by Gabriel Crowley
Further reading
Crowley, G. M. and Garnett, S. T. (1998). Pacific
Conservation Biology 4: 132–148.
Crowley, G. M. and Garnett, S. T. (2000). Australian
Geographical Studies 38: 10–26.
The later in the dry season that a fire is lit, the smaller
the tea-trees will be by the next wet season. Only
very late dry season fires or storm-burns will keep
most re-suckering tea-trees below the grass height.
After four or five years with no fire or early dry
season burns, the grasslands can be completely lost
to tea-tree woodland.
A major implication of grassland thickening on Cape
York is the ensuing loss of habitat, particularly for
granivorous birds such as the golden-shouldered
parrot, star finch, Gouldian finch, buff-breasted
button-quail and black-faced woodswallow.
The effects of fire in different seasons on the development of wood suckers
These consequences of fire are not unique to Cape York Peninsula. Except for the potential high density for tea-tree
suckers, similar effects occur in many grazed and ungrazed woodlands.
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