Grasslands of Cape York Peninsula— a fire-dependent habitat

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Grasslands of Cape York Peninsula— a fire-dependent habitat Powered By Docstoc
					Grasslands of                                                      The processes involved in loss of habitat include
                                                                   changes in vegetation structure.This has led to more
Cape York Peninsula—                                               successful predation by birds such as pied
a fire-dependent habitat                                           butcherbirds and loss of perennial grasses such as
Grasslands in CapeYork are being invaded by woody                  cockatoo grass (Alloteropsis semialata), which seed-
plants, particularly tea-tree (Melaleuca spp.), in the             eating birds rely upon for food at critical periods of
absence of fires or under limited burning. The                     the year (especially the early wet season).
diagram below illustrates the effects of fires at                  Vegetation thickening also results in loss of termite
different seasons on development of woody suckers.                 mounds in which the golden-shouldered parrots nest.
Grasses compete with tea-trees through the wet                                                     by Gabriel Crowley
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                     Further reading
grass regrowth following an early dry season fire                  Crowley, G. M. and Garnett, S. T. (1998). Pacific
is soon grazed out or dies, while the tea-trees                    Conservation Biology 4: 132–148.
continue to grow.                                                  Crowley, G. M. and Garnett, S. T. (2000). Australian
The later in the dry season that a fire is lit, the smaller        Geographical Studies 38: 10–26.
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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