Biology Reference
In-Depth Information
Figure 2.3:
An area of former woodland that has been extensively cleared and degraded. (Photo by Philip
Gibbons)
amounts of exotic annual grass cover. Conversely, where the ground layer is
dominated by native grass cover, species like the threatened Superb Parrot are
more often found and the diversity of reptiles is higher.
4, 7
Some of the threats listed above can be addressed with good farm management.
For example, the intensity of grazing pressure can be controlled by fencing,
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although the construction of fences needs careful consideration. Barbed wire on
the top strand of a fence should be avoided wherever possible because many kinds
of flying and gliding animals can become entangled in it (Figure 2.4). For those
fences where it is not feasible to substitute barbed wire with straight wire, it can be
useful to enclose barbed wire in a poly-pipe covering or to tie flagging tape to wire
to make it more visible to flying and gliding animals.
Changing from traditional set-stock grazing to rotational or cell grazing
methods is another significant way a land manager can improve the ground layer
of patches of remnant native woodland. Reducing grazing pressure by domestic
livestock and using strategic grazing at certain times (such as in late winter-early
spring) can limit growth and flowering of exotic annual grasses. This will help
promote the development of swards of native grasses (see below), many kinds of
native ground cover plants, and moss and lichen mats.
The use of prescribed fire also may help reduce high levels of phosphorus in the
soil.
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Only an appropriate fire regime or sequence of fires should be applied,
however. Burns that are too frequent may over-simplify the structure of the
understorey layer of some woodland types with the risk of negative impacts for
animals associated with it. In some novel research, sugar was successfully used to
reduce soil nitrate and restore native perennial grass (see Box 2.2). Direct seeding
of other kinds of native ground cover plants also has been found to be successful in
some regions, provided the initial exotic ground cover is controlled or removed.
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Halting practices like raking of leaf litter and fine woody debris is important
for maintaining the integrity of the litter layer and promoting habitat suitability for
