Review of Grassland Management in south-eastern ... - Parks Victoria

Parks Victoria Technical Series No. 39
Grassland Management in SE Australia
grass-dominated systems, the option to graze may be viable to control weed densities of
some species. Grazing, when used in this context, should only be used for very short periods
and should aim to reduce the potential seed set of exotic annuals. There is little knowledge
on the application of grazing to reduce seed set of exotic perennial species and the use of
grazing for this purpose is not seen as applicable with many perennials able to flower and
seed throughout favorable conditions. Grazing should only be utilized during the spring to
early summer period for this purpose. To create a simple framework within which grazing of
remnant vegetation can be justified, a decision tree has been created and presented at the
conclusion of the document.
2. Non-Kangaroo grass-dominated systems (includes Wallaby grass and Spear grassdominated
communities)
The present state (or condition) of non-Kangaroo grass-dominated systems currently within
the conservation reserve system can be considered as being modified since the time of
European settlement. These systems now consist almost entirely of grazing-tolerant species.
For this reason, grazing is generally viewed as having little impact on the persistence of flora
in these regions. However, the evidence to imply that grazing is required to maintain floral
and faunal biodiversity values of these systems is not present in the literature. There is a
growing evidence to suggest that grazing simplifies the complexity, age and size structure of
these communities. This reduces the ability of these systems to persist through, and respond
to, unfavorable and favorable conditions, which may have detrimental impacts on individual
species and, in turn, on the community as a whole. Grazing also maintains plant
communities in early successional states. Grazing impacts ecosystem function via soil
disturbance associated with the use of hoofed animals, nutrient shifting and the introduction
of exotic plant and animal pests. Regardless of how well managed the system is, this
disturbance leads to increases in the fluctuation in bare ground levels, facilitates exotic
annual weed invasion, leads to degradation of soil crusts and reductions in biodiversity
values. The goal of managers should be the removal of grazing in these systems with
subsequent monitoring of habitat structure, complexity and biodiversity. Monitoring of grazing
removal should follow a similar approach to that used at Fabian’s paddock in Terrick Terrick
National Park (and elsewhere, e.g. Kinypanial), where grazing exclusion plots have been set
up since 1994. Monitoring of grazing removal allows managers to assess the impacts of
removal on habitat and diversity and allows managers to act well in advance of any
deleterious effects forewarned by changes in the exclusion plots. By this approach, any
unexpected longer-term negative effects caused by grazing removal will be documented in
the exclusion plots, well before the majority of the area of the native grassland is threatened
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