The tropical savannas are managed by people
with different viewpoints, who want to know if they are managing
the land well. Yet how do we know if the savannas are healthy when
“health” depends upon your point of view.
Health
workshops | Existing measures | A healthy savanna | How
definition will be used |
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Savanna landscapes: to preserve their health, we
first need to define what we mean by "healthy landscapes". Photo:
CSIRO
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The Tropical Savannas CRC recently held two workshops to develop
definitions of what we mean by “healthy” savanna
country. We have done this because if we want to conserve and use
the tropical savannas in the long term, then we need a way of
measuring how sustainably we are managing the savannas now, and
what changes may need to be made in the future.
In other words we need a way of measuring how
“healthy” the country is, where “health” is
a measure of those properties in the landscape that people value
and want to maintain into the future. Thus a healthy savanna
landscape might have viable populations of native plants and
animals, sustainable pastoral activities or intact Aboriginal
cultural values or a combination of all three depending on the
scale considered.
There are already several measures of the “health”
of the savannas but they tend to focus on a particular set of
properties valued by a particular group of people. For example,
pastoralists have developed measures of pasture productivity and
sustainability; parks managers have developed measures of
biodiversity conservation; and Aboriginal communities have
long-standing measures of the cultural values of the landscape.
But each measure on its own may not be a satisfactory way of
gauging the health of whole regions or catchments as these
different values may conflict with each other. The workshops, which
involved a varied group of land managers, planners and researchers
came up with a broad definition of savanna health as follows:
- Maintains basic functions at all spatial scales including:
- nutrient cycling
- water capture
- provision of food and shelter for fauna
- Maintains viable populations of all native species of plants
and animals at appropriate space and time scales; and
- Reliably meets the long-term needs (material, aesthetic and
spiritual) of the people with an interest in the savannas over the
long term.
Under this definition, a healthy landscape needs to have basic
functions intact, such as the ability to effectively store
nutrients like phosporous and nitrogen and capture moisture so that
it can support pastures, native vegetation, traditional foods etc.
Viable populations of all plants and animals native to that
landscape are also necessary—perhaps not at the scale of
paddock, but certainly at the scale of a catchment.
Over and above these biophysical characteristics a healthy
landscape also needs to satisfy various human values such as the
ability to graze cattle sustainably and the ability to support
traditional Aboriginal practices.
To use this definition, land managers and others need a set of
indicators that would vary depending upon the scale considered. To
measure health at the level of a paddock or a reserve only a few
indicators might need to considered: such as the coverage of
perennial grasses or a measure of biodiversity. But at the level of
a catchment a range of indicators would be needed to cover basic
functions, biodiversity, pastoral and Aboriginal values.
The TS-CRC has already coordinated considerable research on a
range of potentially useful indicators and properties. A major task
for the TS-CRC in the future is to refine an appropriate set of
attributes or properties of the savannas that different user groups
value—and a set of easy to measure indicators that tell us
how we are managing these properties. The Centre has therefore
sought the views of a wide range of people, with interests in
savanna management, to describe the attributes of a healthy savanna
and to identify ways in which those attributes can be measured.
In short, the aim of this exercise is to develop shared ideas
about what features of the savannas are particularly important and
need to be maintained over the long run, and to develop
well-understood and widely-accepted methods for tracking how well
we are doing.
