The article
Introduced grasses: triumph or Trojan horse
raises valid concerns about the potential for introduced plant
species to spread beyond what was originally intended and then
disrupting ecosystems through disturbing existing fire,
hydrological or competitive regimes. The need for caution in
introducing plants from overseas is self-evident and would be
shared across many interest groups.
For example, exotic woody weeds in northern Australia are a major
threat to both ecological integrity and pastoral production, and
these weeds have often been a consequence of the plant's
introduction to Australia for ornamental or other reasons. So there
needs to be care, whether the plants are intended for pastoral use
or gardens.
The specific question of introducing plants as potential pasture
species is not always cut and dried. For example, the precautionary
principle taken to the extreme would indicate no introduction of
exotic plants: no roses, no wheat, no ryegrass. Clearly this
position is extreme and narrow. Pasture plants have been important
to the livestock industries in most parts of Australia, and in
extensive areas, a good pasture plant must he hardy as well as
palatable. So, there will always be some potential for the plant to
go beyond where it is intentionally planted. There is always some
risk.
Obviously, we should learn from past mistakes and be more cautious
and stringent about plant introduction and evaluation. We should be
especially careful about introducing plants that have
characteristics not found amongst the native plants (gamba grass
appears to be an example) or that are adapted to particular
habitats (e.g. waterways).
Much of the Australian environment has already been disturbed in
one way or another, even in far northern areas, so the issue is
really about how we manage these changes based on a sound
ecological understanding.
Mick Quirk, Queensland Department of Primary Industries Charters
Towers
Click here to view the forum article
Introduced grasses: triumph or Trojan horse
