A weed is any plant out of place.
Environmental Weeds
Environmental weeds are plants that represent a
threat to the
conservation values of natural ecosystems. They invade native plant
communities and out-compete them causing a reduction in plant diversity
and resulting in a loss of habitat for native animals.
Some examples of
environmental weeds are bridal creeper, bitou bush, boneseed,
blackberry and lantana.
Environmental weeds can also be native
Australian plants that are not local (indigenous) to the area they are
growing in. They have the potential to displace and out-compete plants
within the local plant community. Examples of native Australian plants
that are doing this are sweet pittosporum and coast wattle.
Noxious Weeds
Some serious weeds are required by law to be
controlled by all
landholders in an area. These are known as noxious weeds and the law
that controls these in NSW is the Noxious
Weeds Act 1993.
Weeds that
are declared noxious are those weeds that have the potential to cause
harm
to the community and individuals, can be controlled by reasonable means
and most importantly, have the potential to spread within an area and
to other areas.
A weed is declared noxious because its control
will
provide a benefit to the community over and above the cost of
implementing control programs.
The Noxious
Weeds Act 1993 classifies weeds into numbered control
classes, each of which require a different level of control. The Act
requires that 'the growth and spread of Class 4 weeds must be
controlled according to the measures specified in a management plan
published by the local control authority'. For land within a local
government area, the Council is the local control authority.
The Management
Plan for Class 4 weeds in the Rockdale City Council area includes
Serrated Tussock, Rhus Tree, St John’s
Wort, Prickly Pear, Privet, Asthma Weed, Blackberry, Camphor Laurel,
Castor Oil Plant, Chilean Needle Grass, Harrisia Cactus and Lantana.
Duckweed at
Bicentennial Ponds
During the summer months duckweed does occur at
Bicentennial Ponds. This
plant floats on the water surface in a bright green layer.
This weed is
a native plant and appears in waterways when there is the presence of
excess nutrients.
Duckweed is non toxic and is a food source for
many
animals that live within the wetlands. Its main benefit, however, is
its
ability to remove excess nutrients from the water - a common problem
for urban waterways.
Research has also found that duckweed prevents
a number of noxious
weeds from growing in our waterways, for example, blue green algae.
Are these weeds
affecting your health?
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