By Andrew Stackpool
RAAF
Base Pearce personnel have planted about 10,000 trees on Defence
land in the Swan River’s northern buffer zone.
The zone, which includes the base, falls within the Ellen Brook
catchment area, north of Perth.
According to base Regional Environmental Officer Peter Gell, the
Ellen Brook has been identified as the principal source of nutrients
that are damaging the Swan River.
“Much of the land around the zone should never have been
cleared, as the soils are incapable of sustaining agriculture
or livestock,” he said. “As a result of that clearing,
the land there has reduced capacity to retain nutrients, particularly
when livestock is not well managed.
“The land is being stripped of all vegetation. When fertilisers
are applied to the soil to compensate for this or there are dense
populations of livestock, excess nutrients are leached from the
fertiliser or the animal manure and flushed into the nearby streams,
then finally into the Swan River. They degrade its water quality
and are seen as algal blooms during the warmer months.”
RAAF Base Pearce, in cooperation with the North Swan Landcare
Group, decided to start restoring the situation by planting the
trees.
“We knew the immature trees would not survive as they would
be choked by the thick growth of weeds and grass in the area,”
Mr Gell said.
“We had the area sprayed with an environmentally-acceptable
herbicide. When the grass died, the Bullsbrook Volunteer Fire
Brigade burned the area off, after which we had a ripper prepare
the soil for planting.”
The tree-planting day was a great success with some 8500 trees
planted in about two hours.
Several other tree planting programs have already been implemented
in the buffer zone.
