Bushland Weeds Manual - Environmental Weeds Action Network

Chapter 7 Weed Mapping in Remnant Bushland
Box 7.3 Using maps to monitor change and set priorities at Shenton Bushland
Over the past four years a contractor has been employed to spray the Perennial Veldgrass (Ehrharta calycina)
at Shenton Bushland. Perennial Veldgrass cover was mapped over the period using the method devised by Bob
Dixon at Kings Park. Annual mapping provided a measure of effectiveness for the Perennial Veldgrass control
program over time.
Perennial Veldgrass populations were mapped each May prior to spraying in winter. The maps reflected the
success of the previous year’s control program and were used for allocating the limited resources to priority
areas in the current year. The project began with an $8000 grant to the Friends from the Lotteries commision in
1998. A fire had burnt through the central section of the bushland in October 1997. The Friends used the grant
money to spray a 12 hectare section of unburnt bushland. By 1999 it became clear (with the help of maps) that
the money should have been directed into the burnt areas. From 1999 onwards the Veldgrass populations were
mapped each year and resources allocated accordingly.
1999 Resources available: $2000 grant to the Friends of Shenton Bushland from the Lotteries Commission,
$6000 from Nedlands City Council. Directed to the central bushland area where dense infestations (in red) had
established in good to excellent condition bushland following fire in October 1997.
2000 Resources available: $3500 Community Conservation Grant to the Friends and $6500 from the Nedlands
City Council. The previous year’s work in the good condition bushland was followed up, leaving the dense
infestations around the edges of the bushland until more resources became available.
2001 Resources available: $6000 from Nedlands City Council. With Perennial Veldgrass now at less than 5 %
cover over much of the bushland in good to excellent condition, resources were redirected to the degraded
edges. The dense infestations in these areas were a fire hazard and a seed source capable of re-infesting the
rest of the bushland.
2002 Resources available: $6000 from City of Nedlands and $7000 from Swan Catchment Urban Landcare
Program. Perennial Veldgrass cover across much of the bushland down to around 5 %. Enough resources to do
follow-up work across the bushland excluding the central area.
1999 2000 2001 2002
• 60 - 100% • 5 - 59% •