Battle to save native plant from invasive Boneseed

Monday 30 July, 2012

A program to target the noxious Boneseed weed in the You Yangs Regional Park has commenced in an effort to control its spread and save the threatened native orchid, Brittle Greenhood.

Boneseed (Chrysanthemoides monilifera), an introduced pest plant, has spread to cover three quarters of the You Yangs.

The program’s objective is to protect the natural values of the You Yangs through controlling invasive species.

The $30,000 program is part of the State Government’s $19.7 million flood recovery program.

Following the 2010-11 floods, conditions were ideal for the prolific growth of Boneseed, which is an introduced species that is dispersed by animals such as foxes, through floodwater movement or soil disturbance such as land slips.

The program to control the weed that grows to 1.5 metre bushes was in mechanical, chemical and manual control strategies. He complimented the efforts of volunteers who provide more than 3,000 hours toward controlling the noxious weed every year.

David Flagg, Ranger at the You Yangs, said Boneseed germinates in autumn months and winter and spring are the optimal seasons to treat and control their spread.

“One way we will gauge our success in removing the weed is by observing the resurgence of native plants, like the Brittle Greenhood,” Mr Flagg said.

Boneseed is known to decrease regeneration of native trees and shrubs, negatively affecting wildlife through the displacement of essential food plants. The rare Brittle Greenhood Orchid is classified in Victoria as threatened and the You Yangs is one of only three areas where it is known to grow.

“Brittle Greenhood once covered hectares at You Yangs. Its decline can be attributed to the emergence and invasion of Boneseed. The activity Parks Victoria is undertaking will hopefully return indigenous flora like the Greenhood back to the park,” Mr Flagg said.

Background

Boneseed (Chrysanthemoides monilifera) is a regionally controlled weed in the Port Phillip and Westernport and Corangamite Catchment Management Authorities and is listed as a Weed of National Significance.

Storms caused major erosion and debris flows throughout parks and reserves across Victoria. It is likely these areas will be colonised by invasive species if a seed source is present. In areas there has been a loss of ground cover and the creation of bare ground. The major risks concern loss of significant flora, fauna, soil and vegetation. Ongoing risks include pest plant and pest animal impacts.

Risk assessment is undertaken to establish priorities for the mitigation of risks to areas within the Parks Victoria estate.

Preventing high-risk invasive species from establishing is the most cost-effective approach to managing the threat they pose. Prevention of weed establishment and post establishment management requires the coordination of a number of activities:

• Risk assessment to determine which species need to be addressed;
• Analysis of pathways by which these species may be introduced;
• Surveillance to ensure timely detection;
• Prompt identification of suspected high-risk species;
• Follow-up works and ongoing monitoring.