Pest Plants and Animals

December 2008 Fact Sheet No. 9

Commissioner Environmental SustainabilityVictoria

Threats to our native biodiversity

www.ces.vic.gov.au

This fact sheet is one of a series, developed from material presented in Victoria’s first comprehensive State of the Environment Report. The Report is a major undertaking of the Commissioner for Environmental Sustainability and covers a broad range of environmental issues affecting the State. Its purpose is to improve community understanding of Victoria’s environment, and through the use of recommendations, to enhance its condition for present and future generations. The report was released in December 2008 and is available at www.ces.vic.gov.au

Key Findings

• PestspeciescontinuetoestablishinVictoriaandposeamajor threat to biodiversity, primary production and the aesthetics of natural landscapes.

• WeedsaffectallVictorianlandscapes.Approximately90%of the native bushland in Metropolitan Melbourne is badly affected by weeds.

• Almost80%ofexoticplantsthathaverecentlybecomeestablished in Victoria are of garden origin.

• ThetotalcostofpestspeciesinVictoriaisestimatedat$900million per year.

• Costsofpestcontrolcompromiseresourcesavailableforother resource management activities.

Rabbits and blackberries – a bad idea

Non-native plants, animals and invertebrates have been introduced to Victoria both deliberately and accidentally. Deliberate introductions include: rabbits (Oryctolagus cuniculus), foxes(Vulpes vulpes) and blackberries (Rubus fruticosus). Other species have escaped from domestication (agriculture, forestryandhouseholds),forexample,feralcats(Felis catus), Toowoomba Canary Grass (Phalaris aquatica),RadiataPine(Pinus radiata) andmanyotherenvironmentalweeds.Pestspecieshaveinvaded natural ecosystems and have significant economic and socialimpacts–pestspeciesareestimatedtocostVictoria$900million per year in lost production and eradication.

Figure 1. Numbers of introduced (a) plant species and (b) vertebrate species recorded in Victorian bioregions.

Fox, Vulpes vulpes

Paterson'scurse,Echium plantagineum (Salvation Jane, Riverina bluebell, blue weed, purple bugloss)

Weedscandisplacenativeplantsandchangethestructureofnativevegetation.Weedsratesecondonlytohabitatlossasa threat to Victoria’s biodiversity and weeds have invaded all Victorian landscapes.

Pestanimalsalsothreatennativebiodiversity,eitherdirectlybypreyingonnativespeciesorbychangingtheirhabitat.Pestanimals degrade habitat by grazing, introducing weeds and promoting erosion. Key pest animal species in Victoria include theRedFox,rabbits,feralcatsandwilddogs.

Peststhreatenournativebiodiversity

The number of introduced plant and animal species recorded inVictoriahasremainedrelativelyconstantsince1990.Areassurrounding metropolitan Melbourne have recorded the greatest number of introduced species, probably due to a combination of escaped garden plants and higher survey effort. Remote areas in Victoria’s north and east have fewest introduced species.

Weedinvasionsareoneofthemajorfactorsinlossofbiodiversity, along with land clearing and climate change. Impacts of environmental weeds on ecosystems include: changed stream flows and flooding patterns, increased soil erosion, changed soil chemistry and nutrient cycling patterns, and changes in fire regimes due to changes in vegetation.

Approximately90%ofthenativebushlandinMetropolitanMelbourneisbadlyaffectedbyweeds,withmorethan50%considered severely degraded. This is in large part due to garden escapees, a major source of weeds in Victoria.

Predationbyfoxes,catsanddogsisaknownthreateningprocessfor at least 26 threatened species in Victoria and inflicts large management costs. It is now one of the main threats to the remaining populations of the critically endangered Eastern Barred Bandicoot (Perameles gunnii). Eradication of established pest species is difficult but ongoing management can be successful. Pestanimalsalsocompetewithnativespeciesforfoodandhabitat.

Pestspecies–agradualinvasion

Exoticplantspeciesrepresentapproximately30%oftheVictorianflora, with over 1,280 species considered naturalised in Victoria. This has increased from 878 naturalised species in 1984. It is estimatedthatanaverageof7.3newplantspeciesestablishinVictoriaperyear,andthisthatrateincreaseseachyear.Almost80%ofrecentlyrecordednaturalisationsinVictoriahaveescapedfrom gardens.

Figure 2. Native and naturalised plant species recorded in Victoria.

The area occupied by naturalised plant species increases annually. Some of Victoria’s most significant weed species are likely to become more widespread with climate change and land-use change.

Most pest animals occur and are managed on local scales and statewidetrendsinpestspeciesarenotmonitored.Whilefoxesand rabbits are widespread throughout Victoria, wild dogs and feral pigs are absent or unknown over large areas of Victoria.

State of the Environment Victoria 2008 Fact Sheet SeriesPublishedbytheCommissionerforEnvironmentalSustainabilityMelbourne,Victoria,2008©The State of Victoria, Commissioner for Environmental Sustainability 2008Thispublicationiscopyright.NopartmaybereproducedbyanyprocessexceptinaccordancewiththeprovisionsoftheCopyrightAct1968.

AuthorisedbytheVictorianCommissionerforEnvironmentalSustainability,16/570BourkeStreet,Melbourne,Victoria3000

For further information contact the Office of the Commissioner for Environmental Sustainability, phone +61386362917orvisithttp://www.ces.vic.gov.au/SoE

DisclaimerThis report may be of assistance to you and every effort has been made to ensure that the information provided is correct. It is based largely on data and information provided by the Victorian Government. The Commissioner for Environmental Sustainability does not guarantee that the report is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.

WilddogsoccurmainlyinEastGippslandandnorth-easternVictoria, as well as in the southern Mallee, while feral pigs are localised to relatively small areas, mostly in eastern Victoria.

Victoria’s biosecurity approach

Victoria takes a biosecurity approach to the management of pest plant and animal species. This means protection of the economy, environment, social amenity and human health from the impacts of invasive species. Biosecurity involves prevention of new invasions, surveillance and early identification of outbreaks.

This approach also involves preparedness for, response to and recovery from outbreaks of invasive species, as well as ongoing management of established pests. Biosecurity Victoria has been establishedwithintheDepartmentofPrimaryIndustriestodeliver Victoria’s biosecurity programs.

The Catchment and Land Protection Act 1994 is the primary legislation relating to control of pest plants and animals in Victoria.ThisActsetsoutlandowners’rolesandresponsibilitiesinrelationtoweedsandpests,andlistsnoxiousweeds.

Victoria’snoxiousweedlistiscurrentlybeingrevisedforthefirst time since 1974, which should improve control of important agricultural and environmental weeds.

AnumberofGovernment-fundedprojectsaimedatencouragingbetter weed and pest control have been developed in recent years;forexample,theTacklingWeedsonPrivateLandInitiativeandImprovingProvincialVictoria’sBiosecurity.ThedocumentGuidelines for Managing Environmental Impacts of Weeds on Public Land was published in 2007. These projects aim to provide consistency in weed and pest management across public and private land in Victoria.

WhattheCommissionersays

“The noxious weeds list needs to be updated regularly so that awareness of important weeds is raised and their control can be enforced.

“Victorians must increase their awareness of the potential for plants from gardens to escape and become weeds in bushland.

“The long-term management of pest animals must continue if Victoria’s unique biodiversity is to be protected.”

Whatyoucando

• Donotbuyorgrowplantsthataredeclarednoxiousweeds,which may later invade bushland.

• Containthespreadofweedsbynotdumpinggardenrubbish.• Complywithlocalgovernmentcatcurfews.• Becomefamiliarwithyourresponsibilitiestocontrolpests

and weeds on your property, especially if you live outside the urban area, where pests may be more prevalent.

For more information

• StateofEnvironmentReportVictoria2008:LandandBiodiversitywww.ces.vic.gov.au/soe

• DepartmentofPrimaryIndustries–www.dpi.vic.gov.au