Phytophthora Dieback The biological bulldozer Adapted from presentations by Dr Chris Dunne, Science Division, DEC

Drought/climate change Salinity, water table change Phytophthora dieback Mining activities Land clearing Invasive weeds Consequences of construction developments i.e. road works, recreation Small/declining populations Demographic /genetic effects Grazing by feral/ introduced animals Threats to rare flora of the south-west of WA

What is Phytophthora dieback? Caused by a water mould called Phytophthora cinnamomi Phytophthora is Greek for ‘plant destroyer’ organism was first identified on the roots of a cinnamon tree P. cinnamomi feeds off plant roots Causes root rot which stops plant taking up nutrients and water

A brief history Early European settlers arrive First recorded unexplained tree deaths (Karragullen) Pc identified as causal agent Introduction of European plant species Infested gravel used for roadmaking Quarantine Use of phosphite Research station est. Dwellingup

Lifecycle of P. cinnamomi

Ideal environment >800mm 20 o C-30 o C pH 5-6 Therefore: Forested areas with higher rainfall Grows and spreads best in autumn and spring

Where is dieback found? bushland nurseries horticultural plantations gardens

Impact on native flora Of 5710 recorded species of plant: 2300 (40%) susceptible to Phytophthora dieback 800 (14%) highly susceptible to Phytophthora dieback

Jarrah forest – Dwellingup

Banksia woodland

Stirling Range National Park

South Coast

Impact Impact on animals? Loss of: food habitat shelter

Distribution of Phytophthora cinnamomi

P. cinnamomi in Western Australia

Perth Scarp

How is it spread? 4WD Trail/mountain bikes Hiking boots Animals Road making Irrigation Infected plant material

Management of Phytophthora dieback Interpretation and mapping Is Phytophthora dieback known or likely to be in an area, or at your site? Do you need more information? Identify priority areas, species or communities for protection Declared rare flora Endangered fauna Is the area protectable Prevent accidental introduction Minimise spread Reduce impact

Dieback Interpretation & Mapping Dead “indicator plants” Structural change Chronology of deaths Soil/tissue sampling

Indicator species Banksia grandis (Bull Banksia) Patersonia spp. (Flag Flower) Xanthorrhoea preissii (Balga)

Field Detection Depauperate sedgeland Rich proteaceous shrubland Disease Front Direction of travel

Identify protectable areas Focus resources on areas of highest biodiversity value Declared rare fauna Endangered fauna Threatened ecological communities Focus resources on areas which can be protected Uphill from known infections Large enough to protect (>2ha) Able to be effectively quarantined (limited public access, sources of infection can be mitigated or removed) Focus resources on areas where the benefits of hygiene will last more than a few decades

Prevent accidental introduction Readily introduced in infested material (e.g. soil on footwear or vehicles, infected plant material, gravel for road construction, nursery stock) Impossible to eradicate Prevent introduction by Use of certified dieback free materials Remove and control access Hygiene – footbaths and vehicle washdown

Remove and control access X X X X CLEAN ON ENTRY POINT

Remove access Control access

Hygiene Vehicles Footwear & equipment

Minimise spread Reduce water flow Barriers to infection

Reduce impact - conservation Translocation Seedbank Revegetation

Phosphite Highly effective – gives short term resistance to some plants Low toxicity Environmentally friendly Can be sprayed or injected

What can you do?