26 June 2013

Sustainable vegetation management in golf courses

Paul Barber

Contents

•  Why are trees in golf courses important?

•  Vegetation Disorders in Golf Courses

•  Alternative Approaches to Vegetation Management

•  We All Have Standards

•  In Conclusion

Why are trees in golf courses important? •  Improved health and well-being

•  Increased biodiversity values and refuge (habitat, food, shelter)

•  Reduction of urban heat island effect (UHIE)

•  Increased carbon sequestration and climate regulation

•  Maintenance of heritage and cultural links

•  Increased noise and pollution capture

•  Improved stormwater management and flood mitigation

•  Increased house and course values

•  Increased safety to occupants and nearby commuters

•  Highly valuable asset – social, environment, economy

WHAT ARE THE COSTS:BENEFITS OF MAINTAINING YOUR VEGETATION?

ECONOMIC AND ENERGY COSTS MAY BE HIGH USING CURRENT APPROACH

Vegetation Disorders in Golf Courses – Devt & Overpruning

Yulia, Hardy, Barber and Dell (2013) A severe canker disease of Corymbia ficifolia caused by Quambalaria coyrecup in native and urban forests Western Australia. Forest Pathology (submitted) •  Wounding is required for canker development to occur. ECONOMIC AND ENERGY COSTS MAY BE HIGH USING CURRENT APPROACH

Vegetation Disorders in Golf Courses – Climate

Meineke, Dunn, Sexton and Frank 2013 Urban warming drives insect pest abundance on street trees. PLoS ONE 8 •  First evidence that heat can be a key driver of insect pest outbreaks on urban trees •  Urban warming similar in magnitude to predicted global warming over next 50 years

Vegetation Disorders in Golf Courses – Soil, Water, Nursery Stock

Ishaq, Barber, Hardy, Calver & Dell (2013) Seedling mycorrhizal type and soil chemistry are related to canopy health of Eucalyptus gomphocephala. Mycorrhiza

Cai, Barber, Dell, O’Brien, Williams, Bowen & Hardy (2010) Soil bacterial functional diversity is associated with the decline of Eucalyptus gomphocephala. Forest Ecology & Management

Vegetation Disorders in Golf Courses – Pests & Diseases

Vegetation Disorders in Golf Courses – Pests & Diseases

Barber, Paap, Burgess, Dunstan & Hardy (2013) A diverse range of Phytophthora species are associated with dying urban trees in an Australian capital city. Urban Foresty & Urban Greening (submitted)

Vegetation Disorders in Golf Courses – Pests & Diseases

Paul D. Manion 1991. Disease Decline Concepts

Predisposing Factors • Urban Environment!

Inciting Factors • Poor pruning • Construction • Mowers/Whipper Snippers • Hail damage • Golf Balls! • Pathogens/Pests

Contributing Factors • Phellinus • Phytophthora • Stem-borers

Alternative Approaches – Diagnose & Treat

Disease Triangle

Disease

Pathogen/Pest

Host Environment

Pathogens/Pest • Presence of pathogen/pest • Pathogenic • Adaptability • Dispersal efficiency • Survival efficiency • Reproductive fitness

Environment • Temperature • Rainfall • Humidity • Leaf wetness period • Soil temperature • Soil water content • Soil fertility • Soil organic matter content • Wind • Air pollution • Herbicide damage • Mechanical damage • Pruning

Host • Susceptibility • Growth stage and form • Population density and structure • General health • Suitability to site

Alternative Approaches – Diagnose & Treat

•  Water management is a major concern for tree managers in Australia

•  South-west WA > 25% decrease in rainfall over past 30 years

•  Climate change – more extreme weather events

•  How do trees respond? •  May be delayed in response, or other

inciting or contributing factors

Same same but different....trees are complex!

•  Many endemic pathogens favoured by the urban environment

•  Irrigation, fertilisers, low soil microbial activity, disturbance, mechanical damage

•  New incursions a major threat •  Myrtle rust

•  Increased susceptibility to decay/failure

Alternative Approaches – Diagnose & Treat

Alternative Approaches – Diagnose & Treat

Alternative Approaches – Diagnose & Treat

Alternative Approaches – Look down, not just up! Monitoring change in canopy condition over space and time

Alternative Approaches – Look down, not just up! Quantifying change in canopy cover, impervious layers, soil etc.

•  Model developed to select vegetation within scene. Overlay of shapefile of vegetation (red) on high-resolution true colour airborne imagery.

•  First version of model > 95% accuracy. Calculated 18.4% canopy cover within scene Vegeta

&on  

Impervious  

Soil  

Shadow  -­‐500  

0  

500  

Change  2010  to  2011  

Alternative Approaches – Look down, not just up! Quantifying change in canopy cover and shadow

2009-­‐2010   2009-­‐2011  

|

0

0.5

1

1.5

2

2.5

2007 2008 2009 2010

801

802

803

804

Alternative Approaches – Costs:Benefits Don’t just think short-term costs:benefits when considering your actions, but think more broadly and longer term – client, society, environment, global community

Some Items to consider: •  Trees are long-lived

•  Do you have a long-term plan for your course and the trees? •  Match species to site – also root volume & crown space •  Suitable nursery stock (tube stock V advanced), species to site •  Soil preparation, planting technique, timing of planting, irrigation

Alternative Approaches – Costs:Benefits Some Items to consider: •  Formative pruning to minimise future management

•  Adequate protection to minimise damage

•  Is pruning really necessary? Would you scalp your turf

•  Monitoring program – early diagnosis – pro-active

•  Correct diagnosis = correct management

Alternative Approaches – Costs:Benefits

Aukema et al. 2011 Economic impacts of non-native forest insects in the continental US. PLoS one 6:9

•  Costs largely borne by homeowners and municipal governments

•  Wood-borers (e.g. Emerald Ash Borer (EAB) to cause nearly $1.7 billion in local govt expenditure & $830 million in lost residential property values (replacement & treatment far more expensive than containment)

McCullough & Mercader (2012) Evaluation of potential strategies to slow ash mortality caused by EAB. International Journal of Pest Management 58:1, 9-23.

•  Ash survival dependent on 1) early detection & treatment, 2) # of trees treated, 3) distribution of treated trees c.f. introduction point.

We all have standards

Three standards worth taking note of when it comes to your trees

•  AS 4454 (2012) Composts, soil conditioners and mulches

•  Will go a long way to minimising introduction and spread of disease

•  AS 4970 (2009) Protection of trees on development sites

•  Tree Protection Zone (TPS), Structural Root Zone (SRZ) and lots more

•  AS 4373 (2007) Pruning of Amenity Trees

•  All your pruning should be carried out to this standard….cheaper contractors may cost you more in the long term

In Conclusion… •  Golf courses are incredibly important refuges within the urban area, and the

trees within them provide a wide range of values – social, environment, economy

•  Many predisposing, inciting and contributing factors can impact upon vegetation health

•  Devt & overpruning, climate, soil, water, nursery stock, pests, diseases, pesticides

•  These disorders can be diagnosed

•  Accurate diagnosis is critical to the sustainable and cost-effective management

•  We must think outside the square when it comes to diagnosis, treatment, monitoring, management – there are alternatives to current ‘business as usual’

•  Sit down and weigh up the long-term costs and benefits to different approaches

•  Make careful decisions about how you manage the health of your vegetation – there are standards and many different approaches

Acknowledgements •  AGCSA

•  Darren Wilson & Adam Robertson

•  Contact details

•  Dr Paul Barber | email: p.barber@arborcarbon.com.au | Ph: +61 419 216 229 | www.arborcarbon.com.au