The potential implications of climate change for the wheataphid-YDV pathosystem in WA: a simulation modelling study Hazel Parry1,2, Darren Kriticos1,2, Jean-Philippe Aurambout3, Wendy Griffiths2,3, Garry O’Leary3, Kyla Finlay3, Piotr Trębicki3, Paul De Barro1,2, Jo Luck2,3 1CSIRO
Ecosystem Sciences Research Centre for National Plant Biosecurity 3Department of Primary Industries Victoria
2Cooperative
biosecurity built on science Cooperative Research Centre for National Plant Biosecurity
Wheat-aphid-YDV pathosystem
R. padi BYDV
biosecurity built on science
CLIMATE CHANGE biosecurity built on science
Large scale
biosecurity built on science
Climatic niche 2030 Rhopalosiphum padi No risk Endangered (no change or change unknown) Transient (no change or change unknown) No risk (positive change from endangered or transient)
Kriticos DJ and Macfadyen S (in prep)
biosecurity built on science
Aphids-YDV-climate change Warmer, drier summers Tropical agricultural zone Increased Ryegrass and wheat yield BYDV-RMV and R. maidis increase
Shift in tropical agricultural zone
Parry HR, Macfadyen S and Kriticos DJ (2012) Australasian Plant Pathology
biosecurity built on science
Small scale
biosecurity built on science
eCO2 and aphid fecundity Indirect impacts mediated through changes to host plant For R. padi daily fecundity results from the project conflicted with the literature.
Xing et al. 2003.
Daily reproduction increased with eCO2 (350 vs 550 vs 700 ppm)
P. Trebici (CRC project results)
Daily reproduction decreased with eCO2 (350 vs 650 ppm) biosecurity built on science
Wheat biomass under ambient and elevated CO2 and YDV (early) infection: laboratory and field studies Field Results Elevated CO2 increases Biomass
Laboratory Results
Early YDV infection reduces Biomass
eCO2 Field: 550 ppm eCO2 Lab: 650 ppm
biosecurity built on science
Process-based, mechanistic models Drivers
Temperature Precipitation CO2
Mechanisms
Survival Development Movement Fecundity
Outcomes
Population size and growth Age/size structure Extinction probability Emigrants biosecurity built on science
Avondale case study 1. 2. 3.
Initiation in Irrigated Pasture Wind Dispersal Settling in Wheat
Avondale
Wokalup
biosecurity built on science
Avondale case study Wheat development accelerates with Climate Change 6
5
3.5 3 2.5 2
2030 relative to 1998
1.5
2070 relative to 1998
1 0.5 0 0
200
400
Day of year
Wheat phenostage
Temperature difference 째C
Climate Scenario CSIRO MK-3 A2 emissions
4 1998 Phenostage 2030 Phenostage 2070 Phenostage
3
2
1
0
1998 CO2 = 350 ppm 2030 CO2 = 450 ppm 2070 CO2 = 620 ppm
0
100
200
300
400
Day of year biosecurity built on science
Wheat impacts Biomass and Yield decline with Climate Change
Biomass 8000
6000 5000
1998 average biomass
4000
2030 average biomass
3000
2070 average biomass
2000 1000
Grain harvest (kg/ha)
6000
7000
Biomass (kg/ha)
Yield
5000 4000 3000
1998 Grain 2030 Grain
2000
2070 Grain
1000 0
0 0
100
200
Day of year
300
400
0
100
200
300
400
Day of year
biosecurity built on science
Aphid impacts Aphid migration delayed
Migrant arrivals
Aphid population growth accelerates
Population dynamics
biosecurity built on science
Consequences for wheat yield Projected percentage loss in Grain Yield 2030 and 2070 compared to 1998 with and without YDV
Impact of YDV
biosecurity built on science
Consequences for YDV impact on wheat
biosecurity built on science
Summary: WA case study Climate change = more rapid crop development but lower biomass and yield, most pronounced in 2070. Climate change is projected to: -
Slow aphid population growth over-summer in grasslands Delay aphid timing of migration Increase aphid population growth rate in crop, leading to Earlier alate (winged morph) formation in crop, due to density
Synchronisation issues are more important to YDV impacts on yield than the within-crop aphid population growth. Overall, our simulations suggest YDV impacts on yield will reduce under climate change, although the potential for spread in the crop is greater.
biosecurity built on science
Thank you  For more information, please email hazel.parry@csiro.au
biosecurity built on science