An Introduction The PPQ Weed Risk Assessment

The PPQ Weed Risk Assessment
An Introduction
Anthony L. Koop,
Leslie Newton, Barney Caton, Lisa Kohl, Larry Fowler
USDA-APHIS
Meeting the Challenge: Preventing, Detecting & Controlling Invasive Plants
University of Washington Botanic Gardens
September 16-17, 2014
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APHIS regulates weeds
• Federal Noxious Weeds
• NAPPRA Plants – Not Authorized Pending Pest Risk Analysis.
• Noxious Seeds - Contaminants in vegetable and agricultural seed
Plant Epidemiology and Risk Analysis Laboratory (PERAL)
- Provides the analyses that support regulatory decisions
I focus on WRA
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What is Weed Risk Assessment?
WRA: An evaluation of the
probability of the entry,
establishment, and spread of a
plant, and its potential
consequences (harm & impacts)
Decision making
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Style of the assessment
• Mostly Yes/No questions;
a few multiple choice
• Record uncertainty:
negligible, low, moderate,
high, max
• Evidence, supporting
documents, and reasoning
are recorded for each
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Risk Elements in the WRA
•
•
•
•
Establishment / Spread Potential (23)
Impact Potential (18)
Geographic Potential (36)
Entry Potential (14)
Predictive model
Uncertainty
Analysis
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The Final Product
3 - 4 page summary
–Background/Initiation
–Risk element summary
–Data and figures
–Discussion/Conclusion
References
Appendix: questions,
answers, uncertainty,
and evidence
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The WRA’s core analyses & results
• Risk potential
• Uncertainty analysis
• Geographic potential
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1) Risk Potential
• Calculate risk scores for Establishment/Spread &
Impact of plant species
– Higher values indicate greater capacity
• Determine the final conclusion
– High Risk, Low Risk, or Evaluate Further
• Species with moderate scores (EF)  secondary
screening tool
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Low Risk
5
Mod Risk /
Eval Further
High Risk
4.5
■ Species Risk Score
Impact Potential
4
Invasive Status
Major-Invaders
Minor-Invaders
Non-Invaders
3.5
3
2.5
2
Risk Rating
× High Risk
● Evaluate Further
▲ Low Risk
1.5
1
-20
-15
-10
-5
0
5
10
15
Establishment Spread Potential
20
25
Model Performance
(validation dataset, N=102)
Accuracy
Error
MajInvaders
(True +)
NonInvaders
(True -)
MajInvaders
(False +)
NonInvaders
(False-)
US – PPQ WRA
0.941
0.971
0.000
0.000
US - Aus WRA
Mean (8 other AUS tests)
0.971
0.936
0.794
0.715
0.088
0.164
0.000
0.022
Test
• Overall accuracy is higher than the Australian WRA
• Non-invader and major-invader performance similar
2) Uncertainty analysis
• Summarize & describe uncertainty for
each risk element
• Evaluate the sensitivity of the risk scores
to uncertainty using a Monte Carlo
simulation
• what would the risk score be if…
• N = 5,000
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Evaluate Further
Low Risk
5
High Risk
4.5
Impact Potential
4
3.5
3
2.5
2
1.5
High
EF→High
EF→EF
EF→Low
Low
99.98%
0.02%
0%
0%
0%
1
-20
-15
-10
-5
0
5
10
15
Establishment Spread Potential
20
25
3) Geographic potential
• Geo potential evaluated separately
• Simple analysis that matches on and
overlays
• Plant hardiness zones
• Annual precipitation
• Climate classes
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Representing areas where all three climatic variables
are suitable for its survival
84 Species Assessed with the New Model
5
Evaluate Further
Low Risk
High Risk
4.5
4
Impact Potential
High Risk
EF-HR
3.5
EF-EF
Low Risk
3
2.5
2
1.5
1
-20
-15
-10
-5
0
5
10
Establishment Spread Potential
15
20
25
Hippophae rhamnoides
• Cultivated in the U.S., naturalized in
2 WY counties
• Become invasive in Canadian
prairies
• Forms dense thickets, N-fixer,
alters natural habitats, reduces
access
Falcaria vulgaris
• First reported in 1923
• Few naturalized populations in
plains. But in last 10-15 years one
population has rapidly expanded.
• Forms dense monocultures, root
fragments resprout. Difficult to
control. Maybe a threat for some
grain growers.
Geranium lucidum
Evaluate Further
Low Risk
5
High Risk
• Shade-adapted winter annual
• 1st recorded 1971 in a cow pasture
• Dominates forest understories.
• Persistent seed bank
• Spreading
Impact Potential
4.5
4
Species Risk Score
Simulated Risk
Scores
3.5
3
2.5
2
1.5
High
EF-High
EF-EF
EF-Low
Low
100%
0%
0%
0%
0%
1
-20
-15
-10
-5
0
5
10
15
Establishment Spread Potential
20
25
Austroderia richardii
Evaluate Further
Low Risk
5
4.5
Impact Potential
• New Zealand grass similar &
closely related to Cortaderia
• Naturalized in Tasmania & the U.K.
• Little detailed info on impacts; but it
ranked high on perceived impacts.
High Risk
4
3.5
3
2.5
2
1.5
1
High
EF-High
EF-EF
EF-Low
Low
-20
-15
87.5%
9.7%
2.8%
0%
0%
-10
-5
0
5
10
15
20
Establishment Spread Potential
25
Leptochilus pteropus
• Aquatic ornamental
• Tropical / subtropical fern species
• No evidence of impact or
invasiveness elsewhere.
Working Together
Many potential weeds
What we can do for you
– Share completed WRAs
– Train & mentor you [WRA-101 (Feb 24-27, 2015)]
What you can do for us
– Tell us about new and emerging weed threats
– Identify weeds not yet in the U.S. that could be
problematic
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For more information or to
submit requests for WRA
Tony Koop
Plant Epidemiology and Risk Analysis Laboratory
Center for Plant Health Science and Technology
USDA - APHIS – PPQ
1730 Varsity Drive, Suite 300
Raleigh, NC 27606-5202
Phone: (919) 855-7429
Email: [email protected]
Barney Caton (PERAL Asst. Dir.) – [email protected]
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