A generic risk assessment approachfor multiple stressors & exposures

Geoff Frampton, Guy Poppy, Jamie Sutherland

Funded by

Ecology & Evolutionary Biology GroupSchool of Biological SciencesUniversity of Southampton, UK

Background (1)

Limitations of the Farm-Scale Evaluations (FSE) of genetically-modified herbicide-tolerant crops:

Intensive monitoring, hence expensive (£5.5 million)

Monitoring unfocused, hence inefficient use of resources

Can we optimize targeting of the monitoring resources to where they are needed ?

Background (2)

Currently, agricultural risks are assessed routinely only for GM crops and pesticides

Other more environmentally damaging agricultural practices do not require risk assessments

Proposal: all new (or changed) agricultural practices should be assessed for environmental risk

(UK Advisory Committee on Releases to the Environment (ACRE), 2006)

Discrepancy in current agricultural risk assessment:

How to assess risks of new or changed agricultural practices ?

Receptor ResponsePathway

effect(exposure)

Source

Source – pathway – receptor principle

Receptor ResponsePathway

effect

Source – pathway – receptor principle

(exposure)

Source

REGIONAL risk assessment – e.g. invasive species in marine coastal area (Landis 2003)

Risk Analysis 24 (4) 2003

invasion

Importedinvasivespecies effects

9 predictedimpacts

7 receivinghabitats

7mechanistic

models

23mechanistic

models

effectinvasion

Receptor ResponsePathway

effect

Source – pathway – receptor principle

(exposure)

Source

Co-occurrence

SPATIALLY EXPLICIT risk assessment – e.g. military landscape (Andersen et al. 2004)

Risk Analysis 24 (5) 2004

Spatiallyexplicithazards

Indicator species

effects

Responses

Receptor ResponsePathway

effect

Source – pathway – receptor principle

(exposure)

Source

Co-occurrenceEffectsdepend uponresilience

Responses

TRAIT BASED risk assessment – e.g. arable farmland (Butler et al. 2007)

Science 315 (5810) 2007

Requiredecologicalresources

Affectedecologicalresources

Epigeic inverts

Soil inverts

Seeds

Plant material

Vertebrates

Soil inverts

Seeds

Plant material

Vertebrates

Hedgerow

Crop

Margin

Hedgerow

Crop

Margin

Hedgerow

Crop

NEST SITESDIETSummer Winter

HABITATSummer Winter

Ecological resources of farmland bird species (=receptor)

MarginEpigeic inverts

Ecological resources affected by agricultural activity (=source)

NEST SITESSummer Winter

DIETSummer Winter

HABITAT

Trait-based risk assessment (hypothetical example)

Epigeic inverts

Soil inverts

Seeds

Plant material

Vertebrates

Soil inverts

Seeds

Plant material

Vertebrates

Hedgerow

Crop

Margin

Hedgerow

Crop

Margin

Hedgerow

Crop

NEST SITESDIETSummer Winter

HABITATSummer Winter

MarginEpigeic inverts

NEST SITESSummer Winter

DIETSummer Winter

HABITAT

1 / 5 2 / 5

Trait-based risk assessment (hypothetical example)

Score = 1.6

1 / 32 / 3

Ecological resources of farmland bird species (=receptor)

Ecological resources affected by agricultural activity (=source)

0

0.5

1

1.5

2

2.5

3

0

0.5

1

1.5

2

2.5

3

3.5

4

Mammals (44 spp)Bumblebees (14 spp)

Declining Possibly declining

Stable / increasing

Risk score

Declining Possibly declining

Stable / increasing

Validation of risk scores for past agricultural changes (1970-2000)

(spring to autumn sowing, increased agrochemicals, loss of non-cropped habitat,land drainage, switch from hay to silage, grassland intensification)

Population growth = 7.212 – 3.525 × risk score (p = 0.001)

Population growth = 0.009 – 0.0064 × risk score (p < 0.001)

Population growth = 0.008 – 0.004 × risk score (p = 0.001)

Butterflies (24 spp):

Birds (62 spp):

Broadleaf plants (190 spp):

Trait-based risk assessment for introduction of Miscanthus bioenergy crops

Interpreting output from trait-based risk assessment

Predict population trend

Predict conservation statusIndividual species

Interpreting output from trait-based risk assessment

Example: change from spring to autumn cereals

Proportion of species

0% 20% 40% 60% 80% 100%

Bumblebees (14 spp)

Butterflies (24 spp)

Birds (62 spp)

Mammals (44 spp)

Plants (190 spp)

decrease stable increase

Communities

Predict population trend

Predict conservation statusIndividual species

Summary

Trait-based risk assessment is a potentially powerful approach for assessing agricultural risks (compatible with tiered approach)

How to proceed in the absence of existing population data?

Can trait-based RA be applied to ecological functions?

How can risk assessment be integrated into assessment of agricultural sustainability?

Risk assessors should define what they require the risk assessment to deliver (need for clear assessment endpoints and conceptual models)

Questions arising…