Recovery based on plot experiments is a poor predictor of landscape-level population impacts of agricultural pesticides

TY - JOUR

T1 - Recovery based on plot experiments is a poor predictor of landscape-level population impacts of agricultural pesticides

AU - Topping, Christopher John

AU - Kjær, Lene Jung

AU - Hommen, Udo

AU - Høye, Toke Thomas

AU - Preuss, Thomas G.

AU - Sibly, Richard M.

AU - Van Vliet, Peter

PY - 2014

Y1 - 2014

N2 - Current European Union regulatory risk assessment allows application of pesticides provided that recovery of nontarget arthropods in-crop occurs within a year. Despite the long-established theory of source-sink dynamics, risk assessment ignores depletion of surrounding populations and typical field trials are restricted to plot-scale experiments. In the present study, the authors used agent-based modeling of 2 contrasting invertebrates, a spider and a beetle, to assess how the area of pesticide application and environmental half-life affect the assessment of recovery at the plot scale and impact the population at the landscape scale. Small-scale plot experiments were simulated for pesticides with different application rates and environmental half-lives. The same pesticides were then evaluated at the landscape scale (10km×10km) assuming continuous year-on-year usage. The authors' results show that recovery time estimated from plot experiments is a poor indicator of long-term population impact at the landscape level and that the spatial scale of pesticide application strongly determines population-level impact. This raises serious doubts as to the utility of plot-recovery experiments in pesticide regulatory risk assessment for population-level protection. Predictions from the model are supported by empirical evidence from a series of studies carried out in the decade starting in 1988. The issues raised then can now be addressed using simulation. Prediction of impacts at landscape scales should be more widely used in assessing the risks posed by environmental stressors.

AB - Current European Union regulatory risk assessment allows application of pesticides provided that recovery of nontarget arthropods in-crop occurs within a year. Despite the long-established theory of source-sink dynamics, risk assessment ignores depletion of surrounding populations and typical field trials are restricted to plot-scale experiments. In the present study, the authors used agent-based modeling of 2 contrasting invertebrates, a spider and a beetle, to assess how the area of pesticide application and environmental half-life affect the assessment of recovery at the plot scale and impact the population at the landscape scale. Small-scale plot experiments were simulated for pesticides with different application rates and environmental half-lives. The same pesticides were then evaluated at the landscape scale (10km×10km) assuming continuous year-on-year usage. The authors' results show that recovery time estimated from plot experiments is a poor indicator of long-term population impact at the landscape level and that the spatial scale of pesticide application strongly determines population-level impact. This raises serious doubts as to the utility of plot-recovery experiments in pesticide regulatory risk assessment for population-level protection. Predictions from the model are supported by empirical evidence from a series of studies carried out in the decade starting in 1988. The issues raised then can now be addressed using simulation. Prediction of impacts at landscape scales should be more widely used in assessing the risks posed by environmental stressors.

KW - Animal

KW - Ecological simulation

KW - Ecotoxicology

KW - Landscape

KW - Man simulation system

KW - Population-level risk assessment

KW - Source sink

U2 - 10.1002/etc.2388

DO - 10.1002/etc.2388

M3 - Journal article

C2 - 24038611

AN - SCOPUS:84900513296

SN - 0730-7268

VL - 33

SP - 1499

EP - 1507

JO - Environmental Toxicology and Chemistry

JF - Environmental Toxicology and Chemistry

IS - 7

ER -