Zoning strategies for managing outbreaks of alien plant pests in the European Union: a review

Abstract

Managing outbreaks of alien plant pests is key to preserving biodiversity and safeguarding crop production. Zoning strategies are applied by plant health authorities to tailor measures to the risk of spread in relation to distance from the outbreak epicentre and the biology of the pest. Here we synthesize information on outbreak management to evaluate the diversity and consistency of such approaches. We collected information on the zoning strategies of 121 outbreaks of 25 plant pests in the European Union (EU). According to the organism’s presence and the measures applied, five zones were distinguished: an infested zone (83% of cases), a buffer zone (76%), a clear-cutting zone (28%), an eradication zone (1%) and a containment zone (1%). Infested zones and buffer zones were adjacent non-overlapping zones, while the clear-cutting zone, eradication zone or containment zone was within either the infested zone or buffer zone. A combination of infested and buffer zones was used in 51% of recorded cases. Measures differed within different zones. Destruction of infested plants in the infested zone was done in 78% of the cases, while surveillance was always applied in the buffer zone. Regulation of an organism at EU level led to a convergence of zoning strategies applied by different member states. Regulations often prescribed the greatest widths used before regulations were issued. Further analyses are needed to explore the efficacy of different strategies including the costs of each strategy. Such analyses should combine insight from practice with bio-economic modelling.

Plant health campaign strategy

“…• Emergency measures: Each EU country is responsible for implementing emergency measures in the event of an outbreak of a harmful organism. Some countries have more robust emergency response plans in place or are better equipped to implement specific measures or deal with certain types of outbreaks (Sun et al, 2023). However, in some countries there are more resources dedicated to these tasks.…”

“…• Pests zoning strategies and classifications: EU Member States have different zoning strategies for managing outbreaks that complement EU regulations. These zoning strategies provide additional protection and specification on how the EU rules will be applied in practice in a particular country (Sun et al, 2023). For example, the Cryphonectria parasitica pest is considered a regulated non-quarantine pest (RNQP) in most European countries except in the Czech Republic, Ireland and Sweden where this pest is considered protected zone quarantine pests (PZQP) (Euroseeds, 2019) (annex B) • Inspection and enforcement: The way of inspecting and enforcing the EU regulations varies among countries, some may have stricter penalties.…”