Skip to main content

FinnPRIO: a model for ranking invasive plant pests based on risk


The number of plant pests that may be transported to new areas with international trade is too great for subjecting all of them to a full scale pest risk assessment. There is therefore a need for a quick risk assessment procedure that also ranks the pests according to their risk. The FinnPRIO model can be used to assess the risk of alien plant pests for Finland. It follows the basic structure of a full scale pest risk assessment, i.e. it can be used to separately estimate the probabilities of entry, establishment (including spread), and the likely impacts. The model also includes a section for assessing preventability and controllability of a pest invasion. The model consists of multiple-choice questions with answer options yielding a different number of points. For each question the most likely answer option and the plausible minimum and maximum options are chosen. The total risk score is simulated using a PERT distribution, providing a scale of potential risk for each pest and indicating the level of uncertainty associated with the assessment. The model is accompanied by a guide for the interpretation of the questions and answer options. The model’s functionality has been tested through simulations, and it has been validated by comparing pest rankings produced using the model to those obtained in expert workshops. To date, 95 pests have been assessed with the model. The results indicate that the model is well capable of differentiating pests based on their estimated risk.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  • Baker RHA, Anderson H, Bishop S, MacLeod A, Parkinson N, Tuffen MG (2014) The UK plant health risk register: a tool for prioritizing actions. EPPO Bull 44:187–194

    Article  Google Scholar 

  • Blackburn TM, Pyšek P, Bacher S, Carlton JT, Duncan RP, Jarošik V, Wilson JRU, Richardson DR (2014a) A proposed unified framework for biological invasions. Trends Ecol Evol 26:333–339

    Article  Google Scholar 

  • Blackburn TM, Essl F, Evans T, Hulme PE, Jeschke JM, Kühn I, Kumschick S, Marková Z, Mrugała A, Nentwig W, Pergl J, Pyšek P, Rabitsch W, Ricciardi A, Richardson DM, Sendek A, Vilá M, Wilson JRU, Winter M, Genovesi P, Bacher S (2014b) A unified classification of alien species based on the magnitude of their environmental impacts. PLoS Biol 12:e1001850

    Article  PubMed  PubMed Central  Google Scholar 

  • Dalmazzone S, Giaccaria S (2014) Economic drivers of biological invasions: a worldwide, bio-geographic analysis. Ecol Econ 105:154–165

    Article  Google Scholar 

  • Dawes J (2008) Do data characteristics change according to the number of scale points used? An experiment using 5-point, 7-point and 10-point scales. Int J Market Res 50:61–77

    Google Scholar 

  • D’hondt B, Vanderhoeven S, Roelandt S, Mayer F, Versteirt V, Adriaens T, Ducheyne E, San Martin G, Grégoire J-C, Stiers I, Quoilin S, Cigar J, Heughebaert A, Branquart E (2015) Harmonia + and Pandora +: risk screening tools for potentially invasive plants, animals and their pathogens. Biol Invasions 17:169–1883. doi:10.1007/s.10530-015-0843-1

    Google Scholar 

  • Essl F, Nehring S, Klingenstein F, Milasowszky N, Nowack C, Rabitsch W (2011) Review of risk assessment systems of IAS in Europe and introducing the German-Austrian Black List Information System (GABLIS). J Nat Conserv 19:339–350

    Article  Google Scholar 

  • EPPO (2011) Guidelines on pest risk analysis: decision support scheme for quarantine pests. European and Mediterranean Plant Protection Organization Europe, Paris

    Google Scholar 

  • Gordon DR, Mitterdorfer B, Pheloung PC, Ansari S, Buddenhagen C, Chimera C, Daehler CC, Dawson W, Denslow JS, LaRosa A, Nishida T, Onderdonk DA, Panetta FD, Pyšek P, Randall RP, Richardson DM, Tshidada NJ, Virtue JG, Williams PA (2010) Guidance for addressing the Australian weed risk assessment questions. Plant Prot Q 25:56–74

    Google Scholar 

  • Hawkins CL, Bacher S, Essl F, Hulme PE, Jeschke JM, Kühn I, Kumchick S, Nentwig W, Pergl J, Pyšek P, Rabitsch W, Richardson DM, Vilà M, Wilson JRU, Genovesi P, Blackburn TM (2015) Framework and guidelines for implementing the proposed IUCN environmental impact classification for alien taxa (EICAT). Divers Distrib 21:1360–1363

    Article  Google Scholar 

  • Hayes KR, Barry SC (2008) Are there any consistent predictors of invasion success? Biol Invasions 10:483–506

    Article  Google Scholar 

  • Heikkilä J (2011) A review of risk prioritisation schemes of pathogens, pests and weeds: principles and practices. Agr Food Sci 20:15–28

    Article  Google Scholar 

  • IPPC (2007) ISPM 2. Framework for pest risk analysis. IPPC, FAO, Rome

    Google Scholar 

  • IPPC (2013) ISPM 11. Pest risk analysis for quarantine pests. IPPC, FAO, Rome

    Google Scholar 

  • Kehlenbeck H (1996) Model cases for evaluating the impact of pest introduction and phytosanitary measures. EPPO Bull 26:537–543

    Article  Google Scholar 

  • Leung B, Roura-Pascual N, Bacher S, Heikkilä J, Brotons L, Burgman MA, Dehnen-Schmutz K, Essl F, Hulme PE, Richardson DM, Sol D, Vilá M (2012) TEASIng apart alien species risk assessments: a framework for best practices. Ecol Lett 15:1475–1493

    Article  PubMed  Google Scholar 

  • MacLeod A, Baker RHA (2003) The EPPO pest risk assessment scheme: assigning descriptions to scores for the questions on entry and establishment. EPPO Bull 33:313–320

    Article  Google Scholar 

  • Makowski D, Mittinty MN (2010) Comparison of scoring systems for invasive pests using ROC analysis and Monte Carlo simulation. Risk Anal 30:906–915

    Article  PubMed  Google Scholar 

  • Mataragas M, Skandamis PN, Drosinos EH (2008) Risk profiles of pork and poultry meat and risk ratings of various pathogen/product combinations. Int J Food Microbiol 126:1–12

    CAS  Article  PubMed  Google Scholar 

  • Moignot B, Reynaud P (2013) Developing a methodology for the prioritisation of pests in plant health. Euro Reference 9:5–9

    Google Scholar 

  • Pheloung PC, Williams PA, Halloy SR (1999) A weed risk assessment model for use as a biosecurity tool evaluating plant introductions. J Environ Manage 57:239–251

    Article  Google Scholar 

  • Reichard SH, Hamilton CW (1997) Predicting invasions of woody plants introduced into North America. Conserv Biol 11:193–203

    Article  Google Scholar 

  • Ryan M (2006) Allocating Vote: Biosecurity - towards an ‘economics-based’ approach for setting priorities for the importation of goods. Presentation at New Zealand Agricultural and Resource Economics Society Conference. 25–27 August 2006

  • Sandvik H, Sæther B-E, Holmern T, Tufto J, Engen S, Roy HE (2013) Generic ecological impact assessments of alien species in Norway: a semi-quantitative set of criteria. Biodivers Conserv 22:37–62

    Article  Google Scholar 

  • Santini A, Ghelardini L, De Pace C, Desprez-Loustau ML, Capretti P, Chandelier A, Cech T, Chira D, Diamandis S, Gaitniekis T, Hantula J, Holdenrieder O, Jankovsky L, Jung T, Jurc D, Kirisits T, Kunca A, Lygis V, Malecka M, Marcais B, Schmitz S, Schumacher J, Solheim H, Solla A, Szabò I, Tsopelas P, Vannini A, Vettraino AM, Webber J, Woodward S, Stenlid J (2013) Biogeographical patterns and determinants of invasion by forest pathogens in Europe. New Phytol 197:238–250

    CAS  Article  PubMed  Google Scholar 

  • Schmidt RC (1997) Managing delphi surveys using nonparametric statistical techniques. Decision Sci 28:763–773

    Article  Google Scholar 

  • Van Hauwermeiren M, Vose D (2009) A compendium of distributions. Vose Software, Ghent, Belgium.

  • Vänninen I, Worner S, Huusela-Veistola E, Tuovinen T, Nissinen A, Saikkonen K (2011) Recorded and potential alien invertebrate pests in Finnish agriculture and horticulture. Agr Food Sci 20:96–114

    Article  Google Scholar 

  • Weber J, Panetta FD, Virtue J, Pheloung P (2009) An analysis of assessment outcomes from eight years’ operation of the Australian border weed risk assessment system J Environ Manage 90:798–807

    PubMed  Google Scholar 

  • Yemshanov D, Koch FH, Ducey M, Koehler K (2013a) Mapping ecological risks with a portfolio-based technique: incorporating uncertainty and decision-making preferences. Divers Distrib 19:567–579

    Article  Google Scholar 

  • Yemshanov D, Koch FH, Ben-Haim Y, Downing M, Sapio F, Siltanen M (2013b) A new multicriteria risk mapping approach based on a multiattribute frontier concept. Risk Anal 33:1694–1709

    Article  PubMed  Google Scholar 

Download references


This study was funded by the Finnish Ministry of Agriculture and Forestry.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Jaakko Heikkilä.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (DOCX 39 kb)

Supplementary material 2 (DOCX 335 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Heikkilä, J., Tuomola, J., Pouta, E. et al. FinnPRIO: a model for ranking invasive plant pests based on risk. Biol Invasions 18, 1827–1842 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Invasive alien species
  • Plant health
  • Prioritisation
  • Ranking
  • Risk assessment
  • Expert judgment