Ecological Modelling 247 (2012) 58–63 Contents lists available at SciVerse ScienceDirect Ecological Modelling jo u r n al hom ep age : www.elsevier.com/locate/ecolmodel Short communication Evaluating the suitability of a generic fungal infection model for pest risk assessment studies Simone Bregaglio a,∗ , Giovanni Cappelli a , Marcello Donatelli b,c a University of Milan, Department of Plant Production, Via Celoria 2, I-20133 Milan, Italy b Agriculture Research Council, Research Centre for Industrial Crops, Bologna, Italy c European Commission DG Joint Research Centre, Institute for Environment and Sustainability, MARS-AGRI4CAST, Via Fermi, Ispra, VA, Italy a r t i c l e i n f o Article history: Received 14 April 2012 Received in revised form 6 August 2012 Accepted 7 August 2012 Available online 20 September 2012 Keywords: Potential infection Sensitivity analysis Leaf wetness Climate change a b s t r a c t Pest risk assessment studies are aimed at evaluating if weather conditions are suitable for the potential entry and establishment of an organism in a new environment. For fungal plant pathogens, the crucial aspect to be explored is the fulfillment of the infection process, that constitutes the first phase of the development of an epidemic as mainly driven by temperature and leaf wetness duration. This is of par- ticular interest for climate change studies, because the modified pattern of temperature and moisture regimes could completely alter the known distribution and severity of plant disease epidemics. Biophys- ical process-based models could effectively be used in such studies, because they allow, within their applicability range, estimating organisms responses to climatic drivers in environmental conditions not yet experienced. One of the prerequisite of their adoption in operational contexts is a sensitivity analysis assessment aimed at understanding their ability (i) to differentiate the responses according to different parameterizations and (ii) to be sensitive to the variability of the input data. In this study, a generic potential fungal infection model simulating four pathogens chosen to provide a wide range in temper- ature and moisture requirements was analyzed. The model was run under diverse climatic conditions. The sensitivity of the model significantly changed according to the pathogen tested, and the relevance of its parameters in explaining model output resulted strongly linked to the environmental conditions tested, indicating its to be used in pest risk assessment studies. © 2012 Elsevier B.V. All rights reserved. 1. Introduction The damages potentially caused by spatial and temporal changes in the diffusion of plant pests and diseases concern several aspects: economy, ecology, and public health impacts (Andersen et al., 2004). In pest risk assessment studies, the main goal is the evaluation of the potential entry and establishment of a fun- gal pathogen in a new environment. One specific application is to estimate the possible changes of infectiousness under climate change scenarios. The crucial aspect to be explored is whether the weather conditions are conducive for the fulfillment of the infec- tion process, because it is the first phase of the establishment of an epidemic (Magarey et al., 2005). For this reason, the formaliza- tion of the infection process of foliar fungal plant pathogens into process-based models plays a key role in disease forecasting sys- tems (Madden and Ellis, 1988), because it requires the inclusion of the effect of the main driving variables, which are air temperature and the duration of surface leaf wetness or high humidity periods. ∗ Corresponding author. Tel.: +39 02 50316578; fax: +39 02 50316575. E-mail address: simone.bregaglio@unimi.it (S. Bregaglio). There are examples of studies focused on the possible effects of biotic stresses on crops in the future (e.g., Goudriaan and Zadocks, 1995; Garrett et al., 2006; Ghini et al., 2008), indicating that cli- mate change could significantly modify the known patterns of plant diseases by means of altered ranges of some species and introduc- tion of new pathogens and vectors, leading to modified dynamics of current plant disease epidemics and shifts in their geographi- cal distribution. In particular, most authors agree in stating that changes in temperature and moisture availability are two of the main factors that could alter disease infection and severity not only in the short-term but even for a longer perspective in terms of evo- lutionary potential (Coakley et al., 1999; Garrett et al., 2006). In this context, process-based models can be used to explore con- ditions not experienced yet, for the estimation of crop-diseases interactions and expansion in new areas. In fact these biophysical processes show non-linear response to boundary conditions; ana- lytical or empirical models are thus not appropriate to estimate the outcome of the processes of interest. Nevertheless, every process- based model contains a certain degree of empiricism, which limits its reliability and use under conditions different from those exper- imented during its development and validation. For this reason, the limits of applicability of a given plant disease model have to 0304-3800/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ecolmodel.2012.08.004