Prioritizing management actions for emergent invasive alien plants through expert-based knowledge and Species Distribution Models

Innovative tools for rapid and efficient prioritization lists of emergent invasive alien plants (IAPs) are essential to support cost-effective management strategy. In this context, Species Distribution Models (SDMs) are a sound tool for predicting current and future suitable areas for new IAPs. Within this work, we firstly provided the European and Mediterreanean Plant Protection Organization (EPPO) with a list of emergent IAPs for Italy, and after applied a methodological framework that combined SDM, clustering and ordination in order to produce a prioritization management list for emergent IAPs at the national scale (Italy). The identification of emergent IAPs was achieved by members of the Italian Botanical Society (SBI). Occurrences of each IAP were retrieved from GBIF. Current and future suitable areas of each IAP were identified using MaxEnt and bioclimatic variables retrieved from the Chelsa database. After, we estimated the current and future suitability percentage in each Italian bioregion, and we calculated future suitability changes caused by climate change. The suitability percentages were the data to define prioritization list combining cluster analysis, non-metric multidimensional scaling (NMDS) ordination analysis and classification of IAPs. The list of emergent IAPs included 36 species invading or potentially invading at least one of the three biogeographical (Mediterranean – M, Continental – C, Alpine – A) regions of Italy. Overall suitability models showed excellent predictive performances (AUC > 0.945, BCI > 0.786), and most IAPs were classified with high and very high suitability class in M and C regions. Three clusters showing different suitability for the Italian bioregions were identified by cluster analysis, and the three NMDS estimate the cluster internal variability, current distribution pattern of IAPs and classification in the prioritization list. The proposed prioritization framework has proved efficient, fast and reproducible procedure in order to indicate management actions for emergent IAPs in Italy.