Predicting Invasive Alien Species in Global Trade

Invasive alien species (IAS) represent a long-standing threat to ecosystem stability (Roy et al. 2023). Quantification of invasions globally via trade among countries is challenging and usually relies on estimates instead of direct measurements (see, e.g., Seebens et al. 2015). This study contributes to the literature by integrating a predictive model that links international trade flows to the global risk of invasions in a global input-output (IO) model, focusing on plant species.We investigate how trade relationships between countries influence the likelihood and intensity of invasions over time. To answer this question, we follow and extend the approach of Seebens et al. (2015). We estimate a probabilistic model that combines global bilateral trade data with environmental similarity measures — including climatic and geographic distance — and native plant richness. The model decomposes invasion risk into three linked probabilities: (1) that a species is alien between a donor and recipient country; (2) that it is introduced through trade; and (3) that it successfully establishes a population given environmental compatibility. Each probability is parameterized empirically using global datasets on plant invasions, trade, biodiversity, and environmental indicators.We estimate expected invasion counts for 188 countries within a global IO model from 2014 to 2030 as well as for years 2050 and 2100. Results indicate that, on average, 200 to 220 new invasions occur per year worldwide, consistent with the upper range of historical observations. The predicted number of invasions rise modestly but persistently toward 2100, driven mainly by increasing trade volumes. The IO model allows us to derive sector- and country-specific invasion intensities per unit of import value. Our findings offer policymakers a quantitative basis for identifying trade-related ecosystem vulnerabilities and designing preventive measures. Roy, Helen E., Aníbal Pauchard, Peter Stoett, et al. 2023. Summary for Policymakers of the Thematic Assessment Report on Invasive Alien Species and Their Control. Nos. 978-3-947851-35–5. Thematic Assessment Report on Invasive Alien Species and Their Control. IPBES secretariat.Seebens, Hanno, Franz Essl, Wayne Dawson, et al. 2015. “Global Trade Will Accelerate Plant Invasions in Emerging Economies under Climate Change.” Global Change Biology 21 (11): 4128–40.