© 2006 The Authors DOI: 10.1111/j.1366-9516.2006.00249.x

To assess the validity of previously developed risk assessment schemes in the con-ditions of Central Europe, we tested (1) Australian weed risk assessment scheme (WRA; Pheloung et al. 1999); (2) WRA with additional analysis by Daehler et al (2004); and (3) decision tree scheme of Reichard and Hamilton (1997) developed in North America, on a data set of 180 alien woody species commonly planted in the Czech Republic. This list included 17 invasive species, 9 naturalized but non-invasive, 31 casual aliens, and 123 species not reported to escape from cultivation. The WRA model with additional analysis provided best results, rejecting 100 % of invasive species, accepting 83.8 % of non-invasive, and recommending further 13.0 % for additional analysis. Overall accuracy of the WRA model with additional analysis was 85.5%, higher than that of the basic WRA scheme (67.9%) and the Reichard–Hamilton model (61.6%). Only the Reichard–Hamilton scheme accepted some invaders. The probability that an accepted species will become an invader was zero for both WRA models and 3.2 % for the Reichard–Hamilton model. The probability that a rejected species would have been an invader was 77.3 % for both WRA models and 24.0 % for the Reichard–Hamilton model. It is concluded that the WRA model, especially with additional analysis, appears to be a promising template for building a widely applicable system for screening out invasive plant introductions