Invasions by alien biota are nowadays recognized as one of the major threats to global biodiversity. Accordingly, intensive studies of invasive species are continuously being performed during the last three decades, mainly focusing on invasive species traits and habitats, their impact on resident species and communities, and their efficient management. Until recently, there was no systematic research of the invasive flora of Croatia; therefore scientific literature on Croatian invasive plants is rather scarce. This study aimed to detect allelopathic potential of selected invasive species, to find connection between dispersal types of invasive flora and environmental factors, to detect the level of fenotypic plasticity and its impact on CSR strategies of invasive plants, and to explain the relationship between the occurrence of CSR strategies and habitat heterogeneity. As a result, inhibition of seedling emergence and growth of white mustard and wheat, i.e. allelopatic potential, was found in some cases. Study of Mt. Medvednica has shown that environmental factors can influence the occurrence of dispersal types, whereas anemochory was more common in higher altitudes, and anthropochory was more common in areas with more paths/roads. The example of Erigeron annuus has shown that some morphological traits are largely plastic, and different populations can have different CSR strategies. In addition, the analysis on Mt. Medvednica has shown that the number of invasive species is higher in areas with greater habitat and species diversity, while higher altitudes support less invasive species. The analysis of CSR strategies in dependence of habitat heterogeneity did not confirm the expected connection between R-strategists and greater habitat heterogeneity.