Biological invasions are a major threat to biodiversity, but also pose useful natural experiments with the potential to provide many ecological and evolutionary insights. Aiming to explain causes of invasions, much research effort has focused on investigating differences between native and invaded ranges or between the two distinct groups of native and alien species. In contrast, temporal dynamics such as the potential effects of eco-evolutionary changes during the invasion process have received far less attention. By colonising a new region and thereby being exposed to novel biotic and abiotic conditions, alien species have a high potential for rapid evolution. Conversely, while native species may initially be highly impacted by alien species due to a lack of shared evolutionary history, with time they may show evolutionary adaptations in response to invasions, increasing biotic resistance. Consequently, a simple division between native and alien species may thus not account for the continuous variation that the process of biological invasion represents. The aim of this project is therefore to elucidate mechanisms causing differences in invasion dynamics along an alien-native species continuum, which includes species of continuously increasing residence time (from recent neophyte over archaeophyte to native), using Asteraceae in Central Europe as a study system. To investigate how residence time, abiotic dissimilarity between the native and invaded range and biotic dissimilarity between the invader and native community interact to determine the performance and impacts of plant species, the proposed project combines multi-species small-scale common garden experiments and large-scale macroecological analyses. Focusing on 50 annual Asteraceae species with varying residence times, small-scale establishment success and biotic resistance of a native resident grassland community will be investigated. A pairwise competition common garden experiment will examine changing impacts along the alien-native species continuum. Macroecological analyses focusing on all Asteraceae species occurring in Central Europe will investigate how range size is influenced by residence time. Finally, synthesising these two methodological approaches will determine whether the effect of residence time on invader performance results in a unimodal relationship, and how this is mediated by abiotic and biotic dissimilarity. By contributing to a better understanding of the dynamic nature of biological invasions this project will help explain invasion mechanisms and assist in determining appropriate management responses. Moreover, investigating temporal dynamics of invasions and understanding changing biotic interactions will give insights to fundamental ecological and evolutionary processes in general.
Project start 01/03/2016
Project end 30/11/2019
Sponsor mark (sponsor) DFG Project SH 924/1-1
