My current research is positioned between two scientific areas, invasion ecology and restoration ecology. Within these areas I am interested in exploring how ecological theory can be used to improve restoration outcomes that are affected by invasions of alien plants. My most recent work is aiming at understanding how invasive plant species impact plant-microbial interactions and how these changes affect ecological restoration. Further, with the increasing expansion of invasion ecology, I am also interested in research synthesis and looking for more generalizable patterns in invasion ecology.
Theory-based assembly of invasion-resistant communities
Invasions of alien species contribute to ecosystem degradation, complicating efforts to restore degraded systems. A key question is whether we can prevent the successful establishment of IAS during and after restoration by designing resistant plant communities. Along these lines, during previous work, I have explored whether it is possible to develop and apply a theoretical background to predict the biotic resistance of de novo-assembled native communities. I am particularly interested in understanding if trait similarity and phylogenetic relatedness can be used as a proxy for niche overlap among functionally similar species, addressing the Limiting Similarity Hypothesis and Darwin’s Naturalization Hypothesis. The rationale is to lower the performance of invading species through increasing niche similarity (in terms of resource acquisition strategies) between species of the native community and invading species. For this, I have used single- and multi-trait approaches and by assessing if suppression was also explained by phylogenetic similarity. In summary, my research in this area so far addressed questions related to community ecology with implications for grassland restoration and invasion ecology.
The role of soil effects in mediating invasions
My recent work at the Center for Invasion Biology (C•I•B; Stellenbosch University) focused on the implications of plant-soil feedbacks for ecological restoration. Invasive legumes are known to alter soil microbial communities, leading to positive feedbacks and ultimately to their persistence in the invasive range. In this context, I am interested in understanding how invasive legumes impact soil conditions, including plant-soil microbial interactions, and in which way these changes affect their performance and ecological restoration after clearing them. Within my project, I specifically explore the legacy effects of Australian acacias on the overall soil microbial structure and function following restoration in South African fynbos, comparing microbial and plant diversity in invaded, cleared and reference sites. I have also led a collaborative work with researchers from Spain, where we studied the effect of phytochemicals released by invasive acacias on the germination and early growth of acacias and native species from both invaded ranges (Spain and South Africa). Given the increasing amount of areas cleared by the Working for Water program in South Africa (main funder of my project), results from my research can be of significant help for guiding future post-clearing management.
Other research interests
Invasion ecology is a growing field of research, which has come with an increase in the number of hypotheses put forward to explain the success of invasive species. There is a need, therefore, for synthesis and meaningful generalizations in the hope for unveiling general patterns and making better predictions in invasion science. I am part of two collaborative efforts with numerous invasion scientists in which we hope to identify general patterns explaining invasion success based on the links among important hypotheses in invasion ecology and by identifying generalizations in species traits, processes and abiotic conditions.
PhD advisers: Prof. Johannes Kollmann (http://www.professoren.tum.de/en/kollmann-johannes/)
Postdoct host: Prof. Jaco Le Roux; current position (https://researchers.mq.edu.au/en/persons/jaco-le-roux)