Professional summary

Karsten is a UKCEH Fellow whose research is focused on questions about how shared evolutionary history shapes species’ interactions, and how such interactions species distribution, but also their resilience to environmental change.

Parasitism and parasitoid-host interactions tend to be tight and to exaggerate impacts. Similarly, biological invasions are large scale natural experiments of community assembly and perturbations. Of course many such interactions are of both ecological and economical importance.

Karsten used biological invasions to study the ability to predict interactions with natural enemies native to the invaded range. He has been studying social parasites of ants, their adaptations to their life histories and variations within them. These studies involved many species of conservation status: Maculinea/Phengaris butterflies and Microdon hoverflies. He has been focusing on two study systems: trees, their associated herbivores (Cynipid gallwasps) and their natural enemies (Chalcidoid parasitoids) in tri-trophic interactions (trophic cascades or bottom - up versus top-down selection); and, ants and their social parasites. In both, understanding functional phenotypes, including chemical and acoustic communication and the morphology of defensive phenotypes allows the study of species associations in ecological and evolutionary times to assess community resilience to environmental change. 

Selected publications

Harrower C.A. et al. , (2018), Guidance for interpretation of CBD categories on introduction pathways.