The decline in insect populations across large parts of the world poses a real threat to natural ecosystem functioning as well as to global food security. The longest insect biodiversity records, based on ecological monitoring data, only reach back to the 1980s. It is therefore impossible to disentangle centennial-scale natural variability from the effects of recent human impacts.
Subfossil chironomid (non-biting midges) remains as stored in lake sediment records provide a unique way to reconstruct long-term changes in insect diversity. Chironomids are often the most abundant invertebrates in a lake and they are highly sensitive to changes in their environment. The preservation of parts of their exoskeleton in lake sediment records allows us to determine changes in the chironomid fauna through time.
This project will determine to what extent the current decrease in insect numbers has been driven by human-induced climate and environmental change. Short sediment records will be retrieved from shallow lakes in areas that have seen dramatic decreases in insect diversity (e.g. Lake Uddelermeer, The Netherlands; Hatchet Pond, UK). The records will be analysed with a sub-decadal resolution in order to reconstruct past trends in the chironomid fauna. By understanding how insect diversity has varied across the last few centuries we will be better able to predict how the current decline in insects will develop in the near future.
You will receive advanced training in: (a) the generation of highly resolved palaeoecological records, including sedimentological, chronological and palaeoecological techniques; (b) the use of a range of biodiversity metrics; (c) interpretation and presentation of scientific data in the context of (palaeo-) ecological research questions.