The direct and indirect effects of nitrogen enrichment on grassland consumer communities

I am conducting my PhD research within the wider PaNDiv experiment, which is an experimental grassland that assess the direct and indirect effects of nitrogen enrichment on ecosystem functioning. The aim of my research is to assess how the effects of global change can cascade through the ecosystem to affect the diversity and composition of insect and pathogen consumer communities. The main mechanisms underlying the variation in consumer communities relates to changes in plant defences, both physical and chemical, and shifts in plant nutrient contents. The relative importance of different mechanisms in driving consumer abundance and diversity is likely to vary depending on the level of specialism and feeding guild of the consumers. Interactions between consumer groups may also be altered but very little is known about the mechanistic basis of insect-pathogen interactions at the community scale. To address these questions I am assessing plant chemical defences using metabolomics approaches, characterising nutrient profiles (amino acids, sugars) and will link inter- and intraspecific variation in nutrients and defences to consumer communities