Roots comprise one-quarter of the global plant biomass, and therefore potentially provide an ample food source for herbivores. However, we recently found that forest insects consume a ten-fold smaller proportion of root biomass than leaf biomass. We plan to uncover the reasons of underutilisation of plant roots by insects by combining observations, field and laboratory experiments, and research syntheses. Three possible explanations will be tested: 1) excessive energetic cost of locomotion through soil, 2) low quality of roots as food for insects, and 3) high predation on root feeders. We will reveal the factors affecting root herbivory in nature by exploring the global geographic patterns in root losses to insects and comparing these patterns with corresponding patterns in the potential drivers of root herbivory (climate, soil properties, root properties, predation). Our data will pave the way for a deeper understanding of eco-evolutionary processes shaping belowground food webs.

2024

2028