EGU24-10509, updated on 08 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The influence of belowground nematode herbivory on carbon allocation in drought-prone ecosystems

André Franco1 and Laureano Gherardi2
André Franco and Laureano Gherardi
  • 1Indiana University Bloomington, O'Neill School of Public and Environmental Affairs, Bloomington, United States of America (
  • 2University of California Berkeley, Dept of Environmental Science, Policy & Management, Berkeley, United States of America

To understand carbon dynamics and how it is affected by ongoing climate change, we need a better appreciation of the belowground ecological interactions driving plant allocation patterns and ecosystem carbon fixation. It has become increasingly clear that belowground root inputs contribute significantly more to soil carbon sequestration than aboveground plant inputs. Yet, current understanding of the role of belowground root herbivory in ecosystem carbon dynamics is weaker than that of aboveground herbivory. We addressed this gap by merging three complementary and novel areas of research, namely testing how: (1) biotic interactions between plants and nematode herbivores affect belowground biomass allocation in grasses; (2) how these biotic interactions and their consequences for biomass allocation are modified by a pervasive perturbation, namely drought, which is becoming more intense and frequent; and (3) how belowground responses vary across contrasting ecosystems. Results of complementary controlled and multi-site field experiments showed that: (1) nematode root herbivory modulates the relationship between water availability and belowground biomass allocation; (2) drought-induced increases in nematode root herbivory impede plants from increasing biomass allocation to roots under drought; and (3) these nematode effects are greater in magnitude in mesic compared to semiarid and arid grasslands. These findings suggest that the fate of carbon in mesic ecosystems under increasing drought frequency is highly influenced by nematode herbivores in the soil, and encourage investigations into the unknown consequences for soil carbon formation and persistence.

How to cite: Franco, A. and Gherardi, L.: The influence of belowground nematode herbivory on carbon allocation in drought-prone ecosystems, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10509,, 2024.