Reviews and syntheses : Impacts of plant-silica-herbivore interactions on terrestrial biogeochemical cycling

Researchers have known for decades that silicon plays a major role in biogeochemical and plant-soil processes in terrestrial systems. Meanwhile, plant biologists continue to uncover a growing list of benefits derived from silicon to combat abiotic and biotic stresses, such as defense against herbivory. Yet despite growing recognition of herbivores as important ecosystem engineers, many major gaps remain in our understanding of how silicon and herbivory interact to shape biogeochemical processes, particularly in natural systems. We review and synthesize 119 available studies directly investigating silicon and herbivory to summarize key trends and highlight research gaps and opportunities. Categorizing studies by multiple ecosystem, plant, and herbivore characteristics, we find substantial evidence for a wide variety of important interactions between plant silicon and herbivory but highlight the need for more research particularly in non-graminoid-dominated vegetation outside of the temperate biome as well as on the potential effects of herbivory on silicon cycling. Continuing to overlook silicon-herbivory dynamics in natural ecosystems limits our understanding of potentially critical animal-plant-soil feedbacks necessary to inform land management decisions and to refine global models of environmental change