Herbivore species identity and composition affect soil enzymatic activity through altered plant composition in a coastal tallgrass prairie

• Herbivore community composition likely affects soil microbes but is rarely studied.
• Certain species and combinations strongly affected soil enzymatic activity.
• Community effects on microbial activity may be driven by alterations to vegetation.

Although single herbivore species are known to affect soil microbial communities, the effects of herbivore species identity and community composition on soil microbes and their functioning are unknown. We tested the effects of single orthopteran species and species combinations on soil enzymatic activity with an enclosure experiment in a coastal tallgrass prairie. Species effects on soil enzymatic activity were non-additive: one particular mixed feeding species (M. femurrubrum) resulted in 65% higher BG enzyme activity and 35% higher total hydrolytic enzyme activity, whereas certain combinations containing this species had little to no effects. These results suggest that critical species or combinations of species that strongly affect plant functional composition may also have strong effects on soil enzymatic functioning and nutrient limitation.