Lack of evidence for indirect effects from stonefly predators on primary production under future climate warming scenarios

Consumptive and non-consumptive interactions of predators and prey can have strong direct and indirect effects on primary producers, such as stream algae. Increasing water temperatures may alter these interactions and thus influence productivity in streams. For each of 3 temperature treatments (‘ambient’, +2°C and +4°C), we measured the amount of algal biomass removed by grazing mayflies from 91 mesocosms after a 24-hour test period under 3 grazing treatments: lethal predators, non-lethal predators, and no predators. At all temperatures, grazers reduced algal biomass (p