Variation in Plant Response to Herbivory Underscored by Functional Traits

Area of Science:

• Plant Ecology
• Evolutionary Biology
• Ecosystem Dynamics

Background:

• Herbivory significantly influences plant community structure and evolution.
• Predicting herbivory's impact is challenging due to diverse costs and varying pressure across gradients.
• Functional trait approaches offer a standardized method for assessing herbivory effects.

Purpose of the Study:

• To investigate how functional traits influence plant responses to simulated herbivory.
• To determine if baseline traits predict plant resilience to defoliation.
• To explore the role of species' latitudinal distribution in herbivory tolerance.

Main Methods:

• Assessed 26 old-field plant species under simulated defoliation in a greenhouse.
• Measured whole plant and leaf-level traits in control and defoliated groups.
• Utilized log response ratio to quantify treatment effects on plant traits.

Main Results:

• Simulated defoliation did not significantly affect most measured plant traits.
• Baseline leaf traits of healthy plants predicted whole plant responses to defoliation.
• Species' latitudinal distribution correlated with biomass and leaf area responses; northern species were more impacted.

Conclusions:

• Functional traits can predict variability in plant responses to herbivory, even without significant direct impacts.
• Baseline traits are crucial for understanding plant resilience to defoliation.
• Latitudinal distribution influences species' susceptibility to herbivory, with northern species facing greater challenges.