Will like replace like? Linking thermal performance to ecological function across predator and herbivore populations.

Area of Science:

• Ecology
• Climate Change Biology
• Evolutionary Biology

Background:

• Changing climate can disrupt ecological communities and their functions.
• Species resilience may depend on population-level thermal plasticity or adaptation.
• It remains unclear if adapting populations maintain the ecological roles of those they replace.

Purpose of the Study:

• To investigate if "like replaces like" functionally in response to environmental warming.
• To assess how grasshopper and spider populations cope with warming across a latitudinal gradient.
• To determine if physiological or behavioral adaptations maintain ecological functions.

Main Methods:

• Compared survival, thermal performance, habitat use, and food web interactions of grasshopper and spider populations.
• Utilized a latitudinal gradient from New Hampshire (cooler) to Connecticut (warmer).
• Assessed populations in their native sites and a common transplant site in Connecticut.

Main Results:

• Three of four grasshopper populations showed physiological plasticity by adjusting metabolic rates.
• The fourth grasshopper population and all spider populations selected cooler microhabitats.
• Physiologically adapting grasshopper populations altered plant consumption ratios, differing from non-adapting populations.

Conclusions:

• Physiological adaptation by grasshopper populations led to altered feeding patterns, disrupting functional replacement.
• Unlike grasshoppers, spiders adapted behaviorally, changing predator-prey spatial overlap.
• "Like may not replace like" when populations exhibit physiological plasticity in response to warming.