Linking phenological shifts to species interactions through size-mediated priority effects

Area of Science:

• Ecology
• Evolutionary Biology
• Environmental Science

Background:

• Interannual weather variations alter species phenology, affecting community assembly.
• The mechanisms linking phenological shifts to species interactions remain poorly understood.
• Phenological timing, especially offspring arrival, is key to annual community dynamics.

Purpose of the Study:

• To investigate how shifts in relative offspring arrival times affect interspecific interactions.
• To experimentally quantify the role of size-mediated priority effects (SMPE) in mediating these interactions.
• To understand the consequences of SMPE for population and community dynamics.

Main Methods:

• Experimental simulation of altered relative arrival times for two dragonfly species nymphs.
• Assessment of intraguild predator-prey interactions under varying arrival scenarios.
• Quantification of predation strength and habitat use.

Main Results:

• Shifts in relative arrival significantly altered predation strength and interaction outcomes.
• Large arrival differences led to early arriver dominance and late arriver exclusion via SMPE.
• Small arrival differences resulted in mutual predation and coexistence.
• A nonlinear relationship was observed between arrival shifts and predation strength.

Conclusions:

• Size-mediated priority effects (SMPE) are a critical mechanism linking phenological shifts to species interactions.
• SMPE can determine interaction outcomes, demographic rates, and community structure.
• Understanding these mechanisms is vital for predicting community responses to climate change.