Changing climate cues differentially alter zooplankton dormancy dynamics across latitudes

Area of Science:

• Ecology
• Limnology
• Climate Change Biology

Background:

• Dormancy is crucial for species persistence in seasonal climates and structures biodiversity.
• Zooplankton form the base of aquatic food webs, and their dormancy dynamics are sensitive to environmental cues.
• Climate change is predicted to alter temperature and day length, key hatching cues for zooplankton.

Purpose of the Study:

• To investigate how temperature and day length influence zooplankton hatching dynamics.
• To determine if sensitivity to these cues varies with the latitudinal origin of zooplankton egg banks.
• To assess potential latitude-specific shifts in zooplankton communities due to climate change.

Main Methods:

• Collected sediment from 25 lakes across a 1800 km latitudinal gradient.
• Exposed sediment to a factorial combination of two photoperiods (12h, 16h) and two temperatures (8°C, 12°C).
• Analyzed hatching phenology, abundance, and diversity across different zooplankton taxa and latitudinal origins.

Main Results:

• Higher temperatures advanced hatching phenology for all taxa, with cladocerans showing the greatest response.
• Temperature effects on phenology did not vary with latitude, but latitudinal origin influenced egg and hatchling abundance and diversity.
• Zooplankton responses varied by taxa, with copepods peaking at mid-latitudes under high temperature/long photoperiod, while others favored low latitudes/high temperature.

Conclusions:

• Hatching cues differ among zooplankton taxa based on their life-history strategies.
• Latitude-specific responses to altered hatching cues are expected under climate change.
• These shifts can significantly alter the structure and function of aquatic food webs.