Spatial and temporal shifts in photoperiod with climate change

Area of Science:

• Plant biology
• Climate change ecology
• Phenology

Background:

• Climate change drives species shifts in timing (phenology) and geographic distribution.
• Experienced photoperiod, the light duration plants perceive, influences seasonal biological responses, particularly woody plant spring phenology.
• Photoperiodic shifts due to climate change are often overlooked in forecasting, especially for spring events typically attributed to temperature.

Purpose of the Study:

• To synthesize research on the impact of climate-driven temporal and spatial species shifts on experienced photoperiod.
• To assess the relative magnitude of photoperiod changes from temporal versus spatial shifts.
• To evaluate the potential for incorporating photoperiod effects into climate change impact models for plant phenology and distribution.

Main Methods:

• Literature synthesis of published studies on climate change impacts on species phenology and distribution.
• Analysis of experimental data, particularly from growth chamber experiments on woody plants, to quantify photoperiod effects.
• Comparison of estimated photoperiod changes resulting from temporal shifts (e.g., earlier spring) versus spatial shifts (e.g., latitudinal range changes).

Main Results:

• Temporal shifts in species occurrence (e.g., advancing spring) cause much larger changes in experienced photoperiod (up to 1.6 hours) than spatial shifts (approx. 1 minute).
• Existing experimental data, such as from growth chamber studies, can be leveraged to predict climate change impacts on photoperiod.
• Shifts in experienced photoperiod are likely to become a significant constraint on plant responses to future warming.

Conclusions:

• Experienced photoperiod changes driven by climate change, particularly temporal shifts, have substantial implications for plant phenology, distribution, and fitness.
• Integrating photoperiod effects into climate change models is crucial for accurate predictions of future plant responses.
• Further research combining modeling and empirical data is needed to advance understanding of photoperiod's role in climate change-induced spatio-temporal species shifts.