Accurate phenology analyses require bud traits and energy budgets

Area of Science:

• Ecology
• Plant Physiology
• Climate Science

Background:

• Spring phenology, the timing of seasonal plant events like leaf unfolding, is crucial for ecosystem function.
• Temperature is a primary driver of spring phenology in extratropical regions.
• Existing phenology studies often use air temperature, neglecting the difference between air and plant tissue temperatures.

Purpose of the Study:

• To investigate the influence of micrometeorology and bud temperature on spring phenology.
• To highlight the limitations of using air temperature as a proxy for bud temperature in phenological research.
• To propose improved methods for analyzing phenology in response to climate warming.

Main Methods:

• Review of recent observations and energy balance theories.
• Analysis of how solar radiation, wind, and bud traits affect bud temperature.
• Comparison of air temperature and bud temperature as predictors of phenological events.

Main Results:

• Air temperature is an imprecise and potentially biased predictor of bud temperature.
• Differences in energy absorption and loss cause significant temperature variations between plant tissues and the air.
• Bud traits and micrometeorological factors play a key role in modulating bud temperature.

Conclusions:

• Accurate assessment of phenology's response to warming requires direct measurement of bud temperature and traits.
• Integrating energy budget models with plant trait data can improve phenology analyses.
• Future research should focus on collecting detailed micrometeorological and bud temperature data.