Climate, urbanization, and species traits interactively drive flowering duration

Area of Science:

• Ecology
• Phenology
• Climate Change Biology

Background:

• Flowering onset and offset dynamics across environmental gradients are poorly understood.
• Understanding these patterns is crucial for predicting plant, pollinator, and herbivore responses to climate and land-use change.

Purpose of the Study:

• Investigate climatic and landscape drivers of flowering onset, offset, and duration for 52 plant species.
• Assess how traits influence variation in flowering phenology along environmental gradients.

Main Methods:

• Utilized over 270,000 community-science photographs to estimate phenology.
• Developed a novel presence-only phenometric estimation method.
• Analyzed flowering phenophases in relation to climate and urbanization data.

Main Results:

• Longer flowering durations observed in warmer regions, especially for summer-bloomers due to differing offset dynamics.
• Higher human population density and precipitation linked to delayed flowering offset and extended duration.
• Woody perennial offset more sensitive to climate and urbanization than herbaceous species.

Conclusions:

• Flowering durations are projected to increase by 2030 and 2050 under RCP 8.5, particularly for summer-blooming species.
• Hopkins' Bioclimatic Law applies to flowering durations for summer-blooming and herbaceous spring-blooming species.
• Findings provide critical insights into phenological shifts driven by environmental change.