Continental Contrasts in Climate Extremes That Control Tree Fecundity

Area of Science:

• Ecology
• Climate Science
• Forestry

Background:

• Climate extremes, including drought and late freezes, are increasingly impacting agriculture and natural ecosystems.
• The role of these extremes in forest recovery from global diebacks is poorly understood due to a lack of data on tree fecundity.
• Species' tolerance to climate extremes may be influenced by past exposure and phylogenetic conservatism.

Purpose of the Study:

• To analyze the impact of climate extremes (late freeze and drought) on forest fecundity across North America and Europe.
• To investigate the factors, including species traits and phylogeny, that explain differential responses to climate extremes.
• To assess the adequacy of current adaptation strategies in the face of intensifying climate extremes.

Main Methods:

• Continental-scale analysis of climate extremes and forest fecundity data across North America and Europe.
• Examination of species-specific responses to late freeze and drought events.
• Comparison of observed species differences with traditional ecological traits and phylogenetic relationships.

Main Results:

• Significant impacts of late freeze and drought on forest fecundity are evident across North America and Europe.
• Species differences in response to climate extremes are not adequately explained by traditional traits or phylogeny.
• Late freeze appears to be a more common stressor in North America than in Europe, potentially affecting seed production.

Conclusions:

• Forest species are currently responding to climate extremes, but traditional traits and phylogeny offer limited explanations for these responses.
• Past exposure and local adaptation may be insufficient to buffer forests against intensifying climate extremes.
• Understanding species-specific vulnerabilities is crucial for predicting forest resilience and managing ecosystems under climate change.