Climate-driven extinctions shape the phylogenetic structure of temperate tree floras.

Area of Science:

• Ecology
• Evolutionary Biology
• Paleoclimatology

Background:

• Extinction events lead to the irreversible loss of unique evolutionary history.
• Selective extinction, particularly when linked to traits with phylogenetic signal, can disproportionately reduce evolutionary diversity.
• Understanding the conditions driving phylogenetically selective extinction is crucial for predicting future biodiversity.

Purpose of the Study:

• To investigate whether late Cenozoic climate change induced phylogenetically selective regional extinction in northern temperate trees.
• To quantify the loss of phylogenetic diversity (PD) resulting from climate-induced extinction.
• To assess the relationship between extinction severity and the phylogenetic structure of surviving floras.

Main Methods:

• Analysis of regional extinction patterns in northern temperate trees during the late Cenozoic.
• Assessment of phylogenetic signal in cold tolerance among tree taxa.
• Phylogenetic diversity (PD) calculations to quantify evolutionary history loss.
• Simulations using a threshold survival model incorporating phylogenetic signal.

Main Results:

• Late Cenozoic climate change caused phylogenetically selective extinction of northern temperate trees due to a phylogenetic signal in cold tolerance.
• Extinction events led to significantly larger-than-random losses of phylogenetic diversity (PD).
• Regions with more severe extinction showed phylogenetically clustered surviving floras, indicating non-random PD loss.

Conclusions:

• Phylogenetically selective extinction driven by climate change can substantially deplete evolutionary history.
• Increasing extinction severity results in more pronounced non-random losses of phylogenetic diversity.
• Future anthropogenic climate change may lead to phylogenetically and functionally depauperate ecosystems if similar selective pressures occur.