Related Experiment Video
Updated: Aug 15, 2026
10:14
Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area
Published on: October 25, 2024
Forest canopy decline under elevated CO2 during the Paleocene-Eocene Thermal Maximum
Regan E Dunn1,2, Marieke Dechesne3, Brady Z Foreman4
1Samuel Oschin Global Center for Ice Age Research, La Brea Tar Pits, Natural History Museum of Los Angeles County, Los Angeles, CA, USA.
Science (New York, N.Y.)
|August 13, 2026
Summary
Rapid global warming caused forest canopies to open and vegetation to shift dramatically during the Paleocene-Eocene Thermal Maximum (PETM). These ancient climate shifts offer insights into modern forest ecosystem responses to warming.
Area of Science:
- Paleoclimatology
- Ecology
- Paleobotany
Background:
- Anthropogenic warming impacts on forest ecosystems remain uncertain.
- The Paleocene-Eocene Thermal Maximum (PETM) serves as a valuable analog for rapid global warming events.
- Understanding past ecosystem responses can inform predictions of future climate change impacts.
Purpose of the Study:
- To reconstruct forest canopy density and composition changes during the PETM.
- To assess the impact of abrupt warming and carbon increase on vegetation.
- To investigate the relationship between plant community shifts and landscape stability.
Main Methods:
- Developed a proxy to quantify leaf area index (LAI) from palynomorph data.
- Analyzed palynomorphs to assess shifts in floral composition.
- Integrated Wyoming data with regional paleoclimate and paleoecological records.
Main Results:
- Forest canopies abruptly opened at the onset of PETM warming.
- Increased landscape erosion was observed.
- Vegetation shifted from broad-leaved angiosperms to fern- and palm-dominated ecosystems.
Conclusions:
- Continental-scale plant community shifts can lead to landscape destabilization.
- These vegetation changes have implications for long-term climate feedbacks.
- Past warming events provide crucial data for understanding current and future forest ecosystem dynamics.
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