Geographic range of plants drives long-term climate change

Area of Science:

• Paleoclimatology
• Biogeochemistry
• Computational Modeling

Background:

• Long computation times in vegetation and climate models limit deep-time analysis.
• Simulated vegetation often lacks spatial resolution and ignores local climate impacts on plant function.

Purpose of the Study:

• To couple a fast vegetation model (FLORA) with a climate-biogeochemical model (SCION).
• To assess the links between plant geographical range, the long-term carbon cycle, and climate over the Phanerozoic Eon.

Main Methods:

• Coupled FLORA (fast vegetation model) and SCION (spatially-resolved climate-biogeochemical model).
• Simulated vegetation distribution and its impact on carbon fixation and atmospheric CO2 concentrations over geological timescales.

Main Results:

• Limited plant geographical range over Pangea resulted in lower carbon fixation and doubled predicted atmospheric CO2.
• Mesozoic continental dispersion increased plant range to over 90%, enhancing global CO2 removal, aligning with geological data.

Conclusions:

• Plant geographical range is a major, under-explored factor controlling long-term climate change.
• Vegetation models must incorporate spatial distribution and local climate variables for accurate deep-time climate simulations.