Post-processed climate model output and associated source code for "C4 photosynthesis and climate through the lens of optimality". Data files are in netcdf format, ncl source code, and README file included.
CO2, temperature, water availability and light intensity were all potential selective pressures to propel the initial evolution and global expansion of C4 photosynthesis over the last 30 million years. To tease apart how the primary selective pressures varied along this evolutionary trajectory, we coupled photosynthesis and hydraulics models while optimizing photosynthesis over stomatal resistance and leaf/fine-root allocation. We further examined the importance of resource (e.g. nitrogen) reallocation from the dark to the light reactions during and after the initial formation of C4syndrome. We show here that the primary selective pressures − all acting upon photorespiration in C3 progenitors − changed through the course of C4 evolution. The higher stomatal resistance and leaf-to-root allocation ratio enabled by the C4 carbon-concentrating mechanism led to a C4 advantage without any change in hydraulic properties, but selection on nitrogen reallocation varied. Water limitation was the primary driver for the initial evolution of C4 25-32 million years ago, and could positively select for C4 evolution with atmospheric CO2 as high as 600 ppm. Under these high CO2 conditions, nitrogen reallocation was necessary. Low CO2 and light intensity, but not nitrogen reallocation, were the primary drivers during the global radiation of C4 5-10 MYA. Finally, our results suggest that identifying the predominate selective pressures at the time C4 first evolved within a lineage should help explain current biogeographical distributions.
Zhou, Haoran, Brent Helliker, and Erol Akcay. 2018. C4 Photosynthesis and Climate through the Lens of Optimality. bioRxiv doi: 10.1101/048900.
Cite this work
Researchers should cite this work as follows:
- Zhou, H., Helliker, B., Huber, M., Dicks, A. J., Akçay, E. (2018). C4 photosynthesis and climate through the lens of optimality. Purdue University Research Repository. doi:10.4231/R7PR7T75
Miocene Paleoclimate Proxy Data and Models
This publication belongs to the Miocene Paleoclimate Proxy Data and Models group.