The 'Great Dying' was caused by the Siberian Traps in Russia, which spewed carbon dioxide into the atmosphere for about a million years, spiking equatorial temperatures and acidifying the oceans. Yet a refuge of pollen-producing plants in what is now China avoided that fate, and research suggests similar oases existed elsewhere, indicating that plants may have been better able to weather catastrophic climate change than other organisms.
"Plants do indeed sometimes have a lot of resilience because they can't move individually, and even as a population, they're not very good at moving," Chris Thomas, an ecologist and evolutionary biologist at the University of York, told Live Science. As a result, many plants have evolved mechanisms to survive in place despite difficult conditions, he said.
One key adaptation is developmental plasticity. Unlike most animals, plants have indeterminate growth and modular body plans, allowing them to regenerate limbs that can adapt to current conditions. "If we lost an arm, it would be gone forever. But on plants, if you cut off a branch, they can sprout new ones and those new ones can then receive signals from the current environment instead of being stuck with sort of developmental programs from the past environment," Amy Angert, a botanist at the University of British Columbia, told Live Science. For example, resprouts on holm oak trees cope better with drought, and many species resprout after fire, like plants in South Africa's Cape Floristic Region, which depend on fire.
Plants also store seeds underground. Almost 350,000 plant species produce seeds, which can remain dormant in the soil for long periods. "Seeds can live essentially in stasis in the soil," Daniel Anstett, an evolutionary ecologist at Cornell University, told Live Science. This seed bank acts as a reservoir of genetic diversity, allowing populations to reanimate when conditions improve.
Rapid evolution can also help. In a study published in the journal Science, researchers including Angert and Anstett showed that scarlet monkey flower populations in the U.S. and Mexico rapidly evolved to survive prolonged drought between 2010 and 2018. By sequencing their genomes, they could predict which populations would survive based on genetic diversity. Anstett believes this could hold true for other organisms.
Flexible photosynthesis may have been crucial during the Permian-Triassic extinction. Zhen Xu, a paleobotanist at the University of Leeds, thinks CAM photosynthesis, which allows plants to regulate water loss more efficiently, allowed some species to survive then and could become increasingly important today.
While these adaptations offer hope, scientists caution that the speed of modern climate change may outpace many plants' ability to adapt. "Plants do indeed sometimes have a lot of resilience," Thomas said, but the extreme pace of current warming poses a serious challenge.