Outdoor Labs Offer Realistic Insights of Plant Response to Future Climate Change

If a seed is zapped into the future to see how it will react to climate change, how accurate will that prediction be? After all, seeds that essentially grow in the future would have experienced  generations of genetic variations and adaptations that these “time traveling” seeds do not experience.

Researchers from the University of California, Davis, and the University of Southampton in the UK explore that question in a study published recently in the journal Global Change Biology. They learned that dedicated outdoor laboratories more closely bear a resemblance to what takes place in nature than was formerly realized.

About FACE

Atmospheric carbon dioxide (CO₂) has been progressively rising since the Industrial Revolution and is currently at the highest concentration the planet has experienced for several million years. Researchers have been scrutinizing how plants are likely to respond to future climate change at outdoor facilities called Free Air CO₂ Enrichment (FACE), where fields of crops are blasted with air comprising higher volumes of CO₂.

The research authors related plant responses at FACE facilities with plant responses spanning 11 naturally occurring, high-CO₂ springs. Plants at these springs endure very high concentrations of CO₂, up to 1,000 parts per million in certain areas, for a number of years over multiple generations.

“The results say, pretty surprisingly, that yes, all of those experiments we’ve done in FACE facilities are giving us a pretty good idea of how plants are likely to respond in the future,” said corresponding author Gail Taylor, a UC Davis professor and chair of the Department of Plant Sciences.

Global greening could continue

And how are plants expected to respond? Positively, Taylor states. However, there’s a big warning.

As a remote factor, high CO₂ concentrations are projected to yield more plant growth and sustained global greening. However, drought and high temperatures—both of which are projected to increase under future climate estimations—can restrict that growth.

“If plants are exposed to higher temperatures and drought, there will likely be negative impacts, overall, so it’s a tradeoff,” Taylor said. “But our analysis gives us confidence that plants are likely to keep responding positively to rising CO₂ if no other climatic factors are limiting.”

With growing CO₂, crop yields are anticipated to increase in northern latitudes but may decrease nearer to the equator. California is predicted to experience lower crop harvests due to high temperatures and water limitations, while in the UK effects on crops will be variable.

The majority of the FACE experiments have focused on commodity crops like maize, wheat, soybeans, and rice. Specialty crops, like the fruits, nuts, and vegetables grown in California, have not been yet been studied in FACE facilities, but Taylor wishes to change that.

Higher carb future?

While the research did not examine the effects of rising CO₂ on crop nutrition or quality, it did specify that certain crops may possess higher carbohydrate content under future circumstances.

The analysis shows that it's possible to test new varieties of plants in FACE experiments before it is critical that they perform in the wider world. These ‘time-traveling’ plants that move forward and backwards across the decades can be extremely valuable in understanding how plants are likely to respond to the changes projected as a consequence of anthropogenic climate change.

Gail Taylor, Professor and Chair of Department of Plant Sciences, UC Davis.

Other authors include Jasmine Saban and Mark Chapman of the University of Southampton.

The research was financially supported by the Natural Environment Research Council, UC Davis, and the British Council.