Plants are better at adapting their respiration to warming temperatures than previously thought. A study shows plants release less carbon into the atmosphere from respiration when they grow up in warmer temperatures, as opposed to when the temperature changes throughout their life.
With less carbon being released by plants, their impact on climate change may be less than what we believed.
The amount of carbon dioxide from plant respiration is six-times greater than that released into the atmosphere from burning fossil fuels. Plant respiration reacts to warming temperature – a warmer climate, more respiration, and more carbon dioxide. It is believed this would exacerbate climate change as the atmosphere warms.
Adapting to climate change
To investigate how much of an impact plant respiration will have on future climate scenarios, researchers from the University of Minnesota compared 10 North American tree species in different temperatures. The findings were published in Nature.
Plants were grown in different temperatures for three to five years. Plants grown in temperatures 3.4°C warmer than average were compared to those grown in modern temperate conditions.
The results showed that those grown in warmer environments respired 5% more than those grown in the regional average temperature. That means they also released 5% more carbon.
They then moved the plants grown in today's temperature to the warmer environment, to see how they would cope, and how their respiration would change. The researchers found their respiration increased by 23%.
That means plants grown in warmer temperatures acclimatise to their environment, as otherwise the plants grown in warmer temperatures would have shown a much larger respiration rate increase than 5%.
The researchers say that predictions for the amount of carbon dioxide will be released to the atmosphere from plants under warmer global temperatures can now be reduced.
The study concluded: "Our results demonstrated strong acclimation of leaf respiration to both a +3.4°C warming and seasonal temperature increases, which profoundly reduced plant respiratory carbon loss compared to what would have occurred without acclimation.
"If our realistic, long-term field results are broadly indicative, they suggest that leaf respiratory acclimation globally may have a larger ameliorating impact than expected on CO2 losses with rising temperatures as climate changes."