Global study of tundra to desert plants shows leaves respond to warming in remarkably similar ways

March 25th, 2016 @   - 
M_Heskel

Mary Heskel, MBL Postdoctoral Scientist

Plants from all over the globe respond to temperature changes in remarkably similar ways. That’s the finding of a new study led by MBL Ecosystems Center postdoctoral researcher Mary Heskel and published in the Proceedings of the National Academy of Sciences.

Mary, along with a large team of researchers, measured the respiration rates of vegetation at eighteen remote sites around the world that represented seven different types of plant habitat. It was the most comprehensive study of plant respiration responses to temperature ever conducted.

The team found that the sensitivity of respiration to temperature decreases as plants warm.

“The findings have important consequences for estimating carbon storage in vegetation, and for predicting concentrations of atmospheric carbon dioxide and future surface temperatures," Heskel said.

The finding points to universally conserved controls of temperature responsiveness across the world’s plant life.

The study looked at a wide range of plants growing in contrasting environments, from the arid woodlands of Western Australia, to the deciduous forests of New York, the arctic tundra in Alaska, the boreal forests of Sweden and the tropical forests of Costa Rica and Peru, according to Owen Atkin, Professor at the Australian Research Council Centre of Excellence in Plant Energy Biology at the Australian National University (ANU) in Canberra.

“We saw that in the cold, respiration is more sensitive to temperature than previously thought and that the sensitivity of respiration declines at higher temperatures.  Amazingly, these patterns were remarkably uniform across all the habitats and plant types studied,” Atkin said.

Odhran O’Sullivan, a postdoctoral researcher involved in the study who is now at the University of Sheffield, conducted fieldwork at the Arctic LTER site at the Toolik Field Station, which played an important role in defining responses at the cold end of the temperature spectrum experienced by plants.

Mary’s previous work in the Arctic LTER during her PhD improved understanding of the photosynthesis of arctic plants and resulted in several recent papers.

Respiration is the set of metabolic reactions used by plants to make usable energy for growth and cell maintenance. Plants release carbon dioxide during respiration as a by-product of converting sugars into energy.

The finding has important implications for the way that the temperature sensitivity of plants is incorporated into global ecosystem models that predict how ecosystems will respond to climate change. Heskel worked with Atkin at ANU before coming to the Ecosystems Center in November 2014 as a Rosenthal Postdoctoral Scholar.

The reality that respiration is more temperature sensitive that previously assumed and becomes less sensitive as the temperature rises is important for creating accurate climate models.

Plant respiration contributes a large amount of carbon to the atmosphere and plays a key role in the global carbon cycle. Climate models predict how warm the Earth will be later this century. Central to this is the prediction of carbon flows between plants and the atmosphere.

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