July 22, 2014
Size, Age Of Plants Impact Their Productivity More Than Climate, UA Study Shows
Vanessa Buzzard, University of Arizona Department of Ecology and Evolutionary Biology
The size and age of plants has more of an impact on their productivity than temperature and precipitation, University of Arizona researchers have discovered.UA professor Brian Enquist and postdoctoral researcher Sean Michaletz, along with collaborators Dongliang Cheng from Fujian Normal University in China and Drew Kerkhoff from Kenyon College in Gambier, Ohio, have combined a new mathematical theory with data from more than 1,000 forests across the world to show that climate has a relatively minor direct effect on net primary productivity, or the amount of biomass – wood or any other plant materials – that plants produce by harvesting sunlight, water and carbon dioxide.
The findings were made available as an advance online publication by the journal Nature on Sunday.
"A fundamental assumption of our models for understanding how climate influences the functioning of ecosystems is that temperature and precipitation directly influence how fast plants can take up and use carbon dioxide," said Enquist, a professor in the UA Department of Ecology and Evolutionary Biology, whose research lab led the study.
"Essentially, warm and wet environments are thought to allow plant metabolism to run fast, while cold and drier environments slow down metabolism and hence lower biomass production in ecosystems," he said. "This assumption makes sense, as we know from countless experiments that temperature and water control how fast plants can grow. However, when applied to the scale of entire ecosystems, this assumption appears to not be correct."