"This general relationship shows that climate doesn't influence productivity by changing the metabolic reaction rates underlying plant growth, but instead by determining how large plants can get and how long they can live for," said Sean Michaletz, lead author of the study and a postdoctoral researcher at the UA Department of Ecology and Evolutionary Biology. "This means that plants in warm, wet environments can grow more because their larger size and longer growing season enable them to capture more resources, not because climate increases the speed of their metabolism."
The finding does not, however, mean that climate is unimportant for plant productivity, the researchers said.
"Climate is still an important factor," said Michaletz, "but our understanding of how it influences ecosystem functioning has now changed."
The team's new findings suggest that mathematical models used for predicting the effects of global climate change can be improved by accounting for the effects of plant size and plant age on net primary productivity.
"Understanding exactly how climate controls net primary production is important for understanding the plant-atmosphere feedbacks that control climate change," said Michaletz.
Enquist said: "In other words, to better predict how ecosystems will change with climate, we need to understand what influences the amount of plant biomass in a given area as well as its age."
|Contact: Shelley Littin|
University of Arizona