U prof proposes rule of nature

Vadim Lavrusik

It turns out size doesn’t matter.

After three years of work, Peter Reich, senior researcher and professor in the department of forest resources, established a new rule in measuring the carbon dioxide respiration of plants in which the size of the plant makes no difference.

On Thursday, the academic journal Nature published Reich’s data, which shows that the ratio of nitrogen in a plant to the amount of carbon dioxide it emits is 1-to-1.

The new rule augments the old rule, which measured carbon dioxide emission through a three-fourths ratio of the plants’ size. This means that if a plant grows four times in size, the plant’s carbon dioxide emission would increase by three times.

The emission rates depend on the amount of nitrogen in the plants, Reich said, not the size of the plant itself.

In a statement released by Nature, its editor said about Reich’s findings, “This has opened up an enormous front of research and debate.”

“When astronauts go into space, they have to account for gravity as a rule. Ecologists will use our rule when making models that estimate the carbon fluxes released by plants,” Reich said. “This will help us balance the emissions of carbon dioxide into the environment.”

Balancing the carbon cycles is important because it prevents our planet from overheating, he said.

Reich, who, according to the Institute for Scientific Information, is one of the top 15 ecologists in the world, teamed with three of his colleagues and measured the amount of nitrogen in more than 500 plants of various sizes.

Reich compiled the “unprecedented amount” of data after he decided to test the old theory, which originally was used to measure the metabolic rates of animals, not plants.

According to Reich, Max Kleiber established the three-fourths measure in 1932 to measure the metabolic rates of animals. In 1997, a study was released in which the three-fourths rule was used to measure the metabolic rates of a plant system, which indicates the amount of carbon dioxide released by the plant.

“They didn’t read our theory,” said Brian Enquist, University of Arizona ecology and evolutionary biology professor, who helped write the 1997 study.

“I agree with their results. I disagree with their interpretation,” he said. “The rule can’t be applied to larger plants, and nothing that they presented shows that it can.”

Enquist said that while the new rule applies only to smaller plants, the three-fourths rule applies to large plants. Reich said Enquist’s data was very limited and therefore not valid.

“Applying a theory used for animals to plants is like comparing apples and oranges,” Reich said. “Even the three-fourths theory for animals is now being questioned.”

Jacek Oleksyn, department of forest resources research associate, who took part in the project, said, “Not only does our rule disprove the old

theory, but it provides a new fundamental rule on how to measure carbon emission from plants.”

Oleksyn, who has worked with Reich for 17 years on more than 40 publications, said Reich’s leadership has made their department one of the leaders in forest ecology.

Reich and Oleksyn are working on an ecology project that is the largest the National Science Institute has financed.

“We’re constantly trying to learn new things about the way our world works,” said Reich, “It is a building block for how we can make our lives better.”