U profs study rules of plant evolution

Emily Ayshford

Plant leaves just can’t have it all, according to a new study spearheaded by University forest resources professor Peter Reich.

The study, published in the journal Nature last week, revealed that plant leaves grow along a continuum, with plants that live fast and die young on one end, and plants that grow slowly and last longer on the other.

“Plants can be good at one strategy or another, but they can’t be good at both,” said Jeannine Cavender-Bares, an ecology, evolution and behavior professor who researched oak tree traits for the study.

The study, which is the most comprehensive of its kind, documented 2,548 species of plants at 175 sites around the world.

Cavender-Bares said they found the same evolutionary rule of live fast, die young or live slow, last long applied to plants all over the planet.

“Plants, despite the large variety and diversity in plant forms, are all governed by a similar set of rules,” she said. “Natural selection weeds out plants that don’t have a good economic strategy.”

She said although plant traits correlate with climate, there is more variation within a given climate regime, which can explain high diversity of species in a given area.

Local environmental factors such as soil fertility and noncompetitive species interactions might also contribute to the high diversity of plants in an area.

Reich started the project more than 15 years ago after researching ozone effects on plant leaves.

Throughout the years, Reich sought researchers from around the world to create a dataset of leaf traits.

“This is really the work of individual scientists reaching out to other scientists,” he said. Although some National Science Foundation funding came late in the project, Reich said, the scientists had few resources, because the project did not fit in to the qualifications of many grants.

Cavender-Bares said the researchers will use the information to make a quantitative model of leaf traits.

“They were able to put together this vast data set that finally shows that there are these simple principles that work globally for all plants,” she said. “That’s quite valuable in terms of modeling plant responses to changing global climate.”

Reich said he hopes to continue the project by finding a continuum of roots, plants and ecosystems as a whole.

“We want to also further understand and develop better means of using these findings to better predict the ways vegetation will respond to air pollution and climate change,” he said. “We have a long ways to go to do that.”