Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Is that plant a tortoise or a hare? Answer predicts its response to environmental change


As the spring foliage grows, each plant, like an entrepreneur, builds its leaves according to an economic strategy. Some plants live like the proverbial hare, following a "live fast, die young" strategy; their leaves produce and consume energy quickly but soon "burn out" or fall victim to bad weather or hungry herbivores. Other leaves are more tortoiselike, taking a "live slowly and last long" approach. A new study has revealed the global continuum of leaf economics, documenting where 2,548 species growing at 175 sites fit along the "tortoise-hare" continuum. For the first time, scientists can equate plants in Amazonian rain forest, Minnesota prairie or Alaskan spruce woods using the same set of economic strategies. Moreover, a plant’s position on the continuum predicts how it will likely respond to climate change and other factors. The work will be published in the April 22 issue of the journal Nature.

"This is the most comprehensive study of the physiology of natural vegetation ever done," said author Peter Reich, professor of forest resources at the University of Minnesota. "Leaves are little factories. As a factory, each can make money (energy) in a big hurry, but at the risk of running down its equipment fast. Or, a factory can have a slow and steady output. It’s fundamental tradeoff for every leaf, and the strategy it follows determines how it reacts to change." Besides Reich, authors of the paper were Ian Wright (first author) and Mark Westoby of Macquarie University, Australia, Jeannine Cavender-Bares and Jacek Oleksyn from the University of Minnesota, and a long list of researchers from every inhabited continent.

It all began in 1985, when Reich was a postdoctoral fellow at Cornell University. He compared the rates different plants captured and stored energy through photosynthesis and the rates they used energy--a process called respiration. He noticed that two fast-growing "hare" plants--poplar trees and soybeans--were more susceptible to ozone pollution than slower-growing "tortoise" pine trees.

"It’s because poplar trees exchanges gases faster than pine," said Reich. "Therefore, poplar takes in more ozone than pine. Soybeans, wheat and other crops are bred to grow fast, and they tend to be like poplars. This was an important predictor of how these trees and crops would respond to pollution. I wondered how they had come to have these traits in the first place and what the implications were for responses to changes in environment more broadly. So I began to physiologically compare plants whose leaves might have these contrasting economic strategies. I’ve carried portable photosynthesis sensors to more than 20 sites on four continents."

Twenty years later, Reich and his colleagues can say that plants like hares and tortoises are found in every ecosystem, and so plants from boreal forest, rainforest, desert and everywhere else can be compared. For example, "hares" like aspen and birch are better able to use resources when conditions get better. Therefore, if rainfall or nutrient levels increased, these trees would do well. But if conditions were to get drier or less fertile, the slower-growing "tortoises"--such as spruce, hemlock and other evergreens--would be favored, he said. Similarly, if there is little sunlight available in the understory of a forest, the "tortoises" can scale back their operations and live with it. In general, "hares" are good at "ramping up" when conditions improve, but tortoises are better at controlling their energy consumption when times get tough. Thus, the theory works well as a predictor of responses to increasing nitrogen pollution, added Reich.

The researchers also noted that leaves are built in accordance with their economic strategy. Leaves of fast-growing plants tend to be thin and flimsy and full of expensive nutrients like nitrogen and phosphorus. The thinner a leaf, the better the chance that a ray of sunlight will penetrate to the leaf’s photosynthetic machinery--but the greater its chance of being blown or chomped off. And the expensive invesstments in nutrients only pay off when there is a lot of sunlight and conditions are generally good. In contrast, slow growth allows for thick, sturdy leaves that resist weather and herbivores and can pay off under challenging conditions.

Weeds usually fall into the hare category, said Reich. Their strategy is to grow fast and quickly release seeds, and they tend to grow in places where the vegetation is disturbed.

Data for the study were collected from the University of Minnesota’s Cedar Creek Natural History Area, forests in Wisconsin and Minnesota, the New Mexican desert, the Appalachian Mountains, the Amazon Basin, the Australian Outback and numerous other places. The work was supported in part by the National Science Foundation and the U.S. Department of Energy.

Deane Morrison | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel

nachricht Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

TRAPPIST-1 planets provide clues to the nature of habitable worlds

21.03.2018 | Physics and Astronomy

The search for dark matter widens

21.03.2018 | Materials Sciences

Natural enemies reduce pesticide use

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>