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

22.04.2004


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:
http://www.umn.edu/

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

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: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

Decoding cement's shape promises greener concrete

08.12.2016 | Materials Sciences

Will Earth still exist 5 billion years from now?

08.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>