Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Deserts and rainforests are equally productive during drought

30.06.2004


A team of researchers led by Melinda Smith at Yale and Travis Huxman at the University of Arizona report that, from desert to rainforest, during drought conditions, the maximum rain use efficiency (RUEmax), or effective productivity of plant growth per unit of precipitation converges to a common value.

During the late 1960s and early 1970s, the International Biological Program (IBP) began to study how water affects productivity in different ecosystems. It was not until this current group of scientists pooled long-term data in a workshop at the National Center for Ecological Analysis and Synthesis at University of California, Santa Barbara that the scope and similarity of productivity in all ecosystems was seen. Their study, published in the journal Nature, represents datasets from 14 ecosystems.

The RUEmax model predicts that when water is the most limiting resource there will be convergence in the production-precipitation ratio for all biomes. The previous, site model predicts there will be a difference in productivity and that sensitivity of different ecosystems is a function of the different forms of plant growth.



"We looked across nine different biomes - from a forest all the way to a very dry desert - at the sensitivity of production to precipitation," said Smith, associate professor of Ecology and Evolutionary Biology at Yale. "The data showed that if you look at the driest year, when water is most limiting, in any of the 14 sites - and compare growth production in that year - the rate of growth production in all biomes converges to a RUEmax that is very similar to what is seen in deserts."

Therefore, in a forest, during a really dry year there is the same growth production per unit of precipitation as there is in a really dry year in a desert. This data indicates that production sensitivity depends on the extent to which water is the limiting resource.

Although the RUEmax model is based on previously collected and pooled data, experiments in progress uphold this model. At one grassland site in Kansas where rainfall was excluded completely, the observed growth ratio matched RUEmax prediction - much lower than the site model prediction.

"These results have strong implications for the future. Current global models do not take into account climate variation much beyond what has already been seen," said Smith. "A danger is that if we have a sudden drought, according to the RUEmax data, the older global models are likely to overestimate the capacity for plant production. We can’t underestimate the value for this kind of study on making real predictions."

"There will be always be adaptation to different climate, but fluctuations in the rate of change are most important to ecosystem sensitivity and immediate responses will be more drastic," said Smith.

If precipitation becomes more variable, the variability itself will increase the sensitivity and vulnerability of the ecosystem with the same impact as reducing the precipitation.

Janet Rettig Emanuel | EurekAlert!
Further information:
http://www.yale.edu

More articles from Agricultural and Forestry Science:

nachricht Animals and fungi enhance the performance of forests
01.08.2018 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig

nachricht Researchers discover natural product that could lead to new class of commercial herbicide
16.07.2018 | UCLA Samueli School of Engineering

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

Im Focus: World record: Fastest 3-D tomographic images at BESSY II

The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.

Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...

Im Focus: A molecular switch may serve as new target point for cancer and diabetes therapies

If certain signaling cascades are misregulated, diseases like cancer, obesity and diabetes may occur. A mechanism recently discovered by scientists at the Leibniz- Forschungsinstitut für Molekulare Pharmakologie (FMP) in Berlin and at the University of Geneva has a crucial influence on such signaling cascades and may be an important key for the future development of therapies against these diseases. The results of the study have just been published in the prestigious scientific journal 'Molecular Cell'.

Cell growth and cell differentiation as well as the release and efficacy of hormones such as insulin depend on the presence of lipids. Lipids are small...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

NRL's sun imaging telescopes fly on NASA Parker Solar Probe

13.08.2018 | Physics and Astronomy

UT-ORNL team makes first particle accelerator beam measurement in six dimensions

13.08.2018 | Physics and Astronomy

ASU astrophysicist helps discover that ultrahot planets have starlike atmospheres

13.08.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>