Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Soil Nutrients Shape Tropical forests

12.01.2007
Tropical forests are among the most diverse plant communities on earth, and scientists have labored for decades to identify the ecological and evolutionary processes that created and maintain them.
A key question is whether all tree species are equivalent in their use of resources - water, light and nutrients - or whether each species has its own niche.

A large-scale study by researchers at the University of Illinois at Urbana-Champaign and eight other institutions sheds some light on the issue. It indicates that nutrients in the soil can strongly influence the distribution of trees in tropical forests. The finding, published this week in the Proceedings of the National Academy of Sciences, challenges the theory that at local scales tree distributions in a forest simply reflect patterns of seed dispersal, said James W. Dalling, a U. of I. professor of plant biology and a principal researcher on the study.

The study evaluated three sites: two lowland forests, in central Panama and eastern Ecuador, and a mountain forest in southern Colombia. The researchers plotted every tree and mapped the distribution of soil nutrients on a total of 100 hectares (247 acres) at the sites. The study included 1,400 tree species and more than 500,000 trees.

The researchers compared distribution maps of 10 essential plant nutrients in the soils to species maps of all trees more than 1 centimeter in diameter. Each of the sites was very different, but at each the researchers found evidence that soil composition significantly influenced where certain tree species grew: The spatial distributions of 36 to 51 percent of the tree species showed strong associations with soil nutrient distributions.

Prior to the study, the researchers had expected to see some influence of soil nutrients on forest composition, but the results were more pronounced than anticipated.

"The fact that up to half of the species are showing an association with one or more nutrients is quite remarkable," Dalling said.

"Differences in nutrient requirements among trees may help explain how so many species can coexist."

Although plants in temperate forests influence the soils around them (through the uptake of nutrients, decomposition of leaf litter on the forest floor and through root exudates), in tropical forests local neighborhoods contain so many species that the ability of individual species to influence soil properties is likely to be small.

"We interpret these plant-soil associations as directional responses of plants to variation in soil properties," the researchers wrote.

The team also found that certain soil nutrients that previously had not been considered important to plant growth in tropical forests had measurable effects on species distributions.

At the site in Ecuador, calcium and magnesium had the strongest effects. In the Panamanian forest, boron and potassium were the most influential nutrients assayed. And in the Colombian mountain forest, potassium, phosphorous, iron and nitrogen, in that order, showed the strongest effects on the distribution of trees.

"There are all kinds of minerals out there that plants seem to be responding to that we didn't think were likely to be important," Dalling said. Further studies are needed, he said, to evaluate these influences in more detail.

The other principal investigators on the study are Robert John, a post-doctoral researcher in the U. of I. department of plant biology; Kyle E. Harms, Louisiana State University; Joseph B. Yavitt, Cornell University; and Robert F. Stallard of the U.S. Geological Survey.

Researchers on the study also are affiliated with Smithsonian Tropical Research Institute, Panama; the University of Georgia; Pontifical Catholic University of Ecuador; Instituto Alexander von Humboldt, Colombia; and the Field Museum of Natural History, Chicago.

Editor's note: To reach James W. Dalling in Panama, call 011-507-314-9311; e-mail: dallingj@life.uiuc.edu.

Diana Yates | University of Illinois
Further information:
http://www.uiuc.edu

More articles from Studies and Analyses:

nachricht Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Electrode materials from the microwave oven

19.10.2017 | Materials Sciences

New material for digital memories of the future

19.10.2017 | Materials Sciences

Physics boosts artificial intelligence methods

19.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>