Featured Research

from universities, journals, and other organizations

Soil Nutrients Shape Tropical Forests, Large-scale Study Indicates

Date:
January 12, 2007
Source:
University of Illinois at Urbana-Champaign
Summary:
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.

A tropical forest at Barro Colorado Island, Panama, is one of three used in the study of soil nutrients and tree distribution. The insert shows the distribution of two tree species, Ocotea whitei (blue) and Trichilia pallida (red) with differing affinities for calcium at this site. Contour lines show elevation.
Credit: Photo courtesy Christian Ziegler

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, phosphorus, 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.


Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University of Illinois at Urbana-Champaign. "Soil Nutrients Shape Tropical Forests, Large-scale Study Indicates." ScienceDaily. ScienceDaily, 12 January 2007. <www.sciencedaily.com/releases/2007/01/070111133143.htm>.
University of Illinois at Urbana-Champaign. (2007, January 12). Soil Nutrients Shape Tropical Forests, Large-scale Study Indicates. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2007/01/070111133143.htm
University of Illinois at Urbana-Champaign. "Soil Nutrients Shape Tropical Forests, Large-scale Study Indicates." ScienceDaily. www.sciencedaily.com/releases/2007/01/070111133143.htm (accessed August 21, 2014).

Share This




More Earth & Climate News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins