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.
“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: firstname.lastname@example.org.
Diana Yates | EurekAlert!
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Value from wastewater
16.08.2017 | Hochschule Landshut
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
23.08.2017 | Life Sciences
23.08.2017 | Life Sciences
23.08.2017 | Physics and Astronomy