Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Despite hopeful report that fungi help trees weather acid rain, not all species are protected, Cornell forest ecologist warns

19.06.2002


A discovery reported in the latest edition of the journal Nature (June 13, 2002) -- that fungi on the roots of some trees in the Northeastern United States help supply much-needed calcium in forest soils battered by acid rain -- would seem to ease worries about the worrisome form of pollution.



But don’t stop worrying just yet, warns Timothy J. Fahey, the Liberty Hyde Bailey Professor of Natural Resources at Cornell University and a co-author of the report, "Mycorrhizal weathering of apatite as an important calcium source in base-poor forest ecosystems."

"Not all tree species are fortunate enough to be associated with the types of root fungi that supply calcium," he says, pointing to sugar maples, which in some areas have suffered serious declines in recent years.


"And although our findings suggest that trees with the right fungal associations may be able to short-circuit the loss of calcium in the soil, that may not get them around other problems with acidification of soil," he adds. For example, when soil pH is lowered (and acidity rises) more naturally occurring aluminum is available to hinder plant growth. Fahey is co-principal investigator in the soil study sponsored by the National Science Foundation (NSF) at New Hampshire’s Hubbard Brook Experimental Forest.

Also contributing to the Nature report were researchers at the University of Michigan, Syracuse University, the Yale School of Forestry and Environmental Studies, the U.S. Department of Agriculture’s Forest Service and the Institute of Ecosystem System Studies in Millbrook, N.Y.

Although forest scientists have known for more than three decades that acid rain causes the essential plant nutrient calcium to leach from forest soils, the role of the "short-circuiting" fungus was not suspected until about three years ago. That’s when electron-microscopy examination of sand revealed tiny tunnels burrowed through the grains; the mini-miners turned out to be ectomycorrhizal fungi that can penetrate micropores in silicates and take up phosphorus, as well as calcium. Living in symbiotic relationships on some tree roots -- where fungi obtain sugar needed for life processes -- the ectomycorrhizal fungi deliver calcium and phosphorus directly to the trees before the nutrients are lost to acidic soils.

The NSF-sponsored study at Hubbard Brook is testing the long-term result of adding calcium to forested ecosystems to return acid-base ratios to levels that probably existed a century ago, before industrial pollution began to change the chemical landscape of the northeastern United States. The Hubbard Brook researchers were using stable isotope tracing to learn the sources of calcium in plant matter. They found that a significant proportion of calcium in some tree species (particularly conifers, beech and birches) growing in calcium-poor, acidic soil was coming from apatite, a soil mineral mined by fungi on tree roots.

Apatite, pronounced like "appetite," is a calcium phosphate mineral. The trees also were getting some calcium from the better-understood "soil exchange complex," in which calcium is replenished by mineral weathering and atmospheric deposition before being absorbed by roots. But without the beneficial "weathering" of apatite by the ectomycorrhizal root fungi, some trees in acid rain-drenched soils probably would not be getting enough calcium, the researchers reasoned.

Benefits of the fungal association are most pronounced in tree species that can sustain the right kind of mycorrhizae on their roots -- spruce, fir and most other coniferous varieties, as well as certain hardwoods, such as oaks. And a lesser benefit might accrue to trees species with the "wrong" type of root fungi -- including ash, basswood and maples -- if they are growing nearby in mixed-species forests, simply because they are close enough to share calcium mined by other trees’ mycorrhizae, Cornell’s Fahey says.

"But trees trying to grow in the center of a single-species stand, like a sugarbush, could be in trouble," Fahey says, noting that the sugar maple decline in the Northeast has been linked with calcium and magnesium depletion in soils..

And he hopes that anyone who downplays the effects of pollution will not take comfort in the knowledge that obscure fungi are mopping up after acid rain. "There are still numerous deleterious effects of acid rain," Fahey says, "that have nothing to do with mycorrhizae."

Roger Segelken | EurekAlert!
Further information:
http://www.hbrook.sr.unh.edu/hbfound/hbfound.htm

More articles from Ecology, The Environment and Conservation:

nachricht Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Touch Displays WAY-AX and WAY-DX by WayCon

27.06.2017 | Power and Electrical Engineering

Drones that drive

27.06.2017 | Information Technology

Ultra-compact phase modulators based on graphene plasmons

27.06.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>