| . | ![]() |
. |
How will rising levels of carbon dioxide influence ecosystems? Scientists have tackled this question numerous times, but none have tested the assumption that a single-abrupt increase in CO2 concentrations will produce changes similar to gradual increases over several decades. A paper in the Feb. 10 issue of the journal Nature titled Abrupt Rise in Atmospheric CO2 Overestimates Community Response in a Model Plant-Soil System, takes a closer look at this aspect of climate modeling. The team (see below) observed the response of a mycorrhizal fungal community to CO2 concentrations over a span of six years, which included 21 generations. The fungi, which live around the root systems of plants, are considered a beneficial partner to plants - helping them cope with natural stresses, such as low soil fertility, drought and temperature extremes. The fungi were exposed to either an abrupt or gradual increase in this atmospheric gas. The group exposed to a slow rise in CO2 concentration showed less of a decline in the number of species per sample - a standard ecological measure of biodiversity - of the fungi than did the group exposed to the abrupt change, but the difference was not significant. The findings suggest that previous work has overestimated the magnitude of community and ecosystem responses to carbon dioxide changes, the researchers say. The study fulfills a goal in the larger body of climate change research to predict how ecological systems will function and be structured in the future, when the climate is expected to be significantly different from what it is today. Atmospheric CO2 is expected to continue rising during the next century to concentrations of 550 parts per million (ppm), significantly greater than today's concentrations of almost 370 ppm. A major research effort is under way to understand the changes that will occur to population, community and ecosystem structures, and functions in response to these expected CO2 increases. "Climate change is one of several potential responses of the rapidly escalating atmospheric CO2. Subtle ecosystem responses ranging from reduced plant nutrition to increasing crop pest activity are also postulated," said Allen. "Our research demonstrates that communities of organisms can adjust to shifting conditions, and points to the need for careful experiments that study dynamics of our environment integrating time if we are to predict what factors will be of concern to the future health of our cropping and wildland ecosystems." University of California, Riverside Professor of Plant Pathology and Biology, Michael Allen is part of the research team that wrote the paper with John N. Klironomos, Shokouh Makvandi-Nejad, Benjamin E. Wolfe, and Jeff R. Powell of the Department of Botany, University of Guelph, Ontario, Canada; and Matthias C. Rilling and Jeff Piotrowski of the Division of Biological Sciences, University of Montana. The work was supported by the Canadian Government, the U. S. Department of Energy, and the U. S. National Science Foundation. Related Links University of California - Riverside TerraDaily Search TerraDaily Subscribe To TerraDaily Express
Boulder CO (UPI) Feb 21, 2005The United Nations Framework Convention on Climate Change, better known as the Kyoto Protocol, took effect last Wednesday, famously without the participation of the the United States, the world's largest single source of anthropogenic - or human-generated - carbon dioxide, itself otherwise known as the most potent greenhouse gas.
|
| ||||||||||
| The content herein, unless otherwise known to be public domain, are Copyright 1995-2016 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service. |