Wetlands created to replace those lost to environmental degradation or development take up carbon from the atmosphere and so potentially reduce greenhouse warming, a unique 15-year study suggests. Such artificial wetlands caused emissions of methane, which may contribute to warming, smaller than those from natural wetlands.
William J. Mitsch, from the Ohio State University, and his colleagues, describe the development of two 1-hectare wetlands in Ohio created by pumping water from the nearby Olentangy river, starting in 1994. One was manually planted with vegetation, and the other was left to develop naturally.
The results, reported in the March issue of BioScience, show that over time the manually planted and the unplanted wetlands differed principally in the variety of plants present and in how much gas they exchanged with the atmosphere. The manually planted wetland showed more variety, but the unplanted one took up more carbon from the atmosphere. Methane emissions from the unplanted wetland, unlike the planted one, meant that it was estimated to contribute slightly to net greenhouse warming. Both created wetlands, however, removed large amounts of nitrogen and phosphorus from the incoming river water. Emissions of nitrous oxide, which can also increase warming, were small.
This study may prove useful as a model for future wetland reclamation or replacement projects and for determining the amount of human intervention that is necessary for these projects to be successful. The article also provides an example of the benefits of long-term ecological research, since species diversity stabilized only after about five years, and the amount of carbon retained in the soil continued to increase over the entire study.
BioScience, published monthly, is the journal of the American Institute of Biological Sciences (AIBS; www.aibs.org). BioScience is a forum for integrating the life sciences that publishes commentary and peer-reviewed articles. The journal has been published since 1964. AIBS is an umbrella organization for professional scientific societies and organizations that are involved with biology. It represents nearly 160 member societies and organizations. The article by Mitsch and colleagues is available during the month of March at http://www.
The complete list of peer-reviewed articles in the March 2012 issue of BioScience is as follows:
Integrating Ecology and Environmental Ethics: Earth Stewardship in the Southern End of the Americas.
Ricardo Rozzi, Juan J. Armesto, Julio R. Gutiérrez, Francisca Massardo, Christopher B. Anderson, Gene E. Likens, Alexandria Poole, Kelli P. Moses, Eugene Hargrove, Andres O. Mansilla, James H. Kennedy, Mary Willson, Kurt Jax, Clive G. Jones, J. Baird Callicott, and Mary T. K. Arroyo
Creating Wetlands: Primary Succession, Water Quality Changes, and Self-Design over 15 Years.
William J. Mitsch, Li Zhang, Kay C. Stefanik, Amanda M. Nahlik, Christopher J. Anderson, Blanca Bernal, Maria Hernandez, and Keunyea Song
Beyond the Environmentalist's Paradox and the Debate on Weak versus Strong Sustainability.
Frederic Ang and Steven Van Passel
The World's Zoogeographical Regions Confirmed by Cross-Taxon Analyses.
Şerban Procheş and Syd Ramdhani
The Size, Concentration, and Growth of Biodiversity-Conservation Nonprofits
Paul R. Armsworth, Isla S. Fishburn, Zoe G. Davies, Jennifer Gilbert, Natasha Leaver, and Kevin J. Gaston
Research Coordination Networks: Evidence of the Relationship between Funded Interdisciplinary Networking and Scholarly Impact.
Alan L. Porter, Jon Garner, and Todd Crowl
A New Framework for Assessing the Effects of Anthropogenic Sound on Marine Mammals in a Rapidly Changing Arctic.
Sue E. Moore, Randall R. Reeves, Brandon L. Southall, Timothy J. Ragen, Robert S. Suydam, and Christopher W. Clark
A New Model for Training Graduate Students to Conduct Interdisciplinary, Interorganizational, and International Research.
Amanda H. Schmidt, Alicia S. T. Robbins, Julie K. Combs, Adam Freeburg, Robert G. Jesperson, Haldre S. Rogers, Kimberly S. Sheldon, and Elizabeth Wheat