Acid Rain Effects on Forest Soils begin to Reverse plus 1 more

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Title: USGS Newsroom

Acid Rain Effects on Forest Soils begin to Reverse plus 1 more

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Acid Rain Effects on Forest Soils begin to Reverse

Posted: 04 Nov 2015 06:00 AM PST

Summary: Soil acidification from acid rain that is harmful to plant and aquatic life has now begun to reverse in forests of the northeastern United States and eastern Canada, according to an American-Canadian collaboration of five institutions led by the U.S. Geological Survey

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Contact Information:

Gregory Lawrence ( Phone: 518-421-4738 ); Alex Demas ( Phone: 703-648-4421 );

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Soil acidification from acid rain that is harmful to plant and aquatic life has now begun to reverse in forests of the northeastern United States and eastern Canada, according to an American-Canadian collaboration of five institutions led by the U.S. Geological Survey.

The new research shows that these changes are strongly linked to acid rain decreases, although some results differ from expected responses.  

"Reduced acid rain levels resulting from American and Canadian air-pollution control measures have begun to reverse soil acidification across this broad region," said Gregory Lawrence, a USGS soil and water chemist and lead author.  "Prior to this study, published research on soils indicated that soil acidification was worsening in most areas despite several decades of declining acid rain.  However, those studies relied on data that only extended up to 2004, whereas the data in this study extended up to 2014. "

As acid rain acidifies soils, it depletes soil calcium reserves, which are important in preventing the formation of aluminum that is toxic to plants and aquatic life.  Calcium is also a nutrient essential for healthy ecosystems.   Results of this study show that soils are no longer being depleted of calcium and that toxic aluminum levels have substantially decreased. 

The uppermost soil layers have shown a strong recovery response, but deeper layers are actually increasing in aluminum, which suggests further acidification.  However, this may be part of the recovery process as aluminum moves downward in the soil to be stored in a non-toxic form.

"The start of widespread soil recovery is a key step to remedy the long legacy of acid rain impacts on terrestrial and aquatic ecosystems," according to Lawrence.

The results were obtained by resampling soils that had been originally sampled eight to 24 years earlier.  The collaboration among the USGS, U.S. Department of Agriculture, U.S. Forest Service, University of Maine, Canadian Forest Service and the Quebec Ministry of Forests, Wildlife and Parks, was developed through the Northeast Soil Monitoring Cooperative, a group of scientists focused on how soils are responding to our rapidly changing environment.  

The study is available online. Lawrence, G. B., P. W. Hazlett, I. J. Fernandez, R. Ouimet, S. W. Bailey, W. C. Shortle, K. T. Smith, and M. R. Antidormi. 2015. Declining Acidic Deposition Begins Reversal of Forest-Soil Acidification in the Northeastern U.S. and Eastern Canada. Environmental Science & Technology.

New Tool Rates Stream Vulnerability to Unconventional Oil and Gas Development

Posted: 03 Nov 2015 09:00 AM PST

Summary: On average, streams in the Niobrara-Mowry Play of eastern Wyoming, Fayetteville Play of Arkansas, and Barnett Play of Texas ranked most vulnerable to unconventional oil and gas development, but for different reasons, according to recent U.S. Geological Survey coauthored research

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Study Looks at Natural and Man-Made Factors

Contact Information:

Kelly Maloney ( Phone: 570-724-3322x239 ); Sally Entrekin ( Phone: 501-269-2108 ); Alex Demas ( Phone: 703-648-4421 );

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On average, streams in the Niobrara-Mowry Play of eastern Wyoming, Fayetteville Play of Arkansas, and Barnett Play of Texas ranked most vulnerable to unconventional oil and gas development, but for different reasons, according to recent U.S. Geological Survey coauthored research.

Streams in the Fayetteville and Barnett were vulnerable mostly from existing man-made stressors, whereas streams in the Niobara-Mowry were vulnerable largely due to a stream's natural sensitivity to alterations. However, the study also shows that streams in all regions have the potential to be impacted by such development.

A team of academic, USGS, and private-sector researchers computed potential stream vulnerability to unconventional oil and gas development in six shale plays, including the Bakken, Barnett, Fayetteville, Hilliard-Baxter-Mancos, Marcellus and Utica, and Niobrara-Mowry.  The newly developed vulnerability index shows that streams with the highest sensitivity and exposure to stressors may be most vulnerable to unconventional oil and gas development.

"Stream ecosystems show variation in potential vulnerability to unconventional oil and gas development across the contiguous United States," said Kelly Maloney, USGS research ecologist and coauthor of the study. "The index we developed incorporated a stream ecosystem's natural sensitivity to alterations and its exposure to man-made stressors, such as well pads, urbanization and agriculture."

What made areas potentially vulnerable varied across plays due to climatic, geologic and human caused differences. Low annual precipitation in the drier regions of the western US (Niobrara-Mowry, Hilliard-Baxter-Mancos, and Bakken) affected stream vulnerability to unconventional oil and gas development. In contrast, the steeper slopes in the watersheds of Appalachia made streams in the Marcellus-Utica play naturally sensitive.  The Barnett and Marcellus regions had areas with greater urbanization than other plays.

"The indices developed in this paper can be used to identify streams where aquatic life are particularly vulnerable, and then help prioritize stream protection and monitoring efforts," said Maloney.  "These findings can also be used to guide local development activities to help reduce potential environmental effects."

Research partners in this study included the University of Central Arkansas, Waterborne Environmental Inc., University of Arkansas and Wilkes University.

The paper "Stream vulnerability to widespread and emergent stressors: a focus on unconventional oil and gas" is available in PLOS ONE, which is an open-access, peer-reviewed scientific journal and can be downloaded free of charge online.