Navigation Links
Shrinking ponds signal warmer, dryer Alaska

A first-of-its kind analysis of fifty years of remotely sensed imagery from the 1950s to 2002 shows a dramatic reduction in the size and number of more than 10,000 ponds in Alaska. The analysis, by University of Alaska Fairbanks scientists and published this week in the Journal of Geophysical Research, indicates that these landscape-level changes in arctic ponds are associated with recent climate warming in Alaska and may have profound effects on climate and wildlife.

Over the past 50 years, Alaska has experienced a warming climate with longer growing seasons, increased permafrost thawing, an increase in water loss due to evaporation from open water and transpiration from vegetation, and yet no substantial change in precipitation.

The shrinking of these closed-basin ponds may be indicative of widespread lowering of the water table throughout low-lying landscapes in Interior Alaska, write the authors. A lowered water table negatively affects the ability of wetlands to regulate climate because it enhances the release of carbon dioxide by exposing soil carbon to aerobic decomposition.

"Alaska is important in terms of waterfowl production and if you have a lowering of the water table that could have a potentially huge impact on waterfowl production," said Dave Verbyla, co-author and professor in the School of Natural Resources and Agricultural Sciences at UAF.

"This is an issue relevant to flyway management in terms of all the waterfowl that might use the Yukon Flats National Wildlife Refuge and overwinter elsewhere, and this is something that goes beyond the refuges in Alaska," said A. David McGuire, co-author and professor of ecology at the Institute of Arctic Biology at UAF.

National Wildlife Refuges cover more than 77 million acres in Alaska and make up 81% of the national refuge system. These refuges provide breeding habitat for millions of waterfowl and shorebirds that overwinter in more southerly regions of North Amer ica.

"No one has done a state water-body inventory of this magnitude," said Brian Riordan, lead author and data manager for the Bonanza Creek Long-Term Ecological Research program at UAF. "It will allow land managers to stop speculating about possible water body loss and begin to address the implications of this loss."

Using black and white aerial photographs from the 1950s, color infrared aerial photographs from 1978-1982, and digital images from the Landsat satellite from 1999-2002, Riordan outlined each pond by hand. "With automated classification your accuracy goes down," Riordan said. Cloud shadows can look like water and Alaska rarely experiences a cloudless day, said Verbyla.

The most difficult part of the four-year project, said Riordan, was "having the patience to circle 10,000 ponds for each time period."

The main study area was the subarctic boreal region of Interior Alaska, which spans more than 5 million square kilometers bounded on the north by the Brooks Range and on the south by the Alaska Range. To contrast the semi-arid, subarctic sites of discontinuous permafrost in Interior Alaska, the authors also selected a study area in the Arctic Coastal Plain where the temperatures are much colder, the growing season much shorter, and the permafrost is continuous, and a more maritime site south of the Alaska Range.

All ponds in the study regions in subarctic Alaska showed a reduction in area of between 4 and 31 percent, with most of the change occurring since the 1970s. The ponds in the Arctic Coastal Plain showed negligible change.


'"/>

Source:University of Alaska Fairbanks


Related biology news :

1. Hepatitis C responds best to combo of ribavirin and interferon, study concludes
2. Plants respond similarly to signals from friends, enemies
3. Bound for destruction: Ubiquitination protects against improper Notch signaling
4. Viral protein influences key cell-signaling pathway
5. Researchers find promising cancer-fighting power of synthetic cell-signaling molecule
6. Edible bivalves as a source of human pathogens: signals between vibrios and the bivalve host.
7. Scientists discover that three overlapping signals in embryo help get the backbone right
8. After a time-shift, mixed signals from the circadian clock
9. Researchers make surprise discovery that some neurons can transmit three signals at once
10. Structure-building cell signals also may influence learning and memory
11. Fox Chase study shows that weakened T-cell receptor signals change T-cell lineage
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:2/2/2016)... , Feb. 2, 2016   Parabon NanoLabs ... the U.S. Army Research Office and the Defense ... and sensitivity of the company,s Snapshot Kinship ... Mission and, more generally, defense-related DNA forensics.  Although ... capabilities (predicting appearance and ancestry from DNA evidence), ...
(Date:2/1/2016)... February 1, 2016 Rising sales ... drive global touchfree intuitive gesture control market ... Rising sales of consumer electronics coupled with new technological ... size through 2020   ... with new technological advancements to drive global touchfree intuitive ...
(Date:2/1/2016)... 2016  Wocket® smart wallet ( www.wocketwallet.com ) announces the launch of ... Fatone . Las Vegas , where Joey appeared ... Las Vegas , where Joey appeared at the Wocket ... video ad was filmed at the Consumer Electronics Show (CES2016) in ... to meet and greet fans. --> ...
Breaking Biology News(10 mins):
(Date:2/8/2016)... , Feb. 8, 2016  CytRx Corporation (NASDAQ: ... company specializing in oncology, today announced that it ... agreement with Hercules Technology Growth Capital, Inc. and ... million in financing. --> ... $25 million of financing under the loan and ...
(Date:2/8/2016)... Philadelphia, PA (PRWEB) , ... February 08, 2016 ... ... Science Center’s Board of Directors. Todorow is the Executive Vice President for Corporate ... As CFO, Todorow oversees Finance, Accounts Payable, Payroll, Billing Operations, Treasury, Managed Care ...
(Date:2/8/2016)... ... February 08, 2016 , ... Bulk food ... bulk foods at various stages of the production process. Despite frequently inspecting loose ... bulk products post packaging such as sacks of dry powders. , Mettler-Toledo Product ...
(Date:2/8/2016)... Stockton has an active R&D program for the ... area, the Group has a unique research and development center ... in developing Bio Control products. Stockton ... parameters and regulatory guidelines, and is active in more than ... Stockton,s flagship product Timorex Gold ...
Breaking Biology Technology: