Featured Research

from universities, journals, and other organizations

Amazon studied to predict impact of climate change

Date:
April 1, 2014
Source:
Virginia Tech (Virginia Polytechnic Institute and State University)
Summary:
Extreme weather events in the Amazon Basin are giving scientists an opportunity to predict the impacts of climate change and deforestation on ecological processes and ecosystem services of the Amazon River wetlands. "The research fills an important gap in our understanding of the vulnerability of tropical river-forest systems to changes in climate and land cover," said the project's leader.

A fisherman and his sons return from a good day of fishing for tambaqui, one of the Amazon’s most high-value fish species dependent on the floodplains.
Credit: Virginia Tech

Three extreme weather events in the Amazon Basin in the last decade are giving scientists an opportunity to make observations that will allow them to predict the impacts of climate change and deforestation on some of the most important ecological processes and ecosystem services of the Amazon River wetlands.

Scientists from Virginia Tech, the Woods Hole Research Center, and the University of California, Santa Barbara, funded by NASA, are collaborating with Brazilian scientists to explore the ecosystem consequences of the extreme droughts of 2005 and 2010 and the extreme flood of 2009.

"The research fills an important gap in our understanding of the vulnerability of tropical river-forest systems to changes in climate and land cover," said the project's leader, Leandro Castello, assistant professor of fish and wildlife conservation in Virginia Tech's College of Natural Resources and Environment.

The huge study area encompasses 1.7 million square miles, the equivalent of half of the continental United States.

In addition to historical records and ground observations, the researchers will use newly available Earth System Data Records from NASA -- satellite images of the Amazon and its tributaries over the complete high- and low-water cycles.

NASA is funding the study with a $1.53 million grant shared among the three institutions.

"Amazon floodplains and river channels -- maintained by seasonal floods -- promote nutrient cycling and high biological production, and support diverse biological communities as well as human populations with one of the highest per capita rates of fish consumption," said Castello.

The researchers will look at how the natural seasonality of river levels influences aquatic and terrestrial grasses, fisheries, and forest productivity in the floodplains, and how extreme events such as floods and droughts may disturb this cycle.

"We are confident that deforestation and climate change will, in the future, lead to more frequent and severe floods and droughts," said Michael Coe, a senior scientist at the Woods Hole Research Center. "It is important that we understand how the Amazon River and ecosystem services such as fisheries are affected so that we can devise mitigation strategies."

Amazonian grasses, sometimes called macrophytes, convert atmospheric carbon to plant biomass, which is then processed by aquatic microorganisms upon decomposition.

"Terrestrial grasses grow during the short window when water levels are low, sequestering some carbon, and then die when the floods arrive, releasing the carbon into the aquatic system," said Thiago Silva, an assistant professor of geography at Sγo Paulo State University in Rio Claro, Brazil. "They are followed by aquatic grasses that need to grow extremely fast to surpass the rising floods and then die off during the receding-water period."

"Although most of the macrophyte carbon is released back to the atmosphere in the same form that it is assimilated, carbon dioxide, some of it is actually exported to the ocean as dissolved carbon or released to the atmosphere as methane, a gas that has a warming potential 20 times larger than carbon dioxide," said John Melack, a professor at the University of California, Santa Barbara.

Researchers will measure plant growth and gas exchange, and use photographs from the field and satellites.

Two other Amazon resources -- fisheries and forests -- are important to the livelihood of the people of the region.

"We will combine water level, fishing effort, and fish life-history traits to understand the impact of droughts and floods on fishery yields," said Castello, whose specialty is Amazon fisheries. "Floods in the Amazon are almost a blessing because in some years they can almost double the amount of fish in the river that is available for fishermen and society."

The fishery data include approximately 90,000 annual interview records of fisheries activities on the number of fishers, time spent fishing, characteristics of fishing boats and gear used, and weight of the catch for 40 species. The hydrological data include daily water level measurements recorded in the Madeira, Purus, and Amazonas-Solimυes rivers.

The researchers will examine the potential impact of future climate scenarios on the extent and productivity of floodplain forests -- those enriched by rising waters, called whitewater river forests, and nutrient-poor blackwater river forests.

For example, extreme droughts may reduce productivity due to water stress and increases in the frequency and severity of forest fires. Prolonged periods of inundation, on the other hand, may decrease productivity or increase mortality due to water-logging stress.

"We will evaluate these responses for the first time at a regional scale using remotely sensed indicators of vegetation condition and fire-induced tree mortality to measure the response of floodplain forests to inter-annual flood variability and extreme climate events," said Marcia Macedo, a research associate at the Woods Hole Research Center.

Researchers will measure tree litter dry weight, depth of flooding, tree height and diameter, and stand density. They will also use photographs and satellite images.

Previous research has focused on Amazon upland forests and the potential impacts of deforestation, fire, and drought. The research team will compare new greenhouse gas simulations to previous simulations.

"Our research informs large river ecology globally because natural flowing rivers like the Amazon are rare these days, and most research to date, being done in North America and Europe, has focused on degraded systems," Castello said.


Story Source:

The above story is based on materials provided by Virginia Tech (Virginia Polytechnic Institute and State University). Note: Materials may be edited for content and length.


Cite This Page:

Virginia Tech (Virginia Polytechnic Institute and State University). "Amazon studied to predict impact of climate change." ScienceDaily. ScienceDaily, 1 April 2014. <www.sciencedaily.com/releases/2014/04/140401210250.htm>.
Virginia Tech (Virginia Polytechnic Institute and State University). (2014, April 1). Amazon studied to predict impact of climate change. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2014/04/140401210250.htm
Virginia Tech (Virginia Polytechnic Institute and State University). "Amazon studied to predict impact of climate change." ScienceDaily. www.sciencedaily.com/releases/2014/04/140401210250.htm (accessed August 20, 2014).

Share This




More Earth & Climate News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Charter Schools Alter Post-Katrina Landscape

Charter Schools Alter Post-Katrina Landscape

AP (Aug. 20, 2014) — Nine years after Hurricane Katrina, charter schools are the new reality of public education in New Orleans. The state of Louisiana took over most of the city's public schools after the killer storm in 2005. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

Green Power Blooms as Japan Unveils 'hydrangea Solar Cell'

AFP (Aug. 19, 2014) — A solar cell that resembles a flower is offering a new take on green energy in Japan, where one scientist is searching for renewables that look good. Duration: 01:29 Video provided by AFP
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Wildfire Hits California's Angeles National Forest

Wildfire Hits California's Angeles National Forest

Reuters - US Online Video (Aug. 17, 2014) — A wildfire sweeps across the Angeles National Forest prompting campers to quickly leave as officials began evacuating the area -- local media. Gavino Garay reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins