Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WOOD PILE
Rainforest greener during 'dry' season
by Staff Writers
Urbana IL (SPX) Jul 28, 2016


File image.

Although the Amazon Jungle may appear to be perpetually green, a University of Illinois researcher believes there are actually seasonal differences of photosynthesis, with more occurring during the dry season and less during the wet season. Understanding how a rainforest that occupies 2.7 million square miles of South America functions is crucial to the future health of the entire planet.

"With the potential negative effects of climate change, one key question we are trying to answer in the study of tropical ecology is how a tropical forest responds during a long-term drought," says Kaiyu Guan, an environmental scientist at the University of Illinois. "If we don't know their daily performance or their seasonal performance, what confidence can we have to predict the forests' future 20 years, 30 years, or longer?"

Analyzing data from several sources, including individual leaves, camera data from towers above the leaf canopy, and decadal long satellite images, Guan and his colleagues measured the photosynthesis rate over the landscape. Photosynthesis - the process green plants use to convert energy from the sun that plants use to grow - from tropical forests, plays a huge role in determining global atmospheric CO2 concentration, which is closely linked the global temperature and rate of climate change.

"Bringing all of the data together, we find that the dry season in the Amazon has increased photosynthesis," says Guan. "There may be less photosynthesis in the wet season because of the cloud cover which limits the amount of light the plants can use."

Guan explains that understanding the seasonality of photosynthesis can help scientists assess whether or not the Amazon is under stress and how it handles and recovers from stress.

"During the dry season, you would think that the plants would be water stressed and photosynthesis would decrease, but looking at multiple sources of data over the years we find that the plants are not stressed because there is ground water carried over from the previous year," he says.

It does not appear to be just the quantity of leaves driving the higher photosynthesis during the dry season. Guan and his collaborators believe it is actually leaf quality which changes over leaf age that is at work.

"Leaf amount can only explain about 5 percent of all the photosynthesis variations, so what's really going on? It's the leaf quality. Putting it in a different way, when you are a baby, you aren't very productive. When you become more mature, you're more productive. Then, when you're older, your productivity goes down again. It's true for humans and it's also true for plants. Leaves in tropical forests that are 3 or 4 months old are more productive. As you get to the end of the dry season, the leaves are aging and their productivity decreases again. So the combination of the leaf amount and the leaf quality together can satisfactorily explain the pattern," Guan says.

Guan cautions that if the forest experiences several droughts, the carryover of water is depleted - the tropical forest responds to the climate.

"The rainforest also absorbs the majority of carbon," Guan says. "It's the engine that drives the carbon cycle for the whole world, which makes it important when we discuss climate changes. Global warming is dependent upon the atmospheric CO2 concentration, so we need to care about carbon.

"Most of the climate models are showing a drying down trend in tropical forests, with a longer dry season. That's a cause for concern for the future of the Amazon," Guan says. "If we neglect it, it can have consequences around the globe. We need to recognize the importance of this rainforest pattern in which our entire global ecosystem functions. The healthiness of these systems is highly relevant for human beings."

In addition to being an assistant professor in ecohydrology and geoinformatics in the Department of Natural Resources and Environmental Sciences in the College of Agricultural, Consumer and Environmental Sciences at U of I, Guan has a joint appointment as a Blue Waters professor affiliated with the National Center for Supercomputing Applications (NCSA).

Using the same satellite technology, Guan is currently looking at agricultural systems in tropical and temperate regions like the U.S. Corn Belt. "We'd like to build a satellite-based system to monitor the entire United States food productivity in order to predict the crop yield."

The above report is based on four recent articles that appear in Science, Nature, Nature Geoscience, and Global Change Biology with Guan as lead author or co-author along with researchers from institutions in the United States from Arizona, Massachusetts, Michigan, New Mexico, and California, as well as from Brazil, Australia, and Japan.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of Illinois College of Agricultural, Consumer and Environmental Sciences
Forestry News - Global and Local News, Science and Application






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
WOOD PILE
Trees' surprising role in the boreal water cycle quantified
Fairbanks AS (SPX) Jul 22, 2016
Approximately 25 to 50 percent of a living tree is made up of water, depending on the species and time of year. The water stored in trees has previously been considered just a minor part of the water cycle, but a new study by University of Alaska Fairbanks scientists shows otherwise. Research published this week in Nature Scientific Reports is the first to show that the uptake of snowmelt ... read more


WOOD PILE
Scientists release recommendations for building land in coastal Louisiana

Study: Crumbling school buildings yield crummy scores

Taiwan buses recalled after deadly fire disaster

Ex-Marine 'assassinated' Baton Rouge cops: police

WOOD PILE
Safran gets $304 million Laser Target Module Locator II Army contract

NASA to Begin Testing Next Generation of Spacecraft Heat Exchangers

Active tracking of astronaut rad-exposures targeted

Rice's 'antenna-reactor' catalysts offer best of both worlds

WOOD PILE
Mines hydrology research provides 'missing link' in water modeling

Oceanographers grow, sequence genome of ocean microbe important to climate change

World Bank freezes funds for DR Congo dam project

Marine carbon sinking rates confirm importance of polar oceans

WOOD PILE
A recent pause in Antarctic Peninsula warming

How meltwater from the ice sheets disturbed the climate 10,000 years ago

NASA's Field Campaign Investigates Arctic North American Ecosystems

Warming Arctic could disrupt migration patterns of millions of birds

WOOD PILE
Ivory Coast banana growers on the comeback trail

Grain drain, Laos' sand mining damaging the Mekong

More for less in pastures

Top cocoa grower I.Coast stung by caterpillar invasion

WOOD PILE
Nearly 300 dead or missing from China flooding: media

Frank grows into hurricane off Mexico Pacific coast

Flood, landslides kill 33 after heavy rains in Nepal

Study: Magma buildup threatening Salvadoran capital

WOOD PILE
Libya unity government demands explanation over French troops

US, Senegal troops wind up first-ever emergency exercise

Five missing soldiers found in Nigeria: army

Tide turns against Liberia's biggest slum

WOOD PILE
Biologists home in on paleo gut for clues to our evolutionary history

Early humans used mammoth ivory tool to make rope

Technological and cultural innovations amongst early humans not sparked by climate change

Genomes from Zagros mountains reveal different Neolithic ancestry




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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