Agro Times
Recent News |  Archives |  Tags |  Newsletter |  Message Board/Forum |  About |  Links |  Subscribe to AgroTimes.com RSS Feed Subscribe


More Articles
New material steals oxygen from the airNew material steals oxygen from the air

'Programmable' antibiotic harnesses an enzyme to attack drug-resistant microbes'Programmable' antibiotic harnesses an enzyme to attack drug-resistant microbes

Origin of moon's 'ocean of storms' revealedOrigin of moon's 'ocean of storms' revealed

More physical activity improved school performanceMore physical activity improved school performance

Shape up quickly -- applies to fish, too!Shape up quickly -- applies to fish, too!

Engineering new vehicle powertrainsEngineering new vehicle powertrains

Stunning finds from ancient Greek shipwreckStunning finds from ancient Greek shipwreck

All directions are not created equal for nanoscale heat sourcesAll directions are not created equal for nanoscale heat sources

Pressing the accelerator on quantum roboticsPressing the accelerator on quantum robotics

Around the world in 400,000 years: The journey of the red foxAround the world in 400,000 years: The journey of the red fox

Active aging is much more than exerciseActive aging is much more than exercise

Making oxygen before lifeMaking oxygen before life

Protecting our processorsProtecting our processors

Gut bacteria, artificial sweeteners and glucose intoleranceGut bacteria, artificial sweeteners and glucose intolerance

Are the world's religions ready for ET?Are the world's religions ready for ET?

Researchers demonstrate direct fluid flow influences neuron growthResearchers demonstrate direct fluid flow influences neuron growth

Study: New device can slow, reverse heart failureStudy: New device can slow, reverse heart failure

Recreating the stripe patterns found in animals by engineering synthetic gene networksRecreating the stripe patterns found in animals by engineering synthetic gene networks

Communication without detoursCommunication without detours

Chicxulub didn't do it all by itselfChicxulub didn't do it all by itself

First pictures of BRCA2 protein show how it works to repair DNAFirst pictures of BRCA2 protein show how it works to repair DNA

Laying the groundwork for data-driven scienceLaying the groundwork for data-driven science

Hold on, tiger momHold on, tiger mom

Nature's designs inspire research into new light-based technologiesNature's designs inspire research into new light-based technologies

Missing piece found to help solve concussion puzzleMissing piece found to help solve concussion puzzle

Biologists delay the aging process by 'remote control'Biologists delay the aging process by 'remote control'

Geography matters: Model predicts how local 'shocks' influence U.S. economyGeography matters: Model predicts how local 'shocks' influence U.S. economy

Identified for the first time what kind of explosive has been used after the detonationIdentified for the first time what kind of explosive has been used after the detonation

Copied from nature: Detecting software errors via genetic algorithmsCopied from nature: Detecting software errors via genetic algorithms

Plants adapt to drought but limits are looming, study finds (2/11/2013)

Tags:
climate change
Repeat photography is one of the tools range ecologists use to document how lands change: In 1902, photographer David Griffiths' horse-drawn buggy was clearly visible in the open grassland, surrounded by scattered desert hackberry plants at the foot of Huérfano Butte, south of Tucson, Ariz. By 1941, an unknown photographer documented burro weed and cholla cactus popping up, along with velvet mesquite trees. In 2007, the grass cover had given way to velvet mesquite trees, and prickly pear have replaced cholla as the dominant cacti. -  Mitchel McClaran/University of Arizona
Repeat photography is one of the tools range ecologists use to document how lands change: In 1902, photographer David Griffiths' horse-drawn buggy was clearly visible in the open grassland, surrounded by scattered desert hackberry plants at the foot of Huérfano Butte, south of Tucson, Ariz. By 1941, an unknown photographer documented burro weed and cholla cactus popping up, along with velvet mesquite trees. In 2007, the grass cover had given way to velvet mesquite trees, and prickly pear have replaced cholla as the dominant cacti. - Mitchel McClaran/University of Arizona

Scientists with the U.S. Department of Agriculture, or USDA, and their partners have determined that water demand by many plant communities can fluctuate in response to water availability, indicating a capacity for resilience even when changing climate patterns produce periodic droughts or floods.

But their research also suggests that a limit to this resilience ultimately could threaten the survival of these plant communities. Sensitive environments such as the arid grasslands in the Southwestern U.S. already are approaching this limit.

Results from this study were published in the journal Nature by a team of Agricultural Research Service, or ARS, scientists, including three scientists affiliated with the UA. ARS is USDA's chief scientific research agency.

The study was led by UA-affiliated ARS researchers Guillermo Ponce Campos and Susan Moran and an Australian team led by Alfredo Huete from the University of Technology, Sydney.

"We found that plants have a capacity for resilience even in the face of the severe drought over the past decade," said Ponce Campos, the study's lead author. Ponce Campos led the research as part of his doctoral work at the UA and now is a research associate working with Moran.

"From grasslands to forests, plants can tolerate low precipitation, but if drought conditions continue past a certain point, this resilience will fail," said Moran, who graduated from the UA and now is a researcher with the USDA ARS Southwest Watershed Research Center and an adjunct professor in the department of soil, water and environmental science in the UA College of Agriculture and Life Sciences.

Once that limit is reached, water-starved plants lose their ability to take advantage of increased precipitation, even if the drought makes way for wetter conditions, Moran explained.

The researchers conducted their investigation using measurements made during 2000-09 at 29 sites in the United States, Puerto Rico and Australia. This provided data about precipitation patterns in the various types of environments. Globally, the 2000-09 decade ranked as the 10 warmest years of the 130-year (1880-2009) record. The team compared these data with measurements taken from 1975 to 1998 at 14 sites in North America, Central America and South America.

To calculate ecosystem water use, the scientists used satellite observations to approximate above-ground net plant productivity at each site. Then they combined these approximations with field data of precipitation and estimates of plant water loss to generate indicators of plant water use efficiency.

The team observed that ecosystem water-use efficiency increased in the driest years and decreased in the wettest years. This suggests that plant water demand fluctuated in accordance with water availability and that there is a cross-community capacity for tolerating low precipitation and responding to high precipitation during periods of warm drought.

However, the team observed that the water-use efficiency data exhibited a trend of "diminishing returns." This suggests plant communities eventually will approach a water-use efficiency threshold that will disrupt plant water use and severely limit plant production when drought is prolonged.

"Prolonged, warm drought makes a difference," Moran said. "To date, it appears there is resilience, but in the more sensitive biomes like grasslands, we are starting to see evidence of decreasing resilience. And as more and more ecosystems increase in aridity, more will reach this threshold."

The authors report that in some Australian grasslands, ecosystem resilience has decreased with the increasing aridity widely reported as a result of the prolonged warm drought over these biomes.

Moran cautioned that her team also saw the limit in some of the study areas in Utah, Arizona and New Mexico.

"We know what the resilience was in the 1980s and 1990s, and we compared it to the early 21st century," she said. "That's how we know it's decreasing. We certainly found resilience, but it is approaching the threshold."

Moran pointed out this study was only possible through the collaboration of researchers combining long-term observations at study sites across the globe to reach these conclusions, including the oldest, longest-operating range-land research facility in the world: the Santa Rita Experimental Range managed by the UA College of Agriculture and Life Sciences.

Established in 1902, the study area encompasses 52,000 acres, or about 80 square miles, on the western side of the Santa Rita Mountains south of Tucson.

"Here, scientists studying vegetation, animals and soils have documented changes in the environment as a function of land use and how weather and climate have influenced these patterns," said Mitchel McClaran, a professor in the UA's School of Natural Resources and the Environment and the range's director for research, who co-authored the study.

"Making these long-term data available to researchers across the world today is what makes studies like this possible," McClaran said. "We perform experiments and explore best management practices so they can be adopted wildlife managers, ranchers and other natural resources managers throughout the Southwest."

Work like the present study can help resource managers develop agricultural production strategies that incorporate changes in water availability linked to changing precipitation patterns.

"In the United States, much of our agricultural productivity has depended on long-term precipitation regimes. But those patterns are changing and we need information for managing the effects of those shifts," said ARS Administrator Edward Knipling. "These findings can help managers respond to the challenges of global climate change with effective strategies for maintaining agricultural productivity."

Note: This story has been adapted from a news release issued by the University of Arizona

Post Comments:

Search
New Articles
Taking infestation with a grain of saltTaking infestation with a grain of salt

'Grapes of Wrath': Stomping out grape disease one vineyard at a time

Building a bridge from basic botany to applied agricultureBuilding a bridge from basic botany to applied agriculture

Balancing birds and biofuels: Grasslands support more species than cornfields

Wild tomato species focus of antioxidant studyWild tomato species focus of antioxidant study

Clove oil tested for weed control in organic Vidalia sweet onion

Automated imaging system looks underground to help improve cropsAutomated imaging system looks underground to help improve crops

Researchers pump up oil accumulation in plant leavesResearchers pump up oil accumulation in plant leaves

Research paves way for new generation of fungicidesResearch paves way for new generation of fungicides

Natural gene selection can produce orange corn rich in provitamin A for Africa, USNatural gene selection can produce orange corn rich in provitamin A for Africa, US

New approach to boosting biofuel production

Thermotolerant yeast can provide more climate-smart ethanolThermotolerant yeast can provide more climate-smart ethanol

Seed science might save the world

Industrial hemp topic of lecture

Creepy crawlers play key role in structure of grasslands



Archives
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009


Science Friends
Astronomy News
Sports Tech
Biology News
Biomimicry Science
Cognitive Research
Chemistry News
Tissue Engineering
Cancer Research
Cybernetics Research
Electonics Research
Fossil News
Forensics Report
Genetic Archaeology
Genetics News
Geology News
Microbiology Research
Nanotech News
Physics News
Parenting News


  Archives |  Submit News |  Advertise With Us |  Contact Us |  Links
Use of this site constitutes acceptance of our Terms of Service and Privacy Policy. All contents © 2000 - 2015 Web Doodle, LLC. All rights reserved.