Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. Farming News .




FARM NEWS
Shrub growth decreases as winter temps warm up
by Doree Armstrong for UW News
Seattle WA (SPX) May 22, 2014


Discs cut from just above the shrubs' root collar were studied to determine growth. Image courtesy David Hollander.

Many have assumed that warmer winters as a result of climate change would increase the growth of trees and shrubs because the growing season would be longer. But shrubs achieve less yearly growth when cold winter temperatures are interrupted by temperatures warm enough to trigger growth.

"When winter temperatures fluctuate between being cold and warm enough for growth, plants deplete their resources trying to photosynthesize and end the winter with fewer reserves than they initially had. In the summer they have to play catch up," said Melanie Harsch, a University of Washington postdoctoral researcher in biology and applied mathematics. She is lead author of a paper on the subject recently published in PLOS One.

The roots are especially sensitive to temperature fluctuations, Harsch said. Warming winters result in higher root respiration, which uses up carbon reserves as plants make and release oxygen, leading to less carbon available during the regular growing season.

Harsch and her colleagues studied two species of shrubs on Campbell Island, an uninhabited UNESCO World Heritage site in the southwest Pacific Ocean about 375 miles south of New Zealand's mainland. They studied two large shrubs, Dracophyllum longifolium and Dracophyllum scoparium, which are evergreen broadleaf species that can grow up to about 15 feet tall and live up to 240 years.

Researchers found that while warmer, drier winters helped seedlings get established, it adversely affected growth of older plants.

"For growth to occur you need sufficient precipitation and temperature and nutrients. Growth should only happen during the summer on Campbell Island when temperatures are above 5 degrees Celsius," Harsch said. Five degrees C is about 40 F. "On Campbell Island most winters are cool and below this 5 degrees Celsius, so the plants are not active. The plants we studied are evergreen and there is little snow cover, so they are sensitive to changes in temperature."

In this study, researchers cut out discs, called "cookies," from just above the shrubs' root collar, and measured the width between each ring to determine growth. They found that plant growth decreased as winter temperatures went up.

"On Campbell Island the snow is ephemeral, so the plants usually are not covered," Harsch said. "If we're going to see an effect in changing winter conditions, we're going to see it at Campbell Island decades before we see it at, say, Mt. Rainier, where there is a lot of snow and winters are colder."

Harsch said plants in areas like Campbell Island may eventually adjust to warmer winters, but the transition period will be tough as temperatures bounce above and below what plants need to stay dormant, causing the plants to draw down their resources.

"It may eventually be warm enough in the winters so that plants can photosynthesize and grow year round, like they do in the tropics," she said. "It's this transition part that plants are not adapted for."

Harsch plans to do a follow-up study that would measure the microbes and carbon reserves in the soil, and manipulate snow packs to see how it affects establishment and growth.

"How much of this can our tree species withstand?" Harsch said. "Will summer growth eventually compensate for these hard winters, or is this some sort of extra stressor on trees that will be one more nail in the coffin? If you think of all the different factors of increasing vulnerability in climate change, is this really significant? We just don't know."

Co-authors are Matt McGlone and Janet Wilmshurst at Landcare Research in New Zealand. Harsch started the work while pursuing her doctorate at Lincoln University in New Zealand and finished the analysis at the UW. The work was supported in part by the National Science Foundation.

.


Related Links
University of Washington
Farming Today - Suppliers and Technology






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




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





FARM NEWS
With climate changing, Southern plants do better than Northern locals
Davis CA (SPX) May 22, 2014
Can plants and animals evolve to keep pace with climate change? A study published in the journal Proceedings of the National Academy of Sciences shows that for at least one widely-studied plant, the European climate is changing fast enough that strains from Southern Europe already grow better in the north than established local varieties. Small and fast-growing, Arabidopsis thaliana is wid ... read more


FARM NEWS
New Japan satellite to survey disasters, rain forests

Earth Science Applications Travelogue: Maury Estes

GOES-R Propulsion and System Modules Delivered

Experts demonstrate versatility of Sentinel-1

FARM NEWS
Sixth Boeing GPS IIF Spacecraft Reaches Orbit, Sends First Signals

British MoD works on 'quantum compass' technology to replace GPS

Iran to Host Russian Satellite Navigation Facility

Moscow to suspend American GPS sites on Russian territory from June

FARM NEWS
International standards reducing insect stowaways in wood packaging material

Canadian forestry firm sues over environmental audit

Emissions From Forests Influence Very First Stage of Cloud Formation

Emerald ash borers were in US long before first detection

FARM NEWS
Growing Camelina and Safflower in the Pacific Northwest

Boeing, Embraer team for biofuel use

Ames Lab creates multifunctional nanoparticles for cheaper, cleaner biofuel

Plants' Oil-Desaturating Enzymes Pair Up to Channel Metabolites

FARM NEWS
Chemists challenge conventional understanding of how photocatalysis works

Planting the 'SEEDS' of solar technology in the home

Main Street Breaks Ground on 5MW Solar Project in Virgin Islands

Solar energy prospects are bright for Scotland

FARM NEWS
German energy company RWE Innogy starts turbine installation at mega wind project

Irish 'green paper' outlines transition to a low-carbon economy

U.S. moves closer to first-ever offshore wind farm

Offshore wind supported with U.S. federal funding

FARM NEWS
China consumes almost as much coal as the rest of world combined

China coal mine death toll rises to 20: report

Rescuers race to save 22 trapped coal miners in China: Xinhua

U.K. Coal may close two deep mines

FARM NEWS
Practice tai chi? Then you can handle China censors: Jia Zhangke

China detains rights lawyer ahead of Tiananmen anniversary

'Thin Ice' director sees China's art-house scene breaking through

China youth suicides blamed on education system: study




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - 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. 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.