Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




WOOD PILE
The contribution of particulate matter to forest decline
by Staff Writers
Bonn, Germany (SPX) Jun 24, 2013


File image.

Bonn University scientists demonstrate that hygroscopic air pollutants decrease tree drought tolerance. Air pollution is related to forest decline and also appears to attack the protecting wax on tree leaves and needles.

Bonn University scientists have now discovered a responsible mechanism: particulate matter salt compounds that become deliquescent because of humidity and form a wick-like structure that removes water from leaves and promotes dehydration. These results are published in "Environmental Pollution".

Nature conservationists call it "lingering illness", and the latest report on the North-Rhine Westphalian forest conditions confirms ongoing damage. Bonn University scientists have now shown that salt deposits on leaves may decrease the drought tolerance of trees, thereby contributing to forest decline.

"Our study reveals that so-called wax degradation on pine needles may develop from deposited particulate matter", says Dr. Jurgen Burkhardt from the Institute of Crop Science and Resource Conservation. Wax helps to protect leaves and needles from water loss.

It has long been known that air pollutants accelerate wax ageing and that "wax degradation" is closely related to forest damage. "Wax degradation was addressed by many studies in the 1980s and 90s, but sound explanations for both the degradation mechanism and the high correlation with forest damage have yet been missing", Dr. Burkhardt reports.

Previous approaches assumed chemical reactions for wax degradation, whereas the present study reveals physical reasons. "The deposition of hygroscopic salts is capable of decreasing the drought tolerance of trees", co-author Shyam Pariyar says.

Accelerated dehydration of needles treated with salt solutions
The scientists sprayed salt solutions on Scots pine needles and recorded their weight loss after abscission. The needles treated with salt solutions dried out significantly faster than the untreated control needles. Using an electron microscope, the scientists observed the salts becoming deliquescent and moving into the stomata of the needles. Stomata are tiny pores used by plants to take up carbon dioxide for photosynthesis and release water vapor and oxygen.

The deliquescent salts form very thin liquid connections between the surface and interior of the needle, and water is removed from the needles by these wick-like structures. Because the plants are unable to counteract this removal of water, the plants dehydrate more rapidly.

Therefore, polluted air containing large amounts of particulate matter may directly reduce the drought tolerance of trees. Simultaneously, the deliquescent salts make wax appear "degraded". "This newly described mechanism was not considered in earlier explanations of Central European forest decline", states Dr. Burkhardt.

Conceivable aggravation of forest decline by climate change
A new type of electron microscope enabled the observation of particle deliquescence and dynamics under changing air humidity. In addition, a long-lasting scientific paradigm had excluded any aqueous movement into the stomata, and only recently had Bonn University scientists confirmed its existence (http://www3.uni-bonn.de/Pressemitteilungen/227-2012).

Recently, regional forest damage has been reported in the western USA and other parts of the world. A relationship with increasing climate change-type drought has been proposed, but the newly discovered mechanism involving particulate matter might contribute to the regional forest damage. "Particularly because air concentrations of hygroscopic particles have largely increased within the last decades", says Dr. Burkhardt.

Publication: Particulate pollutants are capable to `degrade' epicuticular waxes and to decrease the drought tolerance of Scots pine (Pinus sylvestris L.), "Environmental Pollution", DOI: 10.1016/j.envpol.2013.04.041

.


Related Links
Bonn University
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




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





WOOD PILE
Whitebark Pine Trees: Is Their Future at Risk
Washington DC (SPX) Jun 13, 2013
There's trouble ahead for the whitebark pine, a mountain tree that's integral to wildlife and water resources in the western United States and Canada. Over the last decade, some populations of whitebark pines have declined by more than 90 percent. But these declines may be just the beginning. New research results, supported by the National Science Foundation (NSF) and published in the Jour ... read more


WOOD PILE
WIN-T Increment 1 Enables National Guard to Restore Vital Network Communications Following a Disaster

Australia costs from natural disasters to soar: study

Satellite data will be essential to future of groundwater, flood and drought management

China work safety probe finds 'many' problems: official

WOOD PILE
Noble gases hitch a ride on hydrous minerals

'Chemical architects' build materials with potential applications in drug delivery and gas storage

Researchers Propose New Method for Achieving Nonlinear Optical Effects

Unexpected behavior of well-known catalysts

WOOD PILE
Fiji's Air Pacific bans 'unsustainable' shark fins

Ups-and-downs of Indian monsoon rainfall likely to increase under warming

Looking at sachet water consumption in Ghana

Natural Underwater Springs Show How Coral Reefs Respond to Ocean Acidification

WOOD PILE
The rhythm of the Arctic summer

Global cooling as significant as global warming

Warm ocean drives most Antarctic ice shelf loss

Jet stream changes cause climatically exceptional Greenland Ice Sheet melt

WOOD PILE
Pesticides tainting traditional China herbs: Greenpeace

Research suggests plants capable of employing quantum physics

Talks on EU agriculture policy reforms in make-or-break stage

African palm oil makers hit back at global 'smear campaign'

WOOD PILE
India flood rescue ops intensify, up to 1,000 feared dead

Flooding in Canada forces evacuation in another city

Tropical storm Barry kills three in Mexico

Alberta faces '10-year recovery' after flood: Redford

WOOD PILE
Uganda president's son denies plan to succeed father

Africa juggles East and West, as Obama comes to visit

In Ghana's gold country, Chinese miners flee crackdown

DEA boosts fight against West African narco-terrorists

WOOD PILE
New frontier for cybersecurity: your body

What do memories look like?

Professor finds prehistoric rock art connected; maps cosmological belief

New research backs theory that genetic 'switches' play big role in human evolution




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal 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