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




WOOD PILE
Dartmouth research offers new control strategies for bipolar bark beetles
by Staff Writers
Hanover NH (SPX) Jan 30, 2013


Researcher Sharon Martinson, Dartmouth College, studies bark from beetle-attacked trees in Louisiana to determine why bark beetle population outbreaks occur. Credit: Matt Ayres.

Population explosions of pine beetles, which have been decimating North American forests in recent decades, may be prevented by boosting competitor and predator beetle populations, a Dartmouth study suggests.

Bark beetles are the most destructive forest pests worldwide. Management and climate change have resulted in younger, denser forests that are even more susceptible to attack. Though intensively studied for decades, until now an understanding of bark beetle population dynamics-extreme ups and downs-has remained elusive.

The Dartmouth-led study, published in the January issue of the journal Population Ecology, confirmed, for the first time, that the abundance of a certain animal species-in this case the southern pine beetle-fluctuates innately between extremes, with no middle ground.

"That is different from most species, such as deer, warblers and swallowtail butterflies, whose populations tend to be regular around some average abundance based on food, weather, and other external factors," says Matt Ayres, a professor in the Department of Biological Sciences at Dartmouth and senior author on the paper.

"They don't appear and disappear in cycles. Rather, they exist in two stable equilibrium states-one of high abundance and the other of scarcity." Once the population pendulum swings toward the high end, it won't quickly or easily swing back.

The new research by Dartmouth scientists and their forester colleagues could provide the means to limit this seemingly bipolar dynamic, keeping the bark beetles at the lower stable population level.

The studies identify the presence of bark beetle competitors and predators (specifically two other beetles) as the predominant limiting factor that can keep the bark beetles at a low, stable equilibrium. The authors suggest that the presence of these competitors and predators could be encouraged as a control strategy.

"The pine beetles produce pheromones, chemical signals, that attract enough competitors and predators to prevent outbreaks," says Sharon Martinson, a member of the research team and first author on the new paper.

"Leaving more dead trees in forests can provide habitat for competitor beetles that rarely kill tree, and for predators that eat both beetle species."

The authors suggest that other pest species with catastrophic impacts may also have natural dynamics that include a tipping point between the bipolar population states. By learning what factors control those tipping points, impacts on ecosystems can be averted through monitoring and occasional intervention strategies.

.


Related Links
Dartmouth College
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
Civilians fell rare Syrian trees for firewood
Darkush, Syria (AFP) Jan 26, 2013
Beset by a freezing winter and stifling fuel and electricity shortages, Syrian civilians desperate to stay warm in a northern forest have no choice but to cut down trees for firewood. Once a tourist destination for Syrians and other Arabs across the Middle East, the formerly pristine national park to the north and west of the city of Idlib is being systematically stripped bare. Bald, mud ... read more


WOOD PILE
Australian summer lurches from fire to floods

Congress sends $50 bn Sandy aid bill to Obama

Boss of Fukushima operator quizzed for negligence

Kerry urges 'fresh thinking' to tackle global woes

WOOD PILE
Laser-Plasma Process Gives Nanohybrid Remarkable Properties

DNA and quantum dots: All that glitters is not gold

Liquid metal makes silicon crystals at record low temperatures

Supercomputer sets computing record

WOOD PILE
Old drainage ditches sleeping threat to Cape Cod salt marshes

China reinstates Salween dam plans

Biologists alarmed as data confirm corals decline

How the purple and pink sunscreens of reef corals work

WOOD PILE
Greenland ice cores provide vision of the future

Deep ice shows Greenland was warmer; offers clued to future warming impacts

Greenland Ice Cores Offer Glimpse Into Future Climates

Chile expands Antarctica presence

WOOD PILE
Plants adapt to drought but limits are looming

Global Plant Diversity Hinges on Local Battles Against Invasive Species

Scarecrow gene might trigger big boost in food production

New Zealand's milk safe, government says

WOOD PILE
6.7 magnitude quake hits northern Chile: USGS

Madagascar braces for cyclone Felleng

Fresh flooding hits northern Mozambique

Clean-up launched after deadly Australia floods

WOOD PILE
DR Congo peace deal signing cancelled: UN

Troops and drones to bolster new UN Congo peace bid

Kenya braces for election bloodletting

Outside View: Building a secure Somalia

WOOD PILE
Monkeys move together like humans do

Bindi Irwin slams Hillary Clinton editors over essay

A relative from the Tianyuan Cave

Four-stranded 'quadruple helix' DNA structure proven to exist in human cells




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