2012-11-29

Pine beetles kill forests, builders seek to use the wood

You can't miss it because the devastation runs as far as the eye can see. Driving between Merritt and Kelowna on Highway 97C in British Columbia's southern interior, it is possible to feel a kind of terrible awe while passing mile after mile of rusty-coloured, dead pine forests.

It is the work of one small insect amplified billions of times into a catastrophic infestation, a manmade situation and one of Canada's most graphic indicators of climate change, thanks to hot, dry summers and mild winters. The mountain pine beetle creates these enormous swathes of dead forest when the insects burrow into bark and outer layers of the trees, killing them.

Such forests can be found all over the province and now into Alberta and in several U.S. states.

2012-11-25

Summertime climate response to mountain pine beetle disturbance in British Columbia

The present mountain pine beetle infestation in forests in British Columbia ranks among the largest ecological disturbances recorded in Canada so far. These recent outbreaks are thought to have been favoured by large-scale climatic shifts, and may foreshadow outbreaks of a similar magnitude in North American forests over the coming decades. The associated forest dieback could result in substantial shifts in evapotranspiration and albedo, thereby altering the local surface energy balance, and in turn regional temperature and climate. Here we quantify the impact of the Canadian pine beetle disturbance on the local summertime surface energy budget, using measurements of evapotranspiration, albedo and surface temperature, obtained primarily through remote sensing. We show that over the 170,000 km2 of affected forest, the typical decrease in summertime evapotranspiration is 19%. Changes to the absorbed short-wave flux are negligible, in comparison. As a result, outgoing sensible and radiative heat fluxes increased by 8% and 1%, respectively, corresponding to a typical increase in surface temperature of 1 °C. These changes are comparable to those observed for other types of disturbance, such as wildfire, and may have secondary consequences for climate, including modifications to circulation, cloud cover and precipitation.

Pine beetles contributing to climate change: study

Newly published research suggests mountain pine beetles have become so widespread that they’re not just benefiting from global warming, they’re starting to contribute to it.

“The effects of climate change cascade,” said Holly Maness, whose paper was published Sunday in the journal Nature Geoscience.

“Previous studies have shown that climate change allowed the beetle to flourish. But our work shows that beetle infestations in turn feed back into climate.”

2012-11-14

Pine beetle's 'anti-freezes' subject of long study

Dr. Dezene Huber has spent many a cold day in the forests of northern B.C. trying to learn more about a superbug decimating the woodlands of Western Canada.

University of Northern B.C. researcher Huber has spent the past five years trying to determine why the insect keeps thriving in the extreme cold of northern winters.

Researchers know the beetle has shown great resilience, and Huber's work is the first large-scale look at what's going on in pine beetle larvae as they physiologically prepare for winter and then become adult beetles in the spring.

2012-11-07

Trees slash burned for B.C. mega-energy projects

BC Hydro is warning people living northwestern B.C. of smoke haze in that area as they cut down and burn hundreds of kilometres of timber to make way for the Northwest Transmission Line.

The utility's transmission line project connects an existing substation near Terrace, B.C. and a new substation to be built further north, near Bob Quinn Lake, in 2014.

"In clearing the right of way there's a lot of woody debris that has to be disposed of. And we do have approval... to dispose of that by burning," said BC Hydro spokesperson Lesley Wood.

2012-11-05

Province grapples with forest health and harvests after pine beetle

When Burns Lake logging contractor Klaus Posselt hears of the shortage of wood caused by the mountain pine beetle and provincial efforts to ensure enough sawlogs to keep the Interior’s major sawmills in timber, he shakes his head in dismay.

There’s no question that the beetle has struck a horrendous blow to Interior forests. The Ministry of Forests, Lands and Natural Resource Operations estimates 20 per cent of the timber supply has been affected. Despite those losses, Posselt said, wood that could be salvaged is still being wasted because government policy has not adapted to the new reality of B.C.’s dying pine forests.

When Posselt’s company, Tahtsa Timber, logs a stand, his crew will leave 30 per cent of the volume of timber behind because it’s too decayed or dried out for sawmilling. He sees it as a symptom of a deeper forest management problem that the devastation caused by the beetle has exposed: The primary resource from B.C.’s Interior forests has always been sawlogs and at a time when forest health is declining, forest management policies still revolve mainly around sawlogs. Little is known about how much wood is really left because inventories are a decade out of date. But as the quality of the timber declines, the waste log piles grow bigger.

CU study: 2001-02 drought kicked pine beetle outbreak into high gear

A new University of Colorado Boulder study shows for the first time that episodes of reduced precipitation in the southern Rocky Mountains, especially during the 2001-02 drought, greatly accelerated development of the mountain pine beetle epidemic.

The study, the first ever to chart the evolution of the current pine beetle epidemic in the southern Rocky Mountains, compared patterns of beetle outbreak in the two primary host species, the ponderosa pine and lodgepole pine, said CU-Boulder doctoral student Teresa Chapman. The current mountain pine beetle outbreak in the southern Rockies — which range from southern Wyoming through Colorado and into northern New Mexico — is estimated to have impacted nearly 3,000 square miles of forests, said Chapman, lead study author.

While the 2001-02 drought in the West played a key role in pushing the pine beetle outbreak into a true regional epidemic, the outbreak continued to gain ground even after temperature and precipitation levels returned to levels nearer the long-term averages, said Chapman of CU-Boulder’s geography department. The beetles continued to decimate lodgepole pine forests by moving into wetter and higher elevations and into less susceptible tree stands — those with smaller diameter lodgepoles sharing space with other tree species.