Featured Research

from universities, journals, and other organizations

Tent Caterpillars And Their Parasites: Most Abundant Animals In The Boreal Forest?

Date:
March 19, 2002
Source:
Networks Of Centres Of Excellence Canada
Summary:
Sustainable Forest Management Network Principal Investigator, Dr. Jens Roland has discovered a correlation between forest tent caterpillar infestations and the amount of forest left standing after an area has been harvested. Says Roland, "In larger forest stands, the mortality factors which cause collapse of the tent caterpillars infestation (parasites and disease) are more effective than they are in small stands." Dr. Roland's work suggests that a forest tent caterpillar outbreak and the rate of collapse is a critical indicator of the overall health of Canada's aspen boreal forest, and provides various new options for forest managers who would like to minimize the effects of forest tent caterpillar outbreaks.

Edmonton (March 12) - Sustainable Forest Management Network Principal Investigator, Dr. Jens Roland has discovered a correlation between forest tent caterpillar infestations and the amount of forest left standing after an area has been harvested. Says Roland, "In larger forest stands, the mortality factors which cause collapse of the tent caterpillars infestation (parasites and disease) are more effective than they are in small stands." Dr. Roland's work suggests that a forest tent caterpillar outbreak and the rate of collapse is a critical indicator of the overall health of Canada's aspen boreal forest, and provides various new options for forest managers who would like to minimize the effects of forest tent caterpillar outbreaks.

Related Articles


The impact of forest tent caterpillars should not be underestimated. For comparison purposes, at the peak of a caterpillar outbreak, the biomass of caterpillars per km2 would be equivalent to 657 caribou per km2. Similarly, the biomass of the tiny parasitic flies that attack and feed on these caterpillars would be equivalent to 82 wolves in the same one km2 area.

Given the immense scale of the predator-prey battle going in our backyards, parks, and forests, it is not surprising that the forest tent caterpillar is the principal defoliating insect of trembling aspen in the boreal forest across the country. "During a major outbreak," says Roland, "forest tent caterpillars can completely defoliate an aspen forest; virtually stop their growth - reducing growth increment by as much as four cubic metres of wood per hectare each year. "While we can't stop a tent caterpillar infestation," said Roland, "we don't want to do anything to prolong it either, such as rendering its natural enemies ineffective through effects of altered forest structure." If the number of years of defoliation (out of the 12-year cycle) could be reduced by just one year, then fibre production would be increased by almost 10% over-all.

The research also focused on four species of parasitic flies that are the main enemy of these caterpillars and various viral diseases that also kill forest tent caterpillars. Says Roland, "We were aware that forest cover has an impact on the search behaviour of these flies as they attempt to find their prey, and the rate of spread of viruses. The question we needed to answer is-what is the optimum size of this forest cover which allows these agents to operate normally, and to successfully and rapidly suppress an outbreak?"

Roland and his team of researchers sampled 127 sites covering an area of 400 km2 near Ministik Hills, Alberta in aspen stands ranging in six sizes from as small as .28 hectares to 289 hectares. "What we determined," said Roland, "is that for the parasites and the viruses to be most effective, the size of the forest stand should be a minimum of about 100 hectares. Smaller forest stands served as a caterpillar refuge because of less effective natural enemies-helping to extend the length of the infestation by several years."


Story Source:

The above story is based on materials provided by Networks Of Centres Of Excellence Canada. Note: Materials may be edited for content and length.


Cite This Page:

Networks Of Centres Of Excellence Canada. "Tent Caterpillars And Their Parasites: Most Abundant Animals In The Boreal Forest?." ScienceDaily. ScienceDaily, 19 March 2002. <www.sciencedaily.com/releases/2002/03/020313074748.htm>.
Networks Of Centres Of Excellence Canada. (2002, March 19). Tent Caterpillars And Their Parasites: Most Abundant Animals In The Boreal Forest?. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2002/03/020313074748.htm
Networks Of Centres Of Excellence Canada. "Tent Caterpillars And Their Parasites: Most Abundant Animals In The Boreal Forest?." ScienceDaily. www.sciencedaily.com/releases/2002/03/020313074748.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

AFP (Apr. 21, 2015) As money runs out at Tacugama Chimpanzee Sanctuary in Sierra Leone, around 85 chimps are facing homelessness. The centre closed when the Ebola epidemic was ravaging the country but now that closure is beginning to look permanent. Video provided by AFP
Powered by NewsLook.com
Wild Weather Lashes Sydney Region

Wild Weather Lashes Sydney Region

AFP (Apr. 21, 2015) Sydney and surrounding areas are lashed by wild weather with trees felled, power cuts hitting thousands of homes and sand drifts sweeping inland off the iconic Bondi beach. Duration: 00:50 Video provided by AFP
Powered by NewsLook.com
Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Pee-Power Toilet to Light Up Disaster Zones

Pee-Power Toilet to Light Up Disaster Zones

Reuters - Innovations Video Online (Apr. 20, 2015) Students and staff are being asked to use a prototype urinal to &apos;donate&apos; urine to fuel microbial fuel cell (MFC) stacks that generate electricity to power lighting. The developers hope the pee-power technology will light toilet cubicles in refugee camps, where women are often at risk of assault in poorly lit sanitation areas. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins