Featured Research

from universities, journals, and other organizations

Logging debris suppresses development of an invasive competitor, Scotch broom

Date:
April 2, 2010
Source:
USDA Forest Service, Pacific Northwest Research Station
Summary:
Countless studies and reports exist describing how a landscape is impacted after logging Douglas-fir: What is the impact on the soil? Should one leave the debris in place? Pile it? Burn it or haul it off site in preparation for replanting the area in the future? However, few studies have examined this hypothesis: Is it possible, that the debris remaining on the ground after logging may actually suppress competing vegetation resulting in a positive effect on the survival of Douglas-fir seedlings?

Logging of Douglas fir trees in Washington state.
Credit: iStockphoto/Phil Augustavo

Countless studies and reports exist describing how a landscape is impacted after logging Douglas-fir: What is the impact on the soil? Should one leave the debris in place? Pile it? Burn it or haul it offsite in preparation for replanting the area in the future?

Related Articles


However, few studies have examined this hypothesis: Is it possible, that the debris remaining on the ground after logging may actually suppress competing vegetation resulting in a positive effect on the survival of Douglas-fir seedlings?

At a variety of clearcut sites, research forester Tim Harrington, noticed that plant invaders were sparse when the debris was left behind. He also began to reason that the method of dealing with debris might indirectly affect the survival and growth of conifer seedlings by way of its impact on vegetation that managers may consider a nuisance.

Harrington and Virginia Tech professor, Stephen Schoenholtz, conducted two studies to quantify the effects of different levels of logging debris on the productivity of Douglas-fir. These experiments compared the effects of dispersing, piling, and removing logging debris on the 5-year survival and growth of planted Douglas-fir seedlings at logging sites near Matlock, Washington, and Molalla, Oregon.

"I found that Scotch broom was the key woody competitor at the first location," Harrington says,"and blackberry was rampant at the second." Three treatments were tested at each site: Only harvested logs were removed, leaving branches and treetops; aboveground portions of entire trees were removed; or logs were taken and branches and tops were piled at the site. "By the second or third year of the research, the amount of terrain covered by the key invasive (Scotch broom or blackberry) was much greater where debris had been piled or removed," Harrington explains, adding that as broom cover at the Matlock site increased to 40 percent, Douglas-fir seedling survival decreased by 30 percent. At the Molalla site, stem growth of the young trees decreased by 30 percent as blackberry cover increased to 80 percent. Dispersed logging debris also suppressed development of other invasive plant species, including oxeye daisy and velvet grass.

Some of the other findings of the study include:

  • Debris decays, releases nutrients, adds to soil productivity.
  • Mineral soil is exposed when debris is piled or removed, allowing native plants to be squeezed out while invasive plants grow rapidly.
  • Removal of debris also removes a good source of carbon and nitrogen needed for forest productivity. The problem is especially severe on low-productivity sites having gravelly or sandy soils.
  • Leaving debris behind saves the cost of removal, but it may also increase short-term fire risk.

The study, Effects of logging debris treatments on five-year development of competing vegetation and planted Douglas-fir, appears in the recent issue of the Canadian Journal of Forest Research. The article is coauthored by Harrington and Schoenholtz. Harrington is a research forester at the Forest Service's Pacific Northwest Research Station, USDA Forest Service. He is based in Olympia, Washington. Schoenholtz is a professor in the College of Natural Resources at Virginia Tech, Blacksburg, Virginia.


Story Source:

The above story is based on materials provided by USDA Forest Service, Pacific Northwest Research Station. Note: Materials may be edited for content and length.


Journal Reference:

  1. Harrington et al. Effects of logging debris treatments on five-year development of competing vegetation and planted Douglas-fir. Canadian Journal of Forest Research, 2010; 40 (3): 500 DOI: 10.1139/X10-001

Cite This Page:

USDA Forest Service, Pacific Northwest Research Station. "Logging debris suppresses development of an invasive competitor, Scotch broom." ScienceDaily. ScienceDaily, 2 April 2010. <www.sciencedaily.com/releases/2010/04/100402154917.htm>.
USDA Forest Service, Pacific Northwest Research Station. (2010, April 2). Logging debris suppresses development of an invasive competitor, Scotch broom. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2010/04/100402154917.htm
USDA Forest Service, Pacific Northwest Research Station. "Logging debris suppresses development of an invasive competitor, Scotch broom." ScienceDaily. www.sciencedaily.com/releases/2010/04/100402154917.htm (accessed October 24, 2014).

Share This



More Plants & Animals News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. Video provided by Newsy
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