Featured Research

from universities, journals, and other organizations

79 years of monitoring demonstrates dramatic forest change

Date:
January 6, 2014
Source:
USDA Forest Service - Pacific Southwest Research Station
Summary:
Long-term changes to forests affect biodiversity and how future fires burn. A team of scientists found dramatic differences in forests today compared to historic conditions prior to logging and fire suppression.

In many forests of the western US, increased potential for fires of uncharacteristic intensity and severity is frequently attributed to structural changes brought about by fire exclusion, past land management practices, and climate. Extent of forest change and effect on understory vegetation over time are not well understood, but such information is useful to forest management focused on restoring biodiversity and resilience to these ecosystems.

Related Articles


Scientists re-measured three large (4 ha) historical "Methods of Cutting" (MC) plots in mixed-conifer forest of the central Sierra Nevada installed in 1929 to evaluate the effects of different logging methods. Trees P10 cm were surveyed across the entire plots and understory vegetation (tree seedlings, shrubs, and herbaceous species) was quantified within quadrats in the old-growth condition in 1929 prior to logging, later in 1929 after logging, and again in 2007 or 2008. We also compared forest structure in the MC plots with an adjacent unlogged "control" area and collected fire scar samples from nearby stumps to evaluate the historical fire regime.

The contemporary tree density in the MC plots (739 trees ha-1) was 2.4 times greater than the 1929 pre-logging density (314 trees ha-1). Trees in the small and intermediate size classes (10–75 cm dbh) were significantly over-represented, and trees in the larger size classes (>90 cm dbh) generally significantly under-represented, compared with historical conditions. The proportion of pine dropped from 37% of tree basal area in 1929 to 21% in 2007/08. Density of small to intermediate sized trees was similar in the contemporary logged and unlogged control plots, suggesting that over the long term, ingrowth may have been influenced more by lack of fire than historical logging.

Change to non-tree vegetation was most pronounced for shrub cover, which averaged 28.6% in 1929 but only 2.5% in 2008. CART analysis indicated that the highest shrub cover in 1929 was in areas having four or fewer trees growing within 15 m to the south of the quadrat, suggesting that reduced light was the most likely explanation for the decline over time. Herbaceous species richness in 2008 was significantly lower than in 1931, two years after logging, but did not differ significantly from 1929, prior to logging. Understory vegetation should benefit from thinning or prescribed fire treatments that lead to a greater abundance of higher light environments within stands.


Story Source:

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


Journal Reference:

  1. Knapp, Eric E.; Skinner, Carl N.; North, Malcolm P.; Estes, Becky L. Long-term overstory and understory change following logging and fire exclusion in a Sierra Nevada mixed-conifer forest. Forest Ecology and Management, 310: 903%u2013914

Cite This Page:

USDA Forest Service - Pacific Southwest Research Station. "79 years of monitoring demonstrates dramatic forest change." ScienceDaily. ScienceDaily, 6 January 2014. <www.sciencedaily.com/releases/2014/01/140106133257.htm>.
USDA Forest Service - Pacific Southwest Research Station. (2014, January 6). 79 years of monitoring demonstrates dramatic forest change. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2014/01/140106133257.htm
USDA Forest Service - Pacific Southwest Research Station. "79 years of monitoring demonstrates dramatic forest change." ScienceDaily. www.sciencedaily.com/releases/2014/01/140106133257.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

How To: Mixed Green Salad Topped With Camembert Cheese

How To: Mixed Green Salad Topped With Camembert Cheese

Rumble (Jan. 26, 2015) Learn how to make a mixed green salad topped with a pan-seared camembert cheese in only a minute! Music: Courtesy of Audio Network. Video provided by Rumble
Powered by NewsLook.com
Water Fleas Prepare for Space Voyage

Water Fleas Prepare for Space Voyage

Reuters - Innovations Video Online (Jan. 26, 2015) Scientists are preparing a group of water fleas for a unique voyage into space. The aquatic crustaceans, known as Daphnia, can be used as a miniature model for biomedical research, and their reproductive and swimming behaviour will be tested for signs of stress while on board the International Space Station. Jim Drury went to meet the team. Video provided by Reuters
Powered by NewsLook.com
Husky Puppy Plays With Ferret

Husky Puppy Plays With Ferret

Rumble (Jan. 26, 2015) It looks like this 2-month-old Husky puppy and the family ferret are going to be the best of friends. Look at how much fun they&apos;re having together! Credit to &apos;Vira&apos;. Video provided by Rumble
Powered by NewsLook.com
Scientists Model Flying, Walking Drone After Vampire Bats

Scientists Model Flying, Walking Drone After Vampire Bats

Buzz60 (Jan. 26, 2015) Swiss scientists build a new drone that can both fly and walk, modeling it after the movements of common vampire bats. Jen Markham (@jenmarkham) has the story. Video provided by Buzz60
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