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 December 19, 2014 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 December 19, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) 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