Featured Research

from universities, journals, and other organizations

Large Trees Declining In Yosemite National Park, U.S.

Date:
August 3, 2009
Source:
United States Geological Survey
Summary:
Large trees have declined in Yosemite National Park during the 20th century, and warmer climate conditions may play a role. The number of large-diameter trees in the park declined 24 percent between the 1930s and 1990s. Scientists compared the earliest records of large-diameter trees densities from 1932--1936 to the most recent records from 1988--1999.

Trees and mountain reflected in lake at Yosemite National Park. Large trees have declined in Yosemite National Park during the 20th century, and warmer climate conditions may play a role.
Credit: iStockphoto/Ogen Perry

Large trees have declined in Yosemite National Park during the 20th century, and warmer climate conditions may play a role.

The number of large-diameter trees in the park declined 24 percent between the 1930s and 1990s. U.S. Geological Survey and University of Washington scientists compared the earliest records of large-diameter trees densities from 1932–1936 to the most recent records from 1988–1999.

A decline in large trees means habitat loss and possible reduction in species such as spotted owls, mosses, orchids and fishers (a carnivore related to weasels). Fewer new trees will grow in the landscape because large trees are a seed source for the surrounding landscape. Large-diameter trees generally resist fire more than small-diameter trees, so fewer large trees could also slow forest regeneration after fires.

“Although this study did not investigate the causes of decline, climate change is a likely contributor to these events and should be taken into consideration,” said USGS scientist emeritus Jan van Wagtendonk. “Warmer conditions increase the length of the summer dry season and decrease the snowpack that provides much of the water for the growing season. A longer summer dry season can also reduce tree growth and vigor, and can reduce trees’ ability to resist insects and pathogens.”

Scientists also found a shift to fire-intolerant trees in some forests that had not experienced fires for nearly a century. In these areas, trees changed from fire-tolerant ponderosa pines to fire-intolerant white fir and incense cedar. In burned areas, however, pines remained dominant.

“We should be aware that more frequent and severe wildfires are possible in Yosemite because of the recent shift to fire-intolerant trees in unburned areas and warmer climates bring drier conditions,” said van Wagtendonk.


Story Source:

The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.


Journal Reference:

  1. Lutz et al. Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA. Forest Ecology and Management, 2009; 257 (11): 2296 DOI: 10.1016/j.foreco.2009.03.009

Cite This Page:

United States Geological Survey. "Large Trees Declining In Yosemite National Park, U.S.." ScienceDaily. ScienceDaily, 3 August 2009. <www.sciencedaily.com/releases/2009/07/090729132117.htm>.
United States Geological Survey. (2009, August 3). Large Trees Declining In Yosemite National Park, U.S.. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2009/07/090729132117.htm
United States Geological Survey. "Large Trees Declining In Yosemite National Park, U.S.." ScienceDaily. www.sciencedaily.com/releases/2009/07/090729132117.htm (accessed September 21, 2014).

Share This



More Plants & Animals News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: San Diego Zoo Welcomes Cheetah Cubs

Raw: San Diego Zoo Welcomes Cheetah Cubs

AP (Sep. 20, 2014) The San Diego Zoo has welcomed two Cheetah cubs to its Safari Park. The nearly three-week-old female cubs are being hand fed and are receiving around the clock care. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Chocolate Museum Opens in Brussels

Chocolate Museum Opens in Brussels

AFP (Sep. 19, 2014) Considered a "national heritage" in Belgium, chocolate now has a new museum in Brussels. In a former chocolate factory, visitors to the permanent exhibition spaces, workshops and tastings can discover derivatives of the cocoa bean. Duration: 01:00 Video provided by AFP
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
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:
from the past week

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