Navigation Links
Large trees declining in Yosemite
Date:7/29/2009

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� to the most recent records from 1988�.

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.


'/>"/>

Contact: Jessica Robertson
jrobertson@usgs.gov
703-648-6624
United States Geological Survey
Source:Eurekalert

Page: 1

Related biology news :

1. Mixing large doses of both acetaminophen painkiller and caffeine may increase risk of liver damage
2. Microarray sequence capture speeds large-scale resequencing of targeted genomic regions
3. US fires release large amounts of carbon dioxide
4. Largest study to investigate risk factors of autism to begin enrolling families
5. Single-largest biodiversity survey says primary rainforest is irreplaceable
6. Technique controls nanoparticle size, makes large numbers
7. Texas Hospital nations first to use large-scale cocoon strategy against whooping cough
8. Worlds largest investor coalition seeks further disclosure on climate change and shareholder value
9. Worlds largest marine protected area created in Pacific Ocean
10. Airborne bacteria may play large role in precipitation
11. Are existing large-scale simulations of water dynamics wrong?
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
(Date:3/31/2016)... 31, 2016   ... the "Company") LegacyXChange is excited to release ... soon to be launched online site for trading 100% ... ) will also provide potential shareholders a sense of ... to an industry that is notorious for fraud. The ...
(Date:3/23/2016)... Massachusetts , March 23, 2016 /PRNewswire/ ... im Interesse erhöhter Sicherheit Gesichts- und Stimmerkennung ... Xura, Inc. (NASDAQ: MESG ), ... bekannt, dass das Unternehmen mit SpeechPro zusammenarbeitet, ... aus der Finanzdienstleistungsbranche, wird die Möglichkeit angeboten, ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 27, 2016   Ginkgo Bioworks , a leading ... was today awarded as one of the World ... world,s most innovative companies. Ginkgo Bioworks is engineering ... real world in the nutrition, health and consumer ... with customers including Fortune 500 companies to design ...
(Date:6/24/2016)... ... ... While the majority of commercial spectrophotometers and fluorometers use the z-dimension of ... higher end machines that use the more unconventional z-dimension of 20mm. Z-dimension ... of the cuvette holder. , FireflySci has developed several Agilent flow cell product ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... is pleased to announce the launch of their brand, UP4™ Probiotics, into Target ... over 35 years, is proud to add Target to its list of well-respected ...
(Date:6/23/2016)... , June 23, 2016 A person commits ... the crime scene to track the criminal down. ... U.S. Food and Drug Administration (FDA) uses DNA evidence to ... Sound far-fetched? It,s not. The FDA has ... to support investigations of foodborne illnesses. Put as simply as ...
Breaking Biology Technology: