Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Team of scientists predicts continued death of forests in southwestern US due to climate change

14.12.2010
If current climate projections hold true, the forests of the Southwestern United States face a bleak future, with more severe –– and more frequent –– forest fires, higher tree death rates, more insect infestation, and weaker trees. The findings by university and government scientists are published in this week's issue of the Proceedings of the National Academy of Sciences (PNAS).

"Our study shows that regardless of rainfall going up or down, forests in the Southwest U.S. are very sensitive to temperature –– in fact, more sensitive than any forests in the country," said first author Park Williams, postdoctoral researcher in the Department of Geography at UC Santa Barbara. "Forests in the Southwest are most sensitive to higher temperatures in the spring and summer, and those are the months that have been warming the fastest in this area."

Past forest studies have shown that warmer temperatures are associated with wildfires and bark beetle outbreaks. "We found that up to 18 percent of forest area in the Southwest –– millions of acres –– has experienced mortality due to severe wildfires and bark beetle outbreaks in the last 20 years," said Williams.

Co-author Joel Michaelsen, a professor of geography at UCSB, said: "In order to carry out this research project, Park Williams assembled a very comprehensive data set of over 1,000 tree ring chronologies from all across the United States." Michaelsen is a dendroclimatologist –– a scientist who studies climate using analysis of tree rings.

"Instead of using the chronologies to reconstruct past climate patterns, as is usually done in dendroclimatic work, the relationships between growth and climate were used to study possible impacts of future climate change on forest health," said Michaelsen. "One noteworthy finding was that tree growth throughout the Southwestern U.S., while quite sensitive to precipitation variations, is also negatively impacted by warmer temperatures. This is an important result, because predictions of future warming in the region are considerably more certain than any predictions of precipitation change."

Researchers found that historic patterns of vegetation change, insect outbreaks, fire activity, runoff, and erosion dynamics show that landscapes often respond gradually to incremental changes in climate and land-use stressors until a threshold is reached, at which time there may be dramatic landscape changes, such as tree die-offs or episodes of broad-scale fire or erosion. They also found that the stressors that contribute to tree mortality tipping points can develop over landscape and even sub-continental scales.

Co-author Christopher Still, an associate professor of geography at UCSB, said: "These predicted large-scale changes in forest cover and composition (i.e., types of tree species present) will have large implications for everything from snowpack and the river flows that our society depends on, to the intensity and frequency of fires, to the visual appearance of these landscapes that drives much of the tourism in this region."

Added co-author Craig D. Allen of the U.S. Geological Survey: "Such big, fast changes in Southwest forest vegetation could have significant effects on a wide range of ecosystem goods and services, from watershed protection and timber supplies to biodiversity and recreation. These emerging vulnerabilities present increasingly clear challenges for managers of southwestern forests to develop strategies to mitigate or adapt to the coming changes, in order to sustain these forested ecosystems and their benefits into the future."

Forests help retain rainwater and keep it from flowing down mountains immediately, noted Williams in explaining the importance of forests to landscapes and rivers. "When forests disappear," he said, "water runs downhill more quickly and takes the upper layers of soil with it."

According to Williams, the erosion makes it harder for future generations of trees to establish themselves and makes it more difficult for people to capture storm water as it flows from the mountains. In addition, erosion increases the amount of sediment flowing in rivers and settling in lakes, and causes water to remain in the forest long after the rain.

The paper also points to the many implications of these changes for future management and use of Southwest forests.

The scientific article is part of a special PNAS feature edition called "Climate Change and Water in Southwestern North America."

Note to editors: Park Williams is available by e-mail at williams@geog.ucsb.edu. Christopher Still is available at (805) 450-3070, or by e-mail at cstill@geog.ucsb.edu. For downloadable images see: http://www.ia.ucsb.edu/pa/display.aspx?pkey=2387

The American Geophysical Union (AGU) will hold a press conference on these findings at 5 p.m. today at the Moscone West Building, room 300, in San Francisco. Park Williams and other scientists will present results. To register for the press conference, please contact The AGU at agupressconfs@gmail.com.

Gail Gallessich | EurekAlert!
Further information:
http://www.ucsb.edu

More articles from Agricultural and Forestry Science:

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland

19.01.2017 | Earth Sciences

Not of Divided Mind

19.01.2017 | Life Sciences

Molecule flash mob

19.01.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>