Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using satellite observations to investigate ’greening’ trends across Canada and Alaska

06.09.2005


Recent research results from scientists at the Woods Hole Research Center suggest that ’greening’ has begun to decline in the high latitude forested areas of North America. The work, which represents an important advance by incorporating the full extent of the latest satellite observational record to document unique vegetation responses to climatic warming, and then projecting those trends forward in time, is now being extended to circumpolar forests. The research will be highlighted in upcoming issues of Proceedings of the National Academy of Sciences (PNAS) and in Geophysical Research Letters.



Generally, satellite observations of plant growth across the high latitudes of North America -- in Canada and Alaska -- indicate that tundra vegetation experienced an increase in both peak photosynthesis and growing season length, whereas forests experienced a decline in photosynthetic activity between 1981 and 2003. Climatic warming occurred across the entire region, but the change in the forest response indicates that long-term changes may not be predictable from initial, short-term observations. Fire disturbance has also increased with the warming but does not explain the decline in forest photosynthetic activity.

According to Scott Goetz, a senior scientist with the Center, "We believe this is some of the first evidence that high latitude forests may be in decline following an initial growth spurt associated with warming. The reasons for this decline are not certain, but related work points to increased drying as a likely cause. The observed warming and drying are consistent with climate model predictions for the region."


More specifically, Center researchers analyzed trends in a time series of photosynthetic activity across boreal North America over 22 years, from 1981 to 2003. Nearly 15 percent of the region displayed significant trends, of which just over half involved temperature-related increases in growing season, length and photosynthetic intensity, mostly in tundra. In contrast, forest areas unaffected by fire during the study period declined in photosynthetic activity and showed no systematic change in growing season length. Stochastic (random) changes across the time series were predominantly associated with a frequent and increasing fire regime. These trends have implications for the direction of feedbacks to the climate system and emphasize the importance of longer-term synoptic observations of arctic and boreal biomes.

According to Andrew Bunn, a postdoctoral fellow at the Center, "These studies are important because they describe how vast areas of forest are changing and how those changes are related to climate. They are supported by a variety of field studies from other researchers that show rapid changes in vegetation in response to climate variability."

Elizabeth Braun | EurekAlert!
Further information:
http://www.whrc.org

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>