Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Redwood trees reveal history of West Coast rain, fog, ocean conditions

Many people use tree ring records to see into the past. But redwoods – the iconic trees that are the world’s tallest living things – have so far proven too erratic in their growth patterns to help with reconstructing historic climate.

A University of Washington researcher has developed a way to use the trees as a window into coastal conditions, using oxygen and carbon atoms in the wood to detect fog and rainfall in previous seasons.

Michael Schweppe / Flickr

Coastal redwoods in Northern California use fog as a water source, incorporating the molecules in their trunks.

“This is really the first time that climate reconstruction has ever been done with redwoods,” said Jim Johnstone, who recently completed a postdoctoral position at the UW-based Joint Institute for the Study of the Atmosphere and the Ocean. He is corresponding author of a study published online Oct. 24 in the Journal of Geophysical Research-Biogeosciences.

While coastal redwoods are not the longest-lived trees on the West Coast, they do contain unique information about their foggy surroundings.

“Redwoods are restricted to a very narrow strip along the coastline,” Johnstone said. “They’re tied to the coastline, and they’re sensitive to marine conditions, so they actually may tell you more about what’s happening over the ocean than they do about what’s happening over land.”

The new study used cores from Northern California coastal redwoods to trace climate back 50 years. Weather records from that period prove the method is accurate, suggesting it could be used to track conditions through the thousand or more years of the redwoods’ lifetime.

Tree-ring research, or dendrochronology, typically involves a detailed look at a cross-section of a tree trunk. But the rings of a redwood are uneven and don’t always fully encircle the tree, making it a poor candidate for anything except detecting historic fires.

The new paper uses a painstaking approach that’s more like processing ice cores. It uses the molecules captured in the wood to sample the atmosphere of the past.

Most oxygen in Earth’s atmosphere has an atomic mass of 16, making it O-16, but a small percentage of oxygen is the heavier O-18 isotope. When seawater evaporates off the ocean to form clouds, some drops fall as rain over the ocean, and more of the heavier O-18 molecules rain out. The remaining drops that fall on land thus have a higher proportion of the lighter O-16 molecules.

Fog, on the other hand, forms near shore and blows on land where it drips down through the branches until the trees use it like rainwater.

By looking at the proportion of O-16 and O-18 in the wood from each season, the team was able to measure the contribution of fog and rain. They looked at the spring growth, from April to June, as well as the fall growth, from August to October. Researchers also analyzed carbon atoms to measure the total amount of moisture in the air.

“We actually have two indicators that we can use in combination to determine if a particular summer was foggy with a little rain, foggy with a lot of rain, and various combinations of the two,” Johnstone said.

Related research by Johnstone shows that the amount of West Coast fog is closely tied to the surface temperature of the ocean, so redwoods may be able to tell us something about the long-term patterns of ocean change, such as the Pacific Decadal Oscillation. Understanding of the natural variability cycles could also help to better distinguish natural and human-caused climate change.

“It’s possible that the redwoods could give us direct indication of how that’s worked over longer periods,” Johnstone said. “This is just a piece that contributes to that understanding in a pretty unique place.”

Johnstone conducted the research as part of his doctoral work at the University of California, Berkeley, where he was advised by co-author Todd Dawson. The other co-author is John Roden at Southern Oregon University. The research was funded by the National Science Foundation.

For more information, contact Johnstone at

Hannah Hickey | EurekAlert!
Further information:

Further reports about: Ocean Conditions Redwood carbon atom coastal conditions redwood trees

More articles from Earth Sciences:

nachricht Wandering greenhouse gas
16.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht Unique Insights into the Antarctic Ice Shelf System
14.03.2018 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

A new kind of quantum bits in two dimensions

19.03.2018 | Physics and Astronomy

Scientists have a new way to gauge the growth of nanowires

19.03.2018 | Materials Sciences

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Science & Research
Overview of more VideoLinks >>>