Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tourists, soothsayers & scientists try to predict peak Fall foliage color

07.10.2002


But new study sheds light on what makes leaves turn red



Groundhog behavior is supposedly a harbinger of spring.

Wooly Bear Caterpillars are a possible portent of the severity of winter.


But who knows when the Vermont forests will blaze with autumnal gold, orange and scarlet?

Not the weather forecasters, not the almanacs, not some octogenarian recluse Vermonter. Leave that to the scientists.

Here in Vermont where one out of four of the forests’ trees are maples, predicting peak leaf color is important business. Maples are those trees whose brilliant yellow, orange and red foliage most responsible for making the landscape look like a giant spilled his whole bowl of Trix cereal across the Green Mountains in October.

Tourists spent more than $710 million dollars in Vermont last fall, making 1.5 million trips to the state, according to information gathered by the University of Vermont’s Department of Community Development and Applied Economics, published last month.

So Vermont monitors the changes in its forests as carefully as a tourist on Vermont’s Route 100 studies a road map.

Now scientists at the University of Vermont and US Forest Service who track forest color feel they may have unraveled one of the mysteries concerning leaf color.

While color development is affected by a number of factors, "one common thread may be stress," according to Abby van den Berg research technician at UVM’s Proctor Maple Research Center, who’s spent the last four years studying foliage in Vermont forests. She and a team of University of Vermont and US Forest Service scientists used the data from her master’s thesis research to evaluate potential environmental and chemical triggers of fall color development.

"This data has been a source for deeper understanding and a new hypothesis about the connection between stress and red pigmentation in autumn leaves." says Paul Schaberg, UVM adjunct faculty, US Forest Service scientist and the study’s lead author. He says that their study, soon to be published in the journal Tree Physiology, concludes that "nutrient stress, particularly low nitrogen, can instigate early and more intense red color in maples." Others contributing to the research are: Program Chair of Forest Ecology John Shane, Professor Emeritus John Donnelly and UVM alumni Paula Murakami who is also with the US Forest Service.

"We’re developing new clues about what affects the timing and quality of fall coloration. Very little of this kind of work has ever been done before," van den Berg says.

Researchers tested the chemical composition of thousands of leaves from 16 maple trees, providing important information about various indicators of red fall-color development. They used state-of-the-art computer imaging technology to measure the percentage of color in each leaf throughout the seasonal cycle.

In addition to nitrogen, many other factors – potential climate, drought, pollution and others – could affect color, but it will take years of further study to uncover the many mysteries of autumnal color displays.

Scientists do know that cold temperatures and less daylight trigger the breakdown of green chlorophyll from leaves to reveal the yellow that exist hidden beneath all summer. "Then the leaves can also produce red. But why would a tree make red in a leaf that’s about to die?" asks Schaberg. "That’s one of the fundamental questions that we seek to answer."

An abstract of the soon-to-be published study suggests that a primary function of red pigments is to protect trees from photoxidative damage and thereby enhance nutrient recovery during leaf senescence. That means "the trees probably turn red because it’s a helpful coping response to stress," says Schaberg. "One theory is that red is like a sunscreen that allows the leaf to linger long enough for the tree to absorb more nutrients."

But even scientist Schaberg isn’t a soothsayer. In early September he predicted that due to the stress of last summer’s shortage of rainfall, New England would enjoy an early autumn. Alas, a warm September doused by excess rain from two tropical storms, led to an early October with forests still decked in green leaves.

"We’ve had a warm, wet autumn so far," says van den Berg "so trees are a bit late in losing their green, but it all could change practically overnight. Vibrant fall color is going to happen, I can guarantee it."

Cheryl Dorschner | EurekAlert!
Further information:
http://snr.uvm.edu/vtdc/

More articles from Life Sciences:

nachricht Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden

nachricht The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>