Soils may dictate the array of fall colors as much as the trees rooted in them, according to a forest survey out of North Carolina.
By taking careful stock and laboratory analyses of the autumn foliage of sweetgum and red maple trees along transects from floodplains to ridge-tops in a nature preserve in Charlotte, N.C., former University of North Carolina at Charlotte graduate student Emily M. Habinck found that in places where the soil was relatively low in nitrogen and other essential elements, trees produced more red pigments known as anthocyanins.
Habinck's discovery supports a 2003 hypothesis put forward to explain why trees bother to make red pigments, by plant physiologist William Hoch of Montana State University, Bozeman. Hoch found that if he genetically blocked anthocyanin production in red-leafed plants, their leaves were unusually vulnerable to fall sunlight, and so sent less nutrients to the plant roots for winter storage.
For trees living in nutrient-poor soils, then, it makes sense to produce more anthocyanins, which protect the leaves longer, so as much nutrient as possible can be recovered from leaves before winter sets in. It is, after all, the process of recovering of nutrients from leaves which turns leaves from green to yellow, orange and sometimes anthocyanin-red.
The trees Habinck studied appear to be acting in accordance with Hoch's hypothesis. "It makes sense that anthocyanin production would have a function, because it requires energy expenditure," said Habinck. Put in economic terms, anthocyanins are an investment made by stressed trees in situations where they stand to gain from the extra recovery of nutrients from leaves. It's not about the showy color, but about survival.
"The rainbow of color we see in the fall is not just for our personal human enjoyment -- rather, it is the trees going on about their lives and trying to survive," said Habinck's advisor, Martha C. Eppes, a soil scientist and assistant professor of Earth sciences at the University of North Carolina at Charlotte. Eppes will present the research at the Geological Society of America Annual Meeting, Monday, 29 October, in Denver, CO.
The reason the soil-leaf color connection wasn't made long ago is partly because Hoch's hypothesis was needed to put it into perspective. It also might be that many plant researchers were missing the forest for the trees.
"I think that most of the work has been done by biologists looking at production of anthocyanins in trees themselves," said Eppes. They hadn't stepped back and looked at patterns of tree color.
Eppes wants to follow up Habinck's study with a wider analysis of satellite data showing tree color which can be compared to geological maps of the types of soils over large portions of land.
**WHEN & WHERE**
Correlation of Soil Development and Landscape Position with Fall Leaf Colors
Monday, October 29, 8:00 a.m. – Noon
Colorado Convention Center: Exhibit Hall E/F
View abstract: http://gsa.confex.com/gsa/2007AM/finalprogram/abstract_127703.htm
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- A Billion Years Ago, What Did Earth's Ancient Magnetic Field Look Like?
- How A Former Naturopath Can Help Unravel The Trickery of Alternative Medicine
- Can A New Rule Trigger A Second EU Referendum? Petition Signatures Over 11% Of Total Votes Cast
- Insects Were Already Using Camouflage 100 Million Years Ago
- Finding All-Hadronic Top - Again
- Better Brains With Beer
- Some Celiac Disease May Be Due To Viruses
- "Thanks for your understanding!Cheers,T...."
- "As for comparing America and Europe, I am reminded of “Pyramid” by Robert Abernathy.  ..."
- "Just a link to add to this article at some point. A good Google document about the sorts of issues..."
- "Oh, okay - there's no reason for them to add up, indeed it's a bit of a coincidence that it turned..."
- "Robert, Out of curiosity I added totalled the Ashcroft figures of both Leave and Remain age groups..."
- There’s Been Some Movement on GMO Labeling — Maybe
- How I Got Zika
- How to Feed the World & Other Ways Media Linked to ACSH this Weekend
- Anti-Intellectualism Is Biggest Threat to Modern Society
- Chemistry Can Help Roast the Perfect Coffee Bean
- What Happens To A Soccer Player’s Brain After Missing A Penalty Kick
- Researchers open new path of discovery in Parkinson's disease
- A shampoo bottle that empties completely -- every last drop
- Radioactive cesium fallout on Tokyo from Fukushima concentrated in glass microparticles
- Meet the biohackers
- Seeds of black holes could be revealed by gravitational waves detected in space