Fishbone deforestation increases rainfall

Eric Frei · 18th June 2007, 06:58 PM

Can also be known as herringbone deforestation.

Fishbone Deforestation Pattern Affecting Environment, Research Shows

Quote:

ScienceDaily (Dec. 28, 2006) — Researchers at the University of Illinois at Urbana-Champaign are studying the environmental impact that unique patterns of deforestation in Rondonia, Brazil, have on the land and climate.

Rondonia is a state in the Amazonian region where the establishment of rural development projects has resulted in the construction of orthogonal road networks. Deforestation along the rapidly expanding network of highways and local roads has created a unique fishbone pattern.

Somnath Baidya Roy, a professor of atmospheric sciences at Illinois, is studying the atmosphere dynamics of fishbone deforestation, and will present his findings at the American Geophysical Union meeting in San Francisco, Dec. 11-15.

"People often relate tropical deforestation to clear-cuts," Roy said. "Climate models show that clear-cuts, if they happen on a basin-wide scale, will result in decreased rainfall and bring about a drier, more arid landscape. In the case of fishbone patterns, the deforestation is in isolated segments of the landscape, and our models indicate that it results in increased precipitation over these deforested regions."

Whether there has been a change in the overall amount of precipitation has not been established, but there is definitely evidence for the redistribution of precipitation. Roy attributes this redistribution to "vegetation breezes" that are similar to lake and sea breezes.

A deforested patch is warmer than the neighboring forests. Warm air is lighter and rises, creating a localized low-pressure zone. Cool air then rushes in to fill the void. Because of this convergence, more cumulus clouds and rainfall occur over the deforested patch.

Roy uses a high-resolution computer simulation model to study the effects of deforestation on climate, and the effects that climate change has on the landscape, a process known as "feedback cycle."

Recent studies have indicated that fishbone deforestation can trigger up to 15 millimeters more rain over pastures, stimulating an increased growth of vegetation in these areas.

"It is very counter-intuitive that in these cases, fishbone deforestation results in a negative feedback-cycle," Roy said. "It's negative because it speeds up vegetation recovery and thus offsets the effects of deforestation."

If the deforestation had resulted in less rainfall, leading to a decrease in plant growth, this would be referred to as a "positive" feedback-cycle.

Roy's model is high-resolution, resulting in very detailed data. The drawback to this model is that it cannot be carried out for prolonged periods, unlike more conventional climate models, which provide coarser data but can be carried out continuously.

"Our next goal is to correlate my model with other climate models," Roy said, "so that we may study the longer term aspects of fishbone deforestation, while maintaining the high-resolution."

Sean Freeman · 18th June 2007, 07:53 PM

Here's a map showing it all too well http://maps.google.com/maps?ie=UTF8&om=1&z=8&ll=-10.676803,-61.446533&spn=2.736593,3.735352&t=k

TreeCo · 19th June 2007, 12:59 AM

Interesting.

I like that science site.

Thanks,

Dan

Eric Frei · 19th June 2007, 07:37 AM

Yeah Dan, there's plenty of categories to check out and stacks of legit info, very good.

OsAGe85 · 28th July 2007, 10:06 AM

Great posts and links ekka and boa, for sure

19th June 2007, 07:37 AM	#4
Eric Frei Admin - Razor sharp and independent 2 X Diploma Level 5 qualified arborist Join Date: Jan 2007 Location: Brisbane Posts: 12,792	Yeah Dan, there's plenty of categories to check out and stacks of legit info, very good. __________________ Protect your rights to work - Join Australian Tree Association My businesses:- Qualified Brisbane Tree Lopping \| Stump Grinding Brisbane \| Brisbane - Gold Coast Consulting Arborist

28th July 2007, 10:06 AM	#5
OsAGe85 Semi-mature vigorous tree Join Date: Jul 2007 Location: Littlerock Arkansas US Posts: 59	Great posts and links ekka and boa, for sure __________________ Gotta love the smell 2 stroke and wood chips. Be smart, be safe.

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18th June 2007, 07:53 PM	#2
Sean Freeman Monument Status Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,985	Here's a map showing it all too well http://maps.google.com/maps?ie=UTF8&om=1&z=8&ll=-10.676803,-61.446533&spn=2.736593,3.735352&t=k

19th June 2007, 12:59 AM	#3
TreeCo Mature tree Join Date: Jan 2007 Location: Georgia, USA Posts: 307	Interesting. I like that science site. Thanks, Dan