Do plants make rain?

[Michaelangelica]

you may have noticed this is my Reading the last 12 months of New Scientist month
This article, this month, has astounding implications, especially for Australia.
Unfortunately I left the article on the train. Fortunately most of it is on the web
Rainforests may pump winds worldwide - environment - 01 April 2009 - New Scientist

As I understand it the premise is that coastal forests cause rain.
The rain falls thus decreasing air pressure; this sucks in moist sea air further inland, where forests make more rain; this causes a drop in air pressure resulting in further inward movement of moist air. And this process just gets repeated and repeated. The magazine had a neat little graphic explaining it all much better than words.
This is how some Russian Scientist believe coastal forests suck precipitation (rain) further and further inland.
In Australia the forests we are chopping down are the coastal ones.
The inland is getting dryer.
Australia is like a huge wagon wheel with 'the mud on the edge' the major centres of population. We like to live on the coast, build hot cities made of concrete- spread out-a car oriented society- like LA.

It may be that aboriginal burning of coastal forests over 40-60,000 years (pick a number) may have dried out the continent.

The theory suggests that past civilisations could have had a much greater impact on global climate than we thought. Australia once had forests but is now largely desert. Gorshkov and Makarieva argue that Aborigines burning coastal forests may have switched the continent from wet to dry by shutting down its biotic pump.

The implications of this theory/model are far reaching

• Oz Outback farmers can blame the city dwellers for their drought?
• We may need to green our cities post haste
• get those indoor plants going?
• should we be clearing coastalland to build a sea of concrete roofs, now, with new planning laws, no room to grow a tree-no "backyards."
• should we be wood-chipping coastal forests for the Japanese to make origami?
• how does this affect the Great Barrier reef and its aquifers?
• should we be moving city development inland (more Canberras ! Horror!)

Of course the implications may be similar in other countries.
However the implications may also be GLOBAL

The implications are global, he adds. "We think some of the recycled Amazon moisture is taken on a jet stream to South Africa, and more maybe to the American Midwest. Gorshkov and Makarieva are looking at the front end of an absolutely critical process for the world's climate."
If their theory is correct, it means that large forests help kick-start the global water cycle.

Climatologists are already worried about the state of the Amazon rainforest. Last month, the UK's Met Office warned that if the planet warms by 4 degrees, 85 per cent of the forest could dry out and die.
If Gorshkov and Makarieva are right, the Amazon will be gone before warming kicks in.
They predict that even modest deforestation could shut down the pump and reduce rainfall in central Amazonia by 95 per cent.The same could happen in the world's other large rainforest regions, such as central Africa.

It's not all bad news. If natural forests can create rain, then planting forests can, too. Sheil says, if forests attract rain, then replanting deforested coastal regions could re-establish a biotic pump and bring back the rains. "Once forests are established, the pump would be powerful enough to water them. Could we one day afforest the world's deserts? Makarieva and Gorshkov's hypothesis suggests we might."

http://www.newscientist.com/article/...html?full=true

[Michaelangelica]

Not sure if I approve of this
An award for someone who makes PLASTIC TREES!

Naturally Inspired

By Kenny Berkowitz '81

Abe Stroock examines his “synthetic tree,” which mimics transpiration in plants.
University Photo

Searching for inspiration on a walk through Northern California’s Redwood National Park, Abraham Stroock stopped to look around him. But it wasn’t the physical beauty of the giant sequoias that left him transfixed; it was the beauty of the physics that allows these trees to transport water hundreds of feet in the air, pushing against gravity for a thousand years without expending any biological energy. And though Stroock continues to find his inspiration in nature, the thing that currently excites him is a small piece of polymer no bigger than a stick of gum.

“I’m not a naturalist, so the wonder of life doesn’t come as easily to me as the physical reality of it,” says Stroock, assistant professor of chemical and biomolecular engineering, as he slides his latest “synthetic tree” out of its plastic sandwich bag. “I wouldn’t have pursued this for the last five years, trying to get this to work, if there wasn’t good evidence that plants do this. If we hadn’t studied the physiology of plants, we wouldn’t have had the courage to launch into this project.”

With three days left of spring classes, as the trees on the quad come into full bloom, Stroock holds his synthetic tree up to the window, catching the sunlight in its two small circles etched side by side. After numerous attempts to build porous structures that could replicate the capillary action that gets sap to the highest twig—all unsuccessful—Stroock and his graduate student, Tobias Wheeler, abandoned conventional wisdom and devised a new concept: Instead of thinking of the leaf material that pulls the water to the top of the trees as porous material, like filter paper, they imagined it might be more like a gel, which can hold water at the molecular scale. That would explain why a leaf can remain water-filled even in extremely dry conditions. The polymeric tree in his hand, capable of wicking microscopic amounts of water at very great tension through its photo-lithographed channels, is the result of that breakthrough.

It’s been a long road, but with their work recently published in Nature, Stroock and Wheeler know they are on to something. “We flailed around for two or three years, unsure of what path to take,” says Wheeler, Stroock’s first graduate student, who completed his doctorate in May 2008. “No one had ever tried to tackle this problem before, and for a while it felt like we weren’t making any progress, which was tough. But once we switched from capillaries to this polymeric material, we had the first inklings this approach could in fact work. Things started to fall in place, and we wound up reaching the goal we’d set for ourselves five years earlier.”

If Stroock and Wheeler are right, the implications are enormous. The fundamental challenge—to engineer nanoscaled materials that reproduce the processes of living cells—is even more difficult than it sounds, and these trees represent the first synthetic system to mimic transpiration in plants, pumping water with enough power to reach the top of a giant sequoia.


In one of its narrowest applications, a collaboration with Alan Lakso of the New York State Agricultural Experiment Station in Geneva, this technology could be used to measure water pressure inside grapevines and apple trees, providing a continuous stream of data that would allow growers to quickly adjust irrigation.

“To have a collaboration like this between a plant scientist and a chemical engineer is very unusual,” says Lakso, professor of pomology and viticulture, who sought out Stroock after reading a newspaper article about the synthetic tree. “It’s been great to brainstorm with an engineer who is fascinated by plants, because the physics of plants tends to be extremely complex, which makes them very hard to describe and even harder to model as they change over time.”

In its widest applications, this same technology could provide the foundations for a large-scale passive system for heat transfer, a microfluidic lab-on-a-chip, or an electrode for low temperature fuel cells.

“The synthetic tree is a real tour de force, but it’s just one of the things that makes Abe so extraordinary,” says Paulette Clancy, William C. Hooey Director of Chemical and Biomolecular Engineering. “It’s this sense of innovation, this incredible boldness he brings to everything he does. He’ll jump into a field that is already heavily populated, which is awfully difficult to do, and make a real impact. He brings a very thorough approach and a deep physical understanding to reach some very creative solutions—which is rare.”

In the five years since coming to Cornell, Stroock has published 16 papers covering a wide range of projects in microfluidics, which he’s balanced with a teaching load of both undergraduate and graduate courses, winning a College of Engineering Excellence in Teaching Award in 2006.

“With Abe, we have somebody trained as a physicist, who teaches chemical engineering courses so well that he wins awards for teaching,” says Clancy. “He took a standard course in heat and mass transfer, which is typically about the effects that come into play when you scale up to a large industrial process, and turned that on its head, asking ‘What happens when you scale it down to microscopic length? What additional factors do you need to take into account?’ That’s the kind of innovative approach that really benefits our students. Even now, during his tenure year, when most academics would be concerned with themselves, he’s been taking time to lobby for daycare facilities on campus, and I think that kind of selflessness speaks volumes about who he is as a person.”

Stroock started exploring the world as child, growing up outside Boulder, Colo., as the son of a mathematician and an early childhood educator. (His father, Daniel, is an MIT professor best known for his work in diffusion processes; his mother, Lucy, is currently on the adjunct faculty of the Urban College of Boston.) When he was a teenager, the family moved to Cambridge, Mass., where his father began teaching at MIT and Stroock began his undergraduate career. Two years later, he transferred to Cornell, where he graduated cum laude in 1995 with a bachelor’s degree in physics.

Unsure of what to do next, Stroock moved to France, where he had lived as a high school exchange student with the family of Laure Mougeot, who has since become his wife. After receiving a master’s degree in solid state physics from the University of Paris—and getting married—Stroock returned to Cambridge, completing his Ph.D. in chemical physics from Harvard in 2002 while Laure began writing case studies for the Harvard Business School. Then, after his Ph.D. and a brief post-doc with Harvard’s George Whitesides, who Clancy calls “the world’s preeminent expert on microfluidics,” Stroock returned to Cornell as an assistant professor, where he met the newly arrived Wheeler.



The microscope image (above) shows water-filled, spherical voids within the hydrogel that plays the key role in the leaf and root of the synthetic tree. These water capsules serve as miniature laboratories for studying the properties of water at large negative pressures (down to -220 atmospheres).
Tobias Wheeler
“The first summer I worked with him, he came to the lab almost every day,” says Wheeler. “That says a lot about his approach, which has always felt very collaborative, very cooperative. My first impression was that he looked very young, and when we initially began meeting people to talk about the synthetic tree, they thought he was a graduate student and I was his undergraduate assistant. We were amused, but it’s easy to see how people might have thought that, because he’s so enthusiastic and open to new ideas. And that energy carried through my Ph.D., recharging me whenever we encountered a barrier in our research.”


In a second, equally ambitious microfluidics project, Stroock is collaborating with researchers at Weill Cornell Medical College to develop a biodegradable bandage to transport fluid to and from a wound; and in a third, he’s collaborating with Professor Lawrence Bonassar to engineer scaffolded, tissue-like, functional materials that could be used to either foster the growth of healthy cells for transplantation or restrict the growth of tumors.


“At its core, we want to make a device that can mimic the way the body delivers nutrients to its tissues,” says Bonassar, associate professor of biomedical engineering with a joint appointment in mechanical engineering. “Tissues contain within themselves a network of channels—blood vessels—through which they get nutrients. What we did was to take this basic architectural feature of the body and superimpose it on a hydrogel, which is mostly water and polysaccharide, to make a better tool for culturing cells. It’s a material that has a long history in medicine, but we’re using it in an entirely new application.

“Abe has this wonderful combination of precision, creativity, and relentlessness,” continues Bonassar. “We both knew very quickly that we had something special, and when you have lightning in a bottle, there’s a temptation to share it as quickly as possible. But Abe was always very focused on the task at hand. He was the one who kept saying, ‘We just need one more experiment to nail this down.’ And as one turned into two, then ten, he kept going until he was 100 percent certain of what we had. In many ways, Abe is the kind of person I came to Cornell to work with: someone who would challenge me, send me in new directions, and do things no one had ever done before.”

Taken together, the projects have earned Stroock a National Science Foundation Career Award, a 3M non-tenured faculty grant, an Arnold and Mabel Beckman Foundation Young Investigator grant, participation in the Frontiers of Engineering Symposium at the National Academy of Engineering, and membership in Technology Review’s 2007 list of 35 top innovators under 35 years old. And for all their differences, the three projects share a common root in plant science, biomimicry, and fluid mechanics.

Cornell Engineering : Naturally Inspired
I have quoted much of the article as it seems more of a press release.
More here

Synthetic tree: A means to remove CO2 from the air
Wednesday, September 24, 2008, 18:00
This news item was posted in Science category and has 1 Comment so far.


In 2003, a Dr. Klaus Lackner, a Columbia University physicist, had designed a synthetic tree that could draw carbon dioxide from air and retain the carbon. It was the first step in application of carbon sequestration technology.


However, Dr. Lackner’s synthetic tree did not look like a tree or perform any of the functions of a real tree. The synthetic tree was merely an air capture device to remove carbon from the atmosphere and store it.

Now, in September 2008, Abraham Stroock and Tobias Wheeler, of Cornell university, have created a synthetic tree that simulates the process of transpiration by which trees draw water to its branches and leaves.

What are synthetic trees?
A synthetic tree is a palm-sized microfluidic system that mimics the main features of transpiration. In synthetic trees, evaporation or transduction of water in the vapour phase into negative pressures in the liquid phase, takes place followed by stabilization and flow of liquid water at very high negative pressures.
A real tree can transfer water to great heights, up to 85 meters tall, from the roots to its leaves, through its trunk. The synthetic trees, created by Stroock and Tobias Wheeler, can transfer liquids in a similar way to amazing heights.

The synthetic tree comprises two networks of parallel channels placed next to each other in a thin sheet of hydrogel - a material used to make contact lenses - connected to a main channel, thus replicating a tree’s vascular system.

In an synthetic tree, the tranparent sheet of hydrogel is 1 millimeter thick. There are 80 parallel channels etched into the hydrogel sheet. These parallel sheets are connected to a main channel that enters into a network of microchannels in the leaf or root network. The channels, in a synthetic tree are approximately 100 micrometers wide.

How do synthetic trees work?
Real trees use xylem, a tubular tissue-like substance, to pull water out of the ground and pass it to the leaves.

Because of negative pressure, the water remains in a metastable state, something between a liquid and vapor.

For their synthetic tree, Stroock and Wheeler decided to use hydrogel, or polyhydroxyethyl methacrylate, to replicate the plant membrane. Hydrogel is a porous solid with the mixture of the solid and liquid phase at the molecular level. This makes the pores very tiny - much less than the maximum allowable 10 nanometers to hold the water - so that the negative pressure is high enough to suck the water. If the pores are larger than 10 nanometers, then the pores will fail to hold on to the liquid.

Synthetic trees to remove CO2 from air, carbon extraction and synthetic tree technology for environment and air cleaning | DWS Tech

ISTM that the most interesting thing about this is the low energy pumping of water.
Part of the problem with water scarcity is getting it to where it is needed (Demonstarted last week in Oz wher 1/2metre of rain fell on the coast (in one day!) and the inland and Murry Darling & W. Victoria is still in drought)

[stereologist]

I've been to a lecture in which the presenter showed how plants can extract water from passing clouds. The plants collect the mist on their surfaces and the water drips off next to the plant. Last I heard their were efforts to promote moisture in the soil by placing fences in the area to extract water from the passing clouds where plants no longer existed.

[Turtle]

Originally Posted by stereologist

I've been to a lecture in which the presenter showed how plants can extract water from passing clouds. The plants collect the mist on their surfaces and the water drips off next to the plant. Last I heard their were efforts to promote moisture in the soil by placing fences in the area to extract water from the passing clouds where plants no longer existed.

Interesting! Do you recall where that is going on? I recently heard this bit on collecting water from fog with nets. What won't we silly human bags of water think of next.

Water collection WASH Technology

Fog harvesting: a solution for Cape Verde’s water shortages?
January 29, 2009
... Residents here have little access to safe drinking water due to a shortage of purification facilities and declining rainfall, a situation shared by 25 percent of the population – more than 100,000 people.

Close to the sea, the government-protected park on Santiago Island has ample fog, which does not often produce rain.

With the help of 200sqm of netting erected in 2005, Serra Malagueta’s residents are collecting fog water to supply their water needs. The nets capture fog, which then turns into water that drips into a trough and flows through pipes. The filtered water is fed into holding tanks that supply the water to the elementary school and community faucets. ...

[stereologist]

The lecture was by a guy named Vogel or Vogelmann. He was working with a group in Mexico to reestablish forests where they once stood. He had great photos of lone trees in mist with wet ground under the trees. Very simple and dramatic work. What they wanted to know was whether or not this water did anything other than wet the upper surface.

[Michaelangelica]

Originally Posted by stereologist

The lecture was by a guy named Vogel or Vogelmann. He was working with a group in Mexico to re-establish forests where they once stood. He had great photos of lone trees in mist with wet ground under the trees. Very simple and dramatic work. What they wanted to know was whether or not this water did anything other than wet the upper surface.

Thanks stereologist
I've done a bit of googling and come up with a few leads.

Tropical montane cloud mist forests are among the most biologically rich and diverse ecosystems, providing habitats for many of the world's endangered species.

More about how to make measurements.
Changes in Land Use and Water Use and Their Effects on Climate, Including Biogeochemical Cycles III Posters - Biogeosciences [B]

What is a cloud forest?

Also known as the bosque mesófilo de montaña, the cloud forest constitutes one of the most beautiful natural settings in Mexico. This is a magical place, made up of evergreens, covered with brilliantly colored orchids, bromeliads, mosses and lichens. Here too, you will find dozens of beautiful and surprisingly large trees wrapped in the nearly constant mist, which evokes fascination and respect. The the expression cloud forest is not a scientific term, it is gerenerally used to describe a habitat or bioregion in ehich clouds and mist in the air determine the type of vegetation and conditions for growth. The Mexican cloud forest in Veracruz is often covered by mist, which in addition to rainfall, contributes to the hydrological cycle and influences climate and biodiversity.

Cloud Forest in Danger

While this eco-system possesses the greatest biodiversity of any found in Mexico, it is also one of the most threatened eco-systems in the world. We are in a distinct transition zone - where species from the northern and southern hemispheres live together harmoniously.

In México, the cloud forest has been reduced in large measure due to coffee cultivation, cattle grazing and increases in human population. Cloud forest deforestation has led to soil erosion, flooding, reduction in water flow, and plant and animal extinctions, which upset the ecological equilibrium of the ecosystem. This causes irreversible loss of natural, genetic resources. Increases in rural poverty are also a by-product of deforestation.



Why is it important to save cloud forests?

When cloud forests are cut down for cattle farming, the result is soil compaction. When the soil is compacted water infiltration is reduced and surface runoff increases. Erosion begins as well in upper watersheds. Flood danger increases for lower watersheds, putting communities at high risk. It is critical to protect cloud forests from becoming cultivated land. These fragile ecosystems are critical to the water cycle in the watershed and beyond. The cloud forest eco-system is the most "skilled" system in terms of its ability to "milk the clouds" for their precious liquid. Other environmental services that are provided by the cloud forest include: the creation of a carbon sink, the essential preservation of biodiversity and unparalleled beauty.

cloud forest mexico adopt acre
i don't think we have these much in Australia as most mountain ranges are low by world comparisons.

How is it possible for tropical cloud forest plants to thrive out-of-doors in Coastal California? If one looks into the origins of familiar local garden plants like Fuchsia or Begonia one will find that many of the species we grow are native to higher elevations in the tropics, in these cases the Andean foothills. Section Vireya Rhododendron and Aeschynanthus (lipstick plants) come from the montane tropics of Southeast Asia, particularly New Guinea. These plants can grow here because of striking similarities between coastal California's climate and that of mountainous areas in the tropics.

Cloud Forests - Conservation Education


a bit tecnical, some seach terms may be useful. "Elfin " forests is nice

Summary Diurnal courses of stomatal conductance, leaf water potential, and the components of tissue water potential were measured in six canopy species in an elfin cloud forest.

Water relations - Conductance - Water potential - Tropical trees - Turgor pressure

SpringerLink - Journal Article

It would be nice to know if the plants had any special structures for harvesting the moisture, as "bio-mimicry" is all the rage in Engineering Technology these days.

[carlton-temple]

There was a few days ago an article on the BBC (internet), or was it science daily? about minute bacteria living on certain plants which were swept up into clouds and provided nuclei about which "rain" could form. It seems that these small beasties with a long Latin name have the capacity to increase the clouds temperature from -40 to -6 so "de freezing" the cloud! Another oddity about this lad is that it draws food from leaves by forming an ice cristal on/in the leafs cells so puncturing the cells to obtain its nutrients. Sorry can't be more helpful as to source.

[carlton-temple]

re above note : The article was on the BBC...15/6/09 entitled "Grey sky research"

[Michaelangelica]

Originally Posted by carlton-temple

re above note : The article was on the BBC...15/6/09 entitled "Grey sky research"

Thank you

Grey sky research

Richard Hollingham
Presenter, Frontiers


On the edge of an east London rooftop stands an increasingly bedraggled man. Arms outstretched, the rain lashes at his face and cascades down his beard onto sopping clothes.

In each hand he holds out a dish containing tiny metal crucibles; he grins as the raindrops ping against the containers.

Just another day at the office for University of East London scientist Bruce Moffett and the perfect weather to investigate the biological properties of rain.

The idea that bacteria in the clouds cause rain might, at first, rank as one of the more bizarre scientific theories.
Raindrop
It takes a quarter of a million of these to make one litre

However, over the past 25 years a small group of scientists has been studying the role bacteria in the clouds might play in our weather and, with papers published in leading scientific journals, the evidence that they're right is beginning to stack up.

"It takes something like a quarter of a million rain drops to make one litre," Moffett shouts to me through the wind.

Fortunately we don't need a litre. "I've got to make sure I have a raindrop in each." And then it's back to the lab to see what's in there.

Ice makers

Before rain can fall - at least in temperate climates - the water in clouds has to freeze.

But - and you may not believe this - sometimes, water doesn't freeze at 0C. Pure water will not freeze until -40C, and clouds rarely get that cold.

So to get water to freeze you need some help. A catalyst such as soot or dust will do the trick but if you want water to freeze at relatively warm temperatures, say around -5C or -6C, bacteria turn out to be the best "ice nucleators".

Cindy Morris, a plant pathologist at the French National Research Institute for Agriculture in Avignon, has identified a particular bacterium, Pseudomonas syringae, which is extremely effective at making water freeze.

In her lab she takes a tube of water, cooled to -6C (and not frozen), and puts in a single drop of bacterial culture. Within about two seconds, the water has turned to ice.
Rainclouds and cropfields
Bacteria found in crops may make the best "ice nucleators"

It's an impressive demonstration. "There's nothing magic about it," laughs Morris. "You can't break the laws of physics."

Pseudomonas syringae is found on the leaves of plants. By forming ice, the bacteria damages cell walls, releasing nutrients that it can then feed on.

But these organisms can easily get carried off by the wind and, once airborne in the clouds, pull off the same trick and persuade water droplets to freeze. At least that's the theory.

BBC NEWS | Science & Environment | Grey sky research

Fond this, from NASA, while trying to find BBC site

Impact of Polluted Skies on Clouds and Climate
Few parts of Earth’s climate system have such chameleon-like effects as the tiny airborne particles known as aerosols.
The effect of aerosols on clouds has seemed especially paradoxical. Some observations have shown cloud cover increasing as aerosols increased, while other observations showed cloud cover decreasing as aerosols increased.
New research from NASA scientists has finally zeroed in on when aerosols increase clouds and when they decrease clouds.
Regardless of location or weather conditions,

• aerosols that absorb sunlight decrease cloud formation,
• while aerosols that don’t absorb much sunlight increase clouds.

Impact of Polluted Skies on Clouds and Climate : Image of the Day
And
this
on Night shinning clouds. I wonder if this is like the phosphorescence in the sea at night? Phosphorescence is said to be due to bacteria.
Photo in the News: Mysterious "Night-Shining Clouds" Sighted

[carlton-temple]

Bacteria - plants - rain; one wonders if there may not be a symbiotic connection between certain host plants and their respective rain making bacteria involved ? See L.Margulis ect.