Plants Use Water Wisely - Mostly

[Brooklyn1]

The following news release was issued by Macquarie University in Australia. It describes a project incorporating data collected in ecosystems around the world, including data from the Arctic tundra acquired by Alistair Rogers, a biologist at the U.S. Department of Energy's Brookhaven National Laboratory as part of DOE's Next-Generation Ecosystem Experiments (NGEE Arctic) project. For more information about Rogers' work, see the accompanying sidebar and links. Media inquiries about the overall study should be directed to Amy MacIntyre at Macquarie University: [phone], [e-mail].

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Macquarie University News Release

Plants Use Water Wisely - Mostly

March 2, 2015

Plants trade water for carbon - every litre of water that they extract from the soil allows them to take up a few more grams of carbon from the atmosphere to use in growth. A new global study, led by Australian researchers and published this week in Nature Climate Change, shows that plants trade their water wisely, with different plant species having different trading strategies depending on how much it costs them to obtain their water.

"Our study looks at how much extra water it would take for a plant to gain one more gram of carbon," says Dr Yan-Shih Lin of Macquarie University, lead author of the study.

"We predicted that individual plants should keep this exchange rate constant, but that the exchange rate should differ depending on what type of plant it is and where it grows."

Comparing data from the different ecosystems showed that most of the researchers' predictions were supported, indicating that plants have adapted their water-use strategies to their environments. The biggest surprise was that evergreen savanna trees were among the most spendthrift plants with water, despite living in hot and arid environments.

The researchers expected that plants with costly water transport structures, such as conifers and trees with dense stemwood, would be more conservative with their water, while grassy plants should be more spendthrift. They also predicted that plants growing in cold or dry environments should be more miserly with their water than plants adapted to hot or wet environments.

"We crowd-sourced the data we needed to test these predictions," says Professor Belinda Medlyn, of the University of Western Sydney.

"We couldn't travel the whole world ourselves, so we contacted other researchers around the globe and together we put together data from all kinds of ecosystems, from Arctic tundra to the Amazon rainforest to the backblocks of Australia."

"This work is important because it provides insights into how plants have adapted to their environments" says Dr Lin.

"Vegetation plays a really major role in the Earth system, by storing carbon, moving water around the landscape and cooling the planet's surface. These results provide us with crucial new information needed to predict these effects, especially under different climate-change scenarios."

Yan-Shih Lin et al. "Optimal stomatal behavior around the world" Nature Climate Change, March 2015, Vol. 5. DOI: 10.1038/NCLIMATE2550

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Brookhaven National Laboratory Sidebar: Serendipitous Data Sharing

Alistair Rogers, a Brookhaven Lab biologist with expertise in plant physiology, has been collecting data in Barrow, Alaska, as part of the U.S. Department of Energy's Next-Generation Ecosystem Experiments NGEE-Arctic project. His work is focused on improving how Arctic plant physiology is represented in Earth system models.

Some of this data has now been incorporated into an international effort to improve how the behavior of plant structures that regulate the flow of carbon dioxide (CO2) and water between leaves and the environment are represented in these models. That project, led by Yan-Shih Lin of Australia's Macquarie University and Belinda Medlyn of the University of Western Sydney and published in Nature Climate Change, aimed to build a new global dataset describing how these pore-like structures, called stomata, function in different plant/climate environments, or biomes.

"Stomatal control of the transfer of CO2 into the leaf is an important process controlling CO2 uptake," said Rogers, "but current Earth system models represent this process in a way that treats most vegetation identically. A global dataset incorporating measurements from multiple biomes around the world will improve our understanding of the role stomata play in the global carbon cycle."

Rogers was one of many scientists from around the world participating in this ambitious project.

"Data on Arctic species are particularly rare, so I was excited to have the opportunity to share data from the NGEE-Arctic project-the only Arctic data in this synthesis," Rogers said.

NGEE-Arctic is led by DOE's Oak Ridge National Laboratory and is supported by the DOE Office of Science (BER).

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by the Research Foundation for the State University of New York on behalf of Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit applied science and technology organization.

Related Links

Scientific Paper: "Optimal stomatal behaviour around the world"

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Brookhaven National Laboratory

[~misfit~]

[snipped]

Interesting, thanks. There's a factor in global temperture variation that's rarely mentioned (and is often used to explain the Gaia hypothesis) - that growing plants cool the area in which they are growing due to transpiration, sequestering and slowly releasing water and absorbing solar radiation (that otherwise just heats the ground up). This was mentioned here;

It's always amazed me how, as a race we seem to be fixated on reducing carbon emissions only as a way of preventing a large swing in global temperatures. Surely another useful method would be to start to replace all of the large swathes of vegetation that the planet has lost in the last few millenia?

England used to be covered almost from coast to coast in forest if we go back six or seven thousand years. Here in New Zealand it's been much more recently that the forests that cloaked the country have been decimated (only six or seven hundred years since polynesians arrived and started deforestation, there are artists here who specialise in making furniture and objet d'art out of 500 year old wood sourced from tree stumps dug out of farm land. The last remains of some of the giants which dominated this land). We all know about the decline of the South American rain forest and the way the South-east Asian rain forests are being cleared to grow oil palms....

Heck, in old testament times large areas of the Middle East was largely 'forested' - or at least covered in scrubland Goats were the biggest agents of 'deforestation' there, grazing on young trees until there wasn't enough re-growth and the old trees died off. Goats raised by humans for food.

Ok, we need to reduce the amount of carbon that we're putting into the atmosphere but that's going to happen as we run out of fossil fuel anyway. More importantly we need to get into massive planting programmes so that the plants will sequester the excess carbon that's already there as quickly as possible and get the planet back into the state of balance that it was at before we started geoscaping.

Anyone who's kept a (semi)closed aquatic system knows that for every gram of animal life you need >50g of plant life to keep things in even a semblance of balance. With the human population growing exponentially (and meat animals being raised to satiate our destructive desire to eat too much flesh) we *really* needed to be increasing plant growth on the planet. Instead we've reduced it to maybe 10% of what it was 10,000 years ago. How much would we all weigh? Then add in our food beasts....

The only significant large masses of vegetaion left on the planet (other than remnants of forests) are the algal masses in the oceans and, while they

*do* sequester carbon they don't contribute to global cooling.

We've just had the hottest, driest January and Febuary on record in NZ (yet again!) with major horticultural irrigation systems around the country having to be shut down due to reservoirs running dry. I wonder why?

I suggest that we need to start growing forests and, when we've got enough start 'ploughing (some of) them under' then re-planting. Put all of that carbon back underground where we got it from. Or (and this just popped into my head) use it for making massive amounts of cheaper (goverment/s subsidised? Economy of scale?) carbon-fibre and use it to make light strong structural materials that will last for a very long time.

Sorry for the OT stream-of-consciousness writing provoked by that one sentence.

[David Hare-Scott]

Don't be sorry for that. This kind of thing is on topic because too few gardeners understand very much about how plants work.

At least you are not rambling about the latest social issue (that may be very noble and worthwhile) but that has absolutely nothing to do with gardens.

I think I have seen some studies that considered how much carbon could be sequestered by re-planting forests but I can't recall where. IIRC the conclusion was that it would help but it would not be sufficient.

[Fran Farmer]

Greece too used to well covered with trees in ancient times and now much of it is like parts of Oz - olives and poor land because the top soil went along with the trees.

We all know the answer to that one. Or should I say, those who haven't been put in our Bozo bins, know the answer to that.

What you had to say was both interesting and relevant IMO. I agree with you about trees. I'm always propagating trees of some sort or other. And even if we just restricted the planting of trees to urban areas because they are so good for shade and lowering the temperatures in the city deserts, then I'd still see the value in what you have to say. But we certainly need far more trees on this planet. We could get rid of at least 50% of the population and we'd still have too many humans.

[songbird]

...

i dunno what you've been reading, but there are plenty of people who are working on reforestation and restoration of habitats.

the problem is that the balance is still tipped too heavily in favor of the exploitation of natural resources. until the poisoners and destroyers are put back into balance the system will continue to degrade.

unfortunately, with most people on the planet living in cities there is little knowledge any more at the cultural level about what topsoils and ecologies are like and what they need.

the Greeks and Romans did quite a number, but it just followed on the agricultural practices of peoples in the middle east or northern Africa. however, by upping the extractive practices a notch and never returning organic materials to the soils they soon stripped the topsoils bare.

when you have renters instead of owners there is little incentive to treat the land well.

the overall culture must change to get land restoration to work over the longer term.

...

until more people start dying from ecosytem failures i don't see much changing on the larger scale.

there are localised small patches where people are working to restore and improve things, but it isn't yet a large enough effort to counter the destroyers and poisoners.

songbird

[Brooklyn1]

Ain't that the truth. Today most people rent/lease most everything and few pay their debts, and everything they touch they destroy... under the presenty system those responsible few are punished for the destruction caused by the renters/leasers. The only way to save this planet is to bring back debter's prison, this needs to change, and most importantly institute sterilization of the non productive because the primary cause of this planet's destruction is over population... CULL! Every productive person who volunteers for sterilization is to be totally supported by society; fed well, housed well, clothed well, treated well medically. Debters recieve minimal nourishment and no medical care whatsoever.

[Fran Farmer]

Well the Greeks were the owners and they screwed their own topsoil and I can't see that modern agriculture is a great deal different. To much of it is like strip mining over a long term.

Yep.

Many people are already dying from ecosytem failures. We well fed rich tossers in the western world just aren't listening and nor do we care so long as we can still get cheap shoddy products from whatever low wage country can be convinced to take on the job.

Nope. Denial and/or ignorance and/or self interest is alive and well and living amongst us.

[songbird]

not nearly as badly during that time period as compared to what came afterwards when they were taken over by the Romans, and the same thing goes for much of the rest of Europe, northern Africa, etc. the Romans turned marginal lands into deserts because they exported so much grain and ruined the croplands to do it.

many of those areas have never had a chance to recover. the remaining people who could survive did so by keeping goats, counting much of their wealth by the number of animals, not by improvements in topsoil or pasture diversity.

not nearly as many as what will be coming.

sadly, tossers is a very apt word for what happens to most of that junk too.

if we could get to a more heavily recycled system i wouldn't mind it as much, but we're still a long ways from what it should be.

i keep hoping for bigger changes. a lot of people want them to happen too, but it isn't a majority yet.

songbird

[Hypatia Nachshon]

Copy that. Seen the estimates for the next century or so? Food riots. Po werful eat, vulnerable don't.

The fastest growing segments of the world population are the poor, the mino rities, those in totalitarian societies. What these have in common are ina dequate, unreliable or NO access to planned parenthood. Behind this factor lurks the millennial denigration of females by males. A very large elemen t in rendering females powerless to control their fertility has, of course, been religious dogma, used to support males' right to dominate females by invoking "divine" authority and by blaming females for their own sexual urg es.

However, most of these factors over the last few centuries in the West have operated, as above suggested, to the detriment of the "wretched of the ear th". Prosperous (largely secular or non-observant) societies have had no problem limiting their families, religious dogma or not.

Do we have time to educate the ignorant masses? And will education enable them to become prosperous enough to demand to share power with their former masters -- "religious" and political -- to raise the masses world-wide to where they can control their fertility?

One can only hope that for the sake of future generations, people in the US will concentrate less on the next electronic toy and more on how to defang Our Corporate Masters and their Fundamentalist lackeys in Congress.

As a card-carrying space freak, I still think exporting our current values to Mars or other Earth-like planets might not be such a good idea. Much ea sier to restore our original"garden of eden" right here on Earth.

Nobody said it better than Benjamin Franklin: "We must all hang together o r we will surely hang separately!"

HB

[~misfit~]

Rather than plenty of people I'd say a relative few who get a lot of media exposure. I commend them for what they're doing but it's a drop in the ocean compared with the amount of forested land the world needs to regain balance. Especially when you consider that the animal bioload (us and our foodbeasts) has increased massively in the last ten thousand years or so as the trees have vanished.

Exactly.

[snipped the rest - I mainly wanted to address the "i dunno what you've been reading" comment].

[~misfit~]

When I injured my back a couple decades ago after just starting my own business I ignored my accountant's advice to declare banckrupcy and instead paid off everything I owed. However I was left a pauper having lost my home, my ability to work and my life savings.

I have no children and am hardly likely to now. My sister has four and I've always said she's done the breeding for this generation of our family. She 'got in' before I did - I was waiting until I'd got my business running well and was financally secure. So much for that plan.