Sunday, May 13, 2012

Why Are Forests Dying?

A startling documentary from the public broadcaster ABC Australia explores dying forests. It is happening around the world, in Europe, Asia, Africa, South America and all down the West Coast of North America. Call it bugs, call it fungus, call it drought and record heat. Call it climate change and plain old pollution.

Whether it's satellite photos, or walking through the dying woods, it's heart-breaking. Why are forests dying around the world?

I'm Alex Smith. I've covered climate change in so many Radio Ecoshock programs. Later in this program we'll talk to a key scientist, Lisa Ainsworth, about misplaced expectations that rising carbon dioxide levels will green the planet and feed billions more people.

But first we are going to ground with a citizen activist from New Jersey. Her trees, and all our trees, are weakened and dying from a much simpler cause: plain old pollution. The air looks cleaner, but all that industrial exhaust is still deadly to plants - and our lungs.

The trees are talking to us, but we just aren't listening.

Gail Zawacki is speaking out on the pollution that is killing trees, shrubs and crops - despite all the government back patting on supposedly cleaner air.

First we have to remember there is good and bad ozone. The saying is "Good in the sky, bad nearby." The ozone in the upper stratosphere protects all living things from harmful ultraviolet light from the sun. That was the worry of the ozone hole.

Lower down near the ground, we have what is called "tropospheric" ozone. That is part of the smog, but ozone itself is invisible. It's a type of oxygen, but it has three oxygen atoms instead of two.

As Gail tells us, there are no factories spewing ozone - that is what makes it so difficult to control. Tropospheric ozone is created in an air-borne reaction with other chemicals called "precursors". The main precursor is nitrogen - and we are the nitrogen civilization. We release it from burning fossil fuels, but laying billions of tons of nitrogen on farm fields as fertilizers, and many other sources.

Another precursor is a group of "volatile organic compounds" also known as VOC's. Our industrial society creates plenty of VOC's, especially from the chemical and refinery industries. Some consumer and household products, including paints, also release VOCs.

It turns out trees can release VOC's as well. That is how Ronald Regan was infamously able to claim that trees cause pollution. However, natural forests existed for millions of years without producing harmful smog or dangerous ozone levels. We do that.

Ozone is a "reactive" substance. It oxidizes everything from plant leaves to granite monuments, all of which begin to deteriorate.

Please listen to the Gail Zawacki interview to learn how ozone impacts trees, shrubs and crops. (It also harms our lungs, especially anybody with breathing problems. That's another whole story.)

The leaves begin to shut down. You can find black stippling, or sometimes they "bronze" - turning color well before the fall. Then the plant cannot perform the photosynthesis it needs. As a result, trees and shrubs are weakened, and less able to prevent diseases (like a fungus) or insect pests from doing damage.

We may see the immediate cause of tree deaths as caused by a fungus or boring beetle, but the tree is weakened by ozone damage. Zawacki, and the Australian documentary, compare the dying tree situation to HIV. The AIDS damaged immune system may die due to pneumonia, but the real driver was HIV.

Agricultural agencies, and forest departments, know all about ozone damage. They have pictures on their web sites. But other government agencies hardly ever talk about it. We have been told air pollution in the West is all cleaned up, but really the ozone plague goes on and on.

Gail has wrapped up all her research on the ozone threat in a really great document titled "Pillage, Plunder & Pollute, LLC (A Global Glut of Invisible Trace Gases is Destroying Life on Earth)" It has lots of illustrations and links. You can download it as a free .pdf - or buy the print version from Amazon. It was a real education for me, and part of the reason we asked her to come on Radio Ecoshock.

Gail writes: "This is really well known to the USDA, and by the international scientific community. In fact the USDA in cooperation with many academics at universities has been engaged in research for years, trying to develop ozone "resistant" or "tolerant" crops.... Ozone is also of concern for farmers, not only because it reduces the yield but also quality of protein, minerals etc. - so it also means ruminants like cows and pigs are getting less nutrition for the amount eaten."

In the Journal Nature, I found a paper saying tropospheric ozone has increased 35% over the last century.

The 2003 paper by Wendy Loya and others says increased ozone levels hurts both forests and crops, even when carbon dioxide is increased, as we expect in the coming decades. They conclude "Our results suggest that, in a world with elevated atmospheric carbon dioxide concentrations, global-scale reductions in plant productivity due to elevated ozone levels will also lower soil carbon formation rates significantly."

You can also keep learning from Gail by visiting her blog "Wit's End".

At the close of our interview, I ask about her continued support of the Occupy movement. Gail tells us the mainstream media totally failed to report the May 1st Occupy march in New York City. It was at least tens of thousands of people, filling major avenues as far as you could see. Newspapers and TV played it down, saying the protest "fizzled". Hardly what those attending experienced.

When I asked Gail about solutions to the ozone problem - we had a pause. We would need to cut down on nitrogen use, and nitrogen-producing crops like soy and peas. Chemical factories would need different processes, and the whole fossil fuel burning society would have to find clean alternatives. It's a huge job. I suppose awareness of the problem is a good start.

Here is another of Gail's sites on dying trees.

I also recommend this article from her blog, with a critique of the Australian TV documentary.

In this Radio Ecoshock program you hear a couple of clips from the ABC Australia television program Catalyst which aired on April 26th 2012. Find the the video and a transcript here.

Our theme music this week is Canadian folk artist Bruce Cockburn, "If A Tree Falls" performed live in Montreal in 2005. We also heard brief clips of "I Talk To The Trees" by Thomas L. Thomas in 1950, and updated by Masha Qrella from her album "Speak Low" Berlin 2007


Whether you accept climate change science or not, nobody disputes the fact that carbon dioxide levels are growing in the atmosphere, as we burn fossil fuels. That changes the way plants grow.

Various experts, including some climate modelers, count on increased plant growth as carbon dioxide rates go up in the atmosphere. Others have promised that is how we will feed a more heavily populated planet. Is it true?

Our guest is Lisa Ainsworth, Assistant Professor of Plant Biology and Adjunct Assistant Professor of Crop Sciences, at the University of Illinois. She is co-author of one of the most cited papers on the effects of increased carbon dioxide on plant growth.

She is working with the FACE method of spraying increased carbon dioxide up around the trees, which are more or less in a wild setting. This is better than the former greenhouse methods, because the open air setting allows for real variables such as rain, sunlight, and wind. The official meaning of FACE is "Free Air Concentration Enrichment"

Early climate models depended on greenhouse measurements of extra plant growth with added carbon dioxide. They projected up to 30% increase in plant growth on earth by 2100 with CO2 at 550 parts per million. With the ever-increasing fossil fuel use, scientists now project we will reach 550 ppm CO2 by 2050 instead.

However, the FACE testing shows extra growth due to increased CO2 is less outside, than in greenhouse settings. The increase might be 15%, and it varies according to the crop. The difference is important, because early climate models assumed extra plant growth would soak up a lot more carbon than will really happen.

It turns out plants have worked out several different ways of handling carbon dioxide intake, as evolution continued. For example, most trees have not yet reached their saturation point. If the CO2 increases, they can use more of it. Dr. Ainsworth describes how this works, for what are called "C4" type plants. They will benefit from more CO2, and so will such crops as rice and wheat.

Contrast that with plants like corn and sorghum. These developed a type of super-concentrator for CO2, before it goes into photosynthesis. They are already getting as much CO2 as they can handle. Adding more to the atmosphere will NOT increase their growth. The same applies to the grasslands of the Savannas - one of the largest biomass types on the planet.

One of the limitations of the FACE method is it has only been studied in Western-type countries like the US, Japan, and New Zealand. There have not been open-setting tests in the tropics, where most of the biomass of the planet is. That leaves a huge hole in our knowledge, and a big question mark about how tropical forests and savanna lands will respond to more CO2. We'd better find out quickly, because it takes at least a decade of testing, and 2050 is not that far away.

Not only do we want to know if the extra CO2 will help us feed the expected new billions of people arriving on the planet. We also want to know how it will affect all the natural plants, from forests to grasslands. Plus, there is a feed-back effect that could help us, or not, if plants can soak up more of that carbon dioxide. Add in the predicted droughts and desertification around the sub-tropics, and the forest die-offs we covered earlier, and we see that extra plant growth may not reduce our carbon dioxide laden atmosphere. They may even add to it, becoming a carbon source rather than a carbon sink.

There is so much we do not know, but we have discovered a closer look at the coming reality through FACE, and through scientists like Lisa Ainsworth.


the FACE experiments (Ainsworth et al)

Also, recommended by Ainsworth in interview: SoyFACE (Soybean Free Air Concentration Enrichment) at University of Illinois

and at the Oakridge Nat'l Lab (database of results)

Find out more about rising CO2 levels and plants in this Nature article. Here is a worrying article: Australia's trees may not survive excess carbon dioxide

And see this Sydney Morning Herald video of the FACE experiments in Australia.


As reported by the BBC, Spring is coming earlier than ever, and plants are blooming sooner, according to new research just published in the journal Nature. British scientific bodies and nature lovers have kept such records going back to 1875. Spring is now at least 5 days earlier, with some plants flowering eight times faster than climate models predicted.

The insects are keeping pace, breeding earlier and more often.

In the Australian documentary "Dying Trees", there is a shot of a forest in Spain that suddenly died. The whole thing. Even though I've seen millions of dying trees with my own eyes, right here in British Columbia, I was shocked. That one photo, and all it means, hurt me deep inside.

I'm Alex Smith, your reporter. As I limp off to lick my green wounds, the forests call out to us. Will anybody hear?

Don't forget our new web site, at

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