Wednesday, February 29, 2012

A cartoon, a song, and a video - in honor of the Greedy One Percent (tm)

Thank GOD for the GOP.  I admit, I was worried that without the endless rattling supply of Sarah Palin's skeletons tumbling out of her musky closet, there would never be a comparable source of amusement in the tsunami of bad and frightening news that plagues the modern world.  I shouldn't have worried.  The right wing is a bottomless pit of fatuous lunacy, obliging satirists of every medium.

Greedy One Percent = GOP, tm NewsCorpse

Monday, February 27, 2012

A Prosaic and Amenable Endochronometer

Part of the motivation to create, separately from this Wit's End blog, an aptly named webpage (Dead Trees...Dying Forests - what else?) was to provide a comprehensive, introductory source for evidence that pollution is killing vegetation all over the world - aimed at those people who don't yet understand that, just because you can't see it, doesn't mean it isn't everywhere (that would be most everybody).  My hope was to be able to do shorter and more frequent posts here without each time feeling obliged to consolidate the tiresome fundamentals in every single submission ad nauseam.  I have been trying to make entries more digestible, less "epic", but...OOPS.  I'm afraid this one will have to constitute a very serious relapse.
Where to begin?  As usual, the volume of new information emerging about ozone, even though most of it is well hidden in plain sight, continues to be crushing...even for a devoted Ozonista.  Earlier this week, I was innocently googling for a relatively obscure paper about lichens, when abruptly the search led to a massive bibliography, which was only accessible behind warnings of viral contamination listing (I'm guesstimating) a staggering 2,000 published studies on ozone.  Here, I've been painstakingly trawling for any little reference no matter how obscure or how poorly I can comprehend it, to add to the Basic Premise links to research, and this amazing resource falls in my lap, totally unexpectedly.
For me, this windfall was on a par with an archeologist opening a new tomb in a pyramid...or more precisely perhaps, finding an inscrutable, indecipherable map, leading to a pirate's shipwreck with bullion and jewels intact.  Finally, I tried erasing part of the url and refreshing.  Back-tracking brought me to the main document - ta da! - the EPA draft meant to be the basis for more stringent air quality standards.  Yes, that attempt that was deemed a failure last fall by Obama before anyone could debate the merit of the justifications laid out in this report.
Once I found the main document, the "Integrated Science Assessment for Ozone and Related Photochemical Oxidants" from March 2011, that quickly led to a meticulous critique from last August by members of the Clean Air Scientific Advisory Committee (CASAC).  Next, to further complicate matters while I was slogging through the material, just two days ago the EPA posted the revised (dated September 2011) document based on those recommendations - shorter and condensed, but still! over 1200 pages.  This loose and baggy monster goes back and forth from agency to authors to reviewers, undergoing editing, corrections, refinements and improvements.  It's a monumental undertaking.
Quite frankly, the evidence of damage from ozone in this exhaustive review of literature - which is intended as an update with mainly published research since 2008 - and also, not including for the most part, very many international sources - is so incriminating, I am rather suspicious the Obama administration squelched the expected tightening of standards because they want to avoid having the revelations in this report - however cautiously worded - become the subject of public attention and discussion.
Anyway eventually after we make various detours in this post - the post I had intended to write! - that thrashing behemoth is where we are ultimatey headed...fair warning.  The pictures are from a walk last week through the nearby arboretum, Willowwood.  I haven't been there all winter, and so even I was shocked to see how much further advanced the lichen colonization of the trees is since last time - that, and the thinning of the evergreens.  I went because it was such a warm, brilliantly sunny day, only later to discover, when I checked the blog archives, that the same flowers I had photographed in March - the crocus, snowdrops and sweetly scented witchhazel - of last year are already out.  Well, that's no surprise, given that we had no winter to speak of.
Not only are the evergreens becoming thinner and thinner (and of course, the busy gardeners remove the dead ones constantly so those, you can't see) the color of needles has turned dull - or hideous shades of a purplish black.  This set of conifers looks yellow because the sun was setting, but they actually are much worse now, in the second photo.
March 5, 2011
February 21, 2012
^^      Steady loss of needles - note bare trunks  ^^
and necrotic coloration
Much more noticeable this year are trees that still retain some leaves from last year, a sign of diminished strength, because the process of abscission requires vigor - leaves don't really "fall" off, they have to be pushed.
Given how dead everything looks now, by comparison the pictures I took there in 2009 look positively lush, even though I had started photographing in earnest having realized, in 2008, that everything was dying.  In hindsight I think I must have been rather clever to notice what was happening, it looked so verdant by today's standard.  Back then, I still believed the most likely explanation was drought from climate change, and only suspected it might be pollution.  That was before I saw that even exotic plants from southern climates that were being watered had the identical symptoms of damage, from exposure to air pollution.  See my answer in response to a question in the comments of a July, 2009, post I optimistically titled "Definitive Proof":
...I have not ruled out that it may be pollution, or acid rain, and there are certainly insects and diseases. Age as a factor, not so much, because healthy trees (depending on species) can live for several hundred years. Plus, young wild saplings and recently planted landscape trees are dying at the same rate as mid-range and very ancient trees, and exhibit the same qualities of drought.
I tend to think the diseases and insects are for the most part secondary effects to the underlying cause, stress from climate change, with the exception perhaps of alien imported pests and disease. The extent of damage is just too widespread - indeed at this point I would say universal - and so sudden - that I cannot think of any other mechanism besides climate change with the possible exception of intolerably elevated levels of ozone, that could produce such uniform symptoms across species and ages.
This house belonged to a landscape architect in the early 1900's, and was subsequently turned into a county park.  No...these boxwoods are not dying because they are old.  Boxwood hedges in mazes can typically date back well over a century and besides, as we shall see, very young boxwood look just as bad.  Starting in 2009:
July 11, 2009
October 2009

March 9, 2010
March 5, 2011
Notice from last March to now, not only has the front hedge died back more, but the two large shrubs on either side of the front door are more yellow, and the top of the pine behind the house, above the roof midway between the two dormer windows, is shrinking.
February, 2012

Above is the stone barn in July 2009, over half covered in English Ivy.  Now, every leaf is gone.  There is nothing left but dead vines.  I doubt they killed it on purpose - what's left at the lower left-hand corner of the barn is still labeled, with both a copper tag and a standing post.

July 11, 2009

Same pine, last week, 2/2012

In the essay "Whatever Happened to Ecology", written by Edward Goldsmith back in 2002 (based on an earlier, prescient treatise in 1985), the author says, "The science of Ecology has been taken over by the cult of scientific reductionism and has become a weapon in the war on the living world being waged by industrial man."

"The more credible epistemologists of the last decades... have generally come to agree that scientific knowledge has no special status – contrary to what logical positivists and many scientists still maintain – that distinguishes it from common or garden knowledge."

"At the same time, it has also become clear that, since scientists do not live in a closed scientific community, but are also members of a society with whose world-view, together with the values it reflects, they have, like everybody else, been imbued, and which the scientific paradigm which they entertain also tends to reflect....Consistency with the reigning social paradigm is thus, in effect, the ultimate criterion of scientific truth."  I've linked to his ideas before - it's essential reading to understand how the fundamental concept of an ecosystem as a functioning "organism" has been undermined in academia to serve the destruction of habitat by multi-national corporations.
This mindset is what lies beneath the marginalization ridicule and ostracization of a number of holistic foresters by lumber industry flunkies in the Forest Service and academia - prominent among them Charles Little, author of "The Dying of the Trees" in 1995.
You can see a more extended excerpt here, where he writes: "Amid the tinkling glasses of tourists in the lounge of the Woodstock Inn, former-Vermont Forest Commissioner Mollie Beattie... spoke candidly and earnestly. 'If you ask me if there's a connection between pollution and the maple dieback,' she began, 'I would say yes. If you want proof, that's another matter. In the chronology of a forest, a decline taking 25 years is a sudden eruption, but human consciousness does not take it in that way. To us the change is so slow as to be unobservable. Nobody knows what the natural level of mortality is. It's not that there's no science. It's that science is asking the wrong questions.'"
The whiteness is lichen - ghost trees.
[Since then, there has been exponentially much, much more science about the increase in mortality above natural levels - but science is still obtusely asking the wrong question!]
The lichen goes part and parcel with splitting, peeling, festering bark.
"Beattie also discussed the fate of other forest trees in New England; how the ozone-sensitive white pine seemed to be disappearing; how beech trees had been dying at the rate of ten percent a year in the Adirondacks of New York State. The largest US fabricator of stairway parts -- the Visador Corporation -- now finds it can no longer count on beech wood for lumber and must substitute tulip poplar, a somewhat weaker hardwood. Beattie fears the butternut might actually become extinct."
"Beginning in the late 1940s, even before most of the freeways were built in the land of the three-car garage, commuters came home from a workday in Los Angeles with red eyes, scratchy throats, chest pains and headaches. Particulate matter collected in their lungs, women's nylons melted on their legs and trees were dying."
"Today, auto-generated ozone, far from being confined to Los Angeles, is devastating trees in the distant Sierra Nevada, too. Ozone from the Central Valley travels up the steep canyons of the western flank of the Sierra on a daily basis."
"In the Sierra Nevada, I visited Trent Proctor, an air resources specialist for the Sierra National Forest. 'In the summer,' Proctor said, when the inversion layer of cold air covering the valley lifts, 'in the southern Sierra we see ozone-injury in trees up to about 7000 feet and in the northern Sierra about 5000.' Others have found ozone-caused tree injury as high as 9000 feet."
"Once the ozone is inside the cellular structure of the tree, it bleaches the chlorophyll from the needles -- just like Clorox, also an oxidant -- so that they lose their ability to photosynthesize and then drop prematurely."
"I remember what West Virginia landowner and self-taught naturalist Joe Aliff told me when we were tramping through the 'falling forest' in the Appalachian hollows. To see what is happening, he said, 'All you got to do is look.' By that he meant something more than having one's eyelids in the open position. And when you look, you see that the trees are dying."
Reading that was one of my first awakenings that pollution is the true culprit underlying all the other stressors (so far...pending imminent even worse, extreme climate change), as was this compilation of articles and studies about the global decline of trees from pollution, which I highly recommend.  I reviewed it by chance again today, it's quite amazing that just about everything we know now...and continue to research and refine and elaborate and to prove over and again...was already known decades ago.
But getting back to the complacent ignorance of scientists who "live by the paradigm", one candidate is Dr. Steve Running, who is featured in a series of articles in the Salt Lake Tribune, about trees dying in the west - I'll embed the video from which that screen shot was taken at the very end.  I wrote to Professor Running, after reading the following in a NYTimes article about dying trees:  "Scientists say winter temperatures used to fall to 40 degrees below zero in the mountains every few years, killing off many beetles. 'It just doesn’t happen anymore,' said a leading climate scientist from the University of Montana, Steven W. Running."  Dr. Running never answered my query as to whether beetles might be secondary opportunists following exposure to ozone.  And I'm so annoyed about that, I don't mind posting this screenshot from his interview, in which he is the picture of complacency.

Running and others of his ilk are so mired in their pre-conceived canon that they cannot - or I should say, don't even try to - explain several anomalies about their theory that beetles are proliferating primarily due to temperature increases.  One is clearly demonstrated in this map, titled "Conifer Mortality, Bark Beetles are Ravaging the West's Forestlands".  In many of the areas where conifers are being attacked by bark beetles, certainly Southern California, it's well accepted that they are predisposed because of ozone injury and they aren't located in areas that ever got cold enough to kill the beetles.  What held them in check was the natural defenses of the trees, an ability they have since lost.
Larger view click the map or here
Beetles have a job to do in the ecosystem, and that is, to break down dying trees and recycle their nutrients into the forest.  The bark beetles are native, not an invasive species, and are just doing their job, as described in a video interview with Dr. Allan Carroll, of the Canadian Forest Service.  He said "Normally the populations of beetles exist at extremely low levels in which they're just sort of background beetles, largely innocuous, functioning with other bark beetle species to kill the damaged and suppressed trees in the's just a natural proponent of the forest and what we call a self-thinning other words, they're picking off the weakened individuals and they leave the healthy ones to survive."
Boxwood turning yellow
In the video, the claim is made that the beetle has taken over because they don't get the winters they used to - 20 to 30 degrees below for 2-3 weeks per year.  But look at the graph below - the beetle kill goes all the way south to Vancouver's border with the US (and for all we know, past that).  What is the typical coldest temperature of Vancouver??

According to everything I've been able to find, it never used to be nearly that cold in Southern BC to begin with, east of Vancouver.  This chart from a study of climate trends in BC shows, on the left, changes in Mean Annual Coldest Month temperatures (in Celsius) from 1961-90.
According to this map of mean annual coldest months increases, it looks like it was already too warm in southernmost BC to keep the beetle in check in 1960, long before the outbreak began.

Clearly, there has been (and worse, will continue to be) an increase in temperature.  But obviously, extreme cold like 20 below was never the controlling factor in southern California and many other areas in the US, which are also being ravaged by bark beetles of one sort or another.
Yellow-cedar trees grow in California to Prince William Sound in Alaska.
Yellow-cedar decline occurs along a 600-mile zone from British Columbia to south-east Alaska;
and on about 1/2 million acres in south-east Alaska.  Source
And don't get me started on the yellow-cedar decline.  It's been all over the news that the reason they are dying is reduced snowpack freezing the roots, from climate change.  It could be.  But ozonists always question.  The range where they predominate starts at the north edge of the dying lodge-pole pine and spruce map above - the white area at the top.  The lead author and investigator who has made a career studying the yellow-cedar decline, Paul Hennon, once wrote this:

"Yellow-cedar decline appears to be an outstanding example of a naturally induced forest decline. Extensive mortality before 1900 on numerous remote, undisturbed sites without nearby sources  of anthropogenic pollutants argues against atmospheric pollution as the cause of decline."
A young tree beset by lethal cankers
But when I asked him if perhaps he might revisit the pollution aspect, and pointed out to him that trees of all species everywhere around the world are also in decline, including across Canada's boreal forest - even when factoring out any influence from insects, disease and fungus - he answered me rather cryptically:

Early onset in about 1900, pristine locations, and clean air measurements in this part of alaska.

Let's consider the first assertion - early onset in about 1900.  I'm not very good with graphs so maybe I'm missing some mathematical interpretation, but it sure looks to me like whatever early onset there was in 1900 appears negligible compared to the steep incline that doesn't begin until 1930, and then accelerates rapidly afterwards, in tandem with the explosion of industrialization and emissions of pollutants:
He also mentions clean air measurements but as always for me, this sort of begs the question - clean air compared to what?  Compared to pre-1900 pristine, or compared to contemporary more congested lower latitudes?  Are yellow cedar thriving in warmer climes where they aren't subjected to exposed, freezing roots...or are they dying there too?  Until the Forest Service conducted an aerial survey south into British Columbia in 2004, they were unaware that in fact the dieback extends into BC.  They noted:  "Numerous large areas of concentrated yellow-cedar mortality were found, extending the known distribution of the decline problem 150 km south of the Alaska–British Columbia border.." and that, as in south-east Alaska, the dead stands were typically in proximity to bogs:

Are other trees dying near bogs, besides yellow cedar?
"We landed on a boggy hillside north of Cypress Lake at about 300 m elevation.  Here, we found new
and old snags, nearly all yellow-cedar.  Most of the redcedar was live, although some had spike tops.
All trees were relatively small at this site." Source.
Did they test the soils?  He cites as a reason to discount anthropogenic sources:  "...aluminum toxicity (Lawrence et al., 1995; Lawrence et al., 1997) or high acidity (Klinger, 1990) could potentially reach levels that would damage roots as soils become saturated, but no relationship of either factor with dead trees was found."  Note who he cites:  Klinger.
Acid precipitation in south-east Alaska (photo by Lee Klinger)
So, I looked for that reference because if that's the only soil testing done, one study, it hardly seems adequate to rule it out.  I couldn't find it - but, I did come across a blog hosted by none other than that same Lee Klinger, now living in Big Sur, who has posted the photo, above, with the following fun quote:

“Having been in my progress so often misled by taking for granted the results of others, I have determined to write as little as possible but what I can attest by my own experience.” – John Dalton, Independent Scientist (1766-1844)

Klinger writes:  "Anyone who thinks acid rain does not occur in pristine, unpolluted environments had better think again. Or better yet, go get some litmus paper and check it out for yourself."
"Scientists studying Sudden Oak Death have dismissed acid rain as a relevant factor in oak mortality, pointing out that areas of severe decline are near the coast, upwind of the major sources of pollution, thus rainfall could not be acidic. Here along the coast of California storms blow in from the ocean where there are few sources of manmade pollutants. Rainfall pH, then, is not expected to be any more acidic than about 5.6, which is the theoretical pH of unpolluted rainwater in equilibrium with atmospheric CO2."

"However, I have learned from past research that rainfall in pristine environments can sometimes be quite acidic[1]. So for the past three years I have been recording rainfall at my home in Big Sur using a Stratus RG202 rain gauge."

[1] L.F. Klinger and D.J. Erickson III. 1997. Geophysiological coupling of marine and terrestrial ecosystems. Journal of Geophysical Research-Atmospheres 102: 25,359-25,370.
This article describes Klinger's work in Alaska:

"Klinger's theory about tree death came together in 1985, when he was researching a massive decline of old-growth trees on Kruzof Island in southeastern Alaska. One day he noticed that wherever trees were dying, thick growths of mosses covered the ground and the trunks. On a hunch, he began digging and probing with his shovel, discovering that there were no roots in the soil under the matted moss. His data later confirmed that mosses are highly acidic and that runoff from them causes soil acidification. Industrial pollution such as acid rain, acid fog and other factors also contribute to soil acidity, all of which harm tree roots. And that, according to Klinger, is what's really killing most of the trees that are dying in California and other parts of the world."
I hasten to add, I forgot momentarily that I had a brief exchange with Klinger on his blog in October of 2009, when he insisted that pollution from Asia couldn't possibly be the source of acid deposition on the US west coast.  However, given the overwhelming evidence that has been accumulating since then, I think (I know) he is wrong - but I won't bother to see if he would care to revisit the prospect.  I think Klinger is one of those lost souls who can't help but see the destruction (it is, after all, rather obvious), but can't quite face up to the soul-crushing implications.  So, he conveniently invents more palatable explanations to soothe his anxiety such as his theory that the acidity is coming from naturally occurring organisms in the ocean...and there are solutions, like, sudden oak death can be alleviated by adding nutrients to the soils and painting their trunks.  Many scientists are delusional the same way.  It keeps them from going mad with grief.
Before you think I'm reading too much into his ability to adjust the facts, check out his description of a session of the Geological Society of London which he attended in May last year, wherein he dismisses Lovelock, who addressed the meeting, as an "alarmist" with an "apocalyptic view of climate change", and then expresses his own opinion:

"Personally, while I am seeing significant changes occurring in the earth’s forest ecosystems, I do not see convincing evidence that the major temperature-regulating feedbacks of the planet are severely disrupted. While human signatures can be seen in climate change of many regions, I do not agree that the increase in global surface temperatures in recent decades is due mainly to anthropogenic greenhouse gas emissions."

'Nuf said?

Just for the record I want to cite some evidence, first this one, "A review of surface ozone background levels and trends" out of many, many studies that indicate the massive volume of pollution that crosses the Pacific and impacts the west coast of North America.
P. 3434
"Comparisons of ozone background levels with those measured in the late 19th–early 20th centuries indicates that current ozone levels have risen by approximately two times . The fact that this rise has occurred in parallel with industrial development indicates that present day background ozone includes a substantial anthropogenic component."
Levels have been going up, since the late 1800's - and the fact that places as remote as Denali National Park and Saskatchewan obtain annual maxima in 2004 of 68, and Saturna Island BC of 82, doesn't persuade me that trees in Alaska and Canada haven't been affected by acid rain, fog, dry deposition and/or ozone for quite some time.  I have to jump ahead in terms of references and grab one more telling piece of evidence listed in the EPA review - one entry in a larger chart, which details reductions in growth due to ozone.  This particular model projects that between 1901 and 2100 , gross primary production will decrease globally by 14-23%.  Hm.  Globally...since 1901.  Why would they make a global model starting in 1901 if the effect didn't begin until much later, or was confined to one geographical area?

Here's a more colorful graph, indicating that although south-east Alaska and British Columbia don't have the extremely health-threatening high levels of populated, industrialized parts in the world, they certainly have a measurable amount that is almost certainly not being generated locally, and thus, there's no reason they haven't been receiving precursors from elsewhere for many, many years.  Remember, vegetation is more sensitive to the toxicity of ozone than people.
Annual Average Surface Ozone in 2000 - source
There's nothing new about the notion that pollution travels.  The National Academy of Science said in a statement, "Any air pollutant with an atmospheric lifetime of at least three to four days may be transported across most of a continent, a week or two may get it across an ocean, a month or two can send it around the hemisphere and a year or two may deliver it anywhere on Earth,"

"The academy's new report, prepared by the National Research Council, says the problem involves not only trans-Pacific pollution but also trans-Atlantic pollution, with emissions from the United States reaching Europe. The study zeroed in on ozone, particulate matter, mercury and persistent organic pollutants, which have been tracked by ground-based monitors, airborne monitors and satellite-borne sensors."
Take a look at one path detected by the Mt. Bachelor Observatory in Oregon, where long-range transport of pollution is traced, and they can measure a "...range of acyl peroxy nitrates, including PAN, PPN, PiBN/PnBN, MPAN and APAN. This particular class of compounds are known to act as chemical vehicles in the long-range transport of NOx across the Pacific and can also provide information on pollution sources (e.g. biomass burning, fossil fuel combustion, etc)."

As if the links (cited above) in the Times and of the Canadian boreal countless reports relating localized tree loss just about everywhere aren't enough, a new study measured US urban areas and found they are losing massive amounts of trees.  Using a software tool developed by the Forest Service called i-tree, researchers - or anyone who's interested - can now analyze tree cover.  In this instance, the researchers found that "...tree cover is decreasing at a rate of about 0.27 percent of land area per year in U.S. cities. This is equivalent to about 0.9 percent of existing urban tree cover being lost annually."  Does that mean in a little over ten years they will all be gone?

The original paper I wanted to pursue as mentioned at the very beginning is the final results from an undated USFS request, to fund a study examining the extent nitric acid enhances absorption of ozone in lichens.  I since learned this study was in fact completed, but I haven't got a link to it yet.  Copied below is the correspondence and relevant passages anyway, just because I'm always wondering - even though it's been established that trees have been dying from pollution for many decades - why is is so ubiquitous now, and impacting every annual leaf as well?  Perhaps the interaction of nitric acid and ozone might provide a clue.  Here's my letter from last week to Dr. Padgett, who is on leave at the moment.
Dear Dr. Padgett,

I am writing in reference to a funding request you wrote, for a 3-year project to be the basis of a Ph.D. dissertation for Jen Riddell at Arizona State University under the guidance of Dr. Tom Nash.

I wondered if the project is underway, and if so what year it is in - or if it is completed and published.

In your request, you stated:  "Recent studies of vascular plant leaves have demonstrated that HNO3 causes cuticular lesions, which, if also occurring in lichens, may allow greater penetration of O3."

Can you provide me with links to those recent studies?

You also said, "..although some data suggest that HNO3 may be even more deleterious than O3 under some conditions."

Can you send me links to that data?

Thank you very much for your help.  I appreciate any information you can supply.

Gail Zawacki

Knuckles from Bald Cypress roots
 Following are excerpts from the funding request:

"PROJECT LEADER:  Dr. Pamela Padgett, PSW, Atmospheric Deposition Unit, 951/680-1584" 

"Justification:  Monitoring forest health requires that we not only assess the current status of 
the trees, but gauge the health of ecological processes and functions.  The presence, absence and 
community composition of lichens are currently used by FHM as an indicator of air pollution 
impacts in forests.  In the west where sulfur air pollutants are generally low, ozone (O3) has been 
considered the primary deleterious pollutant. Therefore changes in lichen populations have been 
generally attributed to O3, particularly in the semi-arid forests.  However, this conclusion is not 
universally accepted."

"Advances in pollution monitoring have shown that O3 and nitric acid (HNO3) are co-contaminants. Recent research results have demonstrated that dry deposition of HNO3 to vascular plants directly attacks the cuticle resulting in surface lesions.  The effects of HNO3 on lichen biology are largely unknown. Nitrogen (N) deposition in general is thought to affect the biological activities of all photosynthesizing organisms, but the acidity and oxidation behavior of HNO3 may exacerbate damage due to O3."

Background: Our overarching question is whether gaseous HNO3 deposition predisposes 
lichens to be sensitive to O3 or whether either HNO3 or O3 alone is sufficiently toxic to cause the 
well-documented decline in epiphytic lichens in the western US. In the early 1980's oxidants, with 
an emphasis on O3, were widely regarded as the probable cause of both lichen and ponderosa 
pine decline in southern California.  Subsequently, very high N-deposition was documented in semiarid environments across western US. In forests adjacent to urban centers the oxide forms of N 
gases predominate (HNO3, HNO2, NO, NO2, and PAN) as automobiles are the primary source."

"Both O3 and HNO3 are secondary pollutants created by same photochemical processes from 
the same precursors, NO/NO2 and volatile organic carbon. Although O3 and HNO3 have natural as 
well as anthropogenic sources, human activity has doubled the amount of N entering the global N cycle."
"Ambient concentrations of O3 have increased globally from estimated background levels of 15 ppb, to more than 30 ppb. Highly polluted areas may have concentrations as high as 120 ppb."

"The toxicity of O3 to photosynthesizing organisms is well known; less is known about the toxicity of HNO3, although some data suggest that HNO3 may be even more deleterious than O3 under some conditions. There are virtually no data on the interaction between O3 and HNO3."

And they go on to describe both monitoring and fumigation experiments they want to use to investigate the questions.

Following is an excerpt from one of their collaborations, which will explain a frequently asked question - a paper titled 

"The effect of HNO3 gas on the lichen Ramalina menziesii"

"Just as canaries provide warnings of toxic gases to coal miners, so can the investigation of lichen communities provide information on potential deterioration of ecosystems stressed by air pollutants."
"Lichen species are well known to be differentially sensitive to air pollutants. The most sensitive species may become locally extirpated in urban areas or near industrial facilities, while a few very tolerant species will survive and even flourish. Except for SO2, the mechanisms underlying this differential sensitivity are poorly understood."

Yeah, I think that "tolerant species" must be the one that began plastering trees everywhere I have been, from Massachusetts to California, in just the past three years.

Without further ado, following are excerpts from the first draft of the March 2011 EPA Integrated Science Assessment for Ozone and Related Photochemical Oxidants.  The EPA webpage where each chapter are separate pdf's can be found clicking here.

By far, the bulk of the report is concerned with the many diseases and impairments on human health, and there is also cutting-edge reports on the potential interactions of ground-level ozone with UV radiation from the stratospheric ozone hole, plus a section devoted to the greenhouse-trapping and potential climate changing properties of ozone - which I won't get into, at least much, because the effects on trees are quite enough, thank you.  I'll want to start off, for any slackers that don't intend to read all the way down, with a quote from Professor Ed Avol, member of the Clean Air Science Advisory Committee (CASAC), who summed up my feelings exactly in the review letter:
"The breadth, weight, and size of the first external draft ISA Odocument is testimony to the wealth of information available regarding ambient ozone, its atmospheric formation, and the potential for human and material exposure and detrimental effects."

Yes, truer words were never said.  First of all, there IS a *wealth* of information.  We don't really need to know more in order to know we need to do something.  You don't even have to read or comprehend the evidence in this report, which keep in mind is but a peak built upon a broad foundation of previous understanding, to realize that the sheer bulk of this mountain means ozone has detrimental effects poses an EXISTENTIAL THREAT TO HUMANKIND, ANIMALS AND PLANTLIFE.

Sorry.  I'm shouting now.
Chapter two is a muddled up introduction/summary which has since been extensively revised, but the essence of the points bolded in the original are consistent, and clear enough:

starting on p. 2-53:
  • Evidence is sufficient to conclude that there is a causal relationship between O3  exposure and reduced growth of woody and herbaceous vegetation.
  • Evidence is sufficient to conclude that there is a causal relationship between O3 exposure and changes in reproduction of vegetation.
  • Evidence is sufficient to conclude that there is a causal relationship between ambient O3 exposure and the occurrence of O3-induced visible foliar injury on sensitive vegetation across the U.S.
  • Evidence is sufficient to conclude that there is a causal relationship between O3 exposure  and the alteration of leaf gas exchange in vegetation.
  • Evidence is sufficient to conclude that there is a causal relationship between O3 exposure and reduced yield and quality of agricultural crops.
Chapter 9 (in this first draft, not the revised draft) is devoted to the impacts on vegetation.

9-40  "Antioxidant enzymes appear to increase in quantity in O3-treated plants as a defense mechanism against oxidative stress. However, it appears that plants cannot maintain these elevated levels of antioxidant enzymes for an extended period of time, likely due to the high metabolic costs involved. Therefore, plants exposed to chronic O3 conditions may show more symptoms of exposure as defensive mechanisms are down-regulated over time."

There was a hedge that ran from the stone column in the foreground towards the left, a living wall for the bedded garden.
It's been removed.
They are trying to raise replacements in a protected enclosure, but they are turning yellow and dying anyway.
The CASAC letter from August, which critiques the first draft, begins with general group recommendations, followed by remarks from individuals on particular chapters assigned to them.  I think a few of their remarks give a great feel for the way a consensus document is gone over meticulously.

p 15  "It is clear that stomata provide the principal pathway for ozone to enter and impact plants and to influence water dynamics at plant and potentially ecosystem scales. There are better references for this than cited in the text. The stomatal and gas exchange discussions could be consolidated with the discussion of gas exchange, water use efficiency, stomatal control and impacts on water cycling and watershed-scale effects."
Dying cedars on left; dying cryptomeria on right
"Interactive effects of ozone and climate on tree growth and water use in a southern Appalachian
forest in the USA.  Urbanization effects on tree growth in the vicinity of New York City studies
support arguments about loss of stomatal control however, these observations contrast directly with
more frequently observed stomatal closure caused by ozone. Further discussion of these
discrepancies is required."

p 16..."The coverage of effects on insect and mammal herbivores due to changes in vegetation is rather brief. There is inadequate consideration of the interaction between N deposition and ozone response. There is no consideration in the ISA of the responses of nonvascular plants (e.g., mosses), lichens or lower vascular plants to ozone. Mosses may be of particular significance globally."
Mr. George Allen p. 2:, p 3-31. Woodsmoke in the eastern US and Canada has significant elemental mercury concentrations, which is a potent interference for UV ozone analyzers. Assessment of ozone due to wildfires needs to take this into account.

p. 3  He recommends looking at a “Canadian Smog Science Assessment (2011). Source:  Environment Canada and Health Canada.” which was supposed to be available to the public at the end of 2011, but I can't find it.  He advised including a portion, writing this:

"There are two chapters that are relevant to the PRB (policy relevant background) discussion:
CHAPTER 3:  Ambient Measurements and observations 
CHAPTER 7:  Air Quality at the Regional and Local Scale: The What, Where, Why and How of 
Concentration Variations"

which are followed by these charts which scared the hell out of me.  Can they be showing that Mt. Washington in New Hampshire gets ozone readings over 250 ppb????  Needless to say I have already written Environment Canada to find out.  Maybe this is why Canada is dismantling its monitoring program...remember?

p. 4 & 5

 p. 5

Dr. Ed Avol p. 8

"(POPULATION PROXIMITY TO OZONE MONITORS & SPATIOTEMPORAL VARIABILITY): There is often a systematic difference in the nature of urban vs rural ozone exposures, due to local NO titration of ozone in urban areas. Ozone tends to be “peakier” in urban areas, and more broad and drawn out, in terms of sustained ambient levels, in more rural areas. This has exposure and dose implications for urban and rural populations. These issues are not captured in the current document, and are not likely to be, if the focus is only on the urban exposure."

"(INTRA COMMUNITY VARIABILITY OF OZONE CONCENTRATIONS): The research and regulatory communities have generally considered ozone to be a regional pollutant, with minimal local variability, but our group’s studies (and many others) have repeatedly encountered the diminution of ozone levels caused by NO titration near busy roads and fresh combustion sources... could a finer spatially-resolved sampling approach identify biologically meaningful differences in ambient ozone levels, or is it purely an academic or engineering exercise in measurement performance?"
The northern side of the barn still has ivy - it is a different variety.
But the pine is almost dead.
Dr. Joseph Brain p. 20

"1. I draw attention to section, Adaptation. One of the hallmarks of oxidant injury, especially ozone, is the phenomenon of adaptation. There are levels of ozone, or hyperoxia, which produce serious injury or even death in naïve animals. However, in animals chronically exposed to lower levels of ozone or oxygen, there is morphologic and biochemical adaptation. Subsequent exposures to ozone produce a far lower response. This is important in understanding ozone toxicology in humans as well. It also relates importantly to different patterns of ozone exposure. Citizens, who rarely see significant ozone levels and then suddenly have a two to three day episode of high ozone, may be much more affected than those who enjoy steady state ozone exposures all the time."
Enjoy steady state exposures - all the time??  Did he really say that?  Anyway, I can confidently say this is similar to chronic smokers.  They can smoke a pack a day and feel okay, or at least, not be especially aware they feel lousy.  Someone who never smokes and out of the blue puffs away on just a few cigarettes will typically become dizzy, nauseous, and develop a terrible headache.  I mention this because I have seen this same falsely optimistic notion of "adaptability" applied to the response of trees exposed to chronic low levels of ozone - and I wonder if it isn't analogous.
Before we get to the next critique by Dr. Grantz, I can't help but invoke Isaac Asimov's mockery of scientific turgidity, as described in this article, "The fake chemical compound Isaac Asimov Invented to Punk Science writers".  Dr. Grantz' admonishment to remove the "unwarranted conclusion" that ozone is "sensed" by "specific apoplastic receptor proteins" is too pertinent to Asimov's thiotimoline "knowing" it would be dissolved in advance!  Perhaps should Dr. Grantz employ a prosaic and amenable endochronometer as Asimov proposed, he will be able to measure the exact moment when the ozone is sensed by the apoplastic receptor proteins?

I guess you'll just have to read it - RPauli sent me the link, knowing no doubt it would provoke a delicious schadenfreude after so many failed attempts to penetrate the curtain that shields pure, specialized, reticent scholarship from the gritty ecological synthesis demanded by Gaia.

Dr. David Grantz p. 55

Signalling pathways and antioxidants
The ISA appropriately concludes (2-50/9) that ozone is perceived in many ways by plants and cells. Ozone and its reaction products interact with ROS metabolism at several potential places. However, the further conclusion (2-50/5-6; 9-24/9) that ozone is “sensed” by specific “apoplastic receptor proteins” which “still remain(s) elusive” is unwarranted at this time. While the initial site of attack by ozone remains unknown, it appears certain to be in the apoplast, which can be stated with greater certainty (9– 37/6). It appears that there is no “sensor” in any conventional sense."
"The concept of Foyer and Noctor (2005) that oxidative stress is a misnomer and that ozone is just part of the normal oxidative metabolism of plants, is quantitatively false. Plants in high ozone environments do not perform well, indicating that this is outside the normal range of signaling metabolism. The concept was a metaphor for understanding (much as suggested by Sandermann earlier) that ozone plays into existing signaling pathways that evolved as biotic defense mechanisms. The oxidative burst is widely recognized to be component of plant defense against pathogens, calling for greater certainty than “thought to be” (9-38/1-8). Consequences of the signaling pathways seem to lead to the most damage, rather than the raw oxidative potential of ozone. The ISA appropriately reverts to a paradigm associated with oxidative stress and interaction with these pathways at 9-29/27-31. The concept of an ozone sensor is premature and potentially wrong."
This grotesque streaking has become a feature of the landscape since 2009
"While it is clear that Ca++ and MAPKs and many other components are involved in ozone responses (9- 30/3-16), it is not clear that the entire signaling framework must be described in this chapter. It may be sufficient to note how ozone enters these existing pathways and the havoc that these pre-programmed responses can cause, quite apart from the oxidizing potential of ozone, itself. This establishes plausibility, without getting tangled up in interacting pathways that remain very poorly characterized."

"The coverage of effects on mammals due to changes in vegetation is rather brief. There may be digestibility studies, if not actual feeding studies, related to dairy or beef production. There are ongoing feeding studies on rabbits, but these are not yet published. Similarly, the coverage of effects on insect herbivory is rather brief. An older paper of relevance here (9-87/12-23), is Summers et al., 1994, J. Agric. Entomol. 11: 181-187, showing increased aphid growth at elevated ozone."

Dr. Daniel Jacob p. 61

"10-13, section 10.2.6: I think that the concept of emission-based RF should receive more play because it is so relevant to ozone. It makes the point in particular that only methane controls provide climate benefit. I suggest including (or at least commenting on) Figure 2.22 of IPCC AR4, which shows that present-day methane emissions are more important than CO2 emissions in driving climate change over a 20-year time horizon, in part because of methane as a precursor of ozone."

"3-17, lines 23-30: I’m surprised that not more attention is paid to near-roadway exposure. The report states that ozone would be lower because of titration by NO to NO2, which an uneducated reader might assume would reduce exposure, but in fact ppb for ppb NO2 is no better than ozone."
Prof. Howard Neufeld p. 72

"With respect to welfare effects, I also have a problem with Figure 2.3. I believe the figures are too simplified. The leaf panel is simply too cluttered, and all the arrows make it confusing to figure out what is going on. Some pathways are covered over by the water vapor arrow. There is no mention of reactive oxygen species inside the leaf, nor any distinction between apoplastic and symplastic reactions, even though the text extensively discusses these things. Also, C4 plants, which constitute a significant fraction of our crop plants, do not have this leaf anatomy, and that difference could have significant influences on why most C4 plants appear less sensitive to ozone than C3 plants (if that indeed is true). The ecosystem panel uses the term “water production” but in the key to the side uses the phrase “water cycling”. Cycling is the more proper term. Ecosystems don’t “produce” water; rather, they use and cycle it. A better indication of trophic cascades could be included. As of now, the insects and animals are just standing off to the side as if separate from everything else. In conclusion, I think this figure could be redrawn to higher standards."

p. 73  "There is a new paper, just accepted to Environmental Monitoring and Management (Smith, G., 2011, in press), which summarizes 16 years of FIA monitoring of ozone bioindicators. As Smith states, extreme soil moisture deficits decrease foliar injury on bioindicators, but in some dry years, soil moisture appears to have less effect on controlling injury levels. Soil moisture appears to protect plants against foliar injury no matter what the level of ozone exposure. Finally, when soil moisture balance is positive, high ozone generally causes more injury. Most importantly, the best correlations with injury were with the N100 (number of peak hours at or above 100 ppb) and not with a cumulative index, showing again that peak ozone is critically important in determining plant response."

"Finally, in the section on tropospheric ozone and UV-B (2.8.2), I did not see any mention made of UV- B-induced catalysis of elemental mercury in lakes and re-volatilization into the atmosphere. In areas subject to acid deposition, where DOC is reduced, and the lakes are made ultra-clear, light penetrates further down the water column. If UV-B light is present, it can convert methyl Hg photolytically into a volatile form of elemental Hg that then escapes into the atmosphere. If ozone alters UV-B radiation, then it could inadvertently affect Hg volatilization and transport within and among ecosystems."

"Regarding the action of ascorbate, pictured in Figure 9.4, there is no mention of the mini-review on the chemistry of ozone-ascorbate interactions by Heinrich Sandermann, which appeared in Biochemical and Biophysical Research Communication 366:271-274 (2008). In this review, Sandermann points out that reaction of apoplastic ascorbate (or ascorbate in the respiratory lining of the lungs and airways) results in the production of a zwitterion that decomposes into peroxy-L-threonic acid and oxalic acid when it reacts with ozone. If it reacts with one of the ROS produced upon ozone exposure (singlet oxygen) it produces peroxy-ketone. Singlet oxygen can be produced when ascorbate reacts with ozone. Peroxy ketones can react with water to yield hydrogen peroxide. These secondary toxicants may affect human/animal and plant responses to ozone in ways not yet fully appreciated."
"Section documents the reported interactions between ozone and N deposition. There is a lack of investigations on the interaction between N deposition and ozone responses, which highlights a major research deficiency in our understanding of how ozone responses by plants can be modified by other forms of pollution."
[Howie is on to something here!]
"There are no reports in the ISA of the responses of nonvascular plants (e.g., mosses), lichens or lower vascular plants and their responses to ozone. A quick Web of Science search of papers published since 2006 brought up five papers on lichens and ozone and one for mosses, but none for ferns. Inclusion of a statement that our knowledge of the impacts of ozone on these types of plants has not been a research priority in recent years, and a retrospective summary of past conclusions for these types of organisms might be helpful here. Mosses cover a vast amount of the earth’s surface, and if they are negatively impacted by ozone, this could have an effect on the C balance, and hence global climate."

"Gregg’s data in Section is eye-opening to say the least. If this represents what is happening in the field, then certain genotypes of trees have already, or will soon be, eliminated by ozone from the landscape (maybe this has already happened in some poplar clones and in white pine – see Berrang and Karnosky’s early work on this). That means a decrease in genetic diversity, which can happen without any noticeable change in appearance of the forest or other plant community, since resistance genotypes would appear visually similar to the sensitive ones that are selected against."

"One final comment on something in Chapter 3, page 3-7, line 15. Here, it is stated that coniferous forests are the largest source of VOCs nationwide. In the southeastern states, vast swaths of land have been converted from hardwood forests to production pine plantations. I wonder if anyone has calculated whether this has caused an increase in the VOC emissions in this part of the country compared to what was present when it was mostly hardwood forests?"

Prof. Kathleen Weathers p.  92:

"Overall, I was struck by the fact that there remains a paucity of data and research about the impact of ozone in real field situations and/or that is useful to standard setting. The recent biomonitoring results and programs notwithstanding; much important monitoring and research is yet to be done."
One of the most fascinating unexplained symptoms - corroding bark.
Every now and then, part is still close to the way it should look, and it's so obvious
that it is damaged.  Is it from the inside or is it bathed in acidity?

Dr. Peter Woodbury, p. 93:

"9-83. A more critical discussion of effects of ozone on forests, including the sacred fir forests in Mexico and forests in the Carpathian Mountains is warranted. The text briefly mentions that there are potentially confounding variables such as drought, but further discussion of the strength or weakness of the evidence for ozone effects is warranted."

As mentioned earlier, the new draft incorporating the CASAC recommendations excerpted above is now available online here.  Some sections follow...and just be glad I didn't include anything from Chapter 3, atmospheric chemistry.  Well, except for this, remember how yellow-cedar can't have been dying because the air is pristine?  Here's what the EPA concludes:

Chapter 3.4.1:  "Because the mean tropospheric lifetime of O3 is 30-35 days, O3 can be transported from continent to continent and around the globe in the Northern Hemisphere and O3 produced by U.S. emissions can be recirculated around northern mid-latitudes back to the U.S. High elevation sites are most susceptible to the intercontinental transport of pollution especially during spring."

There is the usual squabble over how to define the all important policy relevant background level (PRB) because that determines in large part the extent to which legislators feel obligated to approve regulation of precursor emissions.  

"In...previous reviews, PRB concentrations were defined by EPA as those concentrations that would occur in the U.S. in the absence of anthropogenic emissions in continental North America (CNA), defined here as the U.S., Canada, and Mexico. For this document, we have focused on the sum of those background concentrations from natural sources everywhere in the world and from anthropogenic sources outside CNA.  North American background concentrations so defined facilitate separation of pollution that can be controlled directly by U.S. regulations or through international agreements with neighboring countries from that which would require more comprehensive international agreements, such as are being discussed as part of the United Nations sponsored Convention on Long Range Transboundary Air Pollution Task Force on Hemispheric Air Pollution."

Fig 3-24  Highest monitor (by county) 3-year average (2007-2009)
of the 8-h daily max ozone concentration
based on the warm-season data set
The highest year-round average concentration of 61 ppb over this period comes from Site #060719002 located at an elevation of 1,244 m in Joshua Tree 21 National Monument, San Bernardino County, CA.

p. 3-37   "...estimates of background concentrations cannot be obtained directly by examining measurements of O3 obtained at relatively remote monitoring sites in the U.S. because of the long-range transport from anthropogenic source regions within North America."

Okay that's all from Chapter 3, the report actually begins:

"New material has been included in this draft, but many of the overall conclusions remain generally the same as the last NAAQS review which was completed in 2008. For example, in relation to short-term exposures, new evidence for O3-induced health effects strengthens the body of evidence for associations with respiratory morbidity and mortality. Also, the current ambient O3 concentrations in many areas of the US are sufficient to impair growth of numerous plant species. Within an ecosystem, O3 can alter timber production, water availability in watersheds and carbon sequestration; and, it can affect ecosystem biodiversity. In addition, as was concluded in the last NAAQS review, O3 can affect the climate by acting as a climate-forcing greenhouse gas. In contrast to the last review, there is now evidence suggesting that respiratory morbidity and mortality are associated with O3 long-term exposure."

fig. 1.1
Schematic Overview of photochemical processes
influencing stratospheric and tropospheric ozone
1.3  "Ozone in rural areas is produced from emissions of O3 precursors emitted directly within the rural areas and from emissions in urban areas that are processed during transport. Because O3 is produced downwind of urban source areas and O3 tends to persist longer in rural than in urban areas as a result of lower chemical scavenging, the result is substantial cumulative exposures for humans and vegetation in rural areas, that are often higher than cumulative exposures in urban areas."

"On a smaller scale, O3 can be influenced by local meteorological conditions, circulation patterns, emissions, and topographic barriers, resulting in heterogeneous concentrations across an individual urban area. On a larger scale, O3 persists in the atmosphere long enough that it can be transported from continent to continent and around the globe. The degree of influence from intercontinental transport varies greatly by location and time."
1.7  "Ozone effects at small spatial scales, such as the leaf of an individual plant, can result in effects at a continuum of larger spatial scales. These effects include altered rates of leaf gas exchange, growth and reproduction at the individual plant level and can result in changes in ecosystems, such as productivity, C storage, water cycling, nutrient cycling, and community composition. The conclusions from the previous NAAQS review and the causality determinations from this review are summarized in the table below. Further discussion of these conclusions is provided below for visible foliar injury, growth, productivity, and carbon storage, reduced yield and quality of agricultural crops, water cycling, below-ground processing, community composition, and O3 exposure-response relationships; discussion for all relevant welfare effects is provided in the ISA.

Table 1.b

Summary of ozone causal determination for welfare effects

All of the above are gone into greater detail in section 1.7.1

Fig. 1-3  Schematic illustrating the effects of tropospheric O3 on climate.
Unfortunately the above schematic has overlooked the major influence of O3 on climate, which isn't direct forcing, but that it is killing trees and other plants that photosynthesize and absorb CO2. There is evidence that losing forests will profoundly alter precipitation (since evapotranspiration of trees is what creates rain) - and dead forests are not carbon sinks.

1.9 Conclusion

"There has been over 40 years of research on the effects of O3 exposure on vegetation and ecosystems. The best evidence for effects is from controlled exposure studies. These studies have clearly shown that exposure to O3 is causally linked to visible foliar injury, decreased photosynthesis, changes in reproduction, and decreased growth. Recently, studies at larger spatial scales support the results from controlled studies and indicate that ambient O3 exposures can affect ecosystem productivity, crop yield, water cycling, and ecosystem community composition."

Affecting "ecosystem community composition" means, in the scientific bureaucratise, that some species will be extirpated killed off, and (they assume) replaced by other, more tolerant species.  Of course, from what I can see, that isn't necessarily the case.  I see a lot of spots of bare earth which I never used to see.  Nature abhors a vacuum and normally plants compete for space - unless they've been poisoned.

Figure 2-4, "An illustrative diagram of the major pathway through which O3 enters leaves and the major endpoints that O3 may affect in plants and ecosystems."

Note, affected ecosystem services includes "decreased productivity" and "decreased C sequestration" but they still didn't include this in impacts to climate, see figure 2-4 above, and section 2.7.2 just below the next passage.

p. 2-27   "...a study assessed the risk of O3-induced visible foliar injury on bioindicator plants in 244 national parks in support of the National Park Service’s Vital Signs Monitoring Network.  The results of the study demonstrated that the risk of visible foliar injury was high in 65 parks (27%), moderate in 46 parks (19%), and low in 131 parks (54%).
[but not "none" in any.]
A very young Chinese Pistachio tree
Some of the well-known parks with a high risk of O3-induced visible foliar injury include Gettysburg, Valley Forge, Delaware Water Gap, Cape Cod, Fire Island, 15 Antietam, Harpers Ferry, Manassas, Wolf Trap Farm Park, Mammoth Cave, Shiloh, Sleeping Bear Dunes, Great Smoky Mountains, Joshua Tree, Sequoia and Kings Canyon, and Yosemite. Overall, evidence is sufficient to conclude that there is a causal relationship between ambient O3 exposure and the occurrence of O3-induced visible foliar injury on sensitive vegetation across the U.S."
2.7.2  "Ambient O3 concentrations have long been known to cause decreases in photosynthetic rates and plant growth. The O3-induced damages at the plant scale may translate to the ecosystem scale, and cause changes in productivity and C storage. The effects of O3 exposure on photosynthesis, growth, biomass allocation, ecosystem production and ecosystem C sequestration were reviewed for the natural ecosystems, and crop productivity and crop quality were reviewed for the agricultural ecosystems."
p. 2-38 "A set of meta-analyses assessed the effects of O3 on plant photosynthesis and growth across different species and fumigation methods (such as OTC and FACE). Those studies reported that current O3 concentrations in the northern hemisphere are decreasing photosynthesis (~11%) across tree species, and the decreases in photosynthesis are consistent with cumulative uptake of O3 into the leaf. The current ambient O3 concentrations (~40 ppb) significantly decreased annual total biomass growth of forest species by an average of 7%, with potentially greater decreases (11-17%) in areas that have higher O3 concentrations (Section The meta-analyses further confirmed that reduction of plant photosynthesis and growth under O3 exposure are coherent across numerous species and various experimental techniques."
p. 2-39  "The suppression of ecosystem C sinks results in more CO2 accumulation in the atmosphere. A recent study suggested that the indirect radiative forcing caused by O3 exposure through lowering ecosystem C sink could have an even greater impact on global warming than the direct radiative forcing of O3." [my bold]

After describing the results of field tests, they write [EPA bold] "Overall, evidence is sufficient to conclude that there is a causal relationship between O3 exposure and reduced plant growth and productivity, and a likely causal relationship between O3 exposure and reduced carbon sequestration in terrestrial ecosystems."

I won't do a screen shot of table 9.3 (p. 9-58) because it's too dense and tiny, but there are some remarkable figures in the studies cited there about reductions in productive and carbon sequestration due to ozone, all around the world, modeled to have been initiated well before the 1950's.

p. 2-40  "The detrimental effect of O3 on crop production has been recognized since the 1960’s and a large body of research has subsequently stemmed from those initial findings. Previous O3 AQCDs have extensively reviewed this body of literature. Current O3 concentrations across the U.S. are high enough to cause yield loss for a variety of agricultural crops including, but not limited to, soybean, wheat, potato, watermelon, beans, turnip, onion, lettuce, and tomato."
Three cryptomeria turned bronze
on the left a blackened cedar, on the right, a tree still retains leaves from autumn
"Continued increases in O3 concentration may further decrease yield in these sensitive crops. Despite the well-documented yield losses due to increasing O3 concentration, there is still a knowledge gap pertaining to the exact mechanism of O3-induced yield loss. Research has linked increasing O3 concentration to decreased photosynthetic rates and accelerated senescence, which are related to yield."

"In addition, new research has highlighted the effects of O3 on crop quality. Increasing O3 concentration decreases nutritive quality of grasses, decreases macro- and micro-nutrient concentrations in fruits and vegetable crops, and decreases cotton fiber quality. These areas of research require further investigation to determine the mechanism and dose-responses."

Chapter 9 goes into more depth about studies and experimental techniques so just for the record, as I've often said, the open air chamber fumigation experiments are underestimating effects because they are comparing projected future, higher levels of ozone with already polluted ambient air, not pre-industrial-revolution clean air:

9.2.4.  "Plume and FACE systems also are unable to reduce O3 levels below ambient in areas where O3 concentrations are phytotoxic."

They also can't remove other pollutants and so are not indictive of what interactions and synergistic effects may be occurring in the real world.  Here's one field experiment that did:

9.2.5  "For example, Gregg et al. (2003) studied cottonwood saplings grown in an urban to rural gradient of Oin the New York City area. The secondary nature of the reactions of Oformation and NOtitration reactions within the city center resulted in significantly higher cumulative Oexposures in the rural sites."
These pines have had no needles for at least a year...
So the imbeciles are running around with backhoes, spewing toxic gases to plant more!
9.2.6  "One potential weakness of laboratory, greenhouse, or field chamber studies is the potential effect of the chamber on micrometeorology. In contrast, plume, FACE and gradient systems are limited by the very small number of possible exposure levels (almost always no more than two), small replication and an inability to reduce O3 levels below ambient. In general, experiments that aim at characterizing the effect of a single variable, e.g., exposure to O3, must not only manipulate the levels of that variable, but also control potentially interacting variables and confounders, or else account for them."

"However, while increasing control of environmental variables makes it easier to discern the effect of the variable of interest, it must be balanced with the ability to extend conclusions to natural, non-experimental settings. More naturalistic exposure systems, on the other hand, let interacting factors vary freely, resulting in greater unexplainable variability. The various exposure methodologies used with O3 vary in the balance each strikes between control of environmental inputs, closeness to the natural environment, noisiness, and ability to make general inferences."

9.3.1.  "Once O3 has entered the substomatal cavity and apoplast, it is thought that the cell must be able to sense the presence of O3 or its breakdown products in order to initiate the rapid changes in signaling pathways and gene expression that have been measured in O3-treated plants. While it remains unclear exactly how O3 and/or its breakdown products are sensed in the apoplast, much progress has been made in examining several different mechanisms that may contribute both to sensing the presence of O3 and its breakdown products, and also initiating a signal transduction cascade, which will be described in Section"

I guess they didn't remove the "sensing" bit!

Of course everyone is going nuts studying genetic responses to ozone, because, why not?  Even thought there are pages and pages more, I'm going to have mercy and save the rest for another day, stopping now with one last special excerpt, p. 9-11:

"The next step in the process is to determine the implications of the measured changes occurring at the cellular level to whole plants and ecosystems, which is an important topic of study which has not been widely addressed."

Really?  They could just ask me what the implications are to whole plants and ecosystems!  Or, they could hark back to Charles Little who wrote:
Should we plant trees? Yes, of course, plant billions. But can we reforest the Earth in such a way that it will stay reforested?

"Reduce the pollution caused by gluttonous fossil-fuel energy use? Yes, of course. But not to the level of 1990, as the policymakers suggest and have legislated. Trees were dying long before that. The mid-50s would be closer to the mark…In the course of my research, I have learned things I wish I had not learned. I have learned that the trees are dying. And that the more trees die, the more will die. I have learned that we have crossed the threshold. And I simply do not know how we can get back safely to the other side."

"Such a conclusion can lead to despair. I think the only antidote to despair is to stay firm in the belief that, as William Wordsworth put it in Tintern Abbey, '...nature never did betray the heart that loved her.'"

"We must begin to love her as we have never been asked to love before. Even then, it will take a century or more for environmental repair; for letting nature heal herself."

"Thus have we come to the crux of the matter: the trees could save us, if we would save the trees."

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