This is the time of year when I generally check in with the USDA Forest Service's annual national Biomonitering Program
, which has been collecting and analyzing samples of leaves for ozone damage at plots around the country, every year since 1994. I wouldn't want the friendly fellow at the Northern Research Station who returned my call to get in trouble, so I'm not going to reveal his name....because this is pretty much how the conversation went, after I asked him about the most recent results:
"Because of anticipated budget cuts, we didn't collect any data this year. Nobody went out in the field."
After a moment of silent, incredulous astonishment, I started laughing a little hysterically. "Seriously? What are you guys doing with all that time on your hands?"
He laughed too. "Well, we're pushing a lot of paper around on our desks."
I'm NOT kidding. That's what he said. Now, presumably foresters are still getting paid their salaries and benefits so, how much savings did the Forest Service realize by NOT sending them out to collect the leaves??
Answer: just about nothing. So, why did they decide to stop collecting?
Answer: the results are getting too scary. Don't even ask WHO exactly made the decision.
I mentioned to my overpopulation google group, not for the first time, that the trees are all dying from exposure to air pollution, and one new correspondent's initial reaction was scornful. A day later, after he did some research, he wrote back to apologize. In a thoughtful missive, he explained that on top of all the other terrible harm we are inflicting on nature, he just couldn't emotionally handle the notion that our pollution was killing trees...but upon reading and reflection, he realized it's quite true. This is how I answered him:
No need to apologize. Ever since I realized all the trees are dying, I am in a constant state of grief. I have always loved trees, I grew up climbing their branches and building little mouse houses of moss and twigs around their roots. They are magnificent, and give us so many gifts besides their beauty. Cool shade and the sound of wind blowing through their leaves, nuts, and fruits, wood for our houses and furniture, paper, maple syrup, oxygen, and a home for most wild creatures. They are the essential foundation of our ecosystem, and they are dying from the "acidification" of the atmosphere as surely as coral reefs, the nurseries of the seas, are dying in the oceans. Fewer people recognize that trees are in terminal decline however; I think because, as your reaction demonstrates, it is too soul-crushing to contemplate. So I very much understand, and I'm sorry to have added another source of dismay to an already crowded field.
The obligatory good news is that if people could get past their natural resistance - especially if, as I suspect, it turns out that the ozone problem is grotesquely exacerbated by biofuel emissions - it would be a first step towards understanding that we must cut back our use of fuels drastically, and our population growth. Of course I realize that's not likely to happen. But I pound away at it, because the prospect of your local farm losing half its crop, and the trees around your house falling on the roof, seems like more of a motivator than contemplating the extinction of rare species in exotic places, like butterflies in Madagascar, or polar bears in the Arctic.
Dr. Rice was kind enough to send me a pdf of the paper
she co-authored, Acidification of Earth, which I've attached. It says:
"Because the sources of atmospheric acids are widely distributed across the landscape, even the short atmospheric residence times of hours to days for the pollutants is adequate to support world-wide occurrence of acidic aerosols and compounds."
This chart, which is for SO2 emissions - a lesser source of ozone than NOx, - compares the developed world to China only, not even including India...so despite the widespread misimpression that we've taken care of pollution with existing regulations, it's pretty obvious why the global background levels of tropospheric ozone continue to rise:
Annoyed that the Forest Service abandoned their ozone biomonitering program - because I am certain any data collected this year would have shown such
extreme deterioration that it couldn't be bureaucratically swept away (by my reckoning, the decline of trees continues to escalate) - I started googling around for other more recent information. I am never disappointed on these expeditions, there is always more to be found, especially now that google has been putting entire books online. First, I found a field guide
, published by the Mountain Studies Institute - the Ozone Bioindicator Manual - which corroborates basic information and provides photos:
“Ozone injury usually appears as black or purple spots (stipple), yellow or white bleached spots (chlorotic mottle, needle tip burn), or leaf browning (necrosis). Ozone may also cause premature leaf drop (senescence).”
"Ozone effects on natural vegetation have been documented throughout the country, particularly in many areas of the eastern U.S. and in California. Ozone injury in cutleaf coneflower has been observed in Rocky Mountain National Park in northern Colorado..."
The USDA Forest Service, Southern Region, hosts a website called "Sick Tree
" which describes ozone damage:
"From July through September in the Eastern United States, many plant species that are sensitive to ozone will show visible injury on the upper leaf surfaces. Normally, the ozone-injured leaf surfaces of bioindicator plants show stippled discoloration. Discoloration will vary among species, ranging from red to purple to brown. These plants may also drop their leaves early. In addition to visible symptoms, studies have shown that plants affected by ozone are smaller, and may produce fewer healthy seeds. Ozone injury may stress plants in other ways, and they may become more susceptible to other problems, such as insects and diseases."
Remember this salient fact, which is persistently and conveniently forgotten by scientists who prefer to point to the fungus that causes sudden oak death, rampant in California, and bark beetles, an epidemic in the Rockies and beyond.
Hands on the Land, a cooperative project involving the NASA Langley Research Center, the Appalachian Science Highlands Learning Center, and various academic and Forest Service scientists, has a program
for students, Welcome to the O-Zone
"...when ozone is generated from pollution sources and collects close to the ground (tropospheric ozone), it can be highly damaging to sensitive tissues in both plants and animals.
How do we know that these symptoms are caused by tropospheric ozone? In 1988, researchers in Great Smoky Mountains National Park set up study chambers with over 100 species of plants growing in them to determine which plants were affected by ozone."
"The result of this study is that 30 species were classified as highly sensitive and another 60 species showed some signs when exposed to high levels of ozone.
The highly sensitive species showed symptoms after being exposed to ozone levels as low as 10 parts per billion (ppb). In contrast, the EPA has set 65 ppb as the National Ambient Air Quality Standard (the level safe for people to be outside with no ill health effects)."
They also produced an "Ozone Monitoring Guide
" using bioindicator plants for the detection of ozone injury that is actually a quite comprehensive primer on ozone.
They sponsor experimental garden plots where students from elementary to high school monitor plant health, fill out charts and produce cool animated graphs of progressive leaf damage through the growing season. Here's an excerpt of one girl's study, on page 29:
"Week 6 shows ozone levels between 52 ppb and 73 ppb. While reviewing her data from each week, she notices that none of the levels are particularly high, only 5 days exceed 65 ppb and no days are considered unhealthy. At the same time, the rate of progression of symptoms is fairly dramatic
The results have raised more questions for the student than answers. She is now wondering about the total number of hours the plants received certain ozone exposures.
The data she received only gave the maximum 8-hour average for the day. The student decides she wants to do more research on the internet to determine if there is a ppb standard for plant health since the plants appear to react to ozone in weeks when ozone levels are as low as 50 ppb at a maximum. Her conclusion is that sustained exposure at low levels of ozone exposure seems to be just as likely to produce symptoms as a short-lived high exposure."
Oh My! Out of the mouths of babes! A simply stunning truth emerges: the damage from exposures not considered unhealthy by the EPA standard is...dramatic.
Now, why might that be? Why don't the standards for air quality set by our government agency, which is tasked with protecting the health of humans and the ecosystem, protect us from dramatic damage
? Well, here's a comment I came across over at Decline of the Empire
that sums it up:
"I've never heard of the term "biostitute" until today by a former biology researcher who was unhappy with a career change he made and was ready to go back into performing research for consulting firms that do field studies required by government regulatory agencies. As he explained it, businessmen have bought off the politicians and regulators so that their construction projects get pushed through, no matter the severity of environmental degradation that they cause. "Money corrupts everything so that the entire earth gets paved over."
"Our associates have Ph.D. degrees in numerous areas and have produced and written hundreds of EA's (Environmental Assessments) and EIS's (Environmental Impact Statements) that were so misleading and cleverly crafted that power companies have been able to fragment and destroy thousands of acres of fragile native forest and other ecosystems, coal mining companies have been able to blast off entire mountain tops, and departments of transportation have been able to spend billions of dollars helping urban blight and sprawl consume thousands of acres of farmland so that the petroleum industry could sell millions of barrels of oil to new hordes of commuters."
To some degree we are all prostitutes to the system."
So remember our first new term for the day - Biostitution - there will be a test on the next post on that topic! Also in the email exchange pasted below, highlighted in red, is another term that is new to me - although it is a phenomena I have observed many, many times on this blog: marginal leaf burn
- from a book! I've been describing this ubiquitous condition edges that are singed or scorched, but now it's official - they have marginal leaf burn from absorbing ozone.
Meanwhile, following are the charts from the study guide showing students how to assess the degree of damage to leaves , from level 1, no ozone, to level 6, severe injury:
These pictures are very important, because it's impossible to find a leaf anywhere that looks like "level 1" - in fact, most currently look in far worse condition that the worst on this scale. Following are photos I took this past few days, of a random assortment, all at high levels of injury - this is even more critical because it's been well established in experiments that stunted growth and other ill effects occur in trees BEFORE their leaves exhibit visible damage.
And remember, we've had no frost - if we had, the flowers and raspberries would be finished.
|The berries look good, but they taste lousy (sigh).|
|All the older leaves are tattered and black - more recent sprouts are green.|
I got rather excited last week when I read an interview
at Forbes, "Climate Shock, UC Berkeley Scientist, Dr. John Harte, Puts the World on Notice." A professor in the Department of Environmental Science, he was so dire in his warnings about the unaccounted feedback effects in climate models used for predicting future temperature increases that I thought surely
, he would be interested to know about the impending feedback comprised by the crucial loss of the forest carbon sink...so I wrote him my usual letter.
|A Clematis still blooms, despite leaves the older leaves that are discolored shriveled.|
Dear Dr. Harte,
I have only today come across your work, via the excellent interview at Forbes. I'm hopeful that you will consider examining, with your expertise, a relatively neglected, existential threat to our ecosystem, which is the cascade of NOx resulting in inexorably increasing levels of background tropospheric ozone.
I live in New Jersey and it is simply appalling how fast the trees here are dying. I've traveled to Seattle, and even in Costa Rica, have found identical symptoms of foliage damaged by ozone. Earlier this month I went to Santa Cruz to see my daughter, who is a grad student there, and frankly, California looks like a graveyard. I really don't understand how it is that the residents don't notice that everything is brown and dying. I know they blame it on insects, disease, and fungus, but all of those things attack trees and crops compromised by exposure to air pollution.
|Cleome - a frost sensitive annual flower, above the withered leaves of the pond lotus|Anyway, I write about this problem and publish photographs on a blog called Wit's End, because I keep hoping that a professional will alert the public that we are going to have a serious shortage of food, soon, if we continue to burn fuel and emit reactive Nitrogen.
I also suspect, but do not have the resources to investigate, that biofuel emissions are much worse than fossil fuel in terms of producing ozone; and perhaps that is why vegetation is dying at a rapidly accelerating rate in just the past few years. If that's the case, we could just stop burning biofuels and conserve like crazy instead, thus returning to a slightly more leisurely pace of destruction from climate change alone.
I welcome any thoughts you may have on this topic, and thank you for your attention.
|A sweet rose outside my kitchen.|
Yes, Gail, and on top of your reasons for scrapping biofuels is the fact that it really does little or nothing to reduce CO2 emissions.
You might enjoy the free, downloadable book my wife and I wrote: www.cooltheearth.us
Linking forest dieback to air pollution is easier in the Eastern US than in CA....not enough research has been done here, but one clear connection is between climate warming and the bark beetle population explosion.
The beetle has done enormous damage to conifers throughout much of the Rockies.
|Chlorotic pine needles. |
Dear Dr. Harte,
Thank you for the link to your book.
With breathtaking brevity in your reply to my concerns, you have managed to hit three of the top denialist points I encounter from academic researchers! A trifecta!
1. It may be happening where you are, but not where I am
(actually, the earliest research in the 50's was done in CA, proving bark beetles were killing pines there, as has been demonstrated by more recent research* and **, and *** - and also in the NCLAN program, see the link to one study at UC Davis, and the USDA page in my last post
2. It's insects (this despite the fact that the aspen in those same western forests are also dying, and they don't get attacked by bark beetle). Common variants of this argument for other species are - it's fungus, it's disease, it's drought.
3. It's warming (this despite the fact that older trees get attacked first, because they are more stressed from more seasons of exposure to ozone...plus, if it was mainly temperature causing the bark beetle to run amock, you'd expect a clear pattern of damage to be worst in the southern range and lower altitudes moving north and higher, but that is not the case to my knowledge).
|Japanese maple leaves, much smaller than normal size.|
* What caused the San Bernardino outbreak
: "...long term exposure to air pollution, particularly ozone, has reduced the health of conifers in the forest. Excessive ozone exposure causes premature loss of pine needles, reducing the trees ability to produce food and tissues."
|Weeping Katsura.|**UC Riverside: Tree mortality and beetle activity were signiﬁcantly higher at the high pollution site. Differences in beetle activity between sites were signiﬁcantly associated with ozone injury to pines, while differences in tree mortality between sites were signiﬁcantly associated with both ozone injury and fertilization level. Tree mortality was 9% higher and beetle activity 50% higher for unfertilized trees at the high pollution site compared to the low pollution site. Tree mortality increased 8% and beetle activity increased 20% under the highest rates of nitrogen additions at the low pollution site. The strong response in beetle activity to nitrogen additions at the low pollution site suggests that atmospheric nitrogen deposition increased tree susceptibility to beetle attack at the high deposition site. While drought conditions throughout the region were a major factor in decreased tree resistance, it appears that both ozone exposure and atmospheric nitrogen deposition further increased pine susceptibility to beetle attack."
*** from a book, Pests of the Native California Conifers, published by UC Berkeley, which says:
"Chlorotic mottling of needles, shorter needles, and reduced needle retention, are the main symptoms of injury [from ozone]. Seriously damaged leaves of deciduous trees in the same area may show distinctive brown edges, called marginal leaf burn. Additional symptoms of serious damage include loss of apical dominance, that is, suppression of terminal bud growth; reduction in overal shoot growth; increased death of lower and mid crown branches; and diminished cone production...With chronic exposure to ozone, symptoms persist, trees continue to decline, and eventually many die, often prematurely from attack by bark beetles." I can't cut and paste from a google book, but the section linked to is worth a read, because it is quite definitive that ozone underlies the secondary attacks by pathogens.
|Ponderosa Pine showing severe ozone damage. Note reduction in needle length and retention.|
[from the book]
I was just in California and there isn't a conifer or a deciduous tree that doesn't have exactly those symptoms described. Go outside and look! I do hope you will consider your previous dismissal of this existential threat. People need to know that the ecosystem is collapsing, or they will not be motivated to stop it.
|A Purple smoke bush.|
I believe you missed or misunderstood the intent of my comments. Of course the effect of pollution on plants in S CA is documented. But many of the other signs of plant damage in the Western US are not linked to pollution. Sudden Oak death, for example, appears to occur in patterns that simply do not link to air quality. And in Colorado, bark beetle outbreak and damage are found in areas with relatively pristine air as well as in area with documented serious air pollution. There is no correlation of outbreaks with pollution in the Rockies.
Do not fall into the trap of assuming a single cause for the destruction that human activity is causing. We are imposing multiple stresses on the planet, and the causes of damage are many and varied.
I neither said nor implied that it is not happening "here".
I never said that it is always insects; I said that in some places it is insects as direct cause, climate as indirect. In other places it is ozone and NOx, and in some places it is acid rain.
You are wrong to infer that climate change should affect more southerly regions before it affects more northerly regions. Not sure where you got that from.
The cause of aspen dieback remains a puzzle...still no established and clear association with specific stresses.
|Leaves of a fringe tree.|
I have to admit I have been accused of being an ozonist, an epithet that is fine with me! It's not that I don't understand there are (many) negative impacts on trees from various sources...what I do think however is that the damage done by ozone is grotesquely under appreciated, at our peril. Pollution seems to be a verboten topic, particularly among climate scientists, which is unfortunate, because they are the ones with access to atmospheric data.
For instance you state that there is no correlation between "pristine" areas of Colorado and bark beetle, but according to the attached map which is on the USDA webpage, the bark beetle outbreak area is smack in the middle of some of the highest levels of ozone in the country. More generally, there is a global trend for forest dieback, and the only truly global influence on trees is the background level of ozone in the troposphere.
I'll give you another example. There are a couple of scientists in Vermont who have published reports that the reason the maple trees are producing measurably significant inferior quality of sap is warming and precipitation changes from CO2. Yet they say this with exactly zero controlled experiments. They appear to make this assumption because they can't find any other explanation to point to for this to occur over the last decade or so - no insects, disease or fungus to blame. And yet they absolutely refuse to consider that reactive nitrogen precursors forming ozone in New England could be the cause - even though there are numerous controlled experiments by the NCLAN, FACE and others, proving that severely reduced yield and quality of plant production results from ambient ozone.
|Very typical condition of maples leaves.|
I won't bother you again and I do appreciate your taking the time to respond. It's sad that something as well documented as "ozone causes cancer, emphysema, asthma, allergies, heart disease and Alzheimer's" isn't translated into the equivalent degree of fatal injury to trees, which are no more evolved to absorb it than people. Instead, I often read that scientists and foresters advise people to plant trees because they "clean the air and reduce pollution" without ever stopping to wonder what happens to those helpful trees.
|Hydrangea leaves, necrosis.|
I didn't expect to hear back again, and I haven't. I should have realized from his first response he is in the CO2 CO2 CO2 camp. Oh, well, hunting season has begun!
Stephen Colbert expresses the prevalent view that we've solved the pollution problem, so shut up about it already!