Down the Rabbit Hole

The other day when I talked to the artist, who was painting the dying trees, I told her that ozone is killing them. She looked up at the sky and said incredulously, "But, it's clear and blue!" So I told her, "Ozone is invisible." So are oxygen and carbon monoxide and carbon dioxide, for heavens sake! Which brings to mind this brilliant observation from one scientist to another, apropos in so many ways:

"We must make the invisible visible. We must make the vastness perceptible. We must make the alien familiar. We have no other choice. And so it falls to the scientists, on top of all their other responsibilities, to do the scaring of the people out of their wits, a job for which they are woefully ill-trained and unsuited."

-Paul Baer, as quoted at the top of the excellent blog, Only In It For The Gold.

While I was looking for (yet more) information about ozone I landed on a UK Royal Meteorological Society web page, and came across a couple of splendid cloud pictures which are marvelously sinister.

I also found a plethora of fascinating documents. The first is a new call by the Royal Society for inclusion of the issue of ozone by the Convention on Biological Diversity, with a reference to the Society's extensive report of 2008, "Ground-level ozone in the 21st century: future trends, impacts and policy implications" about which I had posted here ages ago.

"The report 'Ground-level ozone in the 21st century' highlights that in the UK and other parts of the Northern Hemisphere, background concentrations of ozone have increased by six per cent (two parts per billion in the atmosphere) per decade, since the 1980s.

Policies in the EU, Japan and America have successfully reduced the occurrence of very high peaks of ozone in these regions, which occur for short periods under hot, sunny, stagnant weather conditions. During these episodes ozone concentrations can be particularly dangerous, exceeding 100 parts per billion (ppb).

However, ozone is now believed to have an effect on health, food crops and the environment at the background levels currently experienced by people in the UK, and most industrialized countries of the world, on a daily basis (35- 40ppb)."

Isn't that interesting? I believe the threshold the US EPA has set for levels tolerable for health and the environment is 80 ppb....(click to enlarge)

and even THAT represents a tightening of standards the EPA claimed would produce the benefit of "Reduced yield losses of major agricultural crops, such as soybeans and wheat, and commercial forests by almost $500,000,000."

[the following is an aside, from that Weather Underground link above...since the focus of this blog is ozone effects on trees, not humans...but this deserves wider recognition:

"Death rates due to lung and heart problems increase by a .64% soon after ozone levels peak, according to several publications by Michelle Bell, an air-quality and health expert at Yale University. Bell showed that an ozone increase of 10 parts per billion (ppb), even at levels less than the 80 ppb federal standard, triggered the higher death rates. If ozone levels dropped by 10 ppb, almost 4,000 lives could be saved each year in the 95 cities she studied.

High ozone levels have been linked to increases in the severity of asthma attacks and other respiratory health problems, especially for children and the elderly. About 7 percent of healthy people have shortness of breath with ozone levels at 60 parts per billion (ppb), so the EPA is considering tightening the ozone standard from the current 80 ppb down to 60 ppb."]

Getting back to the Royal Society, from there I went to their link for the Convention on Biological Diversity - which is going to have a gnashing of the teeth and tearing of the hair international meeting in Japan in October, since nobody has any idea how to stem the tide of extinctions - and maintains a page which also recommends that the CBD should start to assess the impact of ozone on life, because so far it hasn't.

"Why urgent attention needed (how it impacts on biodiversity)...

Tropospheric ozone is a global air pollution problem and an important greenhouse gas. In large areas of the industrialised and developing world, it remains one of the most pervasive of the global air pollutants. Current levels are a risk to human health, food production, and natural ecosystems. There is potential also for indirect effects on climate change through reducing CO2 uptake.

Ozone concentrations have continued and will continue to increase in many parts of the world despite the efforts of many countries to reduce the pollutants that lead to ozone formation.

Ozone is a major constituent of photochemical smog. It is a powerful oxidant that damages human health and natural ecosystems, and reduces crop yields. It effects crops/forestry and natural ecosystems directly (through reduced growth/yield, changes in plant competition etc), but also may affect genetic diversity.

Ozone and the pollutants that lead to its formation can be transported by weather systems and jet streams far from their point of origin.

Studies suggest that the areas of greatest risk (where ground level ozone will have the greatest impact on plant biodiversity) may fall in Eastern North America, Central Europe, the Northern half of South America, Central Africa and South-East Asia. There is a need for a globally co-ordinated approach to address the international nature of the problem to protect human health and the environment."

And then I felt just like Alice falling down the rabbit hole, because they list many sources pertaining to ozone, each leading to more, it seemed endless.

It was making me dizzy, and left to wonder, why as there is obviously so much international research, isn't anybody doing anything about it?

One of their links led to our very own US Forest Service Ozone Biomonitoring Program, which says:

"The ozone biomonitoring program uses ozone-sensitive plants to monitor air quality and the potential impacts of tropospheric ozone (smog) on our nation’s forests...

Ground level ozone is considered the most pervasive air pollutant world-wide, and a serious threat to the conservation and sustainability of world forests...

The airborne transport of O3 to remote forested areas has led to increasing concern about how this pollutant is influencing the health of individual trees and forest ecosystems. In the United States, periods of high ozone concentration coincide with the growing season when plants are most vulnerable to injury. Possible impacts of ozone on forest species include reduced growth and vigor, reduced seed production, and increased susceptibility to insects and disease. Long-term ozone stress may lead to changes in species composition, reduced species diversity, and simplification of ecosystem structure and function...

When ozone contaminates the environment, the bioindicator plant shows a visible response usually described as upper-leaf-surface ozone stipple for broad leaf plants, and chlorotic mottle for pine species. A useful bioindicator plant may be a tree, a woody shrub, or a non-woody herb species. The essential characteristic is that the species respond to ambient levels of ozone pollution with distinct visible foliar symptoms that are easy to diagnose...

One way to monitor ozone air quality and potential impacts on our forests is to use bioindicator plants to detect and quantify elevated ozone concentrations in the forest environment. A nationwide network of over 1130 ozone biomonitoring sites has been established in forested areas in 45 states. Each year these sites are evaluated for the amount and severity of ozone injury on sensitive plants. The foliar injury data is used to quantify regional trends in ozone stress in terms of significant changes in the number and distribution of biomonitoring sites with ozone injury, and increases or decreases in injury severity. Results are interpolated across the landscape to predict where plant injury will occur, and identify areas of concern where growth effects studies are warranted..."

So, according to their own webpage, they monitor yearly, in an extensive program with over a thousand collection sites, where they have a list of practically every species rated for sensitivity, and mountains of links to research... which just makes my blood boil! In all the times I have contacted them, nobody has ever mentioned this program, and now, I stumble upon it from a link on a foreign website!? I bet when they started this program in 1994 they had no idea what they would find - and are concealing the most recent data. Go to their webpage and type ozone in the search window and you'll get this:

"No documents match the query."

You have to go to the entirely separate Forest Inventory and Analysis National Program website, then type ozone in the search window, and it will send you to the Biomonitoring Program. Believe me, even there you could follow links all day - to all sorts of programs and workshops and research and maps and charts and reports about insects and diseases - and never find a word about ozone otherwise. Helpfully, once you get there, in a side bar they state:

"Plants are more sensitive than humans to ozone pollution. Unlike humans, the effects of ozone on plants is both cumulative and long-term."

And they also provide useful links to other research, but much of it seems to be ten years old...except this one, which describes the monitoring program:

"States use an intensified ozone grid so two or more biosites may be located in each polygon on the base grid. Biosite locations are mapped, geographic coordinates are recorded, and the same sites are evaluated every year. Ozone injury and our ability to detect that injury increase over the course of the field season. For this reason, the sampling window for the ozone indicator is limited to 3 weeks (from late-July to mid-August) within which the indicator is considered stable. This minimizes variability and the error associated with the data collection system.

At each ozone biosite, 30 individual plants of two bioindicator species, and between 10 and 30 individual plants of additional bioindicator species are evaluated for ozone injury. Each plant is rated for the proportion of leaves with ozone injury (injury amount) and the mean severity of symptoms (injury severity)"

where they have this nifty map of ozone risk to plants dating back to 2002:

and this one indicating the number of grids studied annually:

From a separate, but related website, which also seems to be unnecessarily obscure, I was able to obtain this:

"Air pollutants, such as ground-level ozone, are known to interact with forest ecosystems. Ozone pollution has been shown to reduce tree growth, alter species composition, and predispose trees to insect and disease attack. Ozone also causes direct foliar injury to many plant species. Affected leaves are often marked with discoloration and lesions, and they age more rapidly than normal leaves. This approach is known as biomonitoring and the plant species used are known as bioindicators."

And from there you can even go to a whole bunch of different pages for assessing "decline" such as the Crown Indicator Homepage which says:

"Small, sparsely foliated crowns may represent trees in decline. When biotic or abiotic stresses impact a forest, the first signs of deterioration can often be observed in the tree crowns. Because tree crowns form most of the structural architecture of forest ecosystems, they also influence the composition and vigor of understory flora and fauna, as well as the physical processes that affect soil and water quality."

The Forest Service includes this picture of a transparent crown, a familiar sight for all species nowadays, not just those on the "sensitive" list. It also describes the Forest Inventory and Analysis Program, which I will be very interested to pursue, especially since they haven't had a single "Briefing, Summary or Overview" published since 2004!

"As the Nation's forest census, the FIA Program is responsible for providing the information required to assess America's forests. Most of this information is obtained from a series of permanent ground plots systematically distributed across the landscape. Conventional forest inventory data are gathered at all sample locations; additional data associated with specialized forest health indicators are collected on a 1/16 subset of the plot network."

And then I was astonished to discover a private company, ASL & Associates - which is a consultant for ozone studies! Self description on their webpage:

"A.S.L. & Associates over the past 29 years has developed extensive experience and resources for the purpose of assessing the potential impacts of air pollution on the environment. Corporate clients include major industrial, environmental, and governmental groups. The Company's President and Founder, Dr. Allen S. Lefohn, has focused the Corporation on those environmental issues that directly link pollutant exposure with both human health and vegetation effects."

This excerpt is somewhat confusing...I don't know if this means stratospheric ozone injected into the troposphere is a greater problem than generally thought, or if they are trying to say, we can't control it so why bother limiting emissions?

"For several years, we have had an on-going effort to better understand the range and frequency of occurrence of background ozone levels that may not be affected by emission reduction strategies. In 2001, we published a peer-reviewed paper authored by the research team of Allen Lefohn, Samuel Oltmans, Tom Dann, and Hanwant Singh, confirming that background ozone levels are higher and that the natural short-term variability is more frequent and greater than previously believed. Although modeling results have been published questioning our conclusions about the importance of stratospheric ozone in affecting surface-level ozone concentrations, we believe there are serious shortcomings associated with the modeling efforts, some of which have been documented in EPA's 2006 Ozone Criteria Document (EPA, 2006). Our most current research results continue to support our previous conclusions about the importance of stratospheric-tropospheric exchange processes in affecting surface ozone concentrations at both high- and low-elevation monitoring sites."

There is much to explore...they also have a page devoted to a debate about whether high episodic exposure or lower average concentrations should be used as a standard to assess impacts. Recalling the first quote at the top of this post from the Royal Society that said it has now been determined that background levels of ozone, and not only high episodic exposure, cause damage to health and vegetation, it appears the issue has to do with what criteria should be used in calculating and enforcing emission restrictions.

Next - and last! - here is a paper found by RPauli, from the Alabama Cooperative Extension, that has a tidy and comprehensive description of what constitutes visual damage that can be attributed to ozone exposure...for anyone who is looking to diagnose it:

"Symptoms. Ozone is a very active form of oxygen that causes a variety of symptoms. Symptoms include tissue collapse, interveinal necrosis, and markings on the upper surface of leaves known as stipple (numerous tiny spots of yellow, light tan, red-brown, dark brown, red, black, or purple pigment), flecking (silver or bleached straw white spots), mottling (irregular blotches of green, light green, and yellow), yellowing, bronzing, or bleaching. Plant growth is often stunted. Flowering and bud formation can be depressed. Affected leaves of certain plants, such as citrus, grape, and tobacco, commonly wither and drop early.

Conifers frequently show a yellow to brown mottling and tipburn or a yellow to brown or orange-red flecking and banding of the needles. Susceptible white pines are stunted and yellowed.

The injury pattern in small grains and forage grasses generally occurs as a scattering of small, yel- lowish or white to tan flecks one or both leaf surfaces. The flecks may later merge to form larger, bleached white to yellowish dead areas.

Ozone usually attacks nearly mature leaves first, progressing to younger and older leaves. Young plants are generally the most sensi- tive to ozone; mature plants are relatively resistant. Ozone-killed tissues are readily infected by certain fungi.

Persistence and Transmission.

Ozone is brought down from the stratosphere by vertical winds produced during electrical storms. More importantly, it is produced when sunlight reacts with nitrogen oxides and hydrocarbons formed by refuse burning and the combus- tion of coal or petroleum fuels, especially the exhaust gases from internal-combustion engines."

And there I just have to stop!

The illustrations were found here, a wonderful resource for all things Alice