"We must make the invisible visible. We must make the vastness perceptible. We must make the alien familiar. We have no other choice. " - Michael Tobis
"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 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 pictures which are marvelously sinister.
"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)."
"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."
"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..."
"No documents match the query."
"Plants are more sensitive than humans to ozone pollution. Unlike humans, the effects of ozone on plants is both cumulative and long-term."
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)
"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."
"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."
"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."
"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."
"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."
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