"What's most discouraging is a loss of feeling that government would help us," said Harold Mooney, a veteran biologist from Stanford University.
And there it is, in a nutshell. Scientists thought if only they did the research, and published the results,
You could read this analysis of corporate greenwashing. Or this story about the collapsing population of cod, and the infantile idiocy of the fishing industry, which refuses to restrain the catch, because it tells you all you need to know about exactly how clever people are going to be when confronted with Nature's implacable pitchfork. Or perhaps this horrific description, complete with tragic video, of the callous bulldozing of ancient forests - including their hapless, defenseless indigenous inhabitants, human and otherwise - which tells you all you need to know about how compassionate our superior species will be when we are competing over environmental services that have been exceded by our ravenous burgeoning numbers.
I'm afraid this particular post is not going to be very entertaining. Only aficionados of ozone disaster need read further!
Mired as I am in a sort of perpetual state of pre-traumatic stress syndrome, and the reverberations of cognitive dissonance that echo in my mind - even as I reside in comfort unimaginable to anyone just a few decades ago, and to a large proportion of people on the planet today - I was glad to find these words of wisdom:
“When despair for the world grows in me and I wake in the night at the least sound in fear of what my life and my children's lives may be, I go and lie down where the wood drake rests in his beauty on the water, and the great heron feeds. I come into the peace of wild things who do not tax their lives with forethought of grief. I come into the presence of still water. And I feel above me the day-blind stars waiting with their light. For a time I rest in the grace of the world, and am free.”
~ Wendell Berry
Five-year average 1999-2003 of ambient ozone exposures in the US using SUM60 |
• Ozone injury occurs frequently (25 to 37 percent of sampled biosites) in California forested ecosystems demonstrating that ozone is present at phytotoxic levels.
• The California air basins having the highest percentage of biosites with injury were the South Coast, San Joaquin Valley, and San Diego County.
• The group of biosites in the areas with the highest ozone exposures (SUM601 ≥25,000 parts per billion) had corresponding highest mean percentage of injured biosites (52 percent) and highest mean biosite index.
• In 2005, new areas (previously unreported) of ozone injury were detected in northern California (Trinity, Plumas, and Lassen Counties) as well as in the Mojave Desert area (San Bernadino County).
• Although ozone exposure is moderate to high over much of California, forested areas with the highest risk were estimated (via our plant response model) for the area east of Los Angeles, the southern Sierra Nevada, and portions of the central coast.
• In California, an estimated 1.3 million acres of forest land and 596 million cubic feet of wood are at moderate to high risk to impacts from ozone.
• Despite reports of increasing ozone production and exposure in Oregon and Washington, ozone injury was observed only in the Columbia Gorge.
• Air quality as indicated by the FIA ozone bioindicator shows no consistent pattern of increases or decreases in any of the three states between 2000 and 2005. More years of data are needed to discern any trends."
Cumulative hourly ozone concentrations exceeding 60 parts per billion (SUM60) June 1–August 31, 8 a.m. to 8 p.m., 2001 through 2005 average. |
Since I'm still fuming that Tamino won't even allow a comment about ozone on his post about wildfires, I found this passage from the report illuminating...fancy that!
Ozone also has a variety of ecological effects on forested landscapes, with the potential to alter species composition, soil moisture, and fire regimes and influence pest interactions (McBride and Laven 1999; Miller et al. 1982; Smith 1974; Treshow and Stewart 1973; US EPA 1996b, 2006). Ozone predisposes trees to bark beetle (Dendroctonus spp.) attacks, especially where ozone exposure is high (Pronos et al. 1999). In the highly impacted San Bernadino Mountain forests, reduction of fine-root mass and carbon cycling at both the tree and ecosystem levels has been attributed to ozone exposure (Fenn et al. 2003, Grulke et al. 1998). Arbaugh et al. (2003) reported shifts in mixed-conifer stand composition in the San Bernadino Mountains from predominantly ponderosa pine to predominantly white fir (Abies concolor (Gord. & Glend.) Lindley ex Hildebr.). Similarly, simulations of the physiological and ecological responses of ponderosa pine and white fir to elevated ozone exposure in conifer forests in California showed a decrease in individual tree carbon budgets as well as a subsequent decrease in abundance of
ponderosa pine (Weinstein et al. 2005).
Ponderosa pine with ozone-induced needle loss and discoloration. |
|
"Elevated ozone concentrations also occur downwind of Pacific Northwest urban areas such as Vancouver, British Columbia; Seattle, Tacoma, and Vancouver, Washington; and Portland, Oregon (Bohm 1989, Brace and Peterson 1998, Cooper and Peterson 2000, Edmonds and Basabe 1989, Fenn et al. 2005). Visible injury or other effects on tree health have not been observed, however, in forests in these areas (Campbell et al. 2000, Duriscoe and Temple 1996, USDI NPS 2006)."
Well, I was in the Pacific Northwest on a wonderful trip in 2010 and unfortunately, I observed PLENTY of visible injury of which I photographed dozens of leaves that have identical damage:
1. Blue elderberry, with light ozone injury symptoms (interveinal necrosis), California |
Blue elderberry with moderate ozone injury symptoms (interveinal necrosis) |
Blue elderberry with severe ozone injury symptoms (interveinal necrosis) |
Mugwort with artificially induced ozone injury symptoms (chlorosis and premature senescence) |
Skunkbush with artificially induced ozone injury symptoms (necrotic stippling) |
"Tropospheric Ozone, a Growing Threat" was published in 2006 by the Asia Center for Air Pollution Research. While it is focused on ozone in Japan, it draws on research from all around the world and is certainly relevant. Sometime long ago I posted a link to this report, but it bears revisiting and also, turns out, has some references I didn't follow last time that lead to interesting places. They include this luscious graph that demonstrates the wicked things we are doing in the atmosphere without even being able to actually see any of it:
If you want a full explanation of the chemistry, go to page 6 of the report, which also describes with great clarity the issues of continental transport and effects on human health. You can see from the chart below why the Japanese are a little concerned about pollution from China wafting their way.
Modeling prediction on geographical distribution of ground-level ozone concentrations in 1993 above (average from May to August) and 2025 below. (Lelieveld and Dentener 2000)
A reader of Wit's End (Catman) forwarded a link to a mystifying paper, and I'm happy to report that one of the authors, Dr. Pollack, was kind enough to translate the abstract this way:
"It does seem counter-intuitive that lower emissions could lead to higher ozone on weekends, but that is what makes the 'weekend ozone effect' such an interesting phenomenon to study.
In essence, ozone is formed by a chain of chemical reactions in the presence of sunlight. This process is often refereed to as 'photochemical ozone production', and is a significant contributor to ozone levels observed on weekends in the California South Coast Air Basin. The relative abundances of the ingredients that go into these chain reactions, specifically nitrogen oxide (NOx) and volatile organic compounds (VOCs), play a key role in determining how fast the chemistry proceeds and how efficiently the reactions form ozone. Measurements in the South Coast Air Basin during a field study in 2010 show little change in VOC emissions between weekdays and weekends, yet large decreases in NOx emissions on weekends. Weekday-to-weekend differences in emissions in the South Coast Air Basin have been widely attributed to differences in activity of gasoline-fueled versus diesel-fueled vehicles. Large reductions in NOx on weekends compared to small changes in VOCs result in a relative increase in the ratio of VOCs to NOx on weekends. The increased relative abundance of VOCs compared to NOx makes the chemistry proceed faster and produce ozone more efficiently on weekends compared to weekdays, thereby leading to higher observed ozone levels on weekends."
So there you have it, all you Ozonistos and Ozonistas!
Next, I'm going to reproduce the entire Section 6 of the report from Japan, because it is specifically about trees and forests:
"Forests act as a life-support system on the Earth. Through photosynthesis, trees, a main component of
forest ecosystems, supply the oxygen that is indispensable to support life. Forests also preserve our
environment by fixing carbon dioxide, a major cause of the global warming, and by absorbing air pollutants. Unfortunately, forest decline and tree dieback are being observed in many areas of Japan."
"In the Tanzawa Mountains of Kanagawa Prefecture, the decline and dieback of Japanese beech
(Fagus crenata) have been observed at Mt. Hinokiboramaru and Mt. Hirugatake, and decline of Japanese
fir (Abies firma) has been observed at Mt. Ohyama. In the Oku-Nikko area of Tochigi Prefecture, Veitch’s fir (Abies veitchii), Maries fir (Abies mariesii) and Erman's birch (Betula ermanii) are in a state of decline. In the Sanyo Region, which includes Hiroshima Prefecture, the decline of Japanese red pine (Pinus densiflora) has been observed. In some areas along the Sea of Japan, including Ishikawa, Tottori and Shimane Prefectures, the decline and dieback of konara oak (Quercus serrata) and mizunara oak (Quercus mongolica) have also been observed."
"Several hypotheses have been presented on the causes of forest decline or tree dieback in Europe
and North America. Possible causes differ with each site. Ozone, soil acidification due to acid deposition
and excess nitrogen deposition from the atmosphere have been suggested as causes in northern
Europe; ozone, acid deposition such as acid mist and fog and sulfur dioxide have been suggested in
western Europe; and sulfur dioxide, nitrogen dioxide, ozone and acid deposition such as acid mist/fog
have been suggested in eastern Europe."
"In North America, meanwhile, ozone is thought to be closely related to the forest decline and tree dieback. For example, in the Sierra Nevada-San Bernardino Mountains, ozone is regarded as the main cause of the decline of pine species such as ponderosa pine (Pinus ponderosa) and Jeffrey Pine (Pinus jeffreyi). In the northern Appalachian Mountains, where the decline of red spruce (Picea rubens) has been observed, relatively high concentrations of ozone have been recorded. In the southeastern part of the United States, it has also been suggested that ozone is a factor in the decline of eastern white pine (Pinus strobus)."
"In Japan, tropospheric ozone concentrations have been increasing in recent years, and concentrations of ozone high enough to cause harmful effects on forest tree species have been recorded. Based on these facts, ozone is considered to be one of the main factors relating to forest decline and tree dieback in Japan. In fact, relatively high concentrations of ozone over 100 ppb have been recorded in the Oku-Nikko area and at Mt. Hinokiboramaru in the Tanzawa Mountains, where the decline and dieback of Japanese beech (Fagus crenata) have been observed. Thus, adverse impacts of ambient ozone on growth and physiological functions such as photosynthesis of forest tree species are matters of concern."
"Ozone in the atmosphere is absorbed into the leaf tissues of trees through the stomata, and causes
visible damage on the leaves, as well as a reduction of growth and suppression of physiological
functions such as photosynthesis. Based on the results obtained from several studies conducted in
Japan, there are great differences in ozone sensitivity among Japanese forest tree species, in terms of
growth and net photosynthesis. To clarify the sensitivity of growth of forest tree species to ozone, in one
study, seedlings of 16 tree species were exposed to either charcoal-filtered air or ozone for several
years."
"The study ranked various species for ozone sensitivity of the whole-plant dry mass with accumulated ozone exposure over a threshold of 40 ppb at 20 ppm・h [from high to low sensitivity: Japanese poplar (Populus maximowiczii) > trident maple (Acer buergerianum) > Japanese beech (Fagus crenata) and eastern white pine (Pinus strobus) > Japanese ash (Fraxinus japonica) > Japanese red pine (Pinus densiflora) > Nikko fir (Abies homolepis) > yellow poplar (Liriodendron tulipifera) > Japanese larch (Larix kaempferi) > Japanese white birch (Betula platyphylla var. japonica) and mizunara oak (Quercus mongolica) > konara oak (Quercus serrata) > Japanese cedar (Cryptomeria japonica) and Norway spruce (Picea abies) > Japanese black pine (Pinus thunbergii) > Japanese cypress (Chamaecyparis obtuse)]. The AOT40 values corresponding to a 10 percent reduction in the whole-plant dry mass were approximately 8 ppm・h for Japanese popular, the most sensitive species, and 12-21 ppm・h for Japanese red pine, eastern white pine, Japanese beech, trident maple and Japanese ash."
"In Maebashi City of Gunma Prefecture, the site of the study described above, AOT40 values for six
months were 10-24 ppm・h. At Inukoeji in the Tanzawa Mountains of Kanagawa Prefecture, relatively
high concentrations of ozone over 0.12 ppm were observed, and the AOT40 value from March to June
in 1997 was approximately 30 ppm・h (Aso 1999). Taking these observations and results of
experimental studies into account, it can be deduced that ozone causes harmful effects on relatively
sensitive tree species such as Japanese beech. Since tropospheric ozone concentrations are expected
to increase steadily in Japan, ozone has the potential to adversely affect many Japanese forest tree
species in the future."
I was excited to find some research where controlled fumigation experiments were performed. One, from Japan was just published in 2007:
"Growth and photosynthetic responses of Fagus crenata seedlings to O3 under different nitrogen loads"
"To obtain the basic data for evaluating the critical level of ozone (O3) to protect Japanese deciduous broad-leaved forest tree species, the growth and photosynthetic responses of Fagus crenata seedlings to O3 under different nitrogen (N) loads were investigated. The seedlings were grown in potted andisol supplied with N as NH4NO3 solution at 0, 20 or 50 kg ha−1 year−1 and were exposed to charcoal-filtered air or O3 at 1.0, 1.5 and 2.0 times the ambient concentration for two growing seasons. The interactive effect of O3 and N load on the whole-plant dry mass of the seedlings at the end of the second growing season was significant. The O3-induced reduction in the whole-plant dry mass of the seedlings was greater in the relatively high N treatment than that in the low N treatment. This interactive effect was mainly due to the difference in the degree of O3-induced reduction in net photosynthesis among the N treatments. The degree of O3-induced reduction in N availability to photosynthesis was greater in the relatively high N treatment than that in the low N treatment. In conclusion, the sensitivity of growth and photosynthetic parameters of F. crenata seedlings to O3 become high with increasing amounts of N added to the soil. Therefore, N deposition from the atmosphere should be taken into account to evaluate the critical level of O3 to protect Japanese deciduous broad-leaved forest tree species."
Getting back to damage done to annual crops, a link led to research from 2004 by a Princeton professor, Dr. Mauzerall, which is a bit shocking. She actually describes yield reductions with an emotionally-laden term, "tremendous losses" and no wonder - the percentages of loss predicted for grains and for the economy are staggering:
"Characterizing distributions of surface ozone and its impact on grain production in China, Japan and South Korea: 1990 and 2020"
"Using an integrated assessment approach, we evaluate the impact that surface O3 in East Asia had on agricultural production in 1990 and is projected to have in 2020....We find that given projected increases in O3 concentrations in the region, East Asian countries are presently on the cusp of substantial reductions in grain production....We conclude that East Asian countries may have tremendous losses of crop yields in the near future due to projected increases in O3 concentrations....Between 1990 and 2020 grain yield loss due to O3 exposure is projected to increase by 35%, 65% and 85% in Japan, Korea and China, respectively, with resulting economic costs increasing by approximately the same amount."
"Both the 1990 and 2020 animations include the global distributions of total O3, CO, PAN, HNO3 and NOx. In addition, for each region (North America, Europe, East Asia, Former Soviet Union, Tropical Asia, Africa, and South America), and emission type (fossil fuel combustion and biomass burning) we have conducted “tagged” simulations. In these tagged simulations, the emissions of CO and NOx (including its oxidation species HNO3 and PAN) from one region of the world are separately identified and tracked through their chemical transformations and global transport. The distribution of tagged tracers are shown in two panels – the top panel shows, at any given location, the percentage of the chemical species that originated from the particular region as a fraction of the global total, and the bottom panel shows the actual concentration of the tracer."
It turns out that in Bavaria there was a fumigation experiment on mature trees similar to the FACE sites in the US, which ran from 2002 to 2006, called CASIRO3Z, an acronym derived from: The Carbon Sink Strength of Beech in a Changing Environment: Experimental Risk Assessment of Mitigation by Chronic Ozone Impact - whew!
A study from Germany published in 2007, "Root parameters and types of ectomycorrhiza of young beech plants exposed to different ozone and light regimes":
"Tropospheric ozone (O(3)) triggers physiological changes in leaves that affect carbon source strength leading to decreased carbon allocation below-ground, thus affecting roots and root symbionts. The effects of O(3) depend on the maturity-related physiological state of the plant, therefore adult and young forest trees might react differently. To test the applicability of young beech plants for studying the effects of O(3) on forest trees and forest stands, beech seedlings were planted in containers and exposed for two years in the Kranzberg forest FACOS experiment (Free-Air Canopy O(3) Exposure System, http://www.casiroz.de to enhanced ozone concentration regime (ambient control and double ambient concentration, not exceeding 150 ppb) under different light conditions (sun and shade). After two growing seasons the biomass of the above- and below-ground parts, beech roots (using WinRhizo programme), anatomical and molecular (ITS-RFLP and sequencing) identification of ectomycorrhizal types and nutrient concentrations were assessed...."
"In the ozone fumigated plants the number of types, number of root tips per length of 1 to 2 mm root diameter, root length density per volume of soil and concentration of Mg were significantly lower than in control plants. Trends to a decrease were found in root, shoot, leaf, and total dry weights, total number of root tips, number of vital mycorrhizal root tips, fine root (mass) density, root tip density per surface, root area index, concentration of Zn, and Ca/Al ratio. Due to the general reduction in root growth indices and nutrient cycling in ozone-fumigated plants, alterations in soil carbon pools could be predicted".
Another study, "Tree and stand growth of mature Norway spruce and European beech under long-term ozone fumigation" that came out of that open-air fumigation had the following interesting result:
"In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO(3)) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO(3)). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO(3) caused, on average, a decrease of 10.2 m(3) ha(-1) yr(-1) in European beech.
"Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth"....Well, I suppose that could explain why the Smithsonian and Harvard foresters are able to claim the forest is growing!!!
Generation and transformation process of ozone and nitrogen compounds. O3 is formed through the photolysis of NO2. The production of NO2 is caused by O3 and peroxide radicals. NO2, reacts again to become HNO3 and PAN. Note: R indicates alkyl group, aryl group, etc. PAN indicates peroxyacetylnitrate.
Distribution of NOx emissions in Asia in 1980 (left) and 2000 (right). Units: Tons year-1 per grid cell
Modeling prediction on geographical distribution of ground-level ozone concentrations in 1993 above (average from May to August) and 2025 below. (Lelieveld and Dentener 2000)
"It does seem counter-intuitive that lower emissions could lead to higher ozone on weekends, but that is what makes the 'weekend ozone effect' such an interesting phenomenon to study.
In essence, ozone is formed by a chain of chemical reactions in the presence of sunlight. This process is often refereed to as 'photochemical ozone production', and is a significant contributor to ozone levels observed on weekends in the California South Coast Air Basin. The relative abundances of the ingredients that go into these chain reactions, specifically nitrogen oxide (NOx) and volatile organic compounds (VOCs), play a key role in determining how fast the chemistry proceeds and how efficiently the reactions form ozone. Measurements in the South Coast Air Basin during a field study in 2010 show little change in VOC emissions between weekdays and weekends, yet large decreases in NOx emissions on weekends. Weekday-to-weekend differences in emissions in the South Coast Air Basin have been widely attributed to differences in activity of gasoline-fueled versus diesel-fueled vehicles. Large reductions in NOx on weekends compared to small changes in VOCs result in a relative increase in the ratio of VOCs to NOx on weekends. The increased relative abundance of VOCs compared to NOx makes the chemistry proceed faster and produce ozone more efficiently on weekends compared to weekdays, thereby leading to higher observed ozone levels on weekends."
So there you have it, all you Ozonistos and Ozonistas!
Next, I'm going to reproduce the entire Section 6 of the report from Japan, because it is specifically about trees and forests:
"Forests act as a life-support system on the Earth. Through photosynthesis, trees, a main component of
forest ecosystems, supply the oxygen that is indispensable to support life. Forests also preserve our
environment by fixing carbon dioxide, a major cause of the global warming, and by absorbing air pollutants. Unfortunately, forest decline and tree dieback are being observed in many areas of Japan."
"In the Tanzawa Mountains of Kanagawa Prefecture, the decline and dieback of Japanese beech
(Fagus crenata) have been observed at Mt. Hinokiboramaru and Mt. Hirugatake, and decline of Japanese
fir (Abies firma) has been observed at Mt. Ohyama. In the Oku-Nikko area of Tochigi Prefecture, Veitch’s fir (Abies veitchii), Maries fir (Abies mariesii) and Erman's birch (Betula ermanii) are in a state of decline. In the Sanyo Region, which includes Hiroshima Prefecture, the decline of Japanese red pine (Pinus densiflora) has been observed. In some areas along the Sea of Japan, including Ishikawa, Tottori and Shimane Prefectures, the decline and dieback of konara oak (Quercus serrata) and mizunara oak (Quercus mongolica) have also been observed."
"Several hypotheses have been presented on the causes of forest decline or tree dieback in Europe
and North America. Possible causes differ with each site. Ozone, soil acidification due to acid deposition
and excess nitrogen deposition from the atmosphere have been suggested as causes in northern
Europe; ozone, acid deposition such as acid mist and fog and sulfur dioxide have been suggested in
western Europe; and sulfur dioxide, nitrogen dioxide, ozone and acid deposition such as acid mist/fog
have been suggested in eastern Europe."
"In North America, meanwhile, ozone is thought to be closely related to the forest decline and tree dieback. For example, in the Sierra Nevada-San Bernardino Mountains, ozone is regarded as the main cause of the decline of pine species such as ponderosa pine (Pinus ponderosa) and Jeffrey Pine (Pinus jeffreyi). In the northern Appalachian Mountains, where the decline of red spruce (Picea rubens) has been observed, relatively high concentrations of ozone have been recorded. In the southeastern part of the United States, it has also been suggested that ozone is a factor in the decline of eastern white pine (Pinus strobus)."
"In Japan, tropospheric ozone concentrations have been increasing in recent years, and concentrations of ozone high enough to cause harmful effects on forest tree species have been recorded. Based on these facts, ozone is considered to be one of the main factors relating to forest decline and tree dieback in Japan. In fact, relatively high concentrations of ozone over 100 ppb have been recorded in the Oku-Nikko area and at Mt. Hinokiboramaru in the Tanzawa Mountains, where the decline and dieback of Japanese beech (Fagus crenata) have been observed. Thus, adverse impacts of ambient ozone on growth and physiological functions such as photosynthesis of forest tree species are matters of concern."
"Ozone in the atmosphere is absorbed into the leaf tissues of trees through the stomata, and causes
visible damage on the leaves, as well as a reduction of growth and suppression of physiological
functions such as photosynthesis. Based on the results obtained from several studies conducted in
Japan, there are great differences in ozone sensitivity among Japanese forest tree species, in terms of
growth and net photosynthesis. To clarify the sensitivity of growth of forest tree species to ozone, in one
study, seedlings of 16 tree species were exposed to either charcoal-filtered air or ozone for several
years."
"In Maebashi City of Gunma Prefecture, the site of the study described above, AOT40 values for six
months were 10-24 ppm・h. At Inukoeji in the Tanzawa Mountains of Kanagawa Prefecture, relatively
high concentrations of ozone over 0.12 ppm were observed, and the AOT40 value from March to June
in 1997 was approximately 30 ppm・h (Aso 1999). Taking these observations and results of
experimental studies into account, it can be deduced that ozone causes harmful effects on relatively
sensitive tree species such as Japanese beech. Since tropospheric ozone concentrations are expected
to increase steadily in Japan, ozone has the potential to adversely affect many Japanese forest tree
species in the future."
I was excited to find some research where controlled fumigation experiments were performed. One, from Japan was just published in 2007:
"Growth and photosynthetic responses of Fagus crenata seedlings to O3 under different nitrogen loads"
"To obtain the basic data for evaluating the critical level of ozone (O3) to protect Japanese deciduous broad-leaved forest tree species, the growth and photosynthetic responses of Fagus crenata seedlings to O3 under different nitrogen (N) loads were investigated. The seedlings were grown in potted andisol supplied with N as NH4NO3 solution at 0, 20 or 50 kg ha−1 year−1 and were exposed to charcoal-filtered air or O3 at 1.0, 1.5 and 2.0 times the ambient concentration for two growing seasons. The interactive effect of O3 and N load on the whole-plant dry mass of the seedlings at the end of the second growing season was significant. The O3-induced reduction in the whole-plant dry mass of the seedlings was greater in the relatively high N treatment than that in the low N treatment. This interactive effect was mainly due to the difference in the degree of O3-induced reduction in net photosynthesis among the N treatments. The degree of O3-induced reduction in N availability to photosynthesis was greater in the relatively high N treatment than that in the low N treatment. In conclusion, the sensitivity of growth and photosynthetic parameters of F. crenata seedlings to O3 become high with increasing amounts of N added to the soil. Therefore, N deposition from the atmosphere should be taken into account to evaluate the critical level of O3 to protect Japanese deciduous broad-leaved forest tree species."
Getting back to damage done to annual crops, a link led to research from 2004 by a Princeton professor, Dr. Mauzerall, which is a bit shocking. She actually describes yield reductions with an emotionally-laden term, "tremendous losses" and no wonder - the percentages of loss predicted for grains and for the economy are staggering:
"Characterizing distributions of surface ozone and its impact on grain production in China, Japan and South Korea: 1990 and 2020"
Relative yield loss for 4 crops, from 1990 (L) to 2020 (R) due to ozone |
I went to Professor Mauzerall's webpage at Princeton and found this engaging toy - animations of emissions. You can change dates, regions and timeframes, it's such fun! Below is a screenshot - but you should absolutely click here and play around with it yourself. It's amazing.
Here's the description of how the projections were modeled...and note - the 2020 outcomes are NOT worst case scenarios because they assume, among other variables, "increased concern for environmental and social sustainability". Ha! I guess this was written well before the ascent of the Tea Party, Mittens, Santorum, Gingrich and even Sarah Palin - AND the story at the top, about governments taking no heed whatsoever of actual science when establishing policy.
"The B2 scenario family is intended to represent one where there is moderate population growth, intermediate levels of economic development, increased concern for environmental and social sustainability. Hence, it is not a “worst-case” scenario."
This is a photo from their colorful poster, which can be viewed here |
Personally I think their overall results are a bit sunnier than reality, but keep in mind they were comparing the condition of trees exposed to twice the ambient ozone level to that of trees AT ambient level - and NOT to trees in clean air. Nevertheless, several interesting studies derived from that project - way too many for me to read and post each one. But here are some abstracts:
"Tropospheric ozone (O(3)) triggers physiological changes in leaves that affect carbon source strength leading to decreased carbon allocation below-ground, thus affecting roots and root symbionts. The effects of O(3) depend on the maturity-related physiological state of the plant, therefore adult and young forest trees might react differently. To test the applicability of young beech plants for studying the effects of O(3) on forest trees and forest stands, beech seedlings were planted in containers and exposed for two years in the Kranzberg forest FACOS experiment (Free-Air Canopy O(3) Exposure System, http://www.casiroz.de to enhanced ozone concentration regime (ambient control and double ambient concentration, not exceeding 150 ppb) under different light conditions (sun and shade). After two growing seasons the biomass of the above- and below-ground parts, beech roots (using WinRhizo programme), anatomical and molecular (ITS-RFLP and sequencing) identification of ectomycorrhizal types and nutrient concentrations were assessed...."
"In the ozone fumigated plants the number of types, number of root tips per length of 1 to 2 mm root diameter, root length density per volume of soil and concentration of Mg were significantly lower than in control plants. Trends to a decrease were found in root, shoot, leaf, and total dry weights, total number of root tips, number of vital mycorrhizal root tips, fine root (mass) density, root tip density per surface, root area index, concentration of Zn, and Ca/Al ratio. Due to the general reduction in root growth indices and nutrient cycling in ozone-fumigated plants, alterations in soil carbon pools could be predicted".
"In a 50- to 70-year-old mixed stand of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) in Germany, tree cohorts have been exposed to double ambient ozone (2xO(3)) from 2000 through 2007 and can be compared with trees in the same stand under the ambient ozone regime (1xO(3)). Annual diameter growth, allocation pattern, stem form, and stem volume were quantified at the individual tree and stand level. Ozone fumigation induced a shift in the resource allocation into height growth at the expense of diameter growth. This change in allometry leads to rather cone-shaped stem forms and reduced stem stability in the case of spruce, and even neiloidal stem shapes in the case of beech. Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth. On the stand level, 2xO(3) caused, on average, a decrease of 10.2 m(3) ha(-1) yr(-1) in European beech.
"Neglect of such ozone-induced changes in stem shape may lead to a flawed estimation of volume growth"....Well, I suppose that could explain why the Smithsonian and Harvard foresters are able to claim the forest is growing!!!
This is amazing...and frightening.
ReplyDeleteThank you Gail for your research and pulling in all this information.
ReplyDeleteYou have uncovered a vast barrier of ignorance (denial applies to everyone) - and it is much larger than I had thought.
http://www.youtube.com/watch?v=oduKRKUKKww
ReplyDeleteI've been looking through tons of facebook photos of friends and something I'm noticing is that this tree death has actually been happening since long before I noticed it in 2009. This is so weird, it's almost like my mind must have blocked it out previous to that. Now I understand why people don't seem to see it even now. Just something I wanted to share. I guess this has been going on a long long time, just it took us all a long time to notice.
ReplyDeleteTrue - acid rain was a huge problem and killed a lot of trees starting in the 70's. Cleaning up SOx did a lot to reduce acid rain but the soils are not recovering particularly well. I went to the "New Forest" (which is 1000 years old) in England about 5 years ago and I was really disappointed that all the big old trees I was anticipating were broken and covered with vines. The deep dark woods I thought I would find was hot and light and sunny. So that goes a way back.
ReplyDeleteWhat's different very recently though, aside from the scale and rapidity of tree death, is the visible symptoms on leaves, including annuals, that is everywhere. I know it wasn't like that even 5 years ago, because I garden, and I'm always looking. If you read papers about crop loss, there is definitely an increasing trend in damage over time.
And for instance there are trees and shrubs that I planted 8 - 10 years ago that looked excellent up until 2008. Then their leaves - and those of all the other older trees - drooped, and started having spots and marginal burn - and lately their bark is splitting and so forth.
The first time I saw a mature but not ancient tree fall over, it shocked me, because I had never seen one just up and die. That was 20 or so years ago, but it was just that one until 2009. So it's been going on a while, for sure. But still, there is something dramatic and sudden happening in just the past few years.
I've been living in the same spot since around 1982 and the pine trees, young and old, for example, were so thick you couldn't see through them until they started shedding inner needles around 2009. I know that is when it started, because people have been planting evergreens as privacy screens for ages, and they worked perfectly well until then. Now, you can see through them to the houses and buildings that used to be hidden.
Another dramatic change is the understory of the woods - the perennial shrubs. I used to joke that you needed a machete to walk through the woods behind my house, it was that thick. You couldn't see more than a few feet into the woods from the edge of the lawn. Now, it's clear for hundreds of yards. Some of that is from deer eating young seedling trees. But most of the reason now you can't walk through the woods is all the fallen branches and trunks, and that's not deer.
Keep looking, Anon! Somebody needs to get to the bottom of this before it's too late.
Thanks, Witsend!
ReplyDeleteI suspect, if someone wanted to research this weekday vs. weekend ozone effect in Georgia, they would find the same thing. But I'm just guessing. This might be happening in many places: driving and traffic patterns.
The loblolly pines that survived pine bark beetle show the same yellowed needles here. It's so noticeable, anyone can see it driving along the roads.
Keep on, keepin' on!
catman
Thank you for your tireless work! Thank you for the data, the interpretations, and for honestly and bravely showing your thoughts and despair. Those too matter, as Berry knows and as we're all starting to find out.
ReplyDeleteThanks for taking a global perspective. Looking at the global maps, I see we have it pretty good yet here in the north. I've been thinking of doing a round-the-Baltic nature trip someday, and this would one thing to check out.
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