As trees succumb to air pollution, their branches weakened and their root systems shriveling, it's not surprising to see ever more frequent stories in the news about property damage, power outages, and injuries from falling branches. Sure enough, this week had some classic examples. Of course, the snowstorm in that hit Seattle produced some
terrific photos.
It's only right that trees exact their vengeance on cars, which produce much of the pollution that is toxic to them.
Another predictable consequence of dying vegetation is increased frequency and severity of landslides and mudslides, with fewer roots to anchor soil and absorb precipitation.
The tree below is so covered with moss and lichen, it would have been surprising if it hadn't fallen.
Another tree covered with lichen. This road had so many downed trees it is expected to remain closed for days.
The Humana Challenge, a golf competition, was
shut down on Saturday because of high winds which rendered the course hazardous, strewn with fallen trees. And no wonder, those still standing look terrible.
The trees on
the course have the same corroded bark that New Jersey trees exhibit - falling off the trunks and exposing the raw wood beneath. This one looks rotted.
While I was looking for photos of the golf course, it
turns out that huge trees were falling in Palm Springs, as well:
And in what is becoming a sad but predictably increasing trend, a person
was killed by a falling tree, this time, a ranger in Yosemite.
Reading about that tragedy got me to thinking about the park, which I've never visited. The more I learned about it, the more disgusted I am that I never went there while I was in California and had the chance. Stupid stupid stupid! I guess, because I was living in a remote redwood grove on the Santa Cruz mountains, I felt no urge to travel to see trees. What a mistake. For instance, did you know that sometimes on a night with a full moon, the mist from the falls makes a moonbow? I didn't!
The first place I happened upon is a
blog about Yosemite, which is unwittingly documenting the dying trees there.
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| March 2011 |
Except for the moonbow, these are some pictures from that blog, with a recent diary entry that leads me to believe the animals there are lacking food, something you'd expect as vegetation dies back.
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| Incredible that trees can grow on what seems like just boulders. Now, trees look stunted and some have no needles at all.. |
Did you know that sometimes, the setting sun hits the falls in just the right way so that they look like they are on fire? But the branches in the foreground don't look so good...
"Tony Carlstrom reports observing a California ground squirrel wrestle, subdue and kill a chipmunk atop Sentinel Dome on Tuesday. The chipmunk's body was then dragged off by the squirrel. This kind of gruesome aggression is not something we generally expect from those little snack-beggars. I have observed California ground squirrels feeding on road-killed squirrels in Yosemite Valley."
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| Evergreens along the river have lost most of their needles. |
"Rangers at Hodgdon Meadow watched a mountain lion kill a mule deer buck a few days ago. Local bucks are still in velvet but have full grown racks. Lions generally prefer easier prey than large adults males approaching rutting season."
For a terrifying graph depicting just how fast populations crash when the food chain is disrupted, check out the seal, sea lion and otter study here.
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| These pines are so transparent, it's no wonder they are toppling over. |
That blog had a link to several "Yosemite Nature Notes"
videos, which, although they are produced by the Park Service as sort of promotional advertisements - and are really cool - they also are mutely revealing the dying trees. I couldn't embed them, but I recommend watching them if you're in a nature-loving mood. I took screenshots instead. The series, one of which is about "frazil ice", a sort of fast-moving, sloshy glacier in spring, starts off with an adorable owl.
Think about it. The sequoias are famous for being the largest trees on earth, and the oldest count their years in the thousands...and yet there are much younger trees of all ages lying on the ground (and falling on rangers). Following is official Park
information about ozone and other pollutants that affect Yosemite.
Air Quality at Yosemite National Park
What’s in the Air?
Yosemite NP, California
Most visitors who come to national parks expect clean air and clear views. However, Yosemite National Park (NP), California, experiences some of the worst air pollution of any national park in the U.S. The park is downwind of many air pollution sources, including agriculture, industry, major highways, and urban pollutants from as far away as the San Francisco Bay Area. Air pollutants carried into the park can harm natural and scenic resources such as forests, soils, streams, fish, and visibility.
How is air pollution affecting Yosemite National Park?
- Ground-level ozone in the park often reaches levels harmful to plants; ozone levels also exceed human health standards at times. more »
- Nitrogen and sulfur in air pollution are carried by rain and snow into park ecosystems causing changes to high elevation lakes and streams. more »
- Airborne mercury and pesticides deposit on park lands and waters, potentially accumulating in fish to levels harmful to wildlife and human health. more »
- Fine particles of air pollution, often a result of fire and smoke, cause haze in the park, affecting how well and how far visitors can see vistas and landmarks. Fine particle levels also exceed human health standards at times. more »
Effects of ozone on vegetation at Yosemite NP include:
- Widespread injury to ponderosa pine needles, with up to 30–40% of pines injured at certain survey sites (Peterson et al. 1991; Peterson and Arbaugh 1992; Arbaugh et al. 1998);
- Reduced growth of ozone-injured pines (Peterson et al. 1991; Peterson and Arbaugh 1992);
- Greater ozone injury on low elevation ponderosa pines as compared to ponderosa pines on dry, upslope areas in the park, indicative of stomatal opening and ozone uptake on trees in moist areas (Panek and Ustin 2004).
If you're in the mood for punishment, you can read the NPS Annual Data Summary
2010, Gaseous Pollutant Monitoring Program - or reports from earlier years - which exhaustively document the crazy convoluted methods of calculation for measuring air pollution borrowed from the EPA, all designed to indicate the situation is improving. Nevertheless, here is what
they say in spite of themselves:
"Ozone pollution
, threatens human health and park plants. Ozone is a caustic gas that occurs both at high altitude (in the stratosphere) and near the ground (in the troposphere) in the presence of sunlight. Up high, that stratospheric ozone layer is beneficial, blocking much of the sun's harmful ultraviolet radiation (like a sunscreen). Down low, tropospheric ozone can damage both plant and animal tissues, especially leaf or lung tissue. Ozone is not emitted directly as a pollutant, but forms secondarily in the presence of chemical precursors, called nitrogen oxides (NOx) and hydrocarbons, and in the presence of strong sunlight. Automobiles, power plants, and factories are the main producers, and most ozone, like the haze that obscures Yosemite's vistas, is caused by precursors blown over from urban source regions to the west."
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The "Snowcone" - it develops every spring as the droplets from the waterfall freeze and build up hundreds of feet
Trees on the cliff on the right side have barely any needles left. |
"For plants, ozone's effects become cumulative because they can't move themselves indoors to avoid the ozone damage. Repairing ozone damage saps the energy and nutrients that plants use for defense against other kinds of environmental stress, like drought or pests. The Environmental Protection Agency has proposed more stringent “secondary” standards that track cumulative impacts of ozone on ecosystems; however, those standards and the metrics that comprise them have not been finalized."
[note - Obama just nixed those more stringent standards]
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| This is the Wanona Sequoia, through which a tunnel was cut in 1881 |
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| It became a favorite place for tourists to photograph. |
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The narrater adds, the car then became the ruler, the measurement against which scale was defined. Ack - it burns!
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"Most of the pollution that causes high ozone concentrations contains nitrogen. Some forms of this nitrogen can directly deposit (dry deposition) to landscapes or be scavenged and then deposited by rain or snow during storms (wet deposition). Yosemite has monitored wet deposition for more than two decades. These measurements, combined with more recent estimates of dry deposition, suggest that the deposition of nitrogen from the atmosphere to the Sierra, especially in the fragile high elevations, is up to five times higher than the 19th-century levels."
"As any gardener will tell you, nitrogen is most often a good thing, but over fertilizing with nitrogen can harm your plants. Yosemite soil has very, very low levels of nitrogen due to the nitrogen-poor granite that comprises its soil; the short, dry growing season; and the prevalence of fires that burn off nitrogen from soils. Plants that grow here are adapted to those low nitrogen levels. Weedy, fast-growing, nitrogen-loving plants can easily invade, like dandelions in a lawn, if nitrogen levels are increased. In the nitrogen-poor Great Basin region to the east of Yosemite, research has implicated increased nitrogen deposition with the rapid invasion of cheat grass throughout millions of square miles of sagebrush. This cheat grass now carries fire to the somewhat separate clumps of sage and allows thousands of acres to burn at once, where only small fires occurred before."
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The Wanona fell in the winter of 68/69. It stood close to a hundred years even after being gutted.
Another cautionary tale that something unnatural - caustic? - is causing trees to die so young. |
"Study of Lichen as an Indicator of Nitrogen Deposition: Yosemite is poised to kick off a new research project that will use lichen species diversity and abundance to measure air quality impacts. Specifically, the park plans to research how lichen serves as an indicator of nitrogen deposition as it varies over areas of the park."
Wow!! Did they say something about lichens and nitrogen? The following is from their research page:
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| Don't miss the itty-bitty people in this picture! |
"The diversity and distribution of lichens tell a great deal about air quality and the level of certain types of pollution, especially nitrogen, in the park. Lichens are intimately connected to their environment. They lack roots and rely upon the atmosphere for their water and nutrients. Because they do not have an outer epidermal layer, they cannot discriminate between nutrients and pollutants, and, as a result, both pollutants and nutrients are absorbed. When pollutants accumulate above certain levels, lichen growth and health are impaired. Air quality readily influences the composition of lichen communities because individual species differ in their tolerance levels. Due to little seasonal variation in lichen communities, monitoring lichen community composition has become one of the best biological measures of nitrogen and sulfur-based pollution in forests."
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| Is it just me or do the tops of these ancient trees look disproportionately small to their trunks? |
"Lichen communities in Yosemite are diverse, but several pollution-intolerant species, such as Alectoria sarmentosa, Bryoria fremontii, and Usnea spp. are uncommon and may be in decline. Nitrogen-loving species such as Candelaria concolor, Physcia, Physconia and Xanthoria spp. appear to be increasing in abundance, particularly along the Merced River corridor."
Well, nitrogen-loving species are sure increasing everywhere I look! Unfortunately, the link to results goes back circuitously to the former page...so I'll have to follow up later. Under the umbrella of the US Global Change Research Program (which includes the following governmental agencies: Dept. of Commerce, Dept of Defense, Dept. of Energy, Interior Dept, Dept. of State, Transportation, Health & Human Services, NASA, National Science Foundation, US Agency for International Development, and the Smithsonian Institute, USDA, and EPA - you'd almost think the government believes the climate is changing and we need to prepare for it?) their newest report to Congress on "Our Changing Planet" is due any day now, if history is a guide. Meanwhile, following are excerpts from their section
on Forests:
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| Far too many trees down...and way too much sunlight filtering to the forest floor. |
Effects on Forest Productivity "Several environmental factors that control the water and carbon balances of forests are changing rapidly and simultaneously. The global increases in atmospheric CO2 concentrations are the best-documented factor. However, in some areas, other important atmospheric constituents are also increasing, including nitrogen oxides (a direct product of fossil fuel combustion that causes acid rain) and ground-level ozone ("smog," a product of chemical reactions between hydrocarbons and nitrogen oxides in the presence of sunlight)." "A synthesis of laboratory and field studies and modeling indicates that forest productivity increases with the fertilizing effect of atmospheric CO2, but that these increases are strongly tempered by local conditions such as moisture stress and nutrient availability. Across a wide range of scenarios, it appears that modest warming could result in increased carbon storage in most forest ecosystems in the conterminous US. Yet under some warmer scenarios, forests, notably in the Southeast and the Northwest, could experience drought-induced losses of carbon, possibly exacerbated by increased fire disturbance. These potential gains and losses of carbon will be subject to changes in land-use, such as the conversion of forests to agricultural lands." "Other components of environmental change, such as nitrogen deposition and ground-level ozone concentrations, also affect forest processes. Models identify a synergistic fertilization response between CO2 and nitrogen enrichment, leading to further increases in productivity. Ozone, however, can suppress these gains. Current ozone levels, for example, have likely decreased production by 10% in Northeast forests and 5% in southern pine plantations. Interactions among these physical and chemical changes and other components of global change are important in determining the future of US forests."
"The effects of climate change on the rate and magnitude of disturbance (forest damage and destruction associated with fires, storms, droughts and pest outbreaks) will be an important factor in determining whether transitions from one forest type to another will be gradual or abrupt. If disturbances in New England, for example, do not increase, there is a possibility of a smooth transition from the present maple, beech, and birch tree species to oak and hickory. Where disturbances increase, transitions are very likely to be abrupt." "Potential climate-induced changes in forests must be put into the context of other human-induced pressures, which will undoubtedly change significantly over future decades. While the potential for rapid changes in natural disturbances could challenge current management strategies, these changes will co-occur with human activities such as agricultural and urban encroachment on forests, multiple use of forests, and air pollution."
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| The waterfall splashes are frozen on the rockface. |
One of my concerns about the "abrupt" transition from living forest to dead forest, is that it is inexplicable by merely a confluence of "disturbances" such as drought, pest outbreaks and persistent background ozone, because it is astonishingly widespread and uniform, rather than localized. This has led me to consider whether there is a major disruption that has gone under the radar, and I really wish somebody with some expertise would investigate this. Perhaps it is methane, the sudden huge release of which seems to have taken scientists by surprise...or perhaps it is the use of biofuels, which is a relatively new practice. I suppose it shouldn't be considered perplexing...
...but it turns out the American Enterprise Institute published a critique of biofuel subsidies based partly on the increase in ozone their emissions produce. Following are excerpts, with photos from the Yosemite Park Service video about their black oak trees. |
"The Many Downsides of Ethanol"
"While ethanol promoters make it sound as if ethanol is the solution to all our energy woes--dependence on foreign oil, diminishing oil stocks, the environmental consequences of energy use, the decline of the family farm, and so on--a considerable amount of research has shown that ethanol has far more peril than it does promise."
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| An acorn woodpecker makes holes in a dead branch to store acorns. |
"Ethanol and Greenhouse Gas Emissions. Though ethanol is often pitched as a good solution to climate change because it simply recirculates carbon in the atmosphere, there is more than one kind of greenhouse gas to consider. Ethanol, blended with gasoline, actually turns out to increase the formation of potent greenhouse gases more than gasoline does by itself. As far back as 1997, the U.S. Government Accountability Office determined that the ethanol production process produces relatively more nitrous oxide and other potent greenhouse gases than does gasoline. In contrast, the greenhouse gases released during the conventional gasoline fuel cycle contain relatively more of the less potent type, namely, carbon dioxide.[11]"
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| Even though the film tries to portray the trees in their best light, they can't seem to avoid including broken branches. |
"Last fall, Paul Crutzen, a Nobel-prize-winning chemist, confirmed these findings. Crutzen and his coauthors found that when the extra N2O emission from biofuel production is calculated in "CO2-equivalent" global warming terms, and compared with the quasi-cooling effect of "saving" emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), depending on N fertilizer uptake efficiency by the plants, can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings.[12]"
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| This view of springtime catkins has terminal growth that isn't leafing out at all. |
"Ethanol and Air Pollution. Although the U.S. Environmental Protection Agency (EPA) claims a net decrease in greenhouse gas emissions from using ethanol, they recognize that ethanol use is a problem for conventional air pollutants. Ethanol use, according to the EPA, will increase the emission of chemicals that lead to the production of ozone, one of the nation's most challenging local air pollutants."
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| When the camera is close to the bark, it is evident that clumps are breaking off the trunk. |
"At the same time, other vehicle emissions may increase as a result of greater renewable fuel use. Nationwide, EPA estimates an increase in total emissions of volatile organic compounds and nitrogen oxides (VOC + NOx) between 41,000 and 83,000 tons [due to increased use of ethanol]. . . . Areas that experience a substantial increase in ethanol may see an increase in VOC emissions between 4 and 5 percent and an increase in NOx emissions between 6 and 7 percent from gasoline powered vehicles and equipment.[15]"
[It's hard to tell how healthy this oak is in the winter, but it's easy to see when the leaves are out that this crown is lacking fullness.]
"Increases in pollutants have also been shown at the state and local level. In 2004, the California Air Resources Board released a study that found that gasoline containing ethanol caused VOC emissions to increase by 45 percent when compared to gasoline containing no oxygenates. And in mid-2006, California's South Coast Air Quality Management District determined that gasoline containing 5.7 percent ethanol may add as much as seventy tons of VOCs per day into the state's air.[16]"
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| As the season progresses, the leaves, exposed to ozone, exhibit the same spotting and marginal burn seen in New Jersey. |
"For a sense of scale, consider that an air quality regulator in the region around Los Angeles can become employee of the month by coming up with a way of reducing emissions by one-tenth of a ton per day.[17] More recently, Mark Z. Jacobson, a researcher at Stanford University, estimated that switching to a blend of 85 percent ethanol and 15 percent gasoline--relative to 100 percent gasoline--may increase ozone-related mortality, hospitalization, and asthma by about 9 percent in Los Angeles and 4 percent in the United States as a whole.[18]"
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| The film explains that the black oak provides much food for wildlife, like this bear passing in front of a dead tree. |
"Ethanol and Water Pollution. In Water Implications of Biofuels Production in the United States, the National Academy of Sciences (NAS) points out that if the United States continues to expand corn-based ethanol production without new environmental protection policies, "the increase in harm to water quality could be considerable."[22]"
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| Acorns were a crucial source of food for many tribes of First People, who dried them and then ground them into flour. |
"Corn, according to the NAS, requires more fertilizers and pesticides than other food or biofuel crops. Pesticide contamination is highest in the corn belt, and nitrogen fertilizer runoff from corn already has the highest agricultural impact on the Mississippi River. In short, more corn raised for ethanol means more fertilizers, pesticides, and herbicides in waterways; more low-oxygen "dead zones" from fertilizer runoff; and more local shortages in water for drinking and irrigation."
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| These holes were made when the acorns were pounded with rocks to remove their shells. |
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Of course, acorns are a major part of a squirrel's diet, which reminds me...aren't some eating chipmunks?
And each other? They must be starving to turn to cannibalism. |
"The same phenomenon occurs in the Chesapeake Bay, in some summers affecting most of the waters in the mainstern bay.[23] A recent study by researchers at the University of British Columbia shows that if the United States were to meet its proposed ethanol production goals--15-36 billion gallons of corn and cellulosic ethanol by 2022--nitrogen flows to the Gulf of Mexico would increase by 10-34 percent.[24]"
