The WAGES of Sin...an Environmental Scourge

The witchhazel in front of the porch began blooming before Christmas, its heavenly scent perfuming air so warm it feels as though it should be spring - in fact, it still has green leaves!  Global warming feels so close and unnatural, so alien and dangerous, it almost seems quaint to worry about air pollution killing trees.  For instance, this paper, published last month in Nature Geoscience, estimates that HALF of all the warming we have created thus far by contributing greenhouse gases to the atmosphere has been offset by the concurrent production of aerosol pollution, which reflects UV radiation and has a cooling effect.  Presuming that's anything close to the truth, when industrial civilization comes to its inevitable ignominious end through peak oil or ecosystem collapse (as opposed to, say, nuclear war), and all those aerosols cease to be produced and replenished...it's going to get insanely hot, insanely fast.  Oh, and some version of the Joplin tornado will become a localized spectacle, everywhere.

Youngest daughter came home for the holidays from California, where she has been granted permission to pursue a PhD at Santa Cruz, studying the secret lives of sea otters.  She has kept me busy cooking, demanding Osso Buco, which I made with a Parmesan risotto and baby artichokes.  She also likes to knit, so we went to get some yarn.  The two nearest yarn shops have gone out of business we discovered, whether due to the general economic malaise or lack of interest, I don't know, but either way it doesn't bode well.  The essentials of being self-sufficient are waning when they should be resurrected - we will be needing knitters, weavers, and farmers!

Anyway, this necessitated a trip to the next most convenient yarn shop, in Basking Ridge, an historic town where most of the colonial homes that line the original path for horse-drawn carriages have morphed into mere façades, housing banks, restaurants and stores.  The parking lot is enclosed by an old wrought iron fence, parts of which are physically embedded in a line of trees.  Since the subject of tree tenacity has come up recently in comments at Wit's End, these images seem to be the perfect illustration of that.

The trees are of varying ages.  Below is the largest, and most amazing, because it completely encloses the fence.  It's hard to say how old, but it could be fifty or one hundred or more years old - the buildings are 19th century, and some even earlier.

It's slow growth has distorted the line of the fence, while meanwhile its roots have poured over the Belgian blocks that were added more recently, to line the drive.

Clearly, trees are capable of fantastically incredible feats allowing them to thrive against all odds, and yet...after all the years, even decades, that these particular trees swallowed iron undeterred, they are now being defeated by an invisible threat - air pollution.

Their bark is breaking and falling off, and many of them have opportunistic fungi sprouting from trunks and branches.

It's curious how some of them grew in one dimension.

A few have already died and been removed, as this rotted stump attests.

When I came upon this astonishing sight I was filled with an irrational joy.

I say irrational because even though I was thoroughly impressed at the stoic determination of these trees to thrive, it's impossible not to see simultaneously that for reasons beyond their control, or ability to evolve, they are not long for this world.

For these trees to have come so far only to, in essence, strangle from the fumes of industrial civilization is a cruel prank we have played upon Nature.

I had to take a picture of each one, in tribute.

The tree below isn't close enough to the fence to have started growing around it, but it is in the same poor condition as the others - at the top of the picture bark is cracking, and at the base of the tree, a good portion has fallen off completely.  It's not the fence that is killing them!

This pair, set back from the fence, is smothered in lichen, a sure signal, if not the cause, of impending death.

A decaying foundation is not auspicious where the trunk meets the ground.

The tree on the left of this cluster, further back behind the store, has lost much of its bark.

This is a close-up:

The other trunks are losing bark as well, they're just not as far along.

The fungus is another indication that the trees are dying off.

I took a long loop going home to take photos along the way, which will be interspersed with some of the most recent news and studies, mostly about the cascade of reactive nitrogen pollution.

It was a dark day, with occasionally spectacular clouds, so it was difficult to get bright pictures - but it was the only afternoon this holiday season when I've had time to just wander, so that's what we've got.  Gloom.  As it happens, with the leaves gone now that it's winter (in name if not temperature), it's even more obvious that trees are an endangered species.

This tree in front of Friendly's in Bernardsville is a terrific example because it displays all the symptoms of decline that have become so familiar.  Initiated by damage from ozone, death is often accelerated by - and blamed on - other agents such as insects, disease, fungus, extreme wind and drought.  The crown has lost many major branches.

Oh, and of course it has lichen all over the bark!

Cankers, which are caused by a fungus that is ultimately as lethal as a cancerous tumor, are bulging.  They used to be a rarity but now they are easily to be located, and sometimes there are more than a dozen on a single tree.

There are holes spewing a sort of vomit which over time stains the trunk.

This pattern of fluid staining bark black, white or brown only started, abruptly, a couple of years ago, but now is frequently found everywhere, on all varieties of tree.

And of course, chunks of bark are falling off, revealing the smooth heartwood to insect attack and the elements.  No tree can survive such a loss of protective shield.  Did we miss anything on this specimen?

Remarkably, in 2011, foresters actually admitted that trees are dying all over the world, but they blame it on drought from climate change.  I think it makes more sense to acknowledge that their systems are compromised by ozone, and this makes them more vulnerable to drought from climate change, along with any other threat or synergistic effects.  One reason I think that is because plants grown in nurseries, like these boxwood that should be green, are dying too.  Can this be due to long-term alterations in precipitation from climate change?  Pulease!!  They are being watered, just like they were 20 years ago.  SOMETHING else is killing them - it's not a lack of water, or erratic rainfall.

The rhododendrons are just as bad - they are horribly thin, because their leaves have developed chlorosis - a yellowing because they can't photosynthesize.  They have brown tips, and most have withered and fallen off.

These conifers are at the entrance to the nursery, and they are dying too.  The cedar in the foreground is turning brown, and the two tall white pines are transparent, they have lost so many needles.  The only thing the have in common with the shrubs being irrigated across the drive is the composition of the atmosphere.

When I left the nursery I took a detour past the secluded, exclusive Lake Club in Far Hills...so if the images that follow aren't from a report, they are from that cruise home...a journey down a path of destruction.

It doesn't look nouveau riche, like Donald Trump's Golf course in neighboring Bedminster.  But then, this is an old-money WASP enclave, and it doesn't want or need to advertise with any sort of glitz. 

By way of a quick reminder, or perhaps basic introduction, here is the usual brief description of ozone's influence on plants...this time from Sweden's Air Pollution and Climate Secretariat, because why not?

"Among the air pollutants that cause direct damage to plants, ground-level ozone is by far the most significant. The ozone is formed from nitrogen oxides and volatile organic compounds in the air, under the influence of sunlight."

This is the view across the Lake.  Just a few years ago, you couldn't see any ground beneath the dense canopy, even in winter...only the contour of the topmost treeline.  Now the understory is non-existant and so many pines have died, they lie horizontal on the slopes,  like a game of pick-up-sticks.

"In plants, it has been found that damage can occur at concentrations only slightly higher than current background levels. This has a significance on yields from agriculture and forestry, as well as affecting natural ecosystems."

This little creek runs into the lake; the bark on the trees is splitting and peeling off.

"Measurements that have been in progress since the 1950s show that the levels of ozone in the air over Europe have risen by an average of 2 per cent a year, and that the background level today is two to four times as high as it was in the 1950s. The critical levels, which were presumably only exceeded occasionally at the start of the last century, are now exceeded regularly over almost all of Europe." 

"The limits that have been set to protect people's health are also regularly exceeded by a significant degree. The situation is worst in the Mediterranean countries of Italy, France, Greece and Spain, and in parts of Germany."

"NB. The ozone layer in the stratosphere, at an altitude of 10-40 kilometres, protects us from ultraviolet radiation from the sun and is an essential requirement for all higher life on the Earth. But when ozone is present at ground level it may be harmful to people, animals, plants and materials."

The standing white trunks are dead pines with no needles and no bark.

Without further ado, following are excerpts from the United Nations Economic and Social Council's Executive Body for the Convention on Long-range Transboundary Air Pollution, issued a European Nitrogen Assessment in December at a meeting in Geneva - ahead of planned revisions to the Gothenburg Protocol to be adopted in May.  I won't clutter it with quotations - other than captions for photos, my comments will be [bracketed and italicized].  They begin with a helpful graph:

I. Main messages

Lake Road winds around the shore barely above the level of the water.  Between the barrier and lake itself, there used to be so much vegetation, you could only catch glimpses of the water.  Almost all of the plantlife is simply gone now.

A. Too much nitrogen harms the environment and the economy

If it's drought from climate change that is killing trees, wouldn't you expect those with roots near water to be marginally better off?  Oops...they're not.

• Over the past century humans have caused unprecedented changes to the global nitrogen cycle, converting  atmospheric dinitrogen (N2) into many reactive nitrogen (Nr) forms, doubling the total fixation of Nr globally and more than tripling it in Europe.

• The increased use of Nr as fertilizer allows a growing world population, but has considerable adverse effects on the environment and human health. Five key societal threats of Nr can be identified: to water quality, air quality, greenhouse balance, ecosystems and biodiversity, and soil quality.

• Cost-benefit analysis highlights how the overall environmental costs of all Nr losses in Europe (estimated at €70–€320 billion per year at current rates) outweigh the direct economic benefits of Nr in agriculture. The highest societal costs are associated with loss of air quality and water quality linked to impacts on ecosystems and especially on human health.

[Did you catch those numbers?  Up to 320 billion euros per year!]

Every few feet I stopped and took a picture, in an unbroken progression of decline.

B. Nitrogen cascade and budgets

• The different forms of Nr inter-convert through the environment, so that one atom of  Nr may take part in many environmental effects, until it is immobilized or eventually denitrified back to N2. The fate of anthropogenic Nr can therefore be seen as a cascade  of Nr forms and effects. The cascade highlights how policy responses to different Nr forms and issues are interrelated, and that a holistic approach is needed, maximizing the abatement synergies and minimizing the trade-offs.

• Nitrogen budgets form the basis for the development and selection of measures to reduce emissions and their effects in all  environmental compartments. For instance, the European nitrogen budget highlights the role of livestock in driving the European nitrogen cycle.

The roof of the clubhouse comes into view, under a pine with almost no needles left at all.

C. Policies and management

• Existing policies related to Nr have been largely established in a fragmented way, separating Nr forms, media and sectors. Despite the efforts made over many years to reduce Nr inputs into the environment, most of the Nr-related environmental quality objectives and environmental action targets have not been achieved to date.

The bark of the deciduous tree in front of the pine is breaking off, and holes punctuate the trunk.

• The five societal threats and N budgets are starting points for a more holistic management of Nr. The European Nitrogen Assessment identifies a package of seven key actions for overall management of the European nitrogen cycle. These key actions relate to: agriculture (three actions); transport and industry (one action); wastewater treatment (one action); and societal consumption patterns (two actions).

• The key actions provide an integrated package to develop and apply policy instruments. The need for such a package is emphasized by cost-benefit analysis that highlights the role of several Nr forms, especially nitrogen oxides (NOx), ammonia (NH3) and Nr loss to water, in addition to nitrous oxide (N2O), in the long term.

D. International cooperation and communication

• Tackling Nr necessitates international cooperation. There are various options to implement multilateral environmental agreements; a possible inter-convention agreement on nitrogen needs to be further explored.

• Communication tools for behavioural change should be extended to nitrogen, such as calculating nitrogen “food-prints”.  Messages should emphasize the potential health co-benefits of reducing the consumption of animal products to avoid excess above recommended dietary guidelines.

The Lake Club offers recreational boating, of course, and tennis courts beyond this copse of thinning pines and holey trees.

II. Why nitrogen? Concerns and the need for new solutions

1. Nitrogen is an abundant element on Earth, making up nearly 80% of the Earth’s atmosphere. However, as atmospheric N2, it is unreactive and cannot be assimilated by most organisms. By contrast, there are many Nr forms that are essential for life, but are naturally in very short supply. These include ammonia,  nitrates, amino acids, proteins and many other forms. Until the mid-nineteenth century, limited availability of these Nr compounds in Europe severely constrained both agricultural and industrial productivity.

2. With an increasing population in the late nineteenth century, rates of biological nitrogen fixation were not sufficient for crop needs and Europe became increasingly dependent on limited sources of mined Nr

(guano, saltpetre, coal). At the start of the twentieth century, several industrial processes were developed to fix N2 into Nr, the most successful being the Haber-Bosch process to produce NH3.

3. Since the 1950s, Nr production has greatly increased, representing perhaps the greatest single experiment in global geoenginneering.  Europe’s fertilizer needs have been met, as well as its military and industrial needs for Nr. In addition, high temperature combustion processes have substantially increased the formation and release of NOx. While the Nr shortage of the past has been solved, Europe has stored up a nitrogen inheritance of unexpected environmental effects.

4. Europe remains a major source region for Nr production, with many of the environmental impacts being clearly visible and well studied. There is a wealth of evidence on sources, fate and impacts of N. However, the complexity and extent of the interactions mean that scientific understanding has become scattered and focused on individual sectors.

A parallel fragmentation can be seen in environmental policies related to nitrogen, which are typically separated by media (air, land, water, etc.), by issue (climate, biodiversity,waste, etc.) and by Nr form.

5. While this specialization has advanced understanding, European science and policies related to nitrogen have to a significant degree lost sight of the bigger picture. The occurrence of Nr in many different Nr forms and media means that each component should not be considered in isolation. A more comprehensive understanding of the nitrogen cycle is therefore needed to minimize the adverse effects of Nr in the environment, while optimizing food production and energy use.

The bases of these trees are weeping fluid.

IV. Disruption of the European nitrogen cycle

A. Fertilizers, energy and transport: drivers for increased nitrogen inputs  

Production of Nr is a key input for agriculture and industry, and a persistent side effect of combustion for energy and transport.  Industrial production in Europe of Nr in 2008 was about 34 Tg per year (where 1 Tg = 1 million tons), of which 75% is for fertilizer and 25% for chemical industry (production of rubbers, plastics, and use in electronic, metals and oil industry) [3.5]. The trend in mineral  fertilizer represents the largest change in overall Nr inputs to Europe over the past century.

 

13. The combustion of fossil fuels has allowed a substantial increase in industrial production and transportation, reflected in  the greatly increased emission of nitrogen oxides, which only over the last 20 years have partly been controlled. By contrast, the total contribution of crop biological nitrogen fixation has decreased significantly. 

14. The provision of Nr from the Haber-Bosch process removed a major limiting factor on society, permitting substantial population growth and improving human welfare.  However, accounting for natural sources, humans have more than doubled the supply of Nr into the environment global, and more than tripled this supply in Europe.

Next, a close up of the standing tree on the right, behind the stone wall. 

B. The nitrogen cascade

16. Human production of Nr from N2 causes a cascade of intended and unintended consequences. The intended cascade is that each molecule of Nr contributes to soil fertility and increased yields of crops, subsequently feeding livestock and humans, allowing the formation of amino acids, proteins and deoxyribonucleic acid (DNA). In a well managed system, the intention is for the Nr in manures and sewage to be fully recycled back through the agricultural system.

17. Reactive nitrogen, is however, extremely mobile, with emissions from agriculture, combustion and industry leading to an unintended cascade of Nr losses into the natural environment. Once released, Nr

cascades through the different media, exchanging between different Nr forms and contributing to a range of environmental effects, until it is finally denitrified back into N2. An important consequence of the cascade is that the environmental impacts of Nr eventually become independent of the sources, so that nitrogen management requires a holistic approach. This is important, both to minimize “pollution 

swapping” between different Nr forms and threats, and to maximize the potential for synergies in mitigation and adaptation strategies. 

19.  The budget for 2000 shows that overall human perturbation of the nitrogen cycle is driven primarily by agricultural activities. Although the atmospheric emissions of NOx from traffic and industry contribute to many environmental effects, these emissions are dwarfed by the agricultural Nr

flows.

[This observation raises the possibility that it perhaps fertilizing corn for the production of ethanol is a significant source of the current decimation of plants and trees, although Americans still regard transport as the major source of Nr.]

20. It is important to note the magnitude of the European Nr flow in crop production, which is mainly supported by Nr fertilizers. The primary use of the Nr in crops, however, is not directly to feed people: 80% of the Nr harvest in European crops provides feeds to support livestock (8.7 Tg per year plus 3.1 Tg per year in imported feeds, giving a total of 11.8 Tg per year). By comparison, human consumption of Nr is much smaller, amounting to only 2 Tg per year in crops and 2.3 Tg per year in animal products. Human use of livestock in Europe, and the consequent need for large amounts of animal feed, is therefore the dominant human driver altering the nitrogen cycle in Europe.

There are picnic tables and grills for summertime barbeques.

21. These major intended alterations in Nr flows cause many additional unintended Nr flows. Overall, NH3 from agriculture (3.2 Tg per year) contributes a similar amount to emissions of Nr to the atmosphere as NOx (3.4 Tg per year). Agriculture also accounts for 70% of nitrous oxide (N2O) emissions in Europe, with total N2O emissions of 1 Tg per year. The food chain also dominates Nr losses to ground and surface waters, mainly as nitrates (NO3), with a gross load of 9.7 Tg resulting mainly from losses due to agriculture (60%) and discharges from sewage and water treatment systems (40%).

A closeup of the treetops around the picnic area reveals holes, seeping fluid, and lichen encrusted bark.

22. The comparison between 1900 and  2000 shows how each of these flows has increased, including denitrification back to N2. Denitrification is the largest and most uncertain loss, as it occurs at many different stages during the continuum from soils to freshwaters and coastal seas. Although emissions of N2 are environmentally benign, they represent a waste of the substantial amounts of energy put into human production of Nr, thereby contributing indirectly to climate change and air pollution. This is in addition to the impact on climate change of N2O formed especially as a by-product of denitrification.

  

VI. The key societal threats of excess nitrogen 

34. From a longer list of around 20 concerns, the Assessment identifies five key societal threats associated with excess Nr in the environment:  Water quality,  Air quality, Greenhouse balance, Ecosystems and biodiversity, and Soil quality. Together, these threats can be easily remembered by an acronym as the “WAGES” of excess nitrogen, and visualized by analogy to the four “elements” (water, air, fire, earth) and quintessence of classical Greek cosmology (figure 7). These  five threats provide a framework that incorporates almost all issues related to the longer list of concerns associated with excess Nr.

[WAGES - isn't this cute!?]

B. Nitrogen as a threat to European air quality

38. Air pollution by NOx and NH3 causes formation of secondary particulate matter (PM), while emissions of NOx also increase levels of NO2 and tropospheric ozone (O3). All of these are causes for respiratory problems  and cancers for humans, while ozone causes damage to crops and other vegetation, as well  as to buildings and other cultural heritage.

That is a conifer on the left; no needles.

40. Although NOx emission decreases have reduced peak O3 concentrations, background 

tropospheric O3 concentrations continue to increase. By comparison to the limited progress in reducing NOx emissions, there has been even less success in controlling agricultural NH3 emissions, which therefore contribute to an increasing share of the European air pollution burden.

Apparently there is a perceived need for new trees, but the young trees are losing needles too.

D. Nitrogen as a threat to European terrestrial ecosystems and biodiversity

44. Atmospheric Nr deposition encourages plants favouring high Nr supply or more acidic conditions to out-compete a larger number of sensitive species, threatening biodiversity across Europe. The most vulnerable habitats are those with species adapted to low nutrient levels or poorly buffered against acidification. In addition to eutrophication, atmospheric Nr causes direct foliar damage, acidification and increased susceptibility to pathogens.

I left the Club, heading north, upriver, towards home.  All along the way are trees studded with cankers, if not fallen.

45. Although there are uncertainties in the relative effects of atmospheric nitrate (NO3-) versus ammonium (NH4+), gaseous ammonia (NH3) can be particularly harmful to vegetation, causing foliar damage especially to lower plants. This emphasizes the threat to semi-natural habitats occurring in agricultural landscapes. While uncertain, Nr deposition is expected to act synergistically with climate change and groundlevel ozone.

46. Thresholds for atmospheric concentrations and deposition of Nr components to semi-natural habitats are exceeded across much of Europe, and will continue to be exceeded under current projections of Nr

emissions. In order to achieve ecosystem recovery, further reductions of NH3 and NOx emissions are needed. Due to cumulative effects of Nr inputs and long time lags, rates of ecosystem recovery are expected to be slow, and in some cases may require active management intervention in the affected 

habitats.

52. Environmental damage related to Nr effects from agriculture in the EU-27 was estimated at €20–€150 billion per year. This can be compared with a benefit of N fertilizer for farmers of €10–€100 billion per year, with considerable uncertainty about long-term N benefits for crop yield.

They are replacing trees, but the baby trees are dying already too.

Societal consumption patterns

6.  Energy and transport saving.  Against the success of technical measures to reduce NOx emissions per unit consumption, both vehicle miles and energy use have increased substantially over past decades. Dissuasion of polluting cars and fardistance holidays, and stimulation of energy-saving houses and consumption patterns can greatly contribute to decreasing NOx emissions [23.5].

[Did they just say people shouldn't fly for fun??]

 7.  Lowering the human consumption of animal protein. European consumption of animal protein is above the recommended per capita consumption in many parts of Europe. Lowering the fraction of animal products in diets to the recommended level (and shifting consumption to more N-efficient animal products) will decrease Nr emissions with human health co-benefits, where current consumption is over the optimum.

[Did they just recommend that people consume less meat??]

64. International treaties, such as multilateral environmental agreements, have done much to protect the global environment, promoting intergovernmental action on many environmental issues, but none has targeted nitrogen management policy holistically.

[Did they just intimate that an environmental scourge is occurring totally outside the bounds of regulations?]

71. At present, public and institutional awareness of the global nitrogen challenge is very low. The comparison with carbon and climate change highlights how the nitrogen story is multifaceted, cutting across all global-change themes. This complexity is a barrier to greater public awareness, pointing to the need to distil easy messages that engage the public.

[Does this mean people are grotesquely mis- and un-informed about an existential threat even more imminent than all the extreme, violent, unprecedented weather that menaces us from climate change?]

72. Simple messages for nitrogen include contrasting its huge benefits for society against the environmental threats, and emphasizing the need to extend existing footprinting approaches, for example to calculate “nitrogen food-prints”. Perhaps the strongest message to the public is that there are substantial  health benefits to be gained by keeping consumption of animal products within recommended dietary limits. It is an opportunity to improve personal health and protect the environment at the same time.

[hahahahaha!  Let's see how far they get with that!]

Figure 3

Simplified comparison of the European nitrogen cycle (EU-27) between 1900 and 2000. Blue arrows show intended anthropogenic nitrogen flows; orange arrows show unintended nitrogen flows; green arrows represent the nearly closed nitrogen cycle of natural terrestrial systems.

Figure 3

Figure 7

Summary of the five key societal threats of excess reactive nitrogen, drawn in analogy to the “elements” of classical Greek cosmology. The main chemical forms associated with each threat are shown.

[This final graphic from that report smacks of desperation.  An attempt to assimilate the most grotesque and suicidal defilement of the natural world by the self-appointed masters of the universe with an analogy to the elements of classical Greek cosmology looks like magical thinking.]

Continuing on, why should we restrict our reading to European sources, when our own US Department of Agriculture's Forest Service has many publications regarding ozone...and the nitrogen cascade?  Here's a recent entry, "Assessment of Nitrogen Deposition Effects and Empirical Loads of Nitrogen for Ecoregions of the United States", a grand collaborative effort meant to aid policy makers (I guess that means our totally corrupt government) when they deliberate regulations.  This is a huge undertaking, with endless referrals to original research (which I've removed from quoted passages...but check out the original if you really want to go down the rabbit's hole).  It's well worth perusing and impossible to sum up in one blog post.  Later I will try to follow up on some of the most tantalizing research.

Their purpose is to establish criteria to quantify "critical loads" based on the particular characteristics of various types of ecosystems.  I guess, that's science, but do we have to constantly call for more research before we can say definitively that polluting the air, water and soil is a bad idea?  Kind of like this compilation of research demonstrating - believe it or not, it's true, Happy New Year! - fireworks release all kinds of nasty toxins into the air for people to breathe, in measurably significant amounts!!   But I digress.  Let's return to the nitrogen report, starting with the two sets of photos on the front cover, followed by their descriptions.  I suggest more than a cursory glance at this pair of side-by-side comparisons, because the implications are a little monumental.

Left to right, top: elevated nitrogen inputs to a prairie grassland in Minnesota (control)  resulted in a decrease in species richness and an increase in invasive grasses (N addition).   Photos by David Tilman, University of Minnesota, used with permission.

[A "decrease in species richness" means elevated nitrogen KILLED OFF some species.  They DIED and were replaced by grasses that will not die as quickly.]

Left to right: elevated nitrogen inputs to a high elevation spruce fir forest (control) in Vermont resulted in decreased growth and increased mortality (high treatment).  Photos by Linda Pardo, U.S. Forest Service.

[The photo on the right certainly looks representative of current forest conditions!  Following are some choice excerpts.  First of all, they admit they really don't know how much dry N deposition there is.  Personally, I'd venture a guess that either 1)  it's way more than the models show or 2) the ecosystem is far more sensitive to what is considered a safe amount below " critical load".]

1.2.2 Effects of N deposition

The increases in atmospheric N deposition after the middle of the 20th century initially raised few concerns about detrimental ecosystem impacts. Many terrestrial ecosystems are N limited. Hence, additional N inputs could have a fertilizing effect, which was perceived as beneficial for some ecosystems. Increased tree growth due to N deposition has been demonstrated in northeastern U.S. forests.

[Maybe - but the CO2 folks like to claim credit for that too.  Isn't there some way these experts could get on the same page in this, the age of the intertubes?  And in any case, any increased tree growth has been more than offset by the recent extraordinarily dramatic declines.]

However, substantial debate continues over the existence and magnitude of deposition-induced growth 

enhancement in forests globally. Furthermore, elevated N inputs can lead to detrimental effects on ecosystems, including soil and surface water acidification, plant nutrient imbalances, declines in plant health, changes in species composition, increases in invasive species, increased susceptibility to secondary stresses such as freezing, drought, and insect outbreaks, as well as eutrophication of fresh and coastal waters. High concentrations of ammonia (NH3) can be directly toxic to plants.

The fact that these pine trees are transparent is a harbinger of their death.

Nitrogen saturation can be defined as the condition when available N exceeds plant and microbial demand.  Aber et al. described four stages of N saturation in forest ecosystems (Fig. 1.1): background 

conditions (stage 0), an initial fertilization response (stage 1), flattened response of N mineralization but 

increased net nitrification (stage 2), and detrimental effects on plant health and growth and general decreasing N retention (stage 3). When vegetation is no longer N limited, but before damage is incurred, nitrate (NO3-) immobilization will be reduced and NO3- export is likely to increase gradually.  The increase in NO3- export may occur earlier in this progression of N saturation than initially thought.

Adverse consequences on plant health and growth occur in the last stage of N saturation, resulting from some combination of insufficient allocation of plant carbon to roots and mycorrhizae and soil acidification induced by NO3- leaching. Nutrient imbalances (e.g., elevated N:Ca or N:Mg) may also affect plant health. In addition, alterations in an ecosystem’s N status may lead to increased susceptibility to secondary stresses, including freezing injury, pest outbreak, and drought.

...Among the most significant indicators of N saturation are changes in species composition or community structure in terrestrial and aquatic ecosystems. Alterations in species composition may result from shifts in dominance of species present, for epiphytic lichens, for example, or increased dominance 

of invasive species, and may lead to significant changes in vegetation. Nitrogen deposition may affect species richness and has been implicated in dramatic declines in species richness, for example, in coastal sage scrub grasslands.

[Okay, all these stages are reminiscent of cancer diagnosis.  What they've just worked up to is that there is a nitrogen TIPPING POINT, and in the next section, they admit they have no idea how much nitrogen is out there overburdening the ecosystem.]

3.2 Background on total N deposition

The primary forms of inorganic N deposition that have been measured routinely are secondary products 

of nitrogen oxide (NOx) emissions—nitrate (NO3-; particulate and aqueous) and nitric acid vapor (HNO3) —and ammonium (NH4+; particulate and aqueous).   The primary anthropogenic source of NOx is fossil fuel combustion. Transportation accounted for more than 50 percent of the total NOx emissions in 2002, while the primary sources of ammonia (NH3) and NH4+ are agricultural activities.

 

Nitrogen is deposited from the atmosphere to the Earth’s surface in the form of wet (rain and snow), dry (gases and particles), and cloud and/or fog deposition. Wet N deposition can be measured directly, but often only some of the components are measured.  Dry deposition cannot be measured directly. Moreover, the estimates that exist are either site specific, or are modeled (e.g., dry deposition) 

assuming flat, homogeneous terrain, e.g. Clean Air Status and Trends (CASTNET) sites.

For this reason, a combination of monitoring data, deposition models (e.g., the Multi-Layer Model [MLM] for estimating dry deposition), empirical measures of atmospheric deposition (e.g., throughfall), and emissions-based modeling outputs, are often necessary to estimate total N deposition. In the ecoregion chapters that follow, we consider total deposition to include wet (rain and snow) plus dry and, in some cases, cloud/fog.

[So, we've established that nobody really knows how much reactive Nitrogen is out there polluting the air, acidifying the soils, and causing eutrophication of water.

But that's okay!  The lichens know, and it turns out the National Park Service has a lichen database, and so does the US Geologic Survey and the Forest Service!!!  As if I didn't have enough to look into.  But here's what this report says on p. 27:]

Lichens are adapted to different levels of N availability and most species can be sorted into one of three N indicator groups: oligotrophs are more or less restricted  to nutrient-poor environments; mesotrophs have an intermediate nutrient requirement; and eutrophs thrive in nutrient-enhanced environments. A few  lichens have broad ecological amplitudes and tolerate a large range of N availability. As anthropogenic N is added to background N levels, the excess N favors the small, cosmopolitan eutrophs at the expense of native oligotrophic and mesotrophic forage and N2-fixing lichens.
[Keep in mind that "nutrient-enhanced" is polluted by another name.]

Aside from the obvious dead trunk in the foreground, next will be close ups of the trees nearer the river.

p. 149:

Lichen responses. About half the epiphytic lichen species known to occur during the late 1800s and early 1900s on coast live oak throughout the chaparral and oak vegetation zones of the Los Angeles basin have subsequently disappeared.  This dramatic reduction in species richness was initially 

attributed solely to oxidizing pollutants, chiefly O3, but recent research provides unequivocal evidence for an N deposition effect.  In the Los Angeles air basin, throughfall N deposition in forests downwind of the urban areas can reach 25 to 70 kg ha-1yr-1.  This deposition includes nitric acid (HNO3), a strong gas-phase acid which exhibits diurnal patterns paralleling O3 concentrations. In the mountains downwind of Los Angeles, 24-hr means of up to 27.3 ppb have been recorded, whereas remote 

location means have been ≤0.1 ppb. Unlike O3, once HNO3 is produced, it rapidly deposits to surfaces.

p. 150

Eutrophic lichens benefited from increasing N availability, comprising >50 percent of total abundance in lichen communities at air scores <0.0.

Figure 11.2—Shown are the species numbers (relative to controls) for plots receiving N at three different rates averaged over three Minnesota fields from 1982-2004. Dashed lines correspond to annual standard errors in control plots and arrows indicate the year of first significant (P < 0.01) detection of species loss for that treatment rate.

p. 153

13.4.2 Ecosystem Responses to N Deposition

Research on air pollution effects in mixed-conifer forests began in the 1960s after the initial discovery in the  1950s of unusual symptoms in ponderosa pine that were later confirmed to be caused by O3. Studies on N deposition effects in forests began in the San Bernardino Mountains in some of the original O3 study plots established in the 1970s. Ecosystem responses to N deposition include NO3- leaching, trace gas losses of N, soil acidification, lichen community change, altered forest nutrient 

cycling, and loss of understory diversity. Because of the co-occurrence of O3 and N deposition in the mixed conifer forest of California, the ecological effects of N deposition cannot be evaluated in isolation from the significant impacts of O3 on nutrient cycling and plant growth, development, community succession, and phenology.  The combined ecological effects of N and O3 are dramatic in areas of high pollution exposure.

Forest sustainability, p. 155

Nitrogen deposition, in concert with O3 injury effects, is contributing to a decrease in the sustainability of mixed-conifer forests in the San Bernardino Mountains. Nitrogen deposition increases aboveground growth of coniferous and deciduous species of the mixed-conifer forest. Ozone and increased N fertility 

result in decreases in both C allocation belowground and fine root biomass . Ozone causes premature foliar senescence and abscission.

The combined effects of O3 and elevated N deposition are increased C storage in the bole and woody aboveground biomass and accelerated foliar turnover and litter production.  The is also results in increased accumulation of C and N in the forest floor. In these O3-impacted and N-saturated mixed conifer stands (N deposition 25 to 71 kg ha-1 yr-1), aboveground N pools are much higher than in stands in areas receiving relatively low deposition. For example, at an N-saturated site (N deposition 71 kg ha-1 yr-1) in the San Bernardino Mountains about 30 percent of ecosystem N is stored in the thick forest floor, compared to about 11 percent at an N-limited site (N deposition approximately 7 kg ha-1

yr-1).

Ozone and elevated N deposition cause specific changes in forest tree C, N, and water balance that enhance individual tree susceptibility to drought, bark beetle attack, and disease, and when combined, contribute to whole ecosystem susceptibility to wildfire.  The N deposition levels at which these effects 

begin to occur are not well defined, but regression analysis indicates a 25 percent reduction in fine root 

biomass at 17 kg ha-1 yr-1; dramatic shifts in tree phenology and C allocation are evident at a site with N deposition of 39 kg ha-1 yr-1.

Uncharacteristically deep litter layers develop in mixed-conifer forests impacted by air pollution.

Elevated O3 and N deposition decrease the proportion of whole tree biomass in foliage and roots, the latter effect increasing tree susceptibility to drought and beetle attack. Because both foliar and root mass are compromised, carbohydrates are stored in the bole over winter. Elevated O3 increases drought 

stress by significantly reducing plant control of water loss.  The resulting increase in canopy transpiration, combined with O3 and N deposition-induced decreases in root mass, significantly increases tree susceptibility to drought stress.   The combination of these effects with increased sequestration of bole carbohydrates may contribute to successful host colonization and population increases of bark beetles and possible enhancement of dwarf mistletoe infections, although the latter response has not been confirmed.

[OKAY.  Can somebody please tell me, when it is so very well established that 1) background ozone levels are increasing worldwide 2) the nitrogen cascade is out of control 3) trees are dying 4) trees exposed to ozone and N deposition are "significantly" more susceptible to drought stress, WHY don't scientists include this information when they write papers saying that climate change drought is killing trees all over the world??]

Understory, p. 156

Understory diversity in mixed-conifer forests in the San Bernardino Mountains in southern California 

was recently compared to studies done 30 years prior, in 1973. Both O3 concentrations and particularly N deposition decline from west to east along the air pollution gradient. Nitrogen deposition in throughfall ranges from 9 to 71 kg ha- yr-1 at the understory study sites. Biodiversity loss was pronounced in the sites receiving the highest N deposition and is due to the establishment of exotic invasive species that have become abundant. In three of six sites, including the two westernmost polluted sites, 20 to 40 percent of species were lost between 1973 and 2003.

In the highest deposition sites, understory cover equaled 30 to 45 percent and was equally divided between native and exotic species. At lower deposition sites, understory cover was 3 to 13 percent and was dominated by native species. Because of confounding factors such as precipitation and possibly local disturbances, a simple correlation between air pollution and patterns of native and invasive species cover and richness was not found. However, observational evidence and expert opinion suggest that increased N deposition and precipitation in the westernmost sites are the primary factors contributing to reduced biodiversity and increased cover by invasive species

Co-occurring O3 may be indirectly contributing to the establishment of exotic species as well. Ozone causes premature foliage loss in pine, while N deposition stimulates foliar growth, leading to greater litter production and accumulation in the forest floor. Many native plant species are not able to establish where dense litter accumulates.

However, stickywilly (Galium aparine), a weedy annual with both native and introduced forms, thrives under these conditions, which include the acidified N-rich soils that underlie the thick litter layer. Portions of the high-pollution study sites in the western San Bernardino Mountains burned in October 2003. Formerly shady sites in the burned areas are now covered by exotic annual brome grasses. Subsequent clearing of dead trees and brush is further exposing the soil to invasive species. 

This large branch came down in the October snow.  Note, it still has leaves affixed.  It takes energy for trees to push leaves off in the autumn, so when you see trees that have limp, brown leaves remaining well past the time they should have fallen, it indicates a lack of vigor.

[The report's conclusions were jointly written by the authors.  Note that it must be technically impossible to verify how much biodiversity was lost years before these studies were undertaken, which also means that the assessment of what constitutes a critical load is based upon already degraded landscapes.]

Human activity in the last century has led to a substantial increase in nitrogen (N) emissions and 

deposition (Galloway et al. 2003). Because of past, and, in some regions, continuing increases in emissions, this N deposition has reached a level that has caused or is likely to cause alterations and damage in many ecosystems across the United States. In some ecoregions, the impact of N deposition has been severe and has changed the biotic community structure and composition of ecosystems.

Figure 19.10—Map of exceedance of critical loads (CL) for NO3- leaching by ecoregion in the continental United States.  Exceedance was calculated by subtracting critical loads from CMAQ nitrogen deposition. Exceedance (critical load - deposition) is shown for several categories: (1) No exceedance (Below CL), when deposition is lower than the CL range, (2) At CL, when deposition is within +/-1 of the CL range, (3) Above CLmin, when deposition is above the lower end of the CL range, but lower than the upper end of the range, (4) Above CLmax, when deposition is above the upper end of the CL range.

[They don't seem to consider that eventually, as we continue with unabated emissions, the saturation of nitrogen and background ozone will become so extreme that even the n-loving replacement species will also be overcome...and we'll have NOTHING, just lifeless dirt?  It seems kind of obvious to me - like throwing a bunch of people into the open sea.  Some will drown sooner than others, without doubt - but equally without doubt, they will all eventually drown.  DUH.]

[Here's a sad sad part, the sort of interconnected dependence species have upon each other that is going to lead to mass extinctions with very few, most likely the most nasty, survivors.]

The extirpation of the endangered checkerspot butterfly (Euphydryas editha bayensis), because the host plant for the larval stage disappears in N-enriched ecosystems, is just one example of the detrimental 

impacts of elevated N deposition.

The endangered checkerspot butterfly (Euphydryas editha bayensis).  

[Following is a a good summary of the "Cascade"]

In addition to altering ecosystem structure, N deposition can also affect ecosystem function, affecting 

N-cycle processes such as N mineralization, nitrification rates, and nitrate (NO3-) leaching rates, as well as plant tissue N concentration.   These changes indicate early stages of N saturation. Nitrogen saturation is the series of ecosystem changes that occur as available N exceeds plant and microbial demand. In some cases, these early responses may lead to a cascade of alterations in the N cycle that ultimately affect the function or structure of the ecosystem. For example, elevated N inputs may lead to plant nutrient imbalances, which then increase plant susceptibility to inciting stressors such as cold, drought, or pests. 

This series of responses was observed in a southern Vermont montane red spruce (Picea rubens) stand, 

where increased foliar N concentration was associated with reductions in foliar membrane-associated calcium (Ca) and decreased cold tolerance, which resulted in increased winter injury.  Another example of the N cascade is increased soil NO3- leaching, which can result in episodic acidification of surface waters, harming fish species. Other responses to low levels of elevated N deposition, such as increased 

plant growth and increased carbon (C) sequestration by trees, may be perceived as beneficial where forests are managed for tree growth.

In other instances, it is not known whether the early indicators of N saturation will be followed by other 

effects. In these cases, the perceived extent of harm caused by N deposition depends, in part, on which 

ecosystem service is of particular value for different stakeholders. For example, the level or type of change or harm that is unacceptable may vary according to resource management goals.

This house has it all:  the boxwood in the pot is turning yellow the pine to the right has almost no needles remaining; beyond the car, the sycamore trunk is swarming with cankers.

In a conservation area, for example, any alteration in N cycling may be considered unacceptable, whereas for other land areas, changes of a certain magnitude or scope may be acceptable or even desirable based on resource use (such as timber harvesting) or other factors. Land and resources may be valued for a wide range of purposes, including biodiversity, food and wood production, clean water, and recreation. Quantification and then valuation of these ecosystem services for each land area of interest is required to fully account for impacts of N deposition.

There's also a tremendous hole in the tree just to the left of the porch roof.

[I hope your eyes didn't glaze over reading those passages above, about competing interests of "stakeholders" - which is so ludicrous, because it's assuming we can control the cascade, even if long-term it is beneficial, which it can't be.  Trying to make a silk purse out of a pig's ear!]

[Pp. 247-8 has more about lichens, and everyone knows, that in close competition with my role as  ozonista is a fascination with the malevolent lichen:]

Lichens and bryophytes make substantial contributions to biodiversity. About 4100 lichen and 

2300 bryophyte species are known from North America north of Mexico—as about one-fourth of vascular plant diversity, which is about 26,600 species.  Therefore, N critical loads protective of the sensitive lichens and bryophytes help protect biological diversity.
[Imagine - 4100 species of lichen!]

Lichens are symbiotic organisms consisting of a fungus, for which the organism is named, and a green algal and/or a blue-green bacterial partner.

[How cool is that?]

These are supposed to be thick, green pines.

Responses to N inputs.

Depending on the kind of bark it can fall in patches or, in the case of shagbark hickory, spectacular curling strips.

Lichens and bryophytes are among the most sensitive bioindicators of N in terrestrial ecosystems. Unlike vascular plants, lichens and bryophytes lack specialized tissues to mediate the entry or loss of water and gases (e.g., waxy epidermis, guard cells, root steele).  Thus, they rapidly hydrate and absorb gases, water, and dissolved nutrients during high humidity or precipitation events.
[It's true that when it rains now the lichens swell, it's quite remarkable to witness.]

However, they quickly dehydrate to a metabolically inactive state as well, making them slow-growing and vulnerable to contaminant accumulation. Consequently, the implementation of lichen or bryophyte-derived critical loads may prevent undesired impacts to much of the broader forest ecosystem. In some cases, alteration of lichen community composition may signal the beginning of a cascade of changes in ecosystem N cycling, which may markedly alter the structure or function of the ecosystem as a whole.

Well, that's enough of the "Assessment of Nitrogen Deposition Effects etc" for now.  The above text in red rather exactly describes what we are seeing on the East Coast of the US, at a minimum.  Now here is another sad.  Sensitive lichens are considered bioindicators because they are among the first species to disappear in a polluted environment...but it's not just the lichens that melt into oblivion, some of them are the only food other creatures eat, like flying squirrels in the PNW, and reindeer!  Yes, Santa's reindeer eat lichen and so when that goes away they just...oh never mind...they go to McDonalds!  And oh yeah, flying squirrels are the primary prey for the endangered northern spotted owl, so they'll have to go to McDonalds too!  Problem solved.

This view is closer to Oldwick, on the outskirts of the adjacent village of Pottersville.

The narrow road I live on snakes up the hill past the Vliet Farm to the south, and alongside another testament to the tenacity of trees on the high, northerly side, where trees have clung to life despite constant erosion that exposes their roots along the bank.

These trees and others now gone thrived for the 30 years I've been living at Wit's End, passing them walking and driving more times than I can count.  Now, in just the past few years, they are encrusted with lichen and attacked by cankers, their largest branches broken, with suckers sprouting from struggling trunks.

More and more, people are waking up to the impending Great Convulsion, and grappling with the emotional tsunami that occurs when truth and reality intrude on willful obtusity.  I am so very fortunate to have found many virtual intertube (and even some real flesh!) friends who share my thoughts, because it's an excruciating process.

Generally, a bewildered, hopeless and helpless floundering for solutions occurs, despite the horrifying inkling that there is none.  Eventually, after considering the evidence dispassionately, most come to the bitter conclusion that by our very nature, we're fucked - and not only that, we have fucked most other species on earth, that immense wealth of life that took so long to evolve, and which we have relentlessly squandered.  Once that glimmer of knowledge takes hold, there's just a lot of pain, recrimination, confusion and guilt.

Well, I just spent New Year's Eve being ridiculed by family, friends and acquaintances for harboring such ideas.

I'm wondering when I should just stop writing and protesting.  The law Obama passed authorizing citizen detention is deeply frightening, and since the human race is doomed anyway, I am questioning the wisdom of making myself a target for the fascists when they staff the FEMA camps and start rounding up dissidents.  And I saw the story that the day after Christmas broke the last record, which was set the day after Thanksgiving, in background checks for gun purchases, which makes me wonder if I should run for the most distant hills and barricade myself as far from roving starving ruthless gangs as possible... maybe in New Zealand.

So here's the thing, that I use to cheer myself up.  Two things, actually.  First, even though most of my children's generation will likely die prematurely, quite possibly under horrific circumstances, the fact is those who have lived in the American middle class have had charmed lives up to now, for the most part at least.  I mean, they've been REALLY lucky; they have eaten exotic, delicious food imported from all over the world, traveled in airplanes, had fantastic technology at their disposal, and immense creature comfort unimaginable just decades ago...plus they've each been able to pursue whatever path they want in life.  Of course, they've also been manipulated into being mindless consumers, depending on how much teevee they watched.  But still, despite my guilt as a mother, given that it was inevitable that humans eventually destroy our home, Earth, and source of sustenance, Nature, I believe my children couldn't have been born at a better time, so far.

The Cold Brook, that delineates the border of Wit's End.  Are these trees dying from climate change drought?  I think not!

The second thing is that, if you think about it, we humans are horrible, rapacious creatures, capable of committing the worst atrocities, if only by proxy, and still managing to think of ourselves as not just good but superior beings - so we deserve our apocalyptic end.  It's too bad we're taking so much with us but, in a few million years on Earth - or perhaps if not, if we have triggered a runaway Venus effect that will render the planet uninhabitable - then surely somewhere on another planet millions of miles away, there will be life.

A weeping tree in front of the barn at Wit's End.

So to all doomers I say, cheer up, no regrets, Happy New Year!