Last night I attended a talk given by Peter Prebble on climate change, oil sands and Saskatchewan.  It was a delightful talk and Peter’s discussion of climate change, oil sands and Saskatchewan was well researched, thoughtful, balanced and well delivered.  Peter made an interesting moral argument.  He argued that Saskatchewan has the highest per capita (tied with Qatar) greenhouse gas emissions at 72 tonnes per year in the World.  This is well above Canada’s average of around 20 and well above the world average of 5.  As a result, he argued that Saskatchewan should invest around 2% of its GDP (around a billion dollars) to help reduce these greenhouse gases.  He reasoned that we could not ask countries with a much larger greenhouse gas footprint but whose per capita emissions are lower, to reduce emissions if we did nothing to reduce our per capita emissions.  I asked him, if instead of focussing on reduction we should focus on mitigation.  He responded that he thought that mitigation should also be addressed but at a lower rate than reduction.

I disagree with Peter.  The future is bleak for Saskatchewan. We will be facing severe water shortages in our lifetimes.  These water shortages will endanger our ability to grow crops, mine potash and uranium and extract oil.  As a result,  our economic activity will become restricted as we move towards the middle of this century.  When I think about Saskatchewan and our moral obligation to the world.  I think about our ability to provide food, fuel and fertilizers to the world.  For example, potash is key to allowing China to be self sufficient in foodstuffs for example.   Our food exports prevent famine in many parts of the world.  It seems to me that our first obligation should be to insure that we can continue contributing to the worlds food, fuel and fertilizer needs in 2050.  In order to do that, we need to invest heavily in mitigation technologies.   We need to invest in technologies that reduce water use for all of our processes.    Think of it this way, yes our emission rate is high at 72 but there are only 1 million of us, so we only produce 72 million tonnes.  In contrast, emission rates of another country might be 5 tonnes per year but there are 500 million people in that country, so they produce 2.5 billion tonnes.  Would that second country really care that we reduced our emissions to 36 million tonnes but were unable to provide them with fertilizer or food and thus provoked a famine in their country.  I feel it would be much better to have the second country reduce their emission rate to 4.98 t (only a 1.4% reduction) and have Saskatchewan guarantee that we can continue to provide them with fuel, food and fertilizer.  Mother Nature wouldn’t care because global emissions would have been reduced by the same amount.

As a province, we need to begin having this discussion.  Can we afford to both mitigate and reduce or can we only do one?  If we only select one.  What would be best for the world and for us.  Climate change is upon us.  We need to come to a consensus and make our choices.

Arctic soils emit a greenhouse gas called nitrous oxide.  Nitrous oxide is 300 times more powerful than carbon dioxide in warming the planet.  In addition to its potential to warm the planet, nitrous oxide is one way that Arctic soils lose nitrogen.  This is important because nitrogen limits plant growth in the Arctic. Thus, the less nitrogen there is, fewer plants grow and then fewer caribou, muskox, rabbits, etc can live in the Arctic.

The release of nitrous oxide from soil typically increases as the soil temperature increases.  As the Arctic grows warmer, it will begin to contribute to greenhouse gas production.  This is one example of a positive feedback loop. Ecosystems that currently help control our temperature will begin to help increase our global temperature creating a runaway train that may destroy our civilization.  In addition, as these ecosystems grow warmer, they will begin to lose more and more nitrogen to the atmosphere and we do not know if they will then also increase their nitrogen fixation ability.  So, Arctic scientists are very interested in how Arctic soils will respond to temperature increases.

We’ve been investigating this issue at a place called Truelove Lowland which is a beautiful spot on Devon Island in Canada’s Arctic

.

Stream on Truelove Lowland

.  We found that, yes, as soils warm, they do indeed emit more nitrous oxide.  However, surprisingly we found that this increase in emission dependended on the form of nitrogen available in the soil.  There are two major forms of inorganic nitrogen in soil, nitrate and ammonia.  Typically, nitrate is the form that is readily available to animals, plants and bacteria.  But in the Arctic, this is not always the case and normally when we do our analyses, we find that the amount of ammonia is the best predictor of how much nitrous oxide the soil is going produce.  In this experiment, when we fertilized with nitrate we saw large increases in nitrous oxide production with increasing temperature but when we fertilized with ammonia, we didn’t see this large increase.   This surprised us because in the field, we knew that the primary source of nitrous oxide was ammonia and not nitrate.  Using chemicals that inhibit certain groups of organisms, here is what we think is going on:

In the Arctic soil, fungi compete so strongly for nitrate that the only form of nitrogen available for release as nitrous oxide is ammonia.   So, this explains our field results, that is, ammonia dominates in the field settings because fungi suck up all the nitrate.

However, in some parts of the Arctic, in the bits that are soggy and wet, a group of organisms called denitrifiers will rapidly respond to climate change, if they have nitrate. They normally can’t get nitrate so this isn’t a problem, unless…

Many other Arctic scientists have found that nitrate levels can rapidly increase if snow depth increases.  It sounds counter-intuitive, but if the Arctic warms, then snow depth will likely increase.  So, people have been investigating what happens when snow depth increases as well as when the ecosystem warms.  Our results, suggest that Arctic soils that are currently unresponsive to increases in temperature, will suddenly become very responsive.

Is this a problem?  We don’t know yet.  How important is nitrous oxide contribution from Arctic soils to the world’s nitrous oxide budget?  Not really that important.  What will happen to nitrogen levels in these soils as they warm?  No one really knows.  We care about this because 50% of Canada’s carbon is safely stored in the Arctic soils.  If climate change was to suddenly release this carbon, very, very bad things would happen to our planet.

Approximately 50 soil scientists were brought together by Greg Henry to participate in the International Polar Year Project, Climate Change Effects on Canadian Arctic Tundra Ecosystems; Interdisciplinary and Multi-Scale Assessments.  Our goal in this project was to provide an assessment of Canadian Arctic soils.

About half Canada has permafrost, permanently frozen soil, and this permafrost dramatically changes how soils, plants and animals respond and contribute to climate change. We are investigating how these soils differ from one another in their responses and why they differ.  A key response is the storage of carbon because these permafrost soils hold 25% of the carbon sequestered in the terrestrial biosphere.  As a group, we have explored how these soils store, release and process carbon.  We knew that these carbon storage processes were controlled by nitrogen and thus, we also explored how nitrogen processing differed.  Our work in 2008, highlighted the ultimate importance of water for these soils.  Water affected how plants provided nitrogen to the soil; water affected how large organisms in the soil freed up this nitrogen and carbon for further storage and water affected how these soils released greenhouse gas back to the atmosphere.  Most surprisingly, we found that soils that had little water were most susceptible to climate change.  Our work highlighted that the vast desert that sits on the top of Canada, the Polar Desert, may be rapidly changing in response to climate change.  The sustainability of this change is not yet known and we worry that many fragile Arctic soils, such as the dunes and deserts, may be under threat.

The nitrogen cycle, controls carbon sequestration.  A key component of the nitrogen cycle in the Arctic is bryophytes which provide ammonia, which in turn is transformed to nitrate and used by plants.  As expected, bryophytes were controlled by moisture and needed phosphorus for maximum efficiency.  However, the normal organisms convert the nitrogen provided by bryophytes to a form available to the rest of the ecosystem, were absent.  The organisms, autotrophic ammonia oxidizers, were found at very low levels across the Arctic.  Instead, it appears that heterotrophic or archael ammonia oxidizers are the critical organisms in Canada’s Arctic.  This is important because heterotrophic and archael oxidizers respond very rapidly to increases in temperature whereas autotrophic oxidizers do not.  Thus, work in 2009 will focus on identifying what is the key group as this will be essential for predictions on how Arctic systems respond to climate change.

Most of Canada’s carbon is locked in the Arctic soils.  A key activity in 2008 was the collection of samples we need to estimate the Arctic soil carbon storage and if it was declining or increasing over the last 20 years.  This was a two step process, first we estimated soil carbon losses and/or gains over a long time period and then we estimated the variability associated with carbon storage in these soils.  These results are currently being linked to the Canadian Soil Carbon project.

All of our research teams report the same dependency in Arctic systems.  Response and contribution to climate change is highly dependent on plant species present in that soil. In other words, while moisture and temperature are important and have over the long term altered plant communities and soil types.  Current responses are linked intimately to the plant present at the sampling location.  As a group, we wish to highlight this observation as it suggests that invasive species in Arctic climes may have a significant influence on carbon cycling in Canada’s Arctic.

The budget on Tuesday was not a good one for Canadian Science.  The Conservative government has followed its past policy of not supporting Canadian Science.  They renewed the Canadian Foundation for Innovation and supported University infrastructure.  However, the Foundation for Innovation and Infrastructure do not support laboratory operations.  Without this money, science activity withers and fewer students get trained.

For the North, it was a special disaster.  The International Polar Year is winding up.  Most northern researchers are looking at 80-90% reduction in operating funds in the 2010/11 polar year.  Yet, there is nothing in the budget to address this. Without funds available in 2009 to support 10/11 activity, we can count on 2010/11 being a dismal year for Northern research.

The commitment to build a northern research station is welcome but once again, what use is infrastructure if there are no funds to use it.  The Conservatives transferred money to Indian and Northern Affairs Canada for northern reseach but INAC’s mandate is not innovation and much of northern research is not directly linked to INAC’s mandate.

The Conservative budget is even more disappointing because of its missed human resource opportunity.  As has been pointed out to them, there are a wide range of peer-reviewed research projects that were not funded because of a lack of funds.  These projects have been vetted by the Tri-Councils and peers.  These projects all had the goal of training Canadians in the knowledge economy.  If funds had been provided in this budget, Science activity could have exploded in 2009 providing 1000’s of training positions for laid off knowledge workers.  This would have provided Canada with a cohort of highly trained individuals who would be ready to re-enter the economy in 2011.

Instead, we will have empty buildings and our best and brightest will once again be leaving for Obama land.

Contaminants become “trapped” in soil over time because of various chemical and biological processes (e.g., aging, weathering, sequestration, adsorption, degradation, etc.). Trapped contaminants are not readily available for uptake into soil organisms and do not cause even if it is detectible by chemical methods. Therefore, contaminant concentration can exceed established safety standards but represent minimal risk to soil organisms if the contaminant is trapped.

Growing earthworms in contaminated soil is a common method to evaluate the toxic effects of contaminants in soil; however, this process is time consuming. Alternatively, contaminant concentration in soil can be determined by chemical extraction and analysis. This approach is fast, but harsh chemical extractions often over estimate the risk because contaminants trapped in soil may be extracted as well thereby suggesting danger when there is none. Arguably, it is better safe (i.e., over estimating potential danger) than sorry; however, cleaning up soils that pose no actual danger wastes resources that can be used to remediate real problem areas. We designed the Simulated Earthworm Gut (SEG) to mimic the earthworm’s gastrointestinal fluid composition under the theory that soil contaminants that are extractable by the SEG would be representative of the contaminant exposure that an earthworm would experience.

Wai Ma

Petroleum hydrocarbons (PHC) are the most common type of pollutant in polar regions.  The occurrence of PHC spills has a widespread geographic distribution throughout the Canadian Arctic and Circumpolar North, as well as several reported spills at various Antarctic research stations primarily located along the coast of Antarctica.  Due to the widespread and common occurrence of PHC spills in polar regions, much effort has been put forth in the area of bioremediation in cold regions.  As the technology emerges for cleaning up these contaminated sites, new questions associated with the clean up of these sites also arises.  How clean is clean enough?  What is the most sensitive part of the ecosystem?  What biological activity should be monitored to ensure that the ecosystem is being protected?  Do the environmental properties associated with polar regions increase the sensitivity of the ecosystem?  The ecotoxicity of petroleum hydrocarbon spills in polar regions is a growing concern and thus is a focal point for soil toxicology research in our lab group.

The environmental conditions that may increase the sensitivity of polar ecosystems to contaminants include sub-zero temperatures and limited liquid water content.  In polar regions, the amount of liquid water in the soil varies dramatically with the change in soil temperature.  However, even when the soil is frozen, a small amount of liquid water remains in the soil, which allows microorganisms living in the soil to remain biologically active.  The activity of these microorganisms is important, as they supply the nutrients required for plant growth, plants in turn supplies the food for primary consumers, and primary consumers supply the food for secondary consumer.  Therefore, you can see that if there are detrimental effects to soil microorganisms, the effects could manifest themselves up the food chain.  Thus it is important to protect the very basic function and structure of the soil ecosystem. We evaluated the toxicity of PHC soil contamination at an Antarctic research station by examining the effects on microorganisms.  We found that the most sensitive indicator of soil contamination was community composition (the number of different species living in the soil), followed by soil respiration and nitrification activity.  Changes in liquid water content did not seem to affect the toxicity of PHC to the soil microorganisms but it did increase the variability of the measured parameters.

Alexis Schafer

Soils are the safeguard of the western Canada economy.  Every time you pass by an inland terminal, you should see the soil scientists who make sure that there is enough water and fertilizer to grow the wheat, canola, flax and lentils that fill those terminals.  As you eat you steak, chicken or pork tonight you should see the soil scientists who make sure that manure doesn’t get into our food or water.  As you drive home tonight, soil scientists will have made sure that the Canadian oil sands have a safe place to store their excess sulfur and that these oil sand operators can rebuild the forest are demolished to get to the oil sands.  Your house will have been built out of trees that soil scientists made sure could grow. Your home tonight will be heated thanks to soil scientists who figure out how to clean up soil that has been polluted by pipeline spills or test wells.  And finally, as you put your kids to bed tonight, you should know that soil scientists are working feverishly to prevent our world from reach the tipping point of climate change which would see the prairies dry to a dustbowl and the Lake of the Woods become a pond.

Soil scientists secure the foundation of our western Canadian economic juggernaut; we help renewable resource companies renew their resource, reduce environmental impact of our non-renewable resource companies and uncover key starting blocks for technology companies.  To do this, soil scientists go to the field and dig a hole.

In fact, you could say that our western economy is based on soil holes.  A soil scientist might dig over a thousand holes in one year.  At each hole, he or she will take some soil, throw it on the back of a truck, or a helicopter, or an ice breaker, or even a simple back pack.  Soil scientists have been doing this for a hundred years or more and the hard part has always been… what to do with the soil/plant/insect when you get back to the lab.

These days we have fancy machines in our labs that can tell us just about anything you want to know about the soil.  For example, some machines take 1 millionth of a liter of soil water, pressurize it to 4000 pounds per square inch, run it through a nano-engineered piece of tubing and then subject it to laser bombardment.  From this, I can tell you if your well water is going to be poisoned.

So the machines are useful but they are also… delicate.  So delicate, that we don’t like to bring our mud, boots and shovels into the same room as the fancy machine.  That is why we need a field building.  This is the building that from which we launch our Antarctic and Arctic expeditions, it’s also the same building we organize things to take to Tisdale for the week.  It is to this very building that we will bring our samples, dry them out, organize and store them, and clean ourselves up in.  Until our samples have been processed, our fancy machines can’t be used and we can’t tell you how much fertilizer needs to be applied this year.

Soil scientists are there when the rubber hits the road in Western Canada.  We are the field scientists who make sure that the western economy keeps on rolling. We need a bridge, a bridge between our university ivory tower and the real world.  The new field facility is that bridge. If you help build it, I promise you, we will be there.  For you. Your neighbour. Your kids.  Soil science secures the future.

The recent article by Mayer and Holmstrup (Passive Dosing of Soil Invertebrates with Polycyclic Aromatic Hydrocarbons: Limited Chemical Activity Explains Toxicity Cutoff, Environmental Science and Technology 2008 42:7516-7521) is a important step forward for soil ecotoxicology.  Poly Aromatic Hydrocarbons (PAH) are found primarily in pollutants such as a diesel, fuel oil, creosote, etc.  These PAHs are toxic and for higher organisms, such as humans, are largely a concern because they can cause cancer.  However, for invertebrates and other organisms that inhabit the soil, the primary mode of toxic action is ‘narcosis’, or basically the disruption of the lipid membrane.  For narcotic chemicals, what is important is not so much; the ‘identity’ of the chemical but rather how much of the chemical has accumulated in an organism.

In the research article by Mayer and Holmstrup, they wanted to evaluate if they could predict how toxic a narcotic chemical would be by basic chemical properties.  To do this, they dosed a common soil invertebrate, a springtail called Folsomia candida, with a novel testing method that allowed them to provide an infinite source of PAHs to the springtail.  What they found was that the toxicity of the chemical could be predicted by the melting point of the chemical but not the octanol/water partitioning coefficient.  This has two important implications.

First, as noted by the authors, this will allow them to calculate the toxicity of a PAH mixture to an invertebrate.  The reason being that toxicity to the springtail was a function of the chemical activity of the PAH.  When chemical activity reached 0.058, 50% of the springtails died.  For chemicals with a narcotic mode of action, it doesn’t matter if there is one chemical with a chemical activity of 0.058 or 10 different chemicals each with a chemical activity of 0.0058, 50% of the springtails will die.

More controversially the results from this work suggest that aging may not substantially reduce toxicity for soil invertebrates.  In the test system, the springtails were directly exposed to the PAHs with the springtails either directly absorbing the PAHs or inhaling the PAHs; there was no need for the PAHs to be ingested in drinking water.  Thus, the reduction of PAH dissolution into drinking water that occurs as pollutants age, may have no effect on PAH toxicity for invertebrates.

The second significant implication from the work by Mayer and Holmstrup is that typical fugacity based multimedia models may not be accurate for soil invertebrates.  Currently, fugacity models consider biotic accumulation of pollutants to be a function of the octanol:water partitioning coefficient and the amount of lipid present in an organism.  In this scenario, organisms are modelled as ‘bags of octanol’ and the amount of contaminant present in the organisms is a function of how much a chemical likes octanol compared to water.  However, the results from Mayer and Holmstrup indicate that for springtails, it is chemical activity (which can be modelled from melting temperature) that determined the amount of PAHs accumulated by the springtails.

We’ve been working with the citizens of Iqaluit to assess how many and what sort of contaminants are present in their soil.  In a neighbourhood called Lower Base, some of the soil has been contaminated as a result of historical activities.  We’ve been analyzing the soil for hydrocarbons and metals.  Our initial results indicate that while the Lower Base region is contaminated, the levels of pollutants are too low to be much of a cause of concern.  This is great news as it indicates that there is likely no significant risk to human health in this heavily populated region of Nunavut.

Over the course of this winter and next summer, we will be monitoring the amount of soil that is suspended in the air and adhering to the hands of Iqaluit residents.  Using this data we can update our models of how humans are exposed to contaminated soil.

Soils are our history and our foundation. A soil profile tells us what has happened over the last 100 years and what will happen over the next 100 years. It is the legacy we leave our grandchildren. So, we must manage it. Manage it well and we can’t make any mistakes because if the soil goes wrong, no plants can grow, not animals can scamper and no birds can sing. If you don’t believe me, go to Haiti, go to the Sahara, go the middle east which used to be the World’s breadbasket but is now a desert. Why, because their soils were wrecked. So if you want to save the world, you need to save the soils first.

What will a soil’s education give you? Just this, a chance to immediately get a job. This job will be either helping protect our ecosystems from industrial damage or helping produce food. If you don’t believe me, in the 100 years since settlers came to the prairies, 50% of the organic matter and hence, the ability of soils to support human use, was lost. But beginning in the 70’s, soil scientists figured out better ways to manage the soil. As a consequence, for the last 20 years, we are no longer losing organic matter but are in fact increasing it. Thanks to soil science, our lives on the prairies is more sustainable than ever before.

As a new soil scientist, your challenge is to figure out how to make our mining, oil and gas and forestry industries sustainable. It’s not easy but nothing worthwhile is. Why should you work with me. Arctic soils are the tipping point. Can we stop run away greenhouse warming which will flood Halifax, Vancouver, Montreal, Toronto and all of Bangledash? There is so much carbon and nitrogen stored in Arctic soils that determining what they do will determine, are we going to tip?

Why else should you work with me? Simple really, soils form the basis of life. Our lab group tries to heal sick soils and make sure that sick soils don’t poison people.