Because Dry Valley soils are generally carbon limited, we wanted to test if i) carbon additions will increase soil respiration (a measure of the level of activity of organisms) and biomass of soil communities, ii) the nutrients nitrogen and phosphorus alone will not increase the activity of organisms and iii) elevated levels of nitrogen will increase nematode mortality. In addition, the soils of the Bonney Riegel have high nitrogen and ow carbon and phosphorus content and are expected to respond to the addition of carbon, or carbon and phosphorus, but not to nitrogen additions. Fryxell soils on the other hand have a high phosphorus content, and nematode communities are expected to respond most to carbon and possibly carbon and nitrogen additions, but not to carbon and phosphorus additions.

The experimental design consists of different plots that are organized into replicate blocks within each site. Each plot is treated in one of the following ways:

1. An unamended control
2. Addition of water only as a control for the water that is required to add the nutrient elements
3. Addition of carbon in the form of mannitol, a compound found in algae
4. Addition of nitrogen
5. Addition of phosphorus
6. Addition of both carbon and nitrogen
7. Addition of both carbon and phosphorus

The helicopter leaves after dropping off the wormherders at F6 Camp near Lake Fryxell

Jeb carries a jug with nutrient solution from the landing pad next to F6 Camp to the experimental site.

The Von Guerard stream drains into Lake Fryxell with the Commonwealth Glacier in the background.

The team went to the Fryxell site on Wednesday, December 21 and then to the Bonney site on Friday, December 23. They first sampled all of the plots. The topmost layer of the soil was first collected for measurement of the chlorophyll a concentration, which helps provide an estimate of the photosynthetic productivity of the soils.  Soil samples from each plot were then collected to a depth of 10 cm, to be used in measuring soil chemistry, soil moisture and extractions of the soil animals present. The samples were brought back to the Crary Lab at McMurdo station where the soil invertebrates were extracted and counted. After sampling the soils, the nutrient treatments mentioned above were applied to the plots.

The weather on both days was very nice, and the landscapes were stunning as always. On Friday at Lake Bonney, the helicopter was a little late to pick the team up at Lake Bonney, so there was some time to explore the area. Martijn walked up to the edge of the Taylor Glacier, named after Griffith Taylor, geologist and leader of Scott’s Western Journey Party of the British Antarctic Expedition (1910-14). The glacier had been discovered by Scott during the British National Antarctic expedition (1901-1904) but Scott thought it was a part of the Ferrar Glacier at the time. Taylor, however, discovered that these were not parts of the same glacier, but two glaciers side-by-side.

Jeb and Martijn are using jugs with a pour cap and open top chambers to apply nutrient solutions to the soil plots.

The edge of Taylor Glacier.

F6 is the name for a U.S. field camp situated near where Van Guerard Stream empties into Lake Fryxell. Field camps have been established at strategic locations throughout the Dry Valleys to support ongoing scientific work in the area. They serve as camping, staging, and emergency survival locations for scientists.

F6 field camp

Van Guerard Stream

The BEE plots (stakes and ITEX chambers seen) with Lake Fryxell and the Commonwealth Glacier in the background

There are four different treatments at the BEE plots:

1. Control (no treatment)
2. Soil warming with ITEX chamber
3. Water added
4. Soil warming and water added

The purpose of the experiment is to see how the soil ecosystem throughout Taylor Valley will respond to environmental change. As predicted by climate change models, it is expected that the soil temperature will increase and that more water will be present in the soil.

Zach holding a spare ITEX chamber used to add water to the water only plots. Permanent chambers are staked into the ground in the background.

The first step was to sample soil from the 24 plots. A few of the plots still had ice right underneath the surface from adding water last year! We had to get creative to chisel out enough soil to sample. Next, we needed to add 5.6 liters of water to the “water added” plots. Our final task was to perform maintenance on the ITEX chambers by making sure that they were all strapped down securely. Strong katabatic winds in the Dry Valleys can destroy experiments if they are not securely anchored.

Zach and Martijn filling up a portable watering can with water

Jeremy watering a temperature warming and water added plot

We were able to finish up our work quickly so the helicopter picked us up a little bit early.

The crew this season consists of Dr. Martijn Vandegehuchte and Zach Sylvain, both from Colorado State, joined by Dr. Byron Adams, one of the LTER co-PI’s from BYU, and his student Jeremy Whiting. We’ll also be working with other members of the McMurdo LTER Soils Team throughout the season.

Since this is their first season on the Ice, Martijn and Jeremy had to do snow school, perhaps more famously known as “Happy Camper” school. The basic premise is that snow school prepares you to survive in Antarctica for a few days in case you are in a survival situation. You also learn how to set up a proper field camp. The class lasts a full day and half, including an overnight stay on the McMurdo Ice Shelf.

Martijn built a snow trench, which really ended up being more like a cave. He crafted stairs, built a cold sink (a dip in the cave for the cold air to settle), and had a heavily fortified roof. Despite the snowfall during the night, he was nice and warm inside his trench.

Martijn's cozy snow trench

Jeremy reported that he had a great night of sleep. Everyone was disappointed that he slept in a tent rather than in a snow trench. He said that snow school was a lot of work but contained valuable training for camping in general, especially snow camping.

A row of mountain tents at snow school

We have already returned from our first sampling trip in the field. We went to the south side of Lake Hoare in Taylor Valley to sample the soil of two experiments– the Long Term Monitoring (LTM) plots and the algae addition plots. The LTM plots are a collection of 64 1-meter square plots with a variety of treatments applied to them. The treatments include increasing temperature, adding water, adding simple table sugar (sucrose) mixed with water, adding natural sugar (mannitol, a sugar found in algae) mixed with water, and different combinations of each of those. Additionally, there are plots established as controls. The experiment was set up during the 1993-1994 season and the treatments discontinued during the 2004-2005 season. Since then, Wormherders have continued monitoring the recovery of the soil ecosystem to document the changes. Later, actual dried algae (without water) was added to a separate set of plots and another series of controls were established as well. These 16 plots became known as the algae addition experiment, or just the algae plots. The experiment was established in the 1994-1995 season and was decommissioned at the same time as the LTM experiment, so our current sampling is to document the recovery of the soil ecosystem just like with the LTM plots.

Zach and Byron sampling the Algae plots

Martijn and Byron sampling the LTM plots

After the sampling was complete, we dropped off Byron at a new experiment being established near Lake Fryxell while the rest of the Wormherders returned to McMurdo for sample processing. We’ll talk more about the new experiment in a later post.

Questions about what limits species ranges aren’t limited to organisms like birds, trees or mammals, though. Part of the work we do down here is looking at what controls the ranges of the species of soil animals we find, and how long those animals have been where they are. In order to do this, we have to get out of Taylor Valley (where most of our work, such as the LTER, is carried out) and collect samples from the other valleys and areas of exposed soils (such as nunataks, or mountaintops that stick out from glacial cover). When we do this, our aim is to try and cover a variety of different habitat conditions, such as available moisture, visible mosses, algae or lichen, the amount of salts in the soil, size of the soil particles, how much exposure to sun the area gets and other factors that may influence how habitable different places in the valley are, which can inform us as to why we do or don’t find certain species in a given location. Last year, Byron, Uffe, Diana and Ian Hogg (our colleague from Waikato University in New Zealand) were able to get down to the Beardmore glacier and collect samples at many different locations there, which is much further south than the Dry Valleys. This year, we were fortunate enough to have Ian and Jeb Barrett (another of our colleagues, from Virginia Tech) send us samples from this region again; in addition, a group of New Zealand researchers led by Craig Carey have been sending us samples from some of the more southern Dry Valleys such as Miers and Hidden Valley.

This year, Byron, Uffe and Zach were able to get to some less-visited parts of the Dry Valleys to collect samples. They first started by going to Mount Suess, which is further north in the Transantarctic Mountains than Taylor Valley. Mount Suess sticks up out of the surrounding Mackay Glacier, and has a lower ridge that projects from the east side of the mountain. This ridge is covered with soil and dotted with small meltponds, which harbor mats of algae and patches of moss. Here you can see a picture of the mountain, with the soil-covered ridge in the foreground.

And here is a picture of one of the small ponds.

The three of us each went a different way from the helicopter, while the pilot stayed by the helicopter for our return. Each of us had a radio so that we could check in periodically, and to make sure we were all okay–if something happened to one of us, we could let the others know. Uffe went downhill and sampled by some of the meltponds and surrounding area while Zach moved along a small rocky ridge and Byron moved along the top of the ridge toward some other small ponds. Below you can see an example of one of the patches of soil we sampled, and note the small patches of green moss along the bottom of the rocks in the top-center!

We spent an hour and a half on the ground here collecting samples, and then got back into the helicopter to travel to Wall Valley, named after our own Diana Wall! Wall Valley was a short 30 minute flight west and slightly south of Mount Suess, and we passed over some pretty stunning areas that make you realize how big the Dry Valleys are, as you can see here:

Right before we got to Wall Valley, we passed Virginia Valley, named after Ross Virginia, from Dartmouth College, whom Diana has worked down in Antarctica with for over 20 years! As we made our approach, we got a picture of Wall Valley:

Previous sampling at Wall Valley by the Wormherders wasn’t successful in recovering nematodes, as the soil down at the bottom of the valley is too high in salts, which the nematodes can’t tolerate. So this time, we went up along the edge of the valley, sampling in the scree piles that slope up along the valley’s walls. Here you can see the helicopter on the valley floor, and up to the top right stretches a scree slope that Uffe has gone up to sample:

Again, we collected samples for an hour and a half and then made our way back to the helicopter to travel to our last destination, Hawkins’ Cirque. The Cirque, named after the head helicopter pilot at McMurdo, is a small hemisphere-shaped break in the wall of Wright Valley, and sits nearly all the way back in the valley just above the glacier. Here you can see across the Cirque, with the glacier to the left:

After we finished collecting samples, we posed for a group photo: from left to right are Uffe, Byron and Zach.

Once we’ve extracted and had a chance to examine these samples under the microscope, we can look at these data together with the data from other samples collected by ourselves and our colleagues, and begin to put together a better picture of what governs why we find species of soil animals where we do in the Dry Valleys. By looking at overall patterns in distributions, and through use of several dating tools (both by examining age of the exposed rock surfaces as well as comparing the times that different populations of animals in different areas may have been separated by, using molecular genetics), we can start to explain how dispersal throughout the valleys may have occurred, and why some areas were colonized while others were not!

Suppose for a moment that we were collecting DNA from Siberian ice cores and inferring ecological function based on the taxonomic affinities of the DNA sequences. When we encounter a chunk of frozen wooly mammoth tissue what would we infer about biological diversity and ecological function? That giant herbivores are running around and shaping Siberian ecosystem processes? Clearly our inferences would be a poor reflection of what actually goes on!

Long-term climate observations by the McMurdo Long-Term Ecological Research group are revealing increased frequency and magnitude of ‘pulse- events’ – periods of rapid warming and ice melt that lead to increased liquid water moving across/through the Dry Valley landscape. Which microbes are active in dry soils? Which microbes are responding to pulse events? Which microbes are completely dormant, waiting for more favorable conditions?

To answer these questions we set up a contained experiment that will capture the microbial response to a pulse wetting event. In the experiment we wet some soils with stable isotope labeled water (O18). The microbes that respond to the wetting event by taking up the O18 will incorporate the label into their DNA. We then extract the DNA from all the microbes in the soil and separate the strands of DNA that have incorporated the label from the strands of DNA that did not incorporate the label. We then sequence the two pools of DNA to reveal which taxa responded to the pulse and which did not – essentially, when it comes to identifying who responds to pulse events, we’ll be able to distinguish the players from the poseurs. Additionally, in order to link the response to actual ecosystem processes, we are measuring CO2 flux in the soils as a surrogate of microbial activity. For example, soils pulsed with water are expected to increase in ecological activity, and thus an increase in CO2 flux through the soil ecosystem.

This involved several steps. First, the experiment was set up conducted near the McMurdo Long-term ecological research (LTER) stoichiometry plots at F6 (Lake Fryxell, Taylor Valley). We outlined a patch of soil 8 m long and 1 m wide, with 8 replicates of 1 m2. Six PVC collars were placed in each of these 8 replicates, color coded to make it easy to tell which sampling period each represented – a control that wasn’t treated at all, so we’d know what the background of each little plot was, and collars to be sampled at 12, 24, 48, 72 and 144 hours after the treatments were added. You can see the collars here:

These collars were placed into the soil, one of each color-coded sample per plot—the locations of these colors within the small plot were randomized beforehand, and here you can see Uffe setting the collars into the soil as Zach reads off where each is supposed to go.

Once the collars were in place, Diana went around with a ruler to measure how much space was between the surface of the soil and the top of the collar—this is important because the machine that Byron would later use to measure how much CO2 was emitted from each plot needs to know how much space is being measured!

Once this information was collected, Uffe and Zach added water to the plots (the treatment), and Byron added the O18 to the experimental plots. Here you can see Uffe and Zach carefully treating their collars, and in the background Byron is taking respiration measurements:

Byron then had to stay out all week (and will have to go out once more) in order to take the respiration measurements at each time period—one 12 hours after the treatments were conducted, one 24 hours later, and so on until all the appropriate readings were taken. The microbial responses are collected in a time series of 12, 24, 48, 72, and 144 hours. The DNA sequencing and analyses will be done off the ice at Brigham Young University. Here you can see him set up to take these measurements.

We began our field season with the necessary (but not exactly pleasant) travel from the United States on the 31st of December. Our field team for the season met once again in Los Angeles, with Diana Wall and Uffe Nielsen flying from Denver, Colorado, Byron Adams from Sacramento, California and Zach Sylvain from Portland, Maine. From LA, it was roughly a 13 hour flight to Auckland, New Zealand and then another hour to Christchurch. Although we left at 11:30pm on December 31st, we didn’t arrive into New Zealand until the 2nd of January because of the International Date Line–a whole day, lost! Fortunately we didn’t have to wait long before heading down to Antarctica, and so late at night on the 3rd, we caught our C17 flight (seen here landing on the ice runway at the end of last field season) down to McMurdo.

Once we had arrived in Antarctica, we spent the morning going through a wide variety of updates about the facilities and responsibilities down here, and then began to set up the lab. The flight had arrived very early in the morning on the 5th (we started our first briefings upon arrival at 5:30am!), and so most of our group opted to take a quick nap before getting to work. What sort of work goes into setting up the lab, you ask? First, many pieces of equipment must be picked up and moved into our empty lab, such as microscopes and a variety of chemicals as well as glassware such as beakers, flasks, and vials. How much glass (and plastic) ware do we need to carry out all the extractions we do while we’re down here? Quite a bit!


On the left is a cart full of plastic falcon tubes that we use to collect the nematodes during extractions (and the caps to the tubes), with a pile of plastic spoons and scoops below–to the right are all of the plastic beakers we need for our extractions, as we mix soil with water in these prior to sieving (more on extractions later!).

After two days of gathering everything we required to start working, we finally were able to begin extracting soil samples in order to see what animals (nematodes, rotifers and tardigrades) we can find. This is the good stuff–taking the soil and running it through all the steps we do in order to see what lives within it is exciting, letting us explore the mystery of where we might find life on this harsh continent. Fortunately, we had many samples from a colleague stored in a freezer waiting for us, so we were able to get to work today without having had to go into the field just yet! Each of us helped in extracting the samples in order to get the animals out and under the microscope. Zach began by weighing out 100g of each soil sample into one of those plastic beakers shown above: we weigh the soil samples so that we can compare each sample to every other sample more easily.

After a sample has been weighed, it gets mixed with water in the plastic beaker, and the water is then poured over two sieves stacked together–this helps strain out some of the soil and rocks and collects liquid with the soil animals on the sieve at the bottom, which has very small holes in it to catch the animals but let most of the water flow through. The sieve is then rinsed over a funnel into one of those small plastic falcon tubes to collect the soil animals (and some residual soil). Here you can see Diana rinsing the sieves between samples, which she is doing in order to prevent one sample from contaminating another: if she didn’t do this, we may end up with animals from one sample being transferred to another, which would provide incorrect data of what lives in each area the samples were collected from.

Samples in the falcon tubes are then passed to someone operating the centrifuge. Here, the samples from the first run of the sieves are checked to make sure the water levels are roughly equal and then are added into the centrifuge four at a time: this first run lasts five minutes, and helps to move all the soil animals down onto a pack of soil. Once this first spin through the centrifuge is complete, all but the very last remnants of water are poured out as waste–the vast majority of soil animals are all tightly packed along with the soil at the bottom, and not in the water in the tube. We then add a solution of water and sugar, mix the soil up into this to re-suspend the nematodes into the solution, and then replace the tubes into the centrifuge for an additional minute. In this last centrifugation, the soil is spun into the bottom of the tubes while the soil animals remain suspended in the sugar solution. Here you can see Byron checking the level of water in the falcon tubes prior to operating the centrifuge:

When the second spin through the centrifuge is complete, the samples are passed back to be sieved once more, this time over a small sieve with an extremely fine mesh. This sieve is then rinsed once more over a new falcon tube, and all of the soil animals are concentrated into this tube for examination under the microscope. In this image, Uffe is looking at a sample under the microscope, where he will count the number of living and dead nematodes from each species present, as well as the number of rotifers, tardigrades and other soil animals.

These numbers will be entered onto a data sheet and then be checked so that we can conduct analyses on our data later. Once we have completed looking at all the samples from a given experiment, the samples will be preserved with formalin and then packaged to be shipped back to the US, along with the unused soil from each sample that wasn’t used in the extractions or for obtaining characteristics of the soil such as soil moisture or nutrient levels (such as carbon, nitrogen and phosphorus).

Our experiments for the Long Term Ecological Research (LTER) work we do here are spread out along the south sides of three lakes in the Taylor Valley. From east (on the right, closest to the Ross Sea) to west (on the left, closest to the polar plateau) the lakes are Lake Fryxell (with F6 camp), Lake Hoare and Lake Bonney.

Over the last week and a half we’ve been to each of our sites at these three lakes and sampled from and then treated another of our long-term experiments, the Biotic Effects Experiment. This experiment has four treatments: added water, increased temperature (about 2 degrees Celsius), increased temperature and added water and a control (which if you remember from our discussion of the stoichiometry experiment is there to provide us with baseline data without the influence of the treatment manipulations).

Adding water is pretty straightforward. Much like the stoichiometry experiment, we added 5.6 liters of water to each plot that was supposed to be watered. We did this with the jugs and watering spouts we used in the stoichiometry experiment. Temperature is also pretty straightforward, and to raise the temperature of the plots we let the sun do the work. The cones we use to outline where we need to water in the Biotic Effects and Stoichiometry experiments are actually used for the temperature treatment. They’re made of nearly-clear fiberglass that helps to trap heat from the sun in the area beneath the cone, and in this way we can leave the cones tightly strapped down to stakes on the plots year-round and let the sun do all of the work for us. You can see the cones placed on the sites below.

With this experiment, we can see what the effects of changes in climate might be on the soil animals in the dry valleys. If the dry valleys get warmer and wetter, our experiment will help to predict in what ways the soil animals will respond. The design also allows us to see how each of these climate variables may affect the soil animals alone, without the influence of the other variable. This means we can also say what proportion of the change we see due to increased temperature and precipitation may be due to the effects of the increased temperature by itself, or the extra water.

While we were out at Lake Bonney, we also set up another experiment that we plan on monitoring for many years to come. Last year this area where our experiments are located got very wet when an increase in streamflow resulted in a large patch of moving water and seeps. We had the boundary of the wet area marked out last year, and this year we were able to put in spikes with copper tags to indicate areas we wanted to sample from over the next several years. Additionally, we also ran three lines (transects) that extended from the areas that had been dry throughout last year through the area that had become flooded and then back out again into dry soil. Each of these transects was located roughly parallel to the others, with one toward the base of the slope our experiments are located on, another halfway up the slope, and a third quite far up the slope. Once we had these sampling locations marked out, we took our first batch of samples, as you can see here with Uffe happily getting some soil for us:

When we sample soil, we do two things. First, we scrape off the very top layer of soil in order to see how much photosynthetic activity the algae that live in this area are undergoing, and then we try to collect the top 10 centimeters in the small area directly under where we sampled the algae. This soil is put into bags labeled with the experiment we’re conducting as well as the particular site or plot the sample came from so that we know the origin of each sample. We then take the bags back to the laboratory and there we extract the animals and measure the moisture of the soil.

Measuring soil moisture is very simple. First we weigh small cans and write down their weights. We then add 50 grams of soil into each can and note the number of the can and which soil sample was added into it. Finally we place the soil cans into an oven at 105 degrees Celsius for a day, which causes all of the water in the soil to boil off and leaves only the dried soil. Once these dried soils are weighed, we can subtract the weight of the can itself and then calculate the difference between the wet and dry soils and then determine what percentage of the wet soil was water.

The process to extract soil animals is much more involved, and we usually have three people performing various steps at the same time. The first step is done while we’re weighing out soil for soil moisture: once the soil for soil moisture has been measured out into a soil can, the person working at the balance also measures out 100 grams of soil for extracting the animals. We do this in a special “laminar flow hood” that helps to filter the air blown over the samples in order to minimize contamination–nematodes are everywhere, and we want to try and extract only the nematodes that are in the soils we have collected. This 100 grams of soil is then placed into a small beaker that is half-filled with water. The soil is then mixed up in the water to make a sort of soup. All of the heavy particles such as rocks and bits of sand fall back down to the bottom of the beaker while the lighter particles float around in the water. These lighter particles include small soil particles, but more importantly they also include the nematodes and other soil animals that we’re interested in collecting.

This soil and water mixture is then poured over a series of sieves and sifted out so that only the very small particles are captured and transfered into a centrifuge tube. We then spin the tubes in a centrifuge very quickly for 5 minutes in order to push all of the animals down to the bottom of the tube. After the 5 minutes is up, we pour out the extra water on top (being careful to keep some of the water that might have animals in it) and then add in the magic ingredient: sugar water. Once we add the sugar water, we mix it up with the soil in the centrifuge tube, which tosses the soil animals back up to the top of the water column. This time we centrifuge the tube for only one minute, and then take it out. All of the soil gets tossed to the bottom of the tube but all the animals stay in the water because the sugar keeps them afloat. We then pour the water out over a very fine mesh screen and then rinse the screen into a clean tube, and voila! We have a small sample of water that contains the animals from all the soil we started with.

Here’s Bishwo pouring the soil-water mixture over a set of sieves before the first centrifuge run.

Here is Bishwo rinsing a sieve with Zach weighing soils behind him.

And here is Uffe waiting for the centrifuge to finish up.

When we look at the animals under the microscope, we identify the nematodes to species and then further break them down into the number of males, females and juveniles and how many are alive and dead. We also count other organisms such as mites, tardigrades or rotifers, and you can see some images and movies of these animals here. First you’ll see a tardigrade (or “water bear”) followed by a nematode. Later on, 1:05 in, a rotifer appears. This video gives a good idea of what it’s like to look through soil samples!

Earlier this week Diana, Uffe, Byron and Ian (from the University of Waikato in New Zealand) got a chance to start sampling for another of the grants we have going. Early Tuesday morning they got onto a small “twin otter” plane and flew from the ice shelf outside of McMurdo down to the Beardmore Glacier. This glacier is very far south, and rises from the ice shelf up to the polar plateau–this is the same glacier that Shackleton and Scott used to get up to the plateau and eventually (for Scott) to the south pole. Here they landed near Mount Kyffin, which is mostly covered by snow except for a few areas that have exposed soil. They climbed across the ice and snow over to these exposed areas and collected samples to examine back in the lab.

Here they are back at the plane before heading back to the lab. From left to right: Uffe, Ian, Diana, Paul (their mountaineer) and Byron:

With these samples, they are looking to see what animals are found on the exposed rock surfaces that act like islands amidst the glacier and snowcover. They’ll take the animals they find and sequence their DNA, and then check to see if the populations of animals they collect have diverged through time and if so try to estimate how much time has passed since the populations were together. They can then compare these estimates with the age of the surface of the soil they collected the animals from and determine whether the animals are newer arrivals or whether they’ve been there since the time the soil patches were isolated from each other. Neat stuff!

Fortunately the weather quickly lifted and Bishwo and Zach were called back down to the heliport where they weighed their gear in to let the pilots know how much cargo was on board. Once they had all their equipment they got into the helicopter and then took off–after all the delay, fieldwork at last! The glacier team wasn’t so fortunate, though, and remained stuck in McMurdo for at least another day.

The helicopter flew out over the sea ice and after a half-hour flight over the frozen Ross Sea the pair finally made it to F6 camp on the shore of Lake Fryxell. There’s a permanent hut set up there with a kitchen, entryway and lab area: there’s an outhouse on the side of the building and everyone sleeps in tents. In order to minimize impacts on the Dry Valleys, nothing aside from the huts and other necessary items is left here and all trash and waste must be sealed into containers to return to McMurdo. The research based out of here involves both our work with soils (such as the stoichiometry experiment we described last entry, which is also what Bishwo and Zach flew out to add nutrients to) and work on the many streams that feed into Lake Fryxell from the surrounding glaciers. This work is all conducted for the long-term ecological research site stationed in the Dry Valleys, and involves researchers not only from Colorado State University but also Brigham Young University, Dartmouth College, the University of Colorado and many other universities around the country. Research sites are spread all around both the camp and the lake, making it very much a science-based area.

This was also Zach’s first trip into the Dry valleys, and you can see how excited he was to finally be there!

Once they had landed and gotten their gear offloaded Bishwo and Zach realized that there was another problem. In all the confusion trying to get the helicopter flights out, somehow the last half of the water and nutrient solutions hadn’t been loaded–they wouldn’t be able to work on the experiment without it! A quick call back to McMurdo notified the helicopter crews of the issue and the solutions were to be sent out as quickly as possible. To make use of the time available, Bishwo and Zach walked over with Becky (a member of the soils team from Dartmouth College that had made it out to F6 camp earlier in the week – her blog is here) to check some of the other experiments. The group wanted to be sure that nothing had blown away or broken in the year since the wormherders had last been in Antarctica. Once the team had checked and made sure that everything was still in place and in working order, they went into the hut to get a cup of tea to warm up. While enjoying the tea, a helicopter could be heard getting closer and sure enough, the supplies had arrived and work could begin!

The crew carried the 35 (heavy) 10 L jugs of nutrient solutions over to the stoichiometry plots and got ready to pour the solutions on the appropriate plots. Becky has worked on these plots for several years and so she helped oversee Bishwo and Zach while they carried the solutions over to the plots. They started by adding only water to the plots indicated by Becky that weren’t getting any additional nutrients (the control for the experiment to make sure that any changes in the soil animals were due to the nutrients and not the water that was added).

Once at the indicated plot, they double-checked to make sure they were in the right plot by reading the copper tag anchored on the ground and checking the two plots next to them matched what was shown on the map. Bishwo and Zach then placed clear plastic cones down to outline where they were supposed to pour the liquid and then carefully watered the plots. Each of the different solutions had to be poured on 8 separate plots, and so once they had the water poured they moved on to the carbon and nitrogen solutions, then the phosphorus and carbon/nitrogen and finally the carbon/phosphorus solutions. Here you can see Bishwo carefully applying carbon solution to one of the plots:

The solutions had to be slowly poured onto the plots, so that the water would seep into the soil and not just run off the surface and away from the plots. All of the liquid needs to soak into the soil and completely wet the top 5 inches in order to provide the nutrients to all the animals that lives in that space–if the water were poured too quickly, it would run off the plots and be wasted or could contaminate nearby plots and ruin the experiment. Notice the careful positioning of Zach and Bishwo’s feet as they bent over the cones to pour the solutions without stepping in the plots!

While they had been engrossed in getting the plots treated with the solutions, storm clouds rolled in and it began to snow–no helicopter was going to be able to fly in the storm. The afternoon in the camp was fun and our team got to meet the “stream team” and four “GK-12″ graduate students (their blog is here) from the University of Colorado who were also working out of F6 camp, bringing the total number of people to 9. Everyone played cards and chatted when word came over the radio just as dinner was being prepared around 7:30: There was a helicopter at another camp just to the west that was going to stop at F6 to pick up Bishwo and Zach and bring them back to McMurdo! They quickly rushed to get their gear outside and when the helicopter arrived packed on all of the now-empty jugs and their backpacks and then they were off!

The helicopter quickly flew over the valleys to the edge, where they meet the sea ice. The weather between the Dry Valleys and McMurdo Station wasn’t good enough to fly through, and so the helicopter pilot decided to “boomerang” back to camp. Just in time for dinner!

It snowed off and on all day, with up to an inch of snow on the ground at times. The Dry Valleys are an extremely cold desert (even though they’re cold, they’re also very, very dry as the name suggests) and the snow would disappear quickly–the air is so dry that a lot of the moisture evaporates off before the water in the snow can even get into the soil. Look how different the valleys look covered in snow:

In the afternoon the snow began to clear up, and at 5 pm the helicopter they had tried to go home on the night before took off to refuel and then returned to bring Bishwo and Zach back to McMurdo. They got picked up around 5:45 and after a smooth ride made it back into McMurdo around 6:15. Just in time for dinner!

Now that everyone’s back in town, we’re looking at all of the samples under the microscope to see what nematodes and other soil animals are living in the soil samples we collected. This weekend Zach and Bishwo are going back to F6 camp to work on some of the other experiments there, and Diana, Byron and Uffe are hoping to finally go far south to the Beardmore Glacier with Ian, one of our team members from Waikato University in New Zealand.

Life here wasn’t all work while we get settled in, though! Even though we had to work during the weekend to get everything set up, there was still time to enjoy life in McMurdo. This past weekend featured two of McMurdo’s winter traditions: IceStock, an all-day concert featuring local bands and the Scott’s Hut 10k race.

First up was IceStock on Saturday. The bands started playing at noon on a big stage set up in the middle of town and kept playing until 7. You can see the stage here, all painted up for the festival this year–every year has different stage artwork made up special each year. We missed the first few bands performing, but did manage to hear bands like “Level Five”, “Unsorted Trash” (we have to sort our trash here into things like food waste, recyclables and things they can compress to ship back home to be taken care of) and “Safety Band”. As you may have guessed, Safety Band sang songs about how to avoid getting hurt or doing things that would injure other people–not something you’d hear anywhere else! Here you can see a picture of Bishwo, Diana, Zach, Ross and Uffe at IceStock:

And here’s a picture of the stage artwork:
and one with the last band of the day playing:

There was a short break for dinner at 7, and then the concerts continued until late into the night in different buildings. Some bands played more relaxed, acoustic music and others were more of the loud rock and roll style–something for nearly everyone! Being the diligent scientists that we are, however, we went and made sure that everything was squared away in the lab after dinner and then took the rest of the night off.

Sunday morning, bright and early, was the Scott’s Hut race. The race started at 9 in the morning and was a bit less than 10 kilometers (that’s about 6 miles) from McMurdo Station over to Scott Base (run by the New Zealanders). After running through town, the participants had to race uphill with the wind blowing down on them–not easy–and then down the other side into Scott Base. Once they got there, it was time to turn around and run back. Not many people ran it this year because of the strong winds, but here’s a picture of Bishwo and Byron coming to the finish line!

The real reason we’re here, though, is for the ecology work that we do. Most of the time we’re here is spent getting the lab set up, running our experiments (or keeping them in running condition between years) or looking at all of the soil we collected to see what organisms are present and what effects the experiments might have. Weather has unfortunately kept us from getting into the field just yet–compare the image out our lab window here with the one from last week!

Once we can get into the field, however, we’re going to begin sampling and maintaining the experiments we run here. Our group might change year to year depending on who comes down to work each winter, but our experiments run for many years at a time in order to provide us with information about how the soil system down here works. This week we’re going to be working on the Stoichiometry experiments we have in place at our F6 site. It sounds really confusing, but it’s actually fairly straightforward.

In the Dry Valleys, one of the questions we’re interested in are how differences in nutrients (carbon, nitrogen and phosphorus) between the different sites we have around the lakes in the dry valleys affect the animals and other critters that live in soil. Secondly, we want to learn which of these three nutrients has the greatest effect on the organisms living in soil, so we’re looking for changes in the activity or number of living things in the soil when we add either carbon, nitrogen or phosphorus.

There’s very little plant life to provide carbon to soils (plants undergo photosynthesis and take carbon dioxide in the air and turn it into sugar or use it to grow bigger): you can see how empty these sites look below!

Because there’s so little plant growth in these sites there is very limited amounts of available nutrients in the soils and adding nutrients will therefore increase the number of organisms in the soil and how active they are – nutrients control how quickly organisms (including humans) grow and reproduce. One of the most important and often limiting nutrients is carbon, but sometimes other nutrients also influence growth rates. The field sites we chose for this study differ in the amounts and availability of nitrogen and phosphorus, with nitrogen being limited at Lake Fryxell and phosphorus being limited at Lake Bonney. In contrast, the sites are fairly similar in carbon levels, although carbon is also in short supply. So we predict that carbon additions will have a positive influence at both field sites but that nitrogen is limiting soil function and faunal populations at Lake Fryxell whereas phosphorus is in short supply at Lake Bonney, and a strong positive effect of carbon additions will only be observed if we also add nitrogen and phosphorus at the two sites, respectively.

To get all these nutrients added to the sites, we have to carry in a lot of water with the nutrients dissolved inside. You can see all the containers we have to bring with us below.

We add either carbon, nitrogen or phosphorus by themselves in order to see what happens when only one of the nutrients is added to a plot of soil, and we also add nitrogen or phosphorus with carbon in order to see what happens if two of them are combined–remember, sometimes the soil organisms can’t make use of the extra nitrogen or phosphorus if they don’t have enough carbon to grow. Sometimes we also add nothing, just so we know what the plots are like alone. And finally, because we’re adding all of those nutrients with water, we also add only water to some of the plots in order to make sure that any changes we see are due to the nutrients and not the water!

The first thing he had to do for Snow School was to listen to some discussions about safety theory and how to minimize risk while gone, and then it was time to travel away from McMurdo off onto the ice shelf, where the snow is deep. It isn’t too far to the place where they set up the camp, but you can really tell you’re in a different part of the world, because everything looks so different! McMurdo sits on Ross Island, which is surrounded by water to the north and ice to the south, and the island itself has three mountains, one of which is much more obvious than the others–Mount Erebus, an active volcano! You can see in the picture the material floating away from the top, but the volcano is very quiet and stable, and isn’t a danger.

Once here Zach’s instructor talked to him about how unpredictable weather can be in Antarctica, and how suddenly snow storms can blow up and possibly catch you while you’re out. He talked about how to use a “survival bag” filled with sleeping bags, sleeping pads (to keep you off the snow while you sleep!), tents, food and a small gas-powered stove. Once this was done, Zach and his group picked a spot to set up their camp and began to raise the tents. They then began to saw block-shapes into the snow to make snow bricks! These bricks ended up being used to build a wall to protect them and their tents from the wind, which would help to keep warm. Even though the weather was really nice, with a lot of sun and temperatures right around 34 degrees, wind would pick up every few minutes and make it feel a lot colder–the wall really helped to keep them warm just by stopping all the wind from hitting the little camp! Here you can see the tents all set up, with the snow-brick wall built to the side of the big tent in the middle; everyone is standing in the kitchen, which was built next.

Now that they had a camp built, it was time to learn how to make shelters if the tents were lost. To do this, they learned how to dig holes into the snow and then hollow out little trenches to sleep in, protecting them from the wind and providing a little spot to put a sleeping bag into. Not the most luxurious way to spend New Years Eve, but after a long day of setting up a campsite, it still felt good to sleep in! A hot dinner was made from dehydrated camping food and then they made cocoa, tea or coffee to stay warm for the next few hours. They stayed up to ring in the new year, and then got their sleeping bags out and settled in for a night under the sky.

Everyone slept in the trenches all night, and got a surprisingly good amount of sleep out of it–six or seven hours at least! In the morning, they all made breakfast on the stoves and then took down the tents and packed them back up into sleds to drag over to a nice warm hut for the next part of their training. After some tea or cocoa to warm up after the night spent outside, everyone had to learn how difficult it can be to get around outside in a white-out blizzard. The super high tech solution to let them experience how hard it is to see and hear in really strong storms? Buckets!

With the buckets on our head, their task was to find a “missing camper” who had gotten lost during a white-out. They were allowed to use anything in the hut to assist them in finding the lost person, and finally settled on good, old fashioned rope. Wandering out holding the rope, they managed to stumble out to (and into!) the outhouse, only to find their friend wasn’t there. Finally, after much tripping and walking into bamboo flag poles later, they found the missing camper and safely returned back to the warm hut where they were allowed to remove their stylish headgear. This taught them the number one rule about going out in bad weather: don’t go out in bad weather! The bucket made it impossible to see, but it also made it nearly impossible to hear anything. This meant that once they got more than a few feet away from something, it was very difficult to tell how far away they were and that made it easy to get disoriented and wander.

After that, it was a simple matter of eating lunch and then waiting for the vans to bring them back to McMurdo. Now Zach is ready to go out with the rest of the group to sample and collect the data that we’ll use to conduct our scientific experiments! Until we can get out, though, we can enjoy the wonderful view out our lab window!