Wednesday, January 26, 2022

Soil organisms

In my last post, we talked about "plant-soil feedbacks". I showed you some of the plants that live at our field site. When they grow, they change the soil that is the habitat for the soil organisms. Who are those soil organisms?

When most people think about animals living in Antarctica, they think about penguins and seals. They spend some of their time on land, but they are not year-round residents and usually live only on the coast. The REAL land animals of Antarctica live in the soil. They live there all year, and spend all of their time on land. Some of them are only found in Antarctica, and nowhere else! But, when you look at a picture of the land in Antarctica, you don't see them. That's because they are microscopic!

See the bird sitting on top of the rocks? It is only a part-time resident in Antarctica. The year-round residents live in the soil. There are hundreds of them in this picture, but you can't see them because they are microscopic!

So who are these microscopic organisms that we will be studying? Most of them are bacteria. They are unicellular (made up of just one cell, unlike animals who have loads of cells in one organism). We tend to think of all tiny bacteria like they are one type of organism, but in fact they are very diverse. Just one handful of soil can have thousands of species of bacteria living in it! The different species do different jobs in the soil. Some bacteria are good at recycling nitrogen, others help break down old plant material, some process phosphorus and sulfur... and so many other things! Plants (and humans) couldn't survive without bacteria doing all of their important jobs.

Bacteria, and other unicellular microorganisms like fungi, make up the base of the food web in soils. They are mostly eating old, dead plant material in the soil, and recycling the nutrients. There are also microscopic organisms that eat the bacteria, and predators that eat THOSE organisms. A tiny, microscopic food web that is much more diverse than you might think!

Many of these organisms that live all over the Antarctic continent are nematodes. Those are the "round worms" you might have learned about in your science classes. Nematodes are very cool, because they can live EVERYWHERE on the planet. Some species are only found in Antarctica, and nowhere else. They can survive in Antarctica because of their special ability to freeze-dry themselves for periods of time. That is called "anhydrobiosis", pronounced Ann-hydro-by-O-sis. They curl up into a little spiral and wait through the tough times (like winter in Antarctica), and can spring back to life once water is available again. 

This nematode, Scottnema lindsayae, is native to Antarctica.

Another common group that we find in parts of Antarctica are soil mites. They are bigger than the nematodes. Sometimes they are so big that you can see them without a microscope. Mites are a very common group of organisms found all over the world. You might have heard of mites before, because some of them are parasitic, meaning they live off of another organism. Ticks and chiggers are mites, for example. But soil mites are good for us! They don't harm other animals. They have an important role in soil food webs to help recycle dead plant material. Many of the mites we find in the soil in Antarctica eat fungi. Some soil mites are predators, and eat nematodes or other mites. This mite crawling around under my microscope is one that probably eats fungi:

There are also springtails living in Antarctica. You probably haven't heard of these before, but they are also very common around the world. We have a lot of them in soil in Arizona and all around the United States. They are primitive relatives of insects and also eat fungi. Here is a video of a large group that we found floating on a puddle in Antarctica. 

(If your volume is on, you can hear birds in the background. They are skuas, and they will dive bomb your head to protect their nests. You can hear me yell at one that got a little too close to my head.)

The last group that I will introduce you to are midges. Midges are insects. They are the only insect that can live in Antarctica year-round! You have seen midges before, because they are the small little flies that tend to swarm together. The species that lives in Antarctica don't have wings, though. They can survive being frozen, but they cannot survive in the coldest places in Antarctica.

You can read this cool article in the Smithsonian Mag about Antarctica's native midges.

Now you've met the microorganisms we'll be studying. As they go about their lives in the soil, they help recycle dead plant material and nutrients, which makes the soil more fertile for plants. So even though you can't see them without a microscope, they are a very important part of the ecosystem!

Thursday, January 20, 2022

Plants in Antarctica

Last week I wrote about the new project we are starting this year in Antarctica. We will study the changes that happen to the ecosystem as glaciers retreat. Let's talk a bit more in detail about what that means. (Warning! I'm going to use words that I introduced in my last post. It's time to test your vocabulary!)

A big part of the changes that happen during ecological succession is from the interactions between plants and soil. What do I mean by that? When plants arrive on bare soil, they change the soil. They can add nutrients, protect the soil from the wind and cold temperatures, and eventually become food for other organisms. These changes in the soil help the microscopic organisms (or "microorganisms") living there. If plants add food and nutrients to soil and protect from the weather, it becomes a better habitat for soil microorganisms. When plants start to grow, more organisms can move into the soil! 

Those soil microorganisms are very busy! They help recycle nutrients and eat dead plant material. That makes the soil more fertile for plants. So now even MORE plants can move in, which creates even MORE food for organisms, so MORE organisms can live there... It's a cycle of back-and-forth interactions between the soil and plants! We call this "plant-soil feedbacks". 

On the Antarctic Peninsula, one of the hardy plants that moves in first is moss. Moss are very tough plants! They can survive for a long time, even if they are frozen, completely dry, or in the dark. They become dormant, and wake back up when the weather improves. That's an important skill when you live in Antarctica! Moss can also get their nutrients from both the air and soil, which helps them survive without as much help from the soil.

Another early grower is lichen. Lichens are a unique kind of organism. They are a plant and fungus living together in one organism! They are VERY good at surviving in tough habitats. They are so good at surviving on their own that they don't even need soil. They can grow right on rocks!

The green stuff on the rocks and the tufts on the soil are both examples of lichen.

Moss and lichens are often the first to arrive on new soil. We call them pioneer plants. Just like the pioneers from your history books, they can move into new territory and survive through hard times! But not all species of moss and lichen are good pioneers. Only some species can start growing on the bare soil. Their growth starts the plant-soil feedbacks, and paves the way for other species of moss and lichen to move in.

Eventually, the soil becomes fertile enough for grass to grow. There is only ONE species of grass on the entire continent of Antarctica. It is called Antarctic hairgrass. (Compare that to the thousands of species of grass that live in the United States!) Grass is a "vascular" plant. That means it has veins that move water through the plant, allowing them to grow taller (and farther away from water) than moss and lichen. The only other vascular plant in all of Antarctica is the Antarctic pearlwort. 

Pearlwort in the center surrounded by hairgrass

As succession continues and these vascular plants move in, the community can look like this:

Look that that diversity! Many species of lichens, growing on moss, with grass and pearlwort (that patch of bright green in the lower center), and even mushrooms!

Fun fact: Hairgrass and pearlwort can only grow on the Peninsula, because the rest of the continent is too harsh. They are the wimpiest of the Antarctic plants. :) Moss and lichen are able to grow in many places in Antarctica, but hairgrass and pearlwort can only follow them on the Peninsula.

So these are the species that we will be studying during our research. Mostly, we will focus on the moss, lichens, and hairgrass.

Friday, January 14, 2022

A New Year, a New Project!

The New Year is bringing some new adventures for our research team in 2022. We are starting a new research project in Antarctica! 

The topic of this new project is how the ecosystem changes and develops as glaciers melt. Warmer temperatures on the Antarctic Peninsula have caused ice to melt. For glaciers on land, that melt happens at the edges of the glaciers, and they shrink in size. That's called "retreating". (They're not actually walking backwards. It's just that the edge of glacier moves backwards as it melts.) As glaciers retreat, the ground that was once covered in thick ice is now exposed. That soil being uncovered hasn't seen the light of day for thousands of years!

Not much can live on or in soil beneath a glacier. Not only do glaciers block the light, they also slowly move downhill with gravity. That big, heavy hunk of ice moving downhill scrapes the ground beneath it. (That is called "scouring".) It's hard to be a plant when you're covered by thick ice that's slowly scraping you away from the soil! So under a glacier, plants and many animals can't survive. But once the glacier retreats, that exposed soil can start to grow new life. Now they have sunlight and can take root! This is the beginning of a new ecosystem growing where the glacier once stood.
This video shows the melt occurring at the edge of a glacier in the Dry Valleys of Antarctica. Melt happens every summer, but if melt is faster than ice is being added, the edge of the glacier will start to move backwards and retreat. That exposes the bare soil that was once beneath the glacier.

The ecosystem that grows on the newly exposed soil changes over time. Think about, say, a forest or grassland near where you live. If a fire came through and removed all of the plants and animals, the ecosystem will slowly start to regrow. It doesn't immediately turn into the same forest that lived there before the fire. At first, some very brave plants can grow in that desolate area, but eventually more plants and new trees will grow, and the animals can return. It can take decades before it once again looks like the forest that once stood there. That is called ecological succession

The same thing happens in Antarctica. The first, brave plants to colonize the bare soil will pave the way for more plants and animals, and it will slowly change over decades to become a mature ecosystem. They won't turn into a forest with trees, of course, because trees no longer live in Antarctica. But these bare soils might one day look like the rest of the ecosystem that our team has studied in the past.
The mature ecosystem on King George Island, Antarctica.

We know a lot about how succession happens in the ecosystems where we live. We are pretty good at predicting what a forest would look like as it changes over time. That's because we've lived in those ecosystems for centuries and have watched what happens after fires and other disturbances for a long time. People have not been watching Antarctica for centuries, though. People have only been there for about 100 years total, and only now are we seeing rapid changes like climate change. So, we don't yet know exactly how the ecosystem will change and develop after glaciers melt. 

That is what our research project will be measuring. We are going to study the newly exposed soil at the face of glaciers that have been melting. We will look at how the plant and animal communities have changed over the years after the glacier has retreated, and we will ask why they have changed in that way. But more on that later!

Friday, April 24, 2020

Virtual BioArt exhibit

It's been almost a year since our last group of students traveled to the Arctic for the BioArt course. Things were very busy when we got home, with students finishing their work. The work was exhibited in August & September 2019 at the Fletcher Library at ASU. This spring, the work was set up for display at the South Mountain Environmental Education Center, to be enjoyed by visitors to South Mountain Park. Unfortunately, that display was cut very short. It was up for only one weekend before the visitor center was closed due to the COVID-19 pandemic! Since it's no longer able to be enjoyed in person, I thought I could perhaps publish it here, for people to enjoy remotely all over the world.

New to the concept of BioArt? Read this post for an explanation of why we created this project.

So, without further ado, I present to you the most recent class's BioArt projects from the Arctic!

Each project displayed consists of a scientific research poster, which communicates the project in the traditional scientific format that explains the rationale, hypothesis, methods, and results. Those posters get displayed next to their art  that communicates the research in a more creative way. As viewers travel around the hall, they would see exhibits that look like this:
For example, Elisabeth and Alex explored whether diatom communities differed across types of aquatic habitats. You can learn more in their research poster. Their artwork is a composite of 36 sketch papers, serving as small "slides" that make up the overall landscape of Saana.
For each project, you can open their research poster to read about the science, and the photo of their art project shows how they also communicated that science in a very engaging way. (Click the photo for a larger version to see better detail of the artwork.)

Ana and Kristian studied the impacts of increased temperature and water availability on soil microbes in the Arctic. They used miniature greenhouses to simulate future climate change, and measured the activity of soil microbes as respiration. Read more in their research poster.
They created a short video piece, which is a sonic and visual interpretation of climate change induced glacial melt in the Arctic. All of the visuals, as well as some of the audio, were captured throughout the mountainous regions near Kilpisjärvi, Finland, and is accompanied with an original music score featuring a continuous flute solo by a local Phoenix musician. This immersive art piece follows the journey of water as it travels from mountain tops to marshy lands, and provides a creative perspective for the feedback loop by which this ecosystem is affected. You can see their awesome video here:

Deauna and Jeremy studied how trampling by hikers' feet changes the soil on the trails, and whether that matters for the microscopic organisms living in the soil. Read more in their research poster.
Their creative work is a 3-D environmental model that uses a combination of natural products and artificial foliage to allow viewers to touch and feel a representation of natural Kilpisjarvi soil.  It simulates Mt. Saana Reserve, allowing the viewer to witness the effects of trampling versus staying on the trail. The flooring simulates the spongy, buoyant vegetation that was preserved outside the trails. The samples taken from the spongy areas were more difficult to obtain because of the plant roots that intertwined throughout reserve. The plant matter on the fabric is a visual representation of the different kinds of plants that were observed over the entire reserve. Many of the plants were layered over one another, and that layered effect was captured by bleeding the leaves on to the fabric. The green vegetation was the most abundant, so it was the first color to be hammered into the fabric. On top of the green color were plants that ranged in colors from red to yellow to purple. Finally, the last piece to simulate the environment is a visual and audio recording of trampling and hammering. The trampling was important to capture because of how it affects the land that we did research on. Each recording was taken on the different areas affected by trampling. Upon viewing this installation, your environment is meant to be transformed into the serene landscape where we had the privilege of working. You may choose to follow the trail to view the scientific poster or walk your own path.

Jose and Xavier investigated how pollen of Arctic plants could be used as crime scene evidence. Learn more about their project in their research poster.
They communicated this research through a two-part installation. They recreated a police bulletin board (kind of like ones we see in movies getting used to track evidence in a crime). Showcased on the bulletin board are pictures taken at the Kilpisjärvi Biological Research Station. They show where several pieces of clothing evidence at the crime scene simulation contained various pollen spores.  Red string is used to convey the possible connections between the photos. In the upper right corner, a newspaper speculating about the crime scene simulation is on display. They also created an audio-video display depicting the process of examining slides under a microscope. The camera captures the movement of several slides under the lens as an examiner searches for pollen spores. The video is accompanied by the recorded sounds of the environment in which evidence from clothing at the crime scene was discovered. Curious about their video? You can watch it here:

Robin used his interest in the social sciences to explore how habitat fragmentation is impacting reindeer, and therefore Sami culture. Historically, reindeer would migrate across areas of northern Scandinavia with the seasons, followed by the Sami reindeer herders. But the Arctic is changing, not just in terms of climate and species phenology, but also geography. As countries have erected fences along their borders, reindeer are not able to move according to natural migration patterns, which impacts the reindeer and therefore the Sami who rely on them for their livelihood.
He expressed these relationships in his artwork using materials representative of traditional Sami costume, with rocks and antlers representing the natural aspects of the Arctic landscape. You can see the presence of the fence, and the difference in reindeer numbers and movement to the left of the fence as compared to the right of the fence.

Alex, Karla, and Mariam did not travel to the Arctic with our group. They took a non-traveling version of the course, where they studied the Arctic from afar, by simulating the Arctic Ocean in their back yards. They studied how UV radiation from the sun breaks down plastic that gets created and released at mid-latitudes but can make it all the way to the Arctic through ocean currents. Learn more in their research poster.
Their 3D art piece represents the plastic that lies within the Arctic Ocean as well as the species/marine life being affected by plastic pollution. The two poster boards themselves are fundamentally colored with watercolor to correlate the artwork with the real life ocean water. Plastic caps accumulated by the artists were painted different shades of blue, representing the deeper parts of the ocean, a deeper blue, as well as the more shallow parts of the ocean, the color being a lighter shade of blue. The caps are specifically snaking throughout the art piece to represent the general widespread of plastic throughout the entire ocean, not just in one particular place. On the lower half of the piece, there are species drawn and painted, representing the marine life that is being impacted and disturbed by the ongoing plastic pollution within the Arctic Ocean. Our ultimate achievement is to present a more accessible visual representation of the effects of plastic as well as how much plastic pollution is found within the Arctic Ocean. Even though the Arctic is far away from us in Phoenix, the plastic waste that we generate can reach that distant ecosystem.

(Like BioArt and want to see a few examples from the Sonoran Desert, as well? See our sister Desert Soils blog.)

Wednesday, June 19, 2019

Research wrap-up

We are at the end of our stay at Kilpisjärvi Biological Station. Students have been collecting their last bits of data. Yesterday, they presented drafts of their projects. They of course still have work to do once we get back to the US, but they were able to report on their rationale, hypotheses, methods, results so far, and clips and drafts of their art projects.

For example, here’s Alex and Elisabeth presenting their project on diatoms. They collected water from a variety of different bodies of water around the station, from lakes to ponds to streams to snow. Using a powerful microscope, they’re looking at the diatom community to see if the different types of water bodies house distinct diatom communities. They want to know whether you can tell if something came from a particular type of water source based on the diatom community you find on it. Since their water bodies focus around Saana and Kilpisjärvi, their art project will be a drawing of the Saana landscape, with certain areas expanded to show the diatoms that are unique to those areas.
Here is one of my photos of Saana (the mountain fell in the background).
Now we are almost all packed up. In a few moments, we’ll be getting on our bus to drive to Tromsø, Norway. We will spend the rest of the day there visiting science and art museums to cap our trip the way it began in Helsinki.

Monday, June 17, 2019

Student projects

We have been at the research station for over a week now, and we only have a couple more days left before it's time for us to leave. The students have been making good progress on their research projects, and here's a bit about what some of the teams are working on:

Deauna and Jeremy are studying the impacts of human foot traffic on soil water and therefore the organisms that live in the soil. There has been increasing tourism in this area, which means more hikers and more traffic on trails (and new trails being created by people going off-trail). All of those human feet can compress soil and squeeze out the air spaces, which can make it harder for the soil to let water in, provide habitat for organisms, and support plant life. Even after the foot traffic goes away, the soil will not immediately recover. Jeremy and Deauna are comparing high, medium, and low traffic areas to see how much damage is too much damage.
Jeremy puts our make-shift "infiltrometer" into a medium-traffic path to test how quickly water trickles into the soil. Deauna is ready to run the timer and record the data.
Their art project to communicate the results is very neat. They have collected various plants and soil, and are using a hammer to pound them into cloth to create colors and textures on textile that represent human feet trampling the plants and soil.
Jeremy hammering his textiles on the left, and some in-the-works plant smashing on the right.
Xavier and Jose are studying pollen, and whether it could be used to solve crimes. They have placed a bunch of their clothes around the station, both inside the buildings and outside scattered in the birch forest and fields. Their clothes are simulating a human who may have committed a crime, or been a victim of one. They are then identifying any pollen that may have collected on the clothes to determine whether they can match the "crime" to nearby plants. If they are able to collect pollen from the clothes that is tied to nearby plants, they can suggest that pollen evidence can be used to tie a person to a particular location in the Arctic. However, if pollen on the clothes is not able to be associated with nearby plants, that would suggest that it's not a good source of evidence.
Jose and Xavier use tape to collect pollen off of their test clothing.
Once they collect the pollen, they look at it under a microscope to identify it. They have spent a lot of time collecting pollen from all of the flowering plants around the station to create a pollen bank of what each plant's pollen looks like. That way, as they look at their clothing samples, they can identify the plants on the clothes. The microscope has a camera attached, so one of them can operate the microscope while the other watches from the laptop. Here, Jose is on the laptop capturing still images and video to use in their artwork.
Jose and Xavier viewing their pollen from mock crime scene underwear.
Ana and Kristian have been simulating a warmer Arctic climate to see how that impacts the activity of soil microbes. Soil microbes perform a LOT of important functions in ecosystems, so knowing how they respond to climate is important. Kristian and Ana collected soil and placed it into incubation vessels. Half of their vessels are outside in normal temperatures, and half are inside a little greenhouse that they made out of parts they could find at the station and market. In each of those temperatures, half of the vessels received extra water to simulate ice melting under a warmer climate. They've incubated their vessels for over a week with the extra water and/or warmer temperature, and every couple of days they collect gas samples to see how much the soil microbes are respiring.
More CO2 produced from respiration means more active microbes.
Ana collecting a gas sample from one of her sample vials, next to their home-made greenhouse.
They have also been recording a lot of video and sound of water and wind to represent the melt and the respiration. It will become part of a musical composition with accompanying video. Anywhere we go for a hike, Kristian ends up dropping onto the ground and sticking his camera and sound recorder just above the water to collect the clips for their work.
You can juuust make out the tiny Kristian in the lower right, collecting sound clips from the base of the waterfall at Leenanlampi last week.

I'll tell you about the other projects another day, because the weather has been beautiful and now I'd like to go outside and enjoy some sunshine!

Saturday, June 15, 2019

Station tour

Want to see where we've been living and working for the past week? Here's a short video tour of the main station building where we have our classes, eat our meals, sleep, and work in the lab: