We are on our way!

We have started our journey to Escudero Base in Antarctica! The journey will take us over a week. First, we have to travel to Chile. Here is our route for this first part of the trip:

My other team member from the U.S. is Dr. Hannah from Portland State University. On Saturday morning, we left our homes and met each other in the airport in Houston, TX. After a VERY late night, we then flew from Houston to Santiago, Chile. 

Travel to other countries is hard now, because of COVID-19. We had to be tested for COVID before we left the U.S., and we were tested again yesterday when we arrived in Santiago. We spent three hours in the Santiago airport having our medical papers checked, our passports inspected, and getting tested. All of this was just to be allowed out of the airport and into Chile!

Dr. Becky & Dr. Hannah in line to get our COVID tests in the Santiago airport

We are currently in a quarantine hotel in Santiago where we waited for the COVID test results. Both of our tests were negative, so now we can complete the next part of our journey. Early tomorrow morning we will fly to Punta Arenas at the very southern tip of Chile.

We have to quarantine in Punta Arenas for seven days before we can go to Antarctica. We definitely don't want COVID to spread to the research base in Antarctica, where there are no hospitals. It is possible that we were exposed to COVID during our travel through the airports. We can't go to Antarctica until we know we didn't catch it. If we make it through the seven days without showing signs of COVID, we will be able to go to Antarctica. There is just one flight that is able to take us to Antarctica on February 8. If we do catch COVID, we will not be allowed on the flight and will have to return home. We have tried to be very careful, so hopefully we do not get sick. Otherwise, we will not be able to try again until next year. (That will make for a very short blog this year, wont it?)

For now, we have negative tests so we were allowed to go outside for a walk. Because Chile is in the southern hemisphere, it is late summer, even though it's late winter in the U.S. The seasons are opposite because the Earth is tilted. Right now, the southern hemisphere is closer to the sun, and the northern hemisphere is tilted away from the sun. That means the southern hemisphere has more incoming energy from the sun, so it is warmer.

Image source: https://gifer.com

So, we were able to enjoy some warm, sunny weather for our walk outside. Phoenix is still fairly warm during the winter, but for Dr. Hannah it was a big change, because Portland, Oregon is farther north and much colder during winter!

As the Earth moves around the sun, it will switch and the northern hemisphere will be closer to the sun. When it is summer in the U.S., it will be winter in Chile. 

Image source: Wikimedia

Antarctica is in the southern hemisphere, too. The plants and animals are only active during the summer when temperatures can be above freezing, which is why we are going now (assuming we haven't caught COVID!).

Where in Antarctica?

 Our field work for this project will be on the Antarctic Peninsula, which is the part of the continent that sticks up towards South America.

We will be working on King George Island, which is off the west coast of the Antarctic Peninsula. There are many research stations on King George Island belonging to many different countries. Argentina, Brazil, Chile, China, Peru, Poland, Russia, South Korea, and Uruguay all have stations on the island. 

Image credit: Wikimedia 

As you can see, most of the island is covered in ice. We will be living and working on the western end of the island in an area called the Fildes Peninsula. That is the brown area on the far left. The brown color means there is exposed land, not covered by ice. We will be at one of the Chilean research stations called Escudero. 

You can learn more about Escudero at this website for the Chilean Antarctic Program (but you may have to ask your browser to translate it into English for you). I visited King George Island five years ago, but I was further to the north and east, near Arctowski Station. This will be my first time visiting Escudero Base. Once I see it for myself, I will tell you all about it!

Getting to Escudero will be a long journey. We will fly from the U.S. to Chile, and then from Chile to Antarctica. But we have to stop and get COVID tests at multiple stops along the way, and two different quarantines. It will take a long time, but hopefully we get there safely!

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. There is 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 doesn'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!

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.

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!