MCMLTER: McMurdo Dry Valleys Long-Term Ecological Research
20 Years of Studying Life on the Edge of Existence in Antarctica
The Long-Term Ecological Research (LTER) Network is a program funded by the National Science Foundation. It was created in 1980 to conduct scientific research in a variety of geographical areas. Information gathered on ecological issues over a long span of time has led to important discoveries and conclusions on both a regional and continental scale. Ecology is the study of the relationships that organisms have with their environment.
LTER’s ecological network is the largest in the United States, and it also spans the longest time period. Scientists from many disciplines (areas) have gathered data about diverse (different) ecosystems in the U.S., islands in the Caribbean and the Pacific, and two studies in Antarctica. The LTER network monitors activity and change in each ecosystem. The map below shows where many of these LTER sites are located.
25 LTER sites:
22 in USA; 2 in Antarctica (Palmer Station and McMurdo Station)
16 terrestrial (land) sites
7 coastal/marine (water) sites
2 urban (city) sites (Baltimore and Phoenix)
Studies include areas of prairie, forest, wetland, desert, alpine and Arctic tundra, coral reefs, areas in cities (urban areas), and even areas of agriculture. If scientists study these areas and gather long-term ecological knowledge, they can contribute to the progress of the health and welfare of the global environment. Their goal is to provide the scientific community, society, and people who make policies (people working in government) with the information and understanding that is necessary to “conserve, protect, and manage the nation’s ecosystems, their biodiversity, and the services they provide.” (retrieved from www.lternet.edu/network/ )
Today I met up with Diane McKnight, who is one of the scientists of the LTER network here in Antarctica. Diane has been conducting research in the Dry Valleys for 20 years, focused primarily on Taylor Valley. She studies the linkages between ecosystems such as glaciers, soils, streams, lakes, and wetlands. Like other scientists involved in LTER, Diane studies this environment to understand the relationships of things in this ecosystem. Diane and other scientists sample the lakes and soils in the Dry Valleys. The area of study in the Dry Valleys is the coldest and driest site of the LTER network. The Dry Valleys contain the only liquid water on the continent.
When Robert Scott and his party visited the Dry Valleys during their 1903 expedition, they called Taylor Valley the “valley of the dead.” Not only did they see mummified seals, but the great glaciers were no longer covering all of the Dry Valleys and it didn’t look like much life existed in this region. It is a beautiful but dramatic and barren landscape. What Scott and his men weren’t seeing are the microorganisms that scientists get excited about now. However, scientists do use data from Scott’s expedition to look at changes in the Dry Valleys.
Diane earned her undergraduate degree in Mechanical Engineering at MIT (Massachusetts Institute of Technology). She went on at MIT to earn her Master’s degree in Civil Engineering, and her PhD in Environmental Engineering. She told me that at the time she first entered MIT, the advisers were actively recruiting women to choose mechanical engineering as a major. They supported women in this field of study, which had traditionally been more of a male-dominated field. Diane always loved science and really enjoyed physics in high school. Her father is a PhD scientist in chemistry and biochemistry, and her mother was an elementary educator who went on to earn a Master’s degree and later (at age 55, which was significant for that time period) a PhD. She did this while juggling her teaching and raising a family. Diane’s mother was a great tole model for life-long learning.
Diane worked for the U.S. Geological Survey (USGS) in Colorado, and later took a position at the University of Colorado, Boulder. She first came to the Dry Valleys while working for the USGS in 1987. She started a project studying Lake Fryxell and Lake Hoare in Taylor Valley (Taylor Valley is shown below).
She also studied Pony Lake (Diane says it’s more like a pond), which is just in front of Shackleton’s hut at Cape Royds. Diane wanted to go to a continent with no plants (well, there are microscopic ones) and study organic material in water. Here’s the historic hut at Cape Royds.
And, here’s Pony Lake, with a few of the local Adelie penguin residents hanging out nearby.
Diane was very interested in stream flow and stream ecosystems in the Dry Valleys, and traveled back to Antarctica in 1990 for more research. She wrote a proposal and joined the LTER Network in the 1992-1993 field season. That season she studied the Onyx River where New Zealand scientists had maintained flow records for a number of years. Remember, many other countries have field research teams in Antarctica and New Zealand has a rich history of work in the Dry Valleys region.
The photo below shows scientists measuring the level of a Dry Valley lake. Lake levels have come up in the past decade (a period of ten years) due to more melt water from the glaciers.
Scientists know there have also been cooling trends, interrupted by periods of floods during summers of high solar radiation and strong winds. There is an extreme variation in flow of streams depending on the summer climate. Winds transfer material into lakes and streams; these windblown sediments contain salts, minerals, and organisms. The response of extreme ecosystems to disturbance linked to dynamic climate change is a focus of their studies. Scientists are gaining a broader understanding of changes in ecosystems and responses to these changes in different biomes (the world’s major ecologic communities) by gathering data at the various LTER sites.
In the lakes and streams of Antarctica scientists take samples inside and outside of the wet zone. Diane (shown below) is taking a sample of the algae mat near a Dry Valley stream. Algae are plant organisms that rely on photosynthesis to grow; they occur in most habitats. They can range from small, single-celled organisms to complex organisms, like giant kelp (seaweed) in the ocean. In the Dry Valleys, scientists are studying algae in the lakes and streams.
Algae mats in the Dry Valleys are freeze-dried and dormant throughout much of the year, and the organisms are there, just waiting for the water to come. These microbial (they are full of microbes; tiny plant life) mats bloom when they get wet. Diane and others want to learn more about how this community has adapted to long periods with no liquid water. Pictured below is an algae mat that has bloomed because it came into contact with water.
The algae produces that orange pigment to protect itself from sunlight. Diane told me that this is not unique to Antarctica. Orange algae may be found in desert streams where too much light equals a sunburn. Since the summer season in Antarctica means sunlight 24 hours a day, they have this same adaptation for protection.
Where are the Dry Valleys headed in terms of how they’ll evolve in the future as the climate changes? A recovery of the ozone hole over Antarctica would decrease the current cooling affect. Even now, areas in the Subantarctic are experiencing a very pronounced period of warming. What will places like the Onyx River and Pony Lake look like in 40-50 years? These are questions that Diane and other LTER scientists are asking.
The photo below shows a scientist taking an ice core sample from one of the Dry Valley lakes.
The following photo shows an ice core, with an algae mat on the underside of the ice. Algae needs sunlight to grow. When the ice on a lake melts sooner, the algae respond sooner. They grow faster and possibly longer depending on the available nutrients.
Algae mats also grow in streambeds, and bloom when water flows during the summer months. Water makes its way to the streambeds from the melting that occurs in the glaciers. Here is Diane (far left) and colleagues examining algae mats in a dry streambed.
Here is an example of algae, seen under a microscope.
Like most of the scientific community here in McMurdo, Diane’s research is not limited to Antarctica. She has studied the Okavango Delta in Bostwana, Africa. This delta is a giant floodplain and it floods on an astounding scale. Each year water spreads over an area of 6,000 to 15,000 square kilometers (3,728-9,320 square miles). Diane has studied the movement of organic material in this delta. Diane has also worked in the Arctic, studying stream ecology in Toolik, on the North Slope of Alaska. Diane teaches undergraduate environmental engineering courses and graduate courses in applied stream ecology at the University of Colorado, Boulder. In these field-based courses students learn how to design field studies and sample.
Diane is not only an amazing scientist and educator, she is an author. Her work in the Dry Valleys is incorporated into a children’s book entitle The Lost Seal.
The book is based on a true story of the first documented encounter with a live seal pup that strayed into the remote Dry Valleys. Readers can learn more about the seal’s travels in the Antarctic desert and compare this environment to ones with which they are more familiar. This book is one in a series called the LTER Schoolyard Series. Here is the overall goal of the series:
“The mission of the Schoolyard Series is to engage children and their families in learning about the earth’s ecosystems, both locally and internationally, through narratives that reflect the dynamic research being conducted at the National Science Foundation’s Long Term Ecological Research sites.”
(thanks to Diane for the PowerPoint with this information)
This book series includes the following books:
My Water Comes From the Rocky Mountains
The Lost Seal Pup (Dry Valleys, Antarctica)
Sea Secrets (Palmer Station, Antarctica)
One Night in the Everglades (Florida)
And The Tide Comes In (coastal Georgia salt marsh)
I love the way scientists are telling their stories and sharing their research through engaging children’s books. I enjoy these books as much as children do! We can all learn from the LTER scientists!
Remember, keep learning something new every single day! Thanks to Diane for a great visit this afternoon and another wonderful learning experience for me here in McMurdo.