Keeping track of tundra shrubs

Many scientists have reported on the “greening of the Arctic” and speculated that this might be due to increased productivity of existing shrubs, expansion of shrubs in places they already exist, and then the movement or migration of shrubs onto previously shrub-free tundra. A greening of the Arctic has important consequences to the biophysical feedbacks between the land surface and atmosphere.

One of the critical objectives in NGEE Arctic is in knowing more about what controls shrub distribution in tundra ecosystems. Our first step in tackling this challenge lies in characterizing field sites on the Seward Peninsula for shrub abundance and then working to understand how shrub dynamics vary by landscape position and as influenced by soil water content, active layer thickness, etc.

Today, Mark, Peter, and I began measuring shrub abundance along several 800 to 2200 meter transects established earlier in the year at our field site outside Nome. This involved identifying specific points along those transects and measuring the distance to the closest “tall” shrub in each of four quadrants. We focused on several Salix, Betula, and Alnus species. It was a somewhat tedious process of not only measuring the distance to the nearest shrub, but also using digital calipers to measure stem diameters for anywhere from one to several dozen stems per plant. The alders, in particular, and sometimes the larger Salix, were time-consuming to measure since each shrub might consist of up to 18 stems.

Regardless of the difficulty in making these measurements they are important data to collect and central to several of the major questions being addressed by NGEE Arctic. We will couple this information with data on plant traits, soil temperature, and soil moisture. Insights gained will help improve our description of vegetation dynamics, specifically shrubs, in computer models.

Hydrology and Geochemistry at Teller Field Site

Members of the NGEE Arctic team from Los Alamos National Laboratory have played a major role in areas of hydrology and geochemistry. Their expertise, both in the field and laboratory, is complemented by others at UAF and ORNL. As a result we have gotten off to a quick start with research at our Teller field site beginning this winter with snow ablation and snowmelt measurements, and surface and pore water sampling earlier this spring.

This week Brent, Jeff, Carli, and Lauren are working at the Teller field site to collect additional surface and pore water samples. This site has an interesting pattern of surface and subsurface hydrology due, we believe, to the interaction between permafrost and bedrock. We are investigating these patterns by analyzing water samples for geochemistry. A range of anions and cations present in the samples can be analyzed quite precisely, along with measurements of the isotopic composition of water and its constituents.

Today LANL researchers transported and installed three Teledyne Isco portable water samplers at the field site. Transporting the samplers to the field was the first challenge. Although the loads were bulky, thankfully they were light. Once they were strapped to a backpack frame they could be carried to the field and deployed along a stream that runs the length of the watershed. Isco samplers, powered by 12-volt marine batteries, automatically collect water samples over time. Collection amounts and timing of sampling can be programmed via a keypad and controller. Scientists will revisit the samplers throughout the summer, taking water samples back to their home institutions for analysis.

Team Members Begin to Arrive in Nome…

A lot of people are committed to the success of the NGEE Arctic project. And thankfully, many of them have traveled to Alaska. Some come to conduct research in the field, while others collect samples for analysis back in laboratories at their home institution. Still others come to get a better sense of how multi-scale models should be developed, parameterized, and evaluated using knowledge generated by their colleagues. So, whenever we have large field campaigns, like we are having now, it is especially enjoyable to see members of the NGEE Arctic project from all over the country begin to arrive.

Brent, Jeff, and Carli arrived from Los Alamos National Laboratory. Brent and Jeff have been associated with the project since our beginning and contribute in areas of hydrology and geochemistry. Carli is a post-doctoral research associate and is new to the project; she will assist with installation of equipment and initial collection of surface- and pore-water samples. Lauren, a post-baccalaureate student, will join us in a few days.

Alistair and Shawn from Brookhaven National Laboratory have also arrived. Both have extensive experience working at our field site in Barrow and will spend the next week in Nome conducting leaf gas-exchange and spectral signature measurements on a variety of tundra plants. Mark is completing his post-doctoral research at the University of Alaska Fairbanks and will soon be moving to the University of Illinois, Champaign-Urbana. He has undertaken some exciting analyses of landscape features on the Barrow Peninsula and estimated their contribution to greenhouse gas production. Mark is a creative scientist and we hope that he will continue to work with us once he gets settled into his new position.

Peter from Oak Ridge National Laboratory arrived last night, along with Eugenie from UAF. Both Peter and Eugenie are terrestrial ecosystem modelers who work at a range of scales, including the regional and global scale. They each also have conducted field research and know the value of collecting quality data for use in model development and parameterization. It is great to have them join us in the field as they benefit from, and contribute to, many stimulating discussions that happen in the field.

Several additional colleagues from ORNL also arrived last evening – Colleen, Joanne, and Verity. Colleen leads a Phase 2 task on plant traits. We are looking at shoot and root structure-function relationships and exploring whether this area of research can be used to inform models. The utility of plant traits in modeling is being championed by our sponsor at the DOE and we, along with our sister project NGEE Tropics, are keen to test ideas using field data from our respective field studies. Colleen and Joanne will be busy keeping us organized and on task this week. Amy (UAF) and Holly (ORNL, not pictured) have been in Nome for a week completing community composition assessments. We are fortunate to have Amy on the project as she brings a wealth of knowledge on arctic and boreal vegetation. Finally, Verity just finished her PhD dissertation at the University of Florida last Friday. She will join Colleen at ORNL as a post-doctoral research associate in another month or two. Congratulations Verity on receiving her PhD and welcome to the project!

Others will be joining us in the next few days. I’ll be sure to mention them in the coming week, along with the scientific and technical expertise they bring to the NGEE Arctic project.

Facilities in Nome…

Members of the NGEE Arctic team, or at least those who conduct field research in Alaska, are finding themselves increasingly comfortable living and working in the vicinity of Nome. While it is not a large town – 3,500 people – it nonetheless has resources that make our stay comfortable, efficient, and safe. These come in the form of grocery stores, hardware stores, hotels and B&B’s, restaurants, a regional hospital, a community recreation center, and the UAF Northwest Campus.

Business owners and local citizens are friendly and go out of their way to answer our many questions. Just this morning in response to asking about the different kinds of fish that occupy area streams and rivers I was given a “Fishing Guide”. The guide provides a river-by-river description of fish found in the region and, more specifically, along the Teller, Kougarok, and Council roads; Chinook, pink (humpies), chum, Sockeye, and Coho salmon; Arctic grayling, Dolly Varden, and Northern Pike. Now if we only had the time and, more importantly, the energy to fish or join a pickup game of basketball at the recreation center after long days in the field! Such is the life of a field scientist.

Flight into Nome via Kotzebue

Yesterday was a busy day with flights from Knoxville to Chicago to Anchorage, and then to the Seward Peninsula in western Alaska. Normally I stop in Anchorage for a night to stock up on supplies, but given that the NGEE Arctic team is well equipped I flew straight through to Nome. I had forgotten that flights from Anchorage to Nome include a short stop in Kotzebue (http://www.cityofkotzebue.com/), which is several hundred miles north of Nome. Kotzebue has a population of over 3,000 people and serves as a regional supply hub for 10 satellite villages in the Northwest Arctic Borough and one in the North Slope Borough. We visited Kotzebue in 2012 and enjoyed the area, especially our visit to the Northwest Arctic Heritage Center operated by the National Park Service (https://www.nps.gov/noat/learn/news/nwahc.htm).

The flight from Kotzebue to Nome was short, less than an hour. Flying into Nome provided an opportunity to see some of the surrounding tundra and, in fact, the city itself. The weather in Nome has been cloudy with a few rain showers, but should be sunny and clear by the first of next week.

Although Amy (UAF) and Holly (ORNL) have been in Nome working for three or four days, most members of our team begin arriving tonight. We will welcome several dozen NGEE Arctic students, staff, and faculty in the coming week so there will be a lot of activities on which to report. Later today as I travel around town I’ll be sure to take a few pictures and include those in a post this weekend.

- Stan Wullschleger

Let the Field Research Campaign Begin!

The NGEE Arctic project (http://ngee-arctic.ornl.gov/) has enjoyed five successful field seasons working at our research site near Barrow, Alaska. This year – thanks to the hard work of many people – we begin a new chapter in our efforts to integrate field and laboratory studies in support of advancing climate model development for the Arctic. Our team is expanding to include field sites outside Nome on the Seward Peninsula in western Alaska.

While this is certainly not our first trip to Nome, it will be our largest. Several dozen of our scientists, students, and staff will travel to the area throughout the next few weeks. Our team will conduct a broad range of integrated research activities at an intensive field site along the Teller Road. We are thankful to the Sitnasuak Native Corporation for making this land available for our use. Other native corporations are being engaged to also identify field sites along the Kougarok and Council roads.

 

The NGEE Arctic team will, working first at the Teller site, use an array of geophysical approaches to establish interactions between permafrost and bedrock, and to examine the consequences of those interactions to watershed hydrology. Complementary studies of vegetation, biogeochemistry, and energy balance will help inform our understanding of Arctic tundra and provide insights for developing multi-scale numerical models for inclusion into climate models. Our goal is to better understand the fate of frozen soil organic matter (i.e., the permafrost carbon cycle) in a warming climate and incorporate critical feedbacks into models. We were fortunate to begin collecting initial datasets last year and will continue to expand on those with increasingly detailed field and modeling investigations of the Teller Road watershed.

 

The next three weeks will be a productive time for our team. Our planning has laid a foundation that we will continue to build upon, ensuring that our interdisciplinary science delivers on expectations and does so in a safe and efficient manner. We are thankful that while working thousands of miles away from our home institutions can be challenging, our team has the support and cooperation of people and facilities like Bob, Gretchen, Claudia, and others at the UAF Northwest Campus in Nome.

While the next few weeks will be busy ones, I’ll do my best to provide periodic updates on the science being conducted by our team and how those research results and acquired knowledge is incorporated into models, including global-scale Earth System Models.