More reflections on 2017 field work

Guest post by Jackie Hung:

Going to Cape Bounty for a second field season, the novelty of High Arctic field work has still not worn off. Seeing the Weatherhaven tents through the window of the Twin Otters as we circled the cape brought back all the memories of the previous season. That is, until we had to dig out the tents from over 2 metres of snow.

Opening camp was a completely new, rewarding, and humbling experience. Seeing the landscape transform from late-winter conditions to spring and summer growth gave me a new perspective on the amount of change that the land undergoes and the harsh environment that the flora and fauna endure here. I was able to finally see and take part in some of the research and data collection that is undertaken in the early season, including lake sampling and river channelizing. Coming to the field before the growing season has also given us the chance to see the birds in their nesting season. Camp has been frequented by several visitors so far, including large muskox herds, curious caribou, and large Arctic hares.

 

Snow sampling and working with data loggers that record soil temperature year-round at Cape Bounty. 

 The transition into July and the growing season was a welcome change for me as a soil scientist. We were keen to arrive early into the field to capture the spring-summer transition; however, that occurred a few weeks later than it did last season. The higher amount of snowfall in the Canadian Arctic this summer meant a delayed start to my sampling. My research builds on the knowledge base established from the previous season and looks to explore unanswered questions that came up during my field sampling and analysis. My Master’s research at Ryerson University looked at the spatial and temporal dynamics soil nitrogen availability and how it related to environmental variables in the wet sedge meadows. Moving forward, I am interested in examining the relationships between the soil available nitrogen, gas exchange, and the changing climate in the wet sedge meadows and mesic tundra and linking these questions to remote sensing techniques.

In 2017, my day-to-day activities included taking static CO₂ measurements, trace gas sampling, spectroradiometer work, and soil sampling. Carbon exchange autochambers and buried soil moisture and temperature loggers are allowing me to take continuous measurements in various locations to complement my seasonal data set. Soil samples taken from the field will be used towards laboratory experiments that will allow me to manipulate different biophysical features to see the microbial response the soils to elevated temperature and fertilization. This field season has given me a head start to the sampling for my new role as a Queen’s student and will help in formulating the questions that will form the basis of my Ph.D.

Biogeochemical Research in the High Arctic

Hi! My name is Gillian and I’m a first-year Master’s student at Queen’s. Dr. Melissa Lafrenière, co-manager of the Queen’s Facility for Biogeochemical Research on Environmental Change and the Cryosphere (FABRECC: http://www.queensu.ca/geographyandplanning/fabrecc-lafreniere/home) is my supervisor. We are working to better understand biogeochemical processes at the Cape Bounty Arctic Watershed Observatory. In other words, we study the interactions between the physical, chemical, biological, and geological processes occurring in the High Arctic permafrost environment.

               

Specifically, I study carbon in organic matter. The permafrost of the Arctic stores huge amounts of organic carbon. In fact, researchers estimate that there is twice as much carbon stored in the permafrost as there is carbon in the atmosphere right now. As permafrost degrades due to warming temperatures, some of the permafrost carbon could be released to the atmosphere as greenhouse gases such as carbon dioxide and methane.

Why will only some of the carbon be released? Well, only a portion of the permafrost carbon is decomposable, and carbon must undergo decomposition to produce greenhouse gases. My job is to determine what makes the carbon decomposable and identify where the decomposable carbon is likely to be found on a High Arctic landscape.

Knowing how much carbon is decomposable, and where it’s located, is important for developing climate models. Because data on decomposable carbon are limited, carbon stored in permafrost isn’t well incorporated into current climate models. The results of our research could change that. For example, if we know there is a lot of decomposable carbon stored in areas highly susceptible to enhanced permafrost thaw, then we might conclude there is a high probability of greenhouse gas emissions in those areas. This increased probability can then be accounted for in climate model projections, making them more accurate.

A soil profile at one of my sampling sites at the Cape Bounty Arctic Watershed Observatory on Melville Island, NU.

I collected soil and water samples from sites with varying geomorphology and vegetation at Cape Bounty during the summer of 2016. Back in the lab at Queen’s, I incubated these samples for twenty-eight days. During an incubation, the samples were kept a constant temperature. At specific time points throughout the incubation period, I removed a subset (or aliquot) of each sample and analyzed it to characterize the molecular structure of its carbon compounds and its organic carbon concentration.

Now that the incubation period is finished, I can calculate how much organic carbon was lost (through decomposition) over the twenty-eight days. Better yet, I can compare these data with the molecular structure of the carbon compounds to see if molecular structure is an indicator of decomposability. If they are related, it would be really exciting since the methods used to characterize molecular structure are much easier to perform than the incubations. If molecular structures could be used to predict carbon decomposability instead of incubations, it would save researchers a lot of time and money!

An emission excitation matrix (EEM), like the one shown above, provides insight into the molecular structure of carbon compounds in water samples.

The next step for my project will be to look at how the decomposability of carbon varies by sample site. If we identify a relationship between carbon decomposability and study site characteristics, we could use this to predict how carbon decomposability will vary across the broader landscape. For example, if we find that carbon decomposability is related to a certain vegetation community, we could use vegetation cover maps to predict how carbon decomposability varies across the landscape.

               

The best part about my project is that I get to go back to Cape Bounty next summer for a second field season. So, based on what I find out from the lab work I’m doing now, I can tailor my 2017 sampling plan to better address my research questions. Stay tuned for more results and stories about field season preparations later this winter!