25 May 2012 Science Friday

The day began with a morning team meeting in the dining hall to outline the plan for work for Friday through the weekend. We are getting ready to sample soils in order to look more closely at soil chemistry and microbial action in the soil. It's important to make a plan that allows time for the fieldwork and includes a plan for all the ensuing labwork so that it is accomplished efficiently and nothing is left out or forgotten. The soil coring is considered a destructive harvest; therefore the planning of the sampling process is important as we can't just go back out there and get more samples if we leave out something or mis-follow a protocol.

Today was my first day in the field to see and work in the Advanced Snowmelt project plots. These are located about 10 miles North of the field station, using the Dalton Highway as our route to get there. The plots are located on a gently sloping hill off a side road, and accessed by a boardwalk across the tundra. The tundra here is referred to as tussock tundra. This type of tundra consists of soils that are always moist, and is dominated by tussocks of the plant Eriophorum vaginatum, also known as TussockA plant community that forms a clump. In the Arctic, the tussocks are equal parts graminoids (sedges and grasses), moss and shrubs. Cottongrass. The space in between the tussocks is called, aptly enough, intertussock , and is filled with small shrubs and mosses.

A few weeks ago, Anthony Darrouzet-Nardi coordinated deployment of black fabric cloth over half of the plots. This was done in order to simulate advanced snowmelt, and effect earlier warming of the soils in those plots. The cloths have been removed, and all plots are mostly snow free now, but the advanced snowmelt plots and control plots (non treated with fabric) are a basis of the field setup. Check out the link I posted April 6 for a refresher on the advanced snow melt treatment and a short video of the process of pulling on the cloth.

The goals for today were to deploy the mantis arrays, and take soil cores from the intertussock spaces. You can see Anthony in the picture adjusting the arm on the mantis so that the camera at the end will be positioned over a subsample of tundra. Besides a camera to document plant greenup, other instruments on the mantis array automatically take soil and air temperatures, relative humidity, and soil moisture. The six sided plastic thing you see there is an open top warming chamber (OTC) designed to allow for within-plot warming sites in order to look at soil and moisture temperatures as a result of interaction with the advanced snow melt treatment, and also to look at interactions if there are cooler air temperatures even if snowmelt timing is earlier in the season. Each chamber includes both tussock and intertussock spaces.

Once the mantis's were deployed and made ready for data collection, we turned to our other task; taking soil samples of intertussock tundra within the plots.

Anthony is pounding a sampler into the intertussock space. Notice the distinct high and low spots; a closeup look of the tussock/intertussock composition of the tundra here. This involved pounding in sections of conduit piping (used for containing the soil sample), pulling the pipe out of the ground, then pushing the sample out of the pipe into its waiting, sample specific Ziploc bag. This proved to be fairly labor intensive, as we were sampling in frozen ground, and sometimes the soil was a little reluctant to come out of the sampling tubes. But, with 6 folks on hand, mission accomplished and all thumbs remained unpounded. For today, anyway!

We noticed these interesting formations on the ground, especially near the boardwalks we work off of in order to minimize our impact on the study plots.

They are nests made by voles, and they have cut the grass into little haystacks encircling their living spaces. As we walked on the boardwalks, we could see the voles scurrying ahead of us under the boards. You can read more about the vole attack, and other timely news of the project, in Anthony's Science Blog

My first day in the field was a great introduction to the project, and our sampling of intertussock soils went very well. We brought the samples back to store in the refrigerator in our lab overnight, and the processing of them is scheduled for Saturday!

The weather around here is of constant interest to me. I checked out the site the Toolik staff uses to post our general weather forecasts. You too, may want to check the weather around Toolik! On the National Weather Service, Fairbanks Forecast Office, AK site, go to (http://pafg.arh.noaa.gov/wmofcst.php?wmo=FPAK51PAFG&type=public) When you get to the link, scroll down to the last forecast area, titled Northeastern Brooks Range. We are about 10 miles north of Galbraith Lake, so the forecast is relatively accurate, although it does include some much higher elevation areas such as Atigun Pass. My next journal entry will have some pretty interesting pictures as a result of the forecast for Saturday!

Question of the day: why are these Arctic tundra soils so moist?