Sampling the Tundra

Joined: 23 Mar 2004 Posts: 118

Now that the permafrost layer is lower in the ground in many places, we can take more samples. On the top of the tussocks we can measure down to over 20 cm before hitting ice. In the valleys between tussocks we can measure down as far as 15 cm sometimes, but in locations that are more shaded by tussocks, the ice is still very close to the surface.

To get a sample we cut into the tussock with a serrated knife, then use an instrument called a Theta Meter to get a measurement that tells us the amount of moisture in the sample. Samples are 5 cm cubes, so have a volume of 125 cc. We have a balance out in the field to be able to find the mass right away. We log the information about each sample in a log book and directly on each cup.

The samples in the cups are placed in a drying oven in our lab, and monitored every 24 hours. The change in mass from the fresh sample to the dried sample also gives us information about the amount of moisture in the sample. We try to get samples from a depth of 5 cm and 20 cm on the tussocks, and 5 cm in the valleys.