Monday, August 1, 2016

Digging Deeper

The NGEE Arctic project is interested in plant and soil processes. Not only does this include a focus on the biogeochemical mechanisms that lead to CO2 and CH4 emissions from tundra landscapes, but also on the structure and function of plant roots. Colleen (ORNL), who is one of our Phase 2 task leaders, understands the importance of roots and has made it a central theme for our research on the Seward Peninsula.

Today Colleen, Joanne, Verity, Eugenie, Holly, Mark, and Peter joined forces to collect soil cores and selectively excavate roots from several plants growing at our field site. Soil cores were taken using a battery-powered drill equipped with a specially-designed coring device. Using this technique Colleen was able to collect soil cores up to 35 cm in length in just a few minutes. Once cores were extracted from the barrel it was easy to see the different soil layers including green moss, organic-rich regions that contained most of the roots, and then mineral soil. These are placed in plastic bags, frozen, and shipped back to Colleen’s laboratory for analysis.

Verity, a post-doctoral research associate working on the project, also wanted to collect roots from plants in the field. This is a tedious process in which roots attached near the base of a specific plant had to be excavated and then traced out into the soil. In this way roots of various sizes and “root order” could be collected. Verity attacked this task with enthusiasm. It turned out that Peter was also particularly talented at tracing roots and helped Verity and Joanne collect a large number of roots. Although Peter has a background in field research, most of our colleagues know him for his work with Earth System Models. This week he traded high-performance super computers for helping us in the field; and apparently Peter enjoyed getting first-hand knowledge about how data on root structure and function were obtained for use in global climate models. We were glad to have him as part of the field team!